The Emissions Gap Report 2017
A UN Environment Synthesis Report1Published by the United Nations Environment Programme (UNEP), November 2017
Copyright © UNEP 2017
ISBN: 978-92-807-3673-1
Job Number: DEW/2136/PA
This publication may be reproduced in whole or in part and in any form for educational or non-profit services without special
permission from the copyright holder, provided acknowledgement of the source is made. UNEP would appreciate receivinga copy of any publication that uses this publication as a source.
No use of this publication may be made for resale or any other commercial purpose whatsoever without prior permission inwriting from the United Nations Environment Programme. Applications for such permission, with a statement of the purposeand extent of the reproduction, should be addressed to the Director, Communication Division, UNEP, P. O. Box 30552, Nairobi
00100, Kenya.
Disclaimers
Mention of a commercial company or product in this document does not imply endorsement by UNEP or the authors. The
use of information from this document for publicity or advertising is not permitted. Trademark names and symbols are usedin an editorial fashion with no intention on infringement of trademark or copyright laws.
The views expressed in this publication are those of the authors and do not necessarily reflect the views of the United
Nations Environment Programme. We regret any errors or omissions that may have been unwittingly made.
© Images and illustrations as specified.
Citation This document may be cited as: UNEP (2017). The Emissions Gap Report 2017. United Nations Environment
Programme (UNEP), Nairobi
A digital copy of this report along with supporting appendices are available atwww.unenvironment.org/resources/emissions-gap-report
Supported by:

UN Environment
promotes environmentallysound practices globallyand in its own activities. Our
distribution policy aims to reduce
UN Environment's carbon footprint.

The Emissions Gap Report 2017
A UN Environment Synthesis Report
November 2017

Acknowledgements
UN Environment (UNEP) would like to thank the members of
the steering committee, the lead and contributing authors,
reviewers and the secretariat for their contribution to the
preparation of this assessment report.
Authors and reviewers have contributed to the report in theirindividual capacities. Their affiliations are only mentioned
for identification purposes.

Project steering committee
John Christensen (UNEP DTU Partnership), Navroz K. Dubash(Centre for Policy Research, India), Thelma Krug (Brazilian
National Institute for Space Research), Uwe Leprich (German
Federal Environment Agency), Jian Liu (UN Environment),
Simon Maxwell (Climate and Development Knowledge
Network), Surabi Menon (ClimateWorks Foundation), Bert
Metz (European Climate Foundation), Yacob Mulugetta(University College London), Katia Simeonova (United
Nations Framework Convention on Climate Change), Oksana
Tarasova (World Meteorological Organization), Merlyn van
Voore (UN Environment)

Chapter 1
Lead authors: Anne Olhoff (UNEP DTU Partnership), John
Christensen (UNEP DTU Partnership)

Chapter 2
Lead authors: Michel den Elzen (PBL Netherlands
Environmental Assessment Agency), Taryn Fransen (World
Resources Institute), Takeshi Kuramochi (NewClimate Institute)
Contributing authors: Jasmin Cantzler (Climate Analytics),
Hanna Fekete (NewClimate Institute), Jos Olivier (PBL
Netherlands Environmental Assessment Agency), Paola
Yanguas Parra (Climate Analytics)

Chapter 3
Lead authors: Michel den Elzen (PBL Netherlands
Environ­mental Assessment Agency), Niklas Höhne(NewClimate Institute), Kejun Jiang (Energy ResearchInstitute, China)
Contributing authors: Jasmin Cantzler (Climate Analytics),
Philip Drost (UN Environment), Taryn Fransen (World
Resources Institute), Hanna Fekete (NewClimate Institute),
Takeshi Kuramochi (NewClimate Institute), David Lee(Manchester Metropolitan University), Kelly Levin (World
Resources Institute); Joeri Rogelj (International Instituteiv

The Emissions Gap Report 2017 – Acknowledgements

for Applied Systems Analysis), Fu Sha (National Center for
Climate Strategy and International Cooperation), Michiel
Schaeffer (Climate Analytics) and Zoi Vrontisi (E3M Lab)

Chapter 4
Lead authors: Kornelis Blok (Ecofys), Angélica Afanador(Ecofys), Detlef van Vuuren (PBL Netherlands Environmental
Assessment Agency)
Contributing authors: Tom Berg (Ecofys), Christian Breyer(Lappeenranta University of Technology), Oreane Edelenbosch(PBL Netherlands Environmental Assessment Agency), Ann
Gardiner (SQ Consult), Danny Harvey (University of Toronto),
Atul Kumar (TERI University), Roberto Schaeffer (Universidade
Federal do Rio de Janeiro), Pete Smith (University of Aberdeen),
Lynn Price (Lawrence Berkeley National Laboratory), Irina vander Hoorn (Ecofys), Paul Waide (Waide Strategic Efficiency),
Hans Joosten (Greifswald University)

Chapter 5
Lead authors: Amit Garg (Indian Institute of Management
Ahmedabad), Jan Christoph Steckel (Mercator ResearchInstitute on Global Commons and Climate Change)
Contributing authors: Jesse Burton (University of Cape
Town), Julio Friedmann (Energy Futures Initiative), Frank
Jotzo (Australian National University), Gunnar Luderer(Potsdam Institute for Climate Impact Research), Pao-Yu Oei(German Institute for Economic Research/Berlin Technical
University), Michiel Schaeffer (Climate Analytics), Samantha
Smith (Just Transition Centre), Fabby Tumiwa (Institutefor Essential Services Reform), Adrien Vogt-Schilb (InterAmerican Development Bank), Paola Yanguas-Parra (Climate
Analytics), Xianli Zhu (UNEP DTU Partnership)

Chapter 6
Lead authors: Zbigniew Klimont (International Institute forApplied Systems Analysis), Drew Shindell (Duke University)
Contributing authors: Nathan Borgford-Parnell (UNEnvironment), Lena Höglund-Isaksson (International
Institute for Applied Systems Analysis), Steffen Kallbekken(CICERO Center for International Climate Research), Johan
Kuylenstierna (Stockholm Environment Institute at York),
Luisa Molina (Molina Center for Energy and the Environment/
Massachusetts Institute of Technology), Leena Srivastava(TERI University), Shu Tao (Peking University), Chandra
Venkataraman (Indian Institute of Technology Bombay)Chapter 7
Lead authors: Pete Smith (University of Aberdeen), JulioFriedmann (Carbon Wrangler, LLC)
Contributing authors: Sabine Fuss (Mercator ResearchInstitute on Global Commons and Climate Change),
Noah Deich (Center for Carbon Removal), Giana Amador(Center for Carbon Removal), Jan Minx (Mercator ResearchInstitute on Global Commons and Climate Change), MarkG. Lawrence (Institute for Advanced Sustainability Studies,
Potsdam), Mercedes Bustamante (Departamento de
Ecologia, Universidade de Brasília), Omar Masera (Institutefor Ecosystem Research and Sustainability, Universidad
Nacional Autónoma de Mexico), Annette Cowie (New South
Wales Department of Primary Industries/University of New
England), Oliver Geden (German Institute for Internationaland Security Affairs)

Reviewers
Alan David Lee (World Bank), Asbjørn Torvangers (CICERO
Center for International Climate Research), Ayyoob Sharifi(Global Carbon Project - Tsukuba International Office), Benoit
Gabrielle (INRA - AgroParisTech), Chandra Shekhar Sinha(World Bank), Christine Shearer (CoalSwarm), Cyril Cassisa(Enerdata), Daniel Puig (UNEP DTU Partnership), Djaheezah
Subratty (UN Environment), Durwood Zaelke (Institute forGovernance & Sustainable Development), Edmundo Barrios(Food and Agriculture Organization), Emma W. Littleton(University of Exeter), Etsushi Kato (The Institute of Applied
Energy), Felix Creutzig (Mercator Research Institute on
Global Commons and Climate Change/Technical University
Berlin), Frank Dentener (European Commission, Joint ResearchCentre), Gerd Leipold (Humboldt-Viadrina GovernancePlatform), Glen Peters (CICERO Center for International
Climate Research), Greet Maenhout Janssens (European
Commission, Joint Research Centre), Henri Waisman (Institutefor Sustainable Development and International Relations),
Henry Neufeldt (UNEP DTU Partnership), Jan S. Fuglestvedt(CICERO Center for International Climate Research), Jérôme
Hilaire (Mercator Research Institute on Global Commonsand Climate Change), Joeri Rogelj (International Institute forApplied Systems Analysis), Johannes Gütschow (Potsdam
Institute for Climate Impact Research), Johannes Trueby(International Energy Agency), Juan Carlos Altamirano (WRI/
New Climate Economy), Karan Mangotra (The Energy andResources Institute), Lars J. Nilsson (Lund University), Lera
Miles (UN Environment World Conservation Monitoring
Centre), Luke Kemp (Australian National University), Maria
Belenky (Climate Advisers), Mark Roelfsema (Radboud
University), Matt Phillips (European Climate Foundation),
Michael Lazarus (Stockholm Environment Institute),
Michael Obersteiner (International Institute for Applied
Systems Analysis), Miles Perry (European Commission
Directorate-General for Climate Action), Oscar Widerberg(Vrije Universiteit Amsterdam - Institute for Environmental
Studies), Paul Ekins (University College London), Piers
Forster (University of Leeds), Rachel Chi Kiu Mok (World
Bank), Ravi Prabhu (World Agroforestry Centre), Rob Dellink(Organisation for Economic Co-operation and Development),
Roman Mendelevitch (Humboldt-Universität zu Berlin),Rong Wang (Carnegie Institution for Science), Stefan Kinne(Max Planck Institute for Meteorology), Steffen Dockweiler,(Danish Energy Agency), Sylvain Cail (Enerdata), Thomas Hale(Oxford University), Tim Christophersen (UN Environment),
Tom van Ierland (European Commission Directorate-General
for Climate Action), Toon Vandyck (European Commission,

Joint Research Centre), Valentin Foltescu (UN Environment- Climate and Clean Air Coalition), Wolfgang K. Heidug (King
Abdullah Petroleum Studies and Research Center), Zhao
Xiusheng (Tsinghua University)

Chief scientific editors
Anne Olhoff (UNEP DTU Partnership), John Christensen(UNEP DTU Partnership)

Editorial team
Daniel Puig (UNEP DTU Partnership), Lars Christiansen(UNEP DTU Partnership), Natacha Chater Cure (UNEP DTU
Partnership), Henry Neufeldt (UNEP DTU Partnership)

Project coordination
Lars Christiansen (UNEP DTU Partnership), Natacha Chater
Cure (UNEP DTU Partnership), Anne Olhoff (UNEP DTU
Partnership), John Christensen (UNEP DTU Partnership),
Edoardo Zandri (UN Environment), Philip Drost (UNEnvironment), Volodymyr Demkine (UN Environment)

External global and national modelling data
contributors
Climate Analytics, Climate Action Tracker (Bill Hare, Marcia
Rocha and Michiel Schaeffer), Climate Interactive (Andrew
Jones, Lori Siegel), Danish Energy Agency (Steffen Dockweiler),
Ecofys (Kornelis Blok), Energy Research Institute, China(Chenmin He), International Energy Agency (Laura Cozzi andFabian Kesicke), International Institute for Applied Systems
Analysis (Nicklas Forsell), Joint Research Centre, European
Commission (Alban Kitous, Kimon Keramidas, Bert Saveyn
and Giacomo Grassi), National Center for Climate Change
Strategy and International Cooperation, China (Fu Sha), PBL
Netherlands Environmental Assessment Agency (Kendall
Esmeijer and Heleen van Soest), Pacific Northwest National
Laboratory (Gokul Iyer), Potsdam Institute for Climate
Impact Research (Louise Jeffery), University of Melbourne(Malte Meinshausen)

Media and launch support
David Cole (UN Environment), Roxanna Samii (UN Environment),
Myriam Castanié (European Climate Foundation),
Shuzhi Hou (UN Environment), Mette Annelie Rasmussen(UNEP DTU Partnership), Shereen Zorba (UN Environment),
Jan Dusik (UN Environment), Rehana Velji (UN Environment),
Alessandra Vellucci (UN Information Service) and Diana
D. Rizzolio (Geneva Environment Network)

Design, layout and printing
Caren Weeks (independent consultant), Kailow A/STranslation of Executive Summary
Strategic Agenda

Thanks also toGerman Federal Ministry for the Environment, Nature
Conservation, Building and Nuclear Safety (BMUB), Climate
Works Foundation, The Finnish Innovation Fund SITRA, theNetherlands Ministry of Infrastructure and Environment,
Jacqueline McGlade (UN Environment), Harsha Dave (UNEnvironment), Brigitte Ohanga (UN Environment), Lucy
Ellen Gregersen (UNEP DTU Partnership), Thomas Hebo
Larsen (UNEP DTU Partnership), Susanne Konrad (UNEP DTU
Partnership), Saran Sohi (University of Edinburgh), Thomas
Kragh Laursen (UNEP DTU Partnership, and Pia Riis KofoedHansen (UNEP DTU Partnership)

The Emissions Gap Report 2017 – Acknowledgementsv

Contents
Acknowledgements....................................................................................................................................................................iv
Glossary....................................................................................................................................................................................vii
Acronyms...................................................................................................................................................................................xi
Foreword..................................................................................................................................................................................xiii
Executive summary.................................................................................................................................................................. xiv
Chapter 1: Scoping the Emissions Gap Report 2017.................................................................................................................... 1
1.1
Moving towards implementation of the Paris Agreement: 2018 as a critical juncture......................................................1
1.2
The Emissions Gap Reports and new aspects included in 2017.........................................................................................2
Chapter 2: Pre-2020 action: trends and progress......................................................................................................................... 3
2.1
Introduction........................................................................................................................................................................ 3
2.2.
Trends in current global emissions.....................................................................................................................................3
2.3.
Progress towards achieving the Cancun Pledges: G20 members.......................................................................................5
2.4.
Amplified urgency of enhanced pre-2020 action...............................................................................................................9
Chapter 3: The emissions gap and its implications.....................................................................................................................11
3.1
Introduction...................................................................................................................................................................... 11
3.2
Scenarios considered in the emissions gap assessment...................................................................................................11
3.3
The emissions gap in 2030 and urgency of action......................................................................................................15
3.4
Understanding the current emission trends of G20 members.........................................................................................19
3.5
Subnational and non-state actions to narrow the gap.....................................................................................................25
Chapter 4: Bridging the gap - sectoral greenhouse gas emission reduction potentials in 2030....................................................27
4.1
Introduction...................................................................................................................................................................... 27
4.2
Assessment of emission reduction potentials by sector in 2030......................................................................................27
4.3
Can the gap be bridged: total emission reduction potential in 2030...............................................................................33
4.4
Comparison with results from Integrated Assessment Models........................................................................................36
4.5
Conclusions....................................................................................................................................................................... 37
Chapter 5: Bridging the gap – Phasing out coal..........................................................................................................................38
5.1
Introduction...................................................................................................................................................................... 38
5.2 	Incentivizing and managing a smooth transition..............................................................................................................41
5.3
Country studies................................................................................................................................................................. 44
5.4.
Synthesis and policy discussions.......................................................................................................................................47
Chapter 6: Bridging the gap – The role of short-lived climate pollutants.....................................................................................48
6.1
The contribution of SLCPs to climate change – Introduction and framing.......................................................................48
6.2
Recent SLCP emissions trends and outlook towards 2030...............................................................................................49
6.3
SLCP mitigation potential..................................................................................................................................................52
6.4
Implications for the emissions gap...................................................................................................................................54
6.5
Implications for the Sustainable Development Goals and other policy goals...................................................................56
6.6
Key messages.................................................................................................................................................................... 57
Chapter 7: Bridging the Gap – Carbon dioxide removal..............................................................................................................58
7.1
Introduction...................................................................................................................................................................... 58
7.2.
Land-based carbon dioxide removal options....................................................................................................................60
7.3
Combined land/technology-based option: bioenergy with carbon dioxide capture and storage....................................62
7.4
Technology-based carbon dioxide removal options.........................................................................................................63
7.5.
Governance issues for carbon dioxide removal................................................................................................................65
7.6
Conclusions and recommendations..................................................................................................................................65
References................................................................................................................................................................................68

vi

The Emissions Gap Report 2017 – Contents

Glossary
This glossary is compiled by the lead authors of the report,
drawing on glossaries and other resources available on
the websites of the following organizations, networks andprojects: Intergovernmental Panel on Climate Change,
Non-State Actor Zone for Climate Action, United Nations
Environment, United Nations Framework Convention on
Climate Change and World Resources Institute.
Afforestation: Planting of new forests on lands that
historically have not contained forests.
Agroforestry: Farming management practice characterized
by the deliberate inclusion of woody perennials on farms,
which usually leads to significant economic and/or
ecological benefits between woody and non-woody systemcomponents. In most documented cases of successful
agroforestry, tree-based systems are more productive, moresustainable and more attuned to people’s cultural or material
needs than treeless alternatives. Agroforestry also provides
significant mitigation benefits by sequestering carbon fromthe atmosphere in the tree biomass.
Baseline/reference: The state against which change ismeasured. In the context of transformation pathways, theterm ‘baseline scenarios’ refers to scenarios that are basedon the assumption that no mitigation policies or measures
will be implemented beyond those that are already in force
and/or are legislated or planned to be adopted. Baseline
scenarios are not intended to be predictions of the future,
but rather counterfactual constructions that can serve tohighlight the level of emissions that would occur without
further policy effort. Typically, baseline scenarios are thencompared to mitigation scenarios that are constructed
to meet different goals for greenhouse gas emissions,
atmospheric concentrations or temperature change. The
term ‘baseline scenario’ is used interchangeably with‘reference scenario’ and ‘no policy scenario’. In much of
the literature the term is also synonymous with the term
‘business as usual (BAU) scenario’, although the term has
fallen out of favour because the idea of ‘business as usual’ incentury-long socioeconomic projections is hard to fathom.
Biochar: A solid material obtained from thermochemical
conversion of biomass in an oxygen-limited environment.

Bioenergy: Energy derived from any form of biomass suchas recently living organisms or their metabolic by-products.
Bioenergy and Carbon Dioxide Capture and Storage (BECCS):
The application of Carbon Dioxide Capture and Storage (CCS)
technology to bioenergy conversion processes.
Black carbon: The substance formed through the incomplete
combustion of fossil fuels, biofuels, and biomass, which isemitted in both anthropogenic and naturally occurring soot.
It consists of pure carbon in several linked forms. Black carbon
warms the Earth by absorbing heat in the atmosphere andby reducing albedo – the ability to reflect sunlight – when
deposited on snow and ice.
Bottom-up model: In the context of this assessment, a modelthat represents a system by looking at its detailed underlying
parts. Compared to so-called top-down models, which focus
on economic interlinkages, bottom-up models of energy use
and emissions can provide greater resolution with regards tosectors or mitigation technologies.
Cancun Pledge: During 2010, many countries submitted
their existing plans for controlling greenhouse gas emissions
to the Climate Change Secretariat and these proposals
were formally acknowledged under the United Nations
Framework Convention on Climate Change (UNFCCC).
Developed countries presented their plans in the shape of
economy-wide targets to reduce emissions, mainly up to2020, while developing countries proposed ways to limit
their growth of emissions in the shape of plans of action.
Carbon Dioxide Capture and Storage (CCS): A process
in which a relatively pure stream of carbon dioxide fromindustrial, energy-related sources or captured from the
air is separated (captured), conditioned, compressed, andtransported to a storage location for long-term isolationfrom the atmosphere.
Carbon dioxide emission budget (or carbon budget): Fora given temperature rise limit, for example a 1.5°C or 2°C
long-term limit, the corresponding carbon budget reflects
the total amount of carbon emissions that can be emitted
for temperatures to stay below that limit. Stated differently,
a carbon budget is the area under a carbon dioxide (CO2)The Emissions Gap Report 2017 – Glossaryvii

emission trajectory that satisfies assumptions about limits
on cumulative emissions estimated to avoid a certain levelof global mean surface temperature rise.
Carbon dioxide equivalent (CO2e): A way to place emissionsof various radiative forcing agents on a common footing byaccounting for their effect on climate. It describes, for a given
mixture and amount of greenhouse gases, the amount of
CO2 that would have the same global warming ability, whenmeasured over a specified time period. For the purpose ofthis report, greenhouse gas emissions (unless otherwise
specified) are the sum of the basket of greenhouse gases
listed in Annex A to the Kyoto Protocol, expressed as CO2e
assuming a 100-year global warming potential.
Carbon intensity: The amount of emissions of CO2 released
per unit of another variable such as gross domestic
product, output energy use, transport or agricultural/
forestry products.
Carbon offset: See Offset.
Carbon price: The price for avoided or released CO2 or
CO2e emissions. This may refer to the rate of a carbon tax
or the price of emission permits. In many models that areused to assess the economic costs of mitigation, carbon
prices are used as a proxy to represent the level of effort in
mitigation policies.
Carbon sequestration: The process of removing carbon fromthe atmosphere and depositing it in a reservoir.
Carbon stock: The quantity of carbon contained in a carbon
pool or reservoir.
Carbon tax: A levy on the carbon content of fossil fuels.
Because virtually all of the carbon in fossil fuels is ultimately
emitted as CO2, a carbon tax is equivalent to an emission tax
on CO2 emissions.
Circular carbon economy: An economy or portion of an
economy in which waste, by-product, or ambient CO2
serves as feedstock and is recycled into products (e.g., fuels,chemicals, plastics, carbon composites)
Co-benefits: The positive effects that a policy or measure
aimed at one objective might have on other objectives,
without yet evaluating the net effect on overall social
welfare. Co-benefits are often subject to uncertainty
and depend on, among others, local circumstances andimplementation practices. Co-benefits are often referred toas ancillary benefits.
Conditional INDC: INDC proposed by some countries thatare contingent on a range of possible conditions, such as theability of national legislatures to enact the necessary laws,
ambitious action from other countries, realization of financeand technical support, or other factors.
Conference of the Parties (COP): The supreme body of theConvention. It currently meets once a year to review theConvention’s progress.

viii

The Emissions Gap Report 2017 – Glossary

Current policy trajectory: This trajectory is based on
estimates of 2020 emissions considering projected economic
trends and current policy approaches including policies atleast through 2012. Estimates may be based on either official
data or independent analysis.
Deforestation: Conversion of forest to non-forest.
Double counting: In the context of this assessment,
double counting refers to a situation in which the sameemission reductions are counted towards meeting two
countries’ pledges.
Economic mitigation potential: The mitigation potential,
which takes into account social costs and benefits and social
discount rates, assuming that market efficiency is improvedby policies and measures and barriers are removed.
Emissions gap: The difference between the greenhousegas emission levels consistent with having a likely chance(>66 percent) of limiting the mean global temperature rise
to below 2°C/1.5°C in 2100 above pre-industrial levels andthe GHG emission levels consistent with the global effect of
the INDCs, assuming full implementation from 2020.
Emission pathway: The trajectory of annual greenhouse gas
emissions over time.
Global warming potential: An index representing the
combined effect of the differing times greenhouse gases
remain in the atmosphere and their relative effectiveness inabsorbing outgoing infrared radiation.
Greenhouse gases: The atmospheric gases responsible forcausing global warming and climatic change. The major
greenhouse gases are carbon dioxide (CO2), methane(CH4) and nitrous oxide (N2O). Less prevalent, but very
powerful, greenhouse gases are hydrofluorocarbons (HFCs),
perfluorocarbons (PFCs) and sulphur hexafluoride (SF6).
Hydrofluorocarbons
(HFC)
bank:
Quantities
ofhydrofluorocarbons already produced or in use of which a
portion is likely to eventually be emitted to the atmosphere.
Integrated assessment models: Models that seek tocombine knowledge from multiple disciplines in the formof equations and/or algorithms in order to explore complex
environmental problems. As such, they describe the fullchain of climate change, from production of greenhousegases to atmospheric responses. This necessarily includes
relevant links and feedbacks between socio-economic andbiophysical processes.
Intended Nationally Determined Contribution (INDC):
Submissions by Parties which identify actions each national
government intends to take under the future UNFCCC
climate agreement, negotiated in Paris in December 2015.
INDCs are, in effect, the basis of post-2020 global emission
reduction commitments that will be included in the futureclimate agreement.
International cooperative initiatives (ICIs): Initiatives
outside the UNFCCC aimed at reducing emissions ofclimate forcers by, for example, promoting actions thatare less greenhouse gas intensive, compared to prevailingalternatives. Cooperative initiatives also involve national andsub-national partners (they are often referred to as, simply,‘cooperative initiatives’).
Kigali Agreement: The Kigali Amendment to the Montreal
Protocol on Substances that Deplete the Ozone Layer aims
for the phase-down of hydrofluorocarbons (HFCs) by cutting
their production and consumption.
Kyoto Protocol: An international agreement, standing on its
own, and requiring separate ratification by governments,
but linked to the UNFCCC. The Kyoto Protocol, among otherthings, sets binding targets for the reduction of greenhousegas emissions by industrialized countries.
Land use, land-use change and forestry (LULUCF): A
greenhouse gas inventory sector that covers emissions andremovals of greenhouse gases resulting from direct humaninduced land use, land use change and forestry activities.
Likely chance: A likelihood greater than 66 percent chance.
Used in this assessment to convey the probabilities ofmeeting temperature limits.
Lock-in: Lock-in occurs when a market is stuck with astandard even though participants would be better off withan alternative.
Medium chance: A likelihood of 50–66 percent chance.
Used in this report to convey the probabilities of meeting
temperature limits.
Mitigation: In the context of climate change, a humanintervention to reduce the sources, or enhance the sinks ofgreenhouse gases. Examples include using fossil fuels more
efficiently for industrial processes or electricity generation,
switching to solar energy or wind power, improving theinsulation of buildings and expanding forests and other ‘sinks’
to remove greater amounts of CO2 from the atmosphere.
Monitoring, reporting and verification: A process/conceptthat potentially supports greater transparency in the climatechange regime.
Montreal Protocol: The Montreal Protocol on Substancesthat Deplete the Ozone Layer is an international treaty thatwas designed to reduce the production and consumptionof ozone-depleting substances in order to reduce theirabundance in the atmosphere, and thereby protect the
Earth’s ozone layer.
Nationally determined Contribution: Actions that, by
ratifying the Paris Agreement, each party to the UNFCCC
binds itself to pursuing.
Non-state actor: In the context of climate action, ‘non-state
actor’ includes companies, cities, subnational regions andinvestors. More broadly, non-state actors have been definedas entities that participate or act in international relations.
They are organizations with sufficient power to influenceand cause a change even though they do not belong to any
state institution.

Offset (in climate policy): A unit of CO2e emissions thatis reduced, avoided, or sequestered to compensate foremissions occurring elsewhere.
Party: A state (or regional economic integration organizationsuch as the European Union) that agrees to be bound by atreaty and for which the treaty has entered into force.
Pigouvian tax: A tax levied on any market activity thatgenerates negative externalities (costs not internalized in
the market price).
Pledge case: This case identifies the maximum level ofgreenhouse gas emissions that each country or Party could
emit in 2020 and still meet its pledge – without considering
the use of offsets.
Reforestation: Replanting of forests on lands that havepreviously contained forests but that have been converted
to some other use.
Scenario: A description of how the future may unfold basedon ‘if-then’ propositions. Scenarios typically include an initialsocio-economic situation and a description of the key driving
forces and future changes in emissions, temperature orother climate change-related variables.
Short-lived climate pollutants (SLCPs): Compounds in theatmosphere that cause warming and have lifetimes roughly
below 20 years, including black carbon, ozone, methane,and many hydrofluorocarbons.
Source: Any process, activity or mechanism that releases agreenhouse gas, an aerosol or a precursor of a greenhousegas or aerosol into the atmosphere.
Shared Socio-Economic Pathways (SSPs): Narrativesof possible societal futures that include quantitative
projections of socio-economic factors such as population,
GDP, urbanization, technologies and regional heterogeneity.
SSP3 (Shared Socio-Economic Pathway – narrative 3): ThisSSP narrative is characterized by high challenges to mitigation
and adaptation. It assumes a focus on national and regional
policies, slow economic growth, lack of collaboration,
large population remaining in poverty, and low priority forenvironmental policies, leading to strong environmental
degradation in some regions.
Subcritical coal plant: A subcritical coal fired plant uses coal
to heat water into high-pressure steam to drive an electricalgenerator, whereas the steam in the boiler does not pass
the supercritical point of water (as compared to supercriticalpower plants). The resulting efficiency rates are comparably
low, i.e. below 37 percent.
Sustainable development: Development that meets theneeds of the present without compromising the ability of
future generations to meet their own needs.
Technical mitigation potential: Such potential is estimatedfor given scenarios assuming full implementation of best
available pollutant reduction technology, as it exists today,by 2030 independent of their costs but considering technical

The Emissions Gap Report 2017 – Glossaryix

lifetime of technologies and other key constraints (e.g.,cultural acceptance) that could limit applicability of certain
measures in specific regions.
Top-down model: A model that applies macroeconomic
theory, econometric and/or optimization techniques
to aggregate economic variables. Using historical dataon consumption, prices, incomes, and factor costs, topdown models assess demand and emissions for goods andservices from main sectors, such as energy conversion,transportation, buildings, agriculture and industry.
Tropospheric ozone: Ozone in the lowest portion of theatmosphere extending from the surface to the edge of thestratosphere. Ozone in this region is a powerful greenhousegas, especially in the mid to upper troposphere, whereas the
portion at the surface is damaging to humans and plants.

x

The Emissions Gap Report 2017 – Glossary

Uncertainty: A cognitive state of incomplete knowledge thatcan result from a lack of information or from disagreement
about what is known or even knowable. It may have many
types of sources, from imprecision in the data to ambiguously
defined concepts or terminology, or uncertain projections ofhuman behaviour. Uncertainty can therefore be represented
by quantitative measures (for example a probability density
function) or by qualitative statements (for example reflecting
the judgement of a team of experts).
Unconditional INDCs: INDCs proposed by countries without
conditions attached.
2020 pledge: See Cancun Pledge.

Acronyms
°C
BAU
CCS
CO2
CO2e
COP
EJ
G20
Gt
GW
INDC
IPCC
LULUCF
m2
Mt
NDC
OECD
SLCP
UNFCCC

Degree Celsius
Business as usual
Carbon capture and storage
Carbon dioxide
Carbon dioxide equivalent
Conference of the Parties to the United Nations Framework Convention on Climate Change
Exajoule
Group of 20
Gigatonne
Gigawatt
Intended Nationally Determined Contribution
Intergovernmental Panel on Climate Change
Land use, land-use change and forestry
Square metre
Million tonnes
Nationally Determined Contribution
Organisation for Economic Cooperation and Development
Short Lived Climate Pollutant
United Nations Framework Convention on Climate Change

The Emissions Gap Report 2017 – Acronyms

xi

xii

The Emissions Gap Report 2017

Emissions Gap
Report 2017
Political, industrial and civil leaders are strengthening andimplementing the Paris Agreement on Climate Change. Yet
current state pledges cover no more than a third of theemission reductions needed, creating a dangerous gap,
which even growing momentum from non-state actors
cannot close. This report highlights the dangers of that gap,
the issues behind it and the means at our disposal to close it.
Fossil fuels and cement production still account for about
70 percent of greenhouses gases. The report shows how ashift in technology and investment can reduce emissions,while creating huge social, economic and environmental
opportunities. Even as greenhouse gas emissions continue toincrease, carbon dioxide emissions from energy and industry
have remained largely stable since 2014. This is mainly
thanks to, more renewable energy and energy efficiency,
and better infrastructure, notably in China and India. For
example, record levels of renewable energy were added in2016, but for 23 percent less investment than in 2015. So, it’slittle wonder the sector now employs eight million people,
including more new jobs in China and the United States thanoil and gas.
It proves that using policies and financial frameworks togrow green technology markets can combat climate change,
reduce pollution and creates a more sustainable society.
And it demonstrates why governments, industry and thefinancial community can and must collaborate to provide
the conditions that foster and fast-track innovative solutions.
This is the only way to keep the global temperature rise
below 1.5 degrees and reduce the human and economic
cost of pollution. Many solutions are already available ata reasonable cost and with sound profits. Encouraging afaster transition will generate widely-shared benefits andmomentum for climate action.
To understand the alternative, just look at how Hurricane
Harvey flooded 50,000 homes in Texas with nearly 20 trillion
gallons of rain in just five days. Listen to Annie Smith explain
what it’s like going into labour as the floodwaters rise.
Even in a such a wealthy nation, her survival was down to ahuman chain of neighbours and firefighters. Or what about
the 1,200 people in India, Nepal and Bangladesh who wereless fortunate when the floods hit there? Over 600 Nepalese
were rescued by elephants, while Red Cross and Red
Crescent workers struggled to find a scrap of dry land andsaw farmers left without even drinking water. Such stories
are a frightening reminder that we simply cannot save every
victim, one at a time, with nothing but compassion.
That is why governments, private sector and civil society
must bridge this catastrophic climate gap. Talking less about‘fixing environmental problems’ and more about ‘grasping
economic and social opportunities’ is crucial. I hope thisreport will nurture that change in mind set, to build a more
prosperous future for this planet and its people.

Erik Solheim
Head of UN Environment

The Emissions Gap Report 2017 – ForewordxiiiExecutive summary
The Paris Agreement adopted in 2015 set the specific goalof holding global warming to well below 2 degrees Celsius(°C) compared to pre-industrial levels, and of pursuingefforts to limit warming to 1.5°C. This report, which is theeighth Emissions Gap Report produced by UN Environment,
focuses on the “gap” between the emissions reductions
necessary to achieve these agreed targets at lowest cost andthe likely emissions reductions from full implementation of
the Nationally Determined Contributions (NDCs) forming
the foundation of the Paris Agreement. It also explores
potential for enhanced mitigation efforts in a number ofkey sectors, presenting cost-effective options for enhanced
action to close the emissions gap.
The report has been prepared by an international teamof leading scientists, assessing all available information,
including that reviewed by the Intergovernmental Panel on
Climate Change (IPCC) in its Fifth Assessment Report (AR5),
as well as more recent scientific studies. The assessment
production process has been transparent and participatory.
The assessment methodology and preliminary findings
were made available to the governments and stakeholders
concerned during relevant international forums, aswell as on the UNEP Live website. The governments ofthe countries with specific mention in the report have,throughout the process, been invited to comment on thespecific assessment findings.

1.

The overarching conclusions of thereport are that there is an urgent needfor accelerated short-term action andenhanced longer-term national ambition,
if the goals of the Paris Agreement are toremain achievable — and that practicaland cost-effective options are available
to make this possible.

• The successful Paris Agreement has generated andincentivized action at scale by both governments
and the private sector. Nevertheless, it marks only abeginning. The NDCs that form the foundation of theParis Agreement cover only approximately one thirdxiv

The Emissions Gap Report 2017 – Executive summaryof the emissions reductions needed to be on a leastcost pathway for the goal of staying well below 2°C. The
gap between the reductions needed and the national
pledges made in Paris is alarmingly high.
• Looking beyond 2030, it is clear that if the emissions gap
is not closed by 2030, it is extremely unlikely that the goalof holding global warming to well below 2°C can still bereached. Even if the current NDCs are fully implemented,
the carbon budget for limiting global warming to
below 2°C will be about 80 percent depleted by 2030.
Given currently available carbon budget estimates, theavailable global carbon budget for 1.5°C will already be
well depleted by 2030.
• Action by subnational and non-state actors, including
regional and local governments and businesses, is key toenhancing future ambition. There is still limited evidence
that non-state action will fill a significant part of theemissions gap, although there is significant potential
for it to do so. Enhanced monitoring and reporting of
non-state actions and the resulting emissions reductions
be will be essential to making pledged actions transparent
and credible.
• More ambitious NDCs will be necessary by 2020 andshould build on the existing, extensive knowledge
about the cost-effective policies and measures that canbe taken. A systematic assessment of sectoral mitigation
options presented in the report shows that the gap can
be closed before 2030 by adopting already known andcost-effective technologies, often by simply adopting
or adapting best practice examples already deployed in
the most innovative country contexts. The assessment
in Chapter 4 shows that emissions could be reduced
by up to 30 to 40 GtCO2e per annum, with costs below
US$100/tCO2e. It is remarkable that a large part of thispotential comes from just six relatively standardized
categories: solar and wind energy, efficient appliances,efficient passenger cars, afforestation and stopping
deforestation. These six present a combined potential of
up to 22 GtCO2e per annum.

• This eighth Emissions Gap Report assesses in more detailsome specific options that may contribute to closing thegap. These include addressing the possibilities and risks
associated with technologies and practices to remove
carbon dioxide from the atmosphere via enhanced
land-use sinks and advanced storage technologies.
The land-use related options offer an annual reduction
potential in 2030 of the order of between 4 and
12 GtCO2e, forming part of the sectoral potential
mentioned above. It is still too early to judge the potential
for the emerging technology options.
• The report also covers an assessment of the potential
contribution from reductions in short-lived climate
pollutants (SLCPs), although they are not directlycomparable with reductions in long-lived greenhousegases. Reductions of SLCPs limit the rate of short-termwarming, and when sustained and combined with CO2
reductions, these reductions also help to limit long-termwarming, which is the ultimate aim of closing theemissions gap.
• Finally, the report presents an assessment of recent
developments in the coal sector, and discusses how atransition away from coal could be incentivized. The
assessment shows that a transition could take place
remarkably quickly, if political will and market signals
provide adequate incentives, but it also shows that a justtransition requires careful consideration of the social andenergy system impacts and additional policies to copewith such impacts. If these effects are not addressedfrom the beginning of a transition process, they very
often prevent or hamper the process significantly.
Government policy is essential not only to incentivize
innovation, but also to mitigate adverse effects and toensure social and political acceptability. It is essential
to do everything possible to ensure that the benefits
stemming from a transition are shared.

2.

The Facilitative Dialogue and the2020 revision of the NDCs are thelast opportunity to close the 2030
emissions gap.

These key messages send a set of strong signals to the
Facilitative Dialogue process scheduled to take place under
the aegis of the United Nations Framework Convention on
Climate Change (UNFCCC) during 2018, and suggest thatambition should be significantly enhanced in the new andupdated NDCs that will be submitted in 2020.
If the climate targets in the Paris Agreement are to remain
credible and achievable, all countries will need to contributeto significantly enhancing their national ambitions,
augmenting their national policy efforts in accordance withrespective capabilities and different circumstances, andensuring full accounting of subnational action. Furthermore,
a strong commitment to facilitating and stimulatingwidespread, equitable and accountable innovation will beneeded, to ensure that the best the world can offer in termsof cost-effective technology, policy and business models isavailable wherever needed. Non-state actors need to adhere
to high standards of accountability in this respect.
Missing the 2020 option of revising the NDCs would makeclosing the 2030 emissions gap practically impossible.

3.

Global CO2 emissions from energy andindustry have remained stable since 2014,
but overall greenhouse gas emissions
continue to rise slowly.

Global carbon dioxide (CO2) emissions from fossil fuelcombustion, cement production and other industrial
processes account for about 70 percent of total global
greenhouse gas emissions, and were estimated at a totalof 35.8 GtCO2 for 2016, as shown in figure ES.1. There isincreasing evidence that these emissions have remained
more or less stable for the past three years, reversing theprevious tendency of increases each year. This may indicate
a decoupling of energy- and industry-related CO2 emissions
from economic growth during these years, in which global
Gross Domestic Product increased by between 2 and3 percent annually. The main drivers have been reduced
growth in coal use since 2011, primarily in China andsecondarily in the United States, growing renewable power
capacity and generation, especially in China and India,
combined with enhanced energy efficiency and structuralchanges in the global economy.
However, the trend is still over a relatively short period, andcould potentially be reversed if growth in the world economy
accelerates. Furthermore, continued investment in more
traditional technologies, especially coal-fired power stations,
implies significant technological lock-in and long-term
commitment to continued emissions. The assessment showsthat between 80 and 90 percent of coal reserves worldwide
will need to remain in the ground, if climate targets are to bereached. This compares with approximately 35 percent foroil reserves and 50 percent for gas reserves.
Total global greenhouse gas emissions, including emissions
from land use, land-use change and forestry (LULUCF), areestimated at about 51.9 GtCO2e/year in 2016. The time series
data for global total CO2 and greenhouse gas emissions used
for the Emissions Gap Reports have been updated since the2016 report, with the estimate for global total greenhousegas emissions in 2014 now updated to 51.7 GtCO2e, and theestimate for global total CO2 emissions in 2015 updated to35.6 GtCO2. Emissions still show a slowdown in growth in
the past two years, with calculated increases of 0.9 percent,
0.2 percent and 0.5 percent in 2014, 2015 and 2016
respectively, as shown in figure ES.1.

The Emissions Gap Report 2017 – Executive summaryxv

Figure ES.1.a: Global greenhouse gas emissions for top six
emitting countries and regions (excluding land use, land-use
change and forestry), international transport emissions, and landuse, land-use change and forestry emissions.
Global greenhouse gas emissions

Figure ES.1.b: Global carbon dioxide emissions per region fromfossil fuel use, cement production and other processes, and frominternational transport.

Global CO₂ emissions

GtCO₂e/year
60

GtCO/year
60

50

50

40

40

30

30

20

20

10

10

0
1970

1980

1990

2000

2010 2016

1970

1980

1990

2000

Land-use change emissions (net CO₂)

China

EU-28

Russian Federaon

Other G20 countries

Land-use change fires (CH₄, N₂O)

USA

India

Japan

Other countries

2010

0
2016

Internaonaltransport

Note: Other G20 countries include Argentina, Australia, Brazil, Canada, Indonesia, Mexico, Republic of Korea, Saudi Arabia, South Africa and Turkey. The greenhousegas total are expressed in terms of billions of tonnes of global annual CO2 equivalent emissions (GtCO2e/year). CO2 equivalent is calculated using the Global Warming
Potentials (GWP-100) metric of UNFCCC as reported in the IPCC Second Assessment Report, similar as has been done in the IPCC Fifth Assessment Report.
Source: EDGAR v4.3.2 FT2016 (Olivier et al., 2017).

4.

Global greenhouse gas emissions in 2020are likely to be at the high end of therange of the scenarios consistent with the
2°C and 1.5°C goals respectively, making
it increasingly difficult to be on track tomeet the 2030 emission goals.

G20 countries are collectively on track to meet the middle
range of their Cancun Pledges for 2020, but for somecountries further action is needed and there are still many
opportunities to further reduce emissions in the short term,
as documented in Chapter 4. While praise for meeting atarget is merited, it should be remembered that it does notgive any indication of how ambitious the target was.
The assessment shows that according to all available
estimates, four of the G20 members – China, the EU28, India
and Japan – are on track to meet their 2020 pledges withoutpurchasing offsets. A further three – Australia, Brazil andRussia – are on track according to most estimates.
According to both government and independent estimates,
Canada, Mexico, the Republic of Korea, South Africa and theUnited States are likely to require further action, possibly
supplemented by purchased offsets, in order to meet their2020 pledges. Mexico’s 2020 pledge is conditional on theprovision of adequate financial and technological support
from developed countries as part of a global agreement, andthe fulfilment of this condition has not been assessed.

xvi

The Emissions Gap Report 2017 – Executive summary

Independent estimates of the Republic of Korea’s 2020
emissions are well above the level implied by its pledge.
The country’s amended Green Growth Basic Act, however,replaced the 2020 pledge with the NDC target for 2030,
implying there no longer is a 2020 target.
Insufficient information is currently available to determine
whether Indonesia is on track to meet its pledge.
Independent projections span a wide range, and official
projections reflecting current policies are unavailable.
Finally, Argentina, Saudi Arabia and Turkey have notmade greenhouse gas reduction pledges for 2020. All
three countries submitted post-2020 pledges to the
UNFCCC as part of their Intended Nationally Determined
Contributions (INDCs).
The limited collective ambition of the Cancun Pledges means,however, that the global greenhouse gas emissions in 2020are likely to be at the high end of the range of the scenarios
consistent with the 2°C and 1.5°C targets respectively.
This increases the challenge of meeting the necessary
2030 emission goals. With the limited time to 2020, it will
be difficult to realize any significant additional emission
reductions, but many actions can still be initiated that bothlead to short-term reductions and facilitate pathway changes
for the next decade.

5.

A large gap exists between 2030 emission
levels and those consistent with leastcost pathways to the 2°C and 1.5°C goals
respectively. The 2°C emissions gap for
the full implementation of both theconditional and unconditional NDCs for2030 is 11 to 13.5 GtCO2e. The gap in
the case of the 1.5°C target is 16 to
19 GtCO2e.

The assessed global scenarios show that if least-cost
trajectories are followed, then emissions of all greenhousegases should not exceed 42 GtCO2e in 2030, if the 2°C target
is to be attained with higher than 66 percent chance. The
level for 1.5°C has in earlier reports been reported withhigher than 50 percent probability and is about 5 GtCO2e
lower than the central estimate for the 2°C pathways. New
studies are, however, becoming available that present leastcost pathways starting from 2020 that could return global
warming to below 1.5°C by 2100 with higher than 66 percent
probability. These studies indicate a much lower required
level of around 24 GtCO2e, which would imply a need forsignificantly faster and deeper reductions than previously
anticipated. The number of published studies on this topic
is considered too low to allow for inclusion in the gap
assessment with a high level of confidence in 2017, but it isexpected that further analysis of these 1.5°C pathways withhigher than 66 percent probability will be included in the2018 report.

Figure ES.2: Global greenhouse gas emissions under different scenarios and the emissions gap in 2030 (median estimate and 10th to 90th
percentile range).

Annual Global Total Greenhouse Gas Emissions (GtCO₂e)70

Baseline

60

Current policy trajectory
Uncondional
NDC case

40

Purple area shows pathways
liming global temperature
increase to below 1.5°C by 2100
with 50 to 66% chance

Remaining gap
to stay within
2°C limit

GtCO2e19
GtCO2e16
GtCO2eMedian esmateof level consistent
with 2°C:
42 GtCO₂e(range 31-44)

Remaining gap
to stay within
1.5 °C limit

Uncond. NDC case

2°C
°C
range
e

Blue area shows pathways
liming global temperature
increase to below 2°C by
2100 with > 66% chanceCond. NDC case

GtCO2e13.5

Cond. NDC case

1150

Uncond. NDC case

Condional
NDC case

Median esmateof level consistent
with 1.5°C:
36 GtCO₂e(range 32-38)

1.5°C
range
70
Baseline

60

30
2015

2020

2025

Current policy trajectory2030

Uncondional NDC case
Condional NDC case50

Note: the emissions range for 1.5°C is smaller than for 2°C, as a smaller numberof studies for 1.5°C are available. For current policy, the minimum–maximum
across all assessed studies are provided.

40

2°C
range

30

1.5°C
range

20

10

0
2010

2020

2030

2040

2050

The Emissions Gap Report 2017 – Executive summary

xvii

The emissions gap related to the 2°C goal for the full
implementation of NDCs for 2030 is 11 to 13.5 GtCO2e,
for conditional and unconditional pledges respectively.
These estimates are slightly lower than the 12 to 14 GtCO2e
estimates in the 2016 report, due to updated informationfrom five global studies with lower emission projections
resulting from the NDCs. The emissions gap in the case of
1.5°C with higher than 50 percent probability is found to
be 16 to 19 GtCO2e for conditional and unconditional NDCs
respectively, which is higher than the 15 to 17 GtCO2e
estimates in the 2016 report, due to new studies on 1.5°C
pathways and the harmonization of 2010 emission levels
across scenarios. As indicated above, there are not enoughstudies available to give a reliable estimate for a gap in thecase of higher than 66 percent probability, but it is clear the
gap will be larger.
The alarming number and intensity of extreme weather
events in 2017, such as hurricanes, droughts and floods,
adds to the urgency of early action. These events underline
the importance of the Paris Agreement, which seeks to limit
warming to “well below 2°C above pre-industrial levels andpursue efforts to limit the temperature increase to 1.5°C
above pre-industrial levels”. The particular class of models
referred to in this Emissions Gap Report looks at meeting
the Paris Agreement goals at the lowest possible costs,
and therefore results do not change even when the risks ofclimate change become more apparent.
Implications for the carbon budget: If the current NDCs
are fully implemented, the carbon budget for limiting
global warming to below 2°C with higher than 66 percent
probability will be about 80 percent depleted by 2030. Givencurrently available carbon budget estimates, the available
global carbon budget for 1.5°C with at least 50 percent
probability will already be well depleted by 2030.
Implications for temperature levels in 2100: Full
implementation of the unconditional NDCs and comparable
action afterwards is consistent with a temperature increaseof about 3.2°C by 2100 relative to pre-industrial levels. Full
implementation of the conditional NDCs would lower the
projection by about 0.2°C.

6.

Most G20 countries require new policies
and actions to achieve their NDC pledges.

This 2017 report includes an updated assessment of theemissions associated with the NDC pledges and current
policies of each of the G20 countries, including the EU.
As these countries collectively generate around threequarters of global greenhouse gas emissions, their successin implementing (or exceeding) their NDC pledges will
have a major impact on the achievement of the global
temperature goals.
The assessment shows that for many countries, implementing
their NDC would lead to lower emissions than the current
policies scenario, or in other words that additional policies
will have to be implemented to meet the NDC target. The

xviii

The Emissions Gap Report 2016 – Executive summarylevel of ambition embedded in NDCs varies considerably:
for some countries the NDC target is actually above current
projected policy case emissions.
With this caveat, recent studies assessed suggest that
Brazil, China, India and Russia are likely to – or are roughly
on track to – achieve their 2030 NDC targets with currently
implemented policies. Conversely, Argentina, Australia,
Canada, the European Union, Indonesia, Japan, Mexico,South Africa, the Republic of Korea and the United States arelikely to require further action in order to meet their NDCs,
according to government and independent estimates.

7.

Subnational and non-state action has thepotential to reduce the emissions gap
by a few gigatonnes CO2e/year by 2030.
Improved information about the impact
of subnational and non-state action isurgently required.

Subnational and other non-state actors, such as privatecompanies, make a considerable contribution to global
greenhouse gas emissions. For example, the world’s 100
largest emitting publicly traded companies account foraround a quarter of global greenhouse gas emissions.
State and non-state actions can both overlap and mutually
reinforce each other, but it is currently unclear how many of
the actions by non-state actors are included in the national
pledges. The assessment provided here suggests that theaggregated additional impact of the various non-state
initiatives is of the order of a few GtCO2e in 2030, over
and above current NDCs. This is potentially a significant
contribution to closing the gap, if the initiatives reach theirstated goals, and if these reductions do not displace actions
elsewhere. Coordinated, comparable and transparent
reporting and verification of actions by all actors is essential
to clarify effects and possible overlaps. This would also
help in gaining recognition of ambitious action and would
facilitate replication.

8.

The Kigali Amendment and the ICAO
Offsetting Scheme provide somewelcome additional momentum and may
contribute just under 1 GtCO2e to closing
the gap in 2030.

The Kigali Amendment, signed in December 2016, aims tophase out the use and production of hydrofluorocarbons,and the agreement is expected to accelerate this process,which some countries have already included in their NDCs.
The impact compared to a no-action baseline would globally
be of the order of 0.7 GtCO2e/year in 2030. Since somecountries already include hydrofluorocarbons phase-downin their NDCs, the additional impact compared to the NDCs
will be smaller. UN Environment will in 2018 undertake a
new specific assessment to shed more light on the impactsof implementing the Kigali Amendment.
International aviation emissions are expected to growfrom 0.5 GtCO2e in 2017 to around 1.1 GtCO2e in 2030,

with increasing traffic demand over the coming decades.
Domestic aviation is included in many countries’ NDCs
and related national actions, but international aviation isnot. The ICAO’s Carbon Offsetting and Reduction Scheme
for International Aviation (CORSIA) established to reduce
emissions from international aviation is estimated to havean impact of 0 to 0.3 GtCO2 per year on global emissions in
2030. The wide range implies that the result will depend on
the way the offsetting rules will be set. The long-term impact
will likely be larger.

9.

The assessment of the emissions gap andthe mixed progress on implementationof both the Cancun Pledges and the NDCs
show that there is a significant distance
between the current collective ambitions
and commitments and what is required tomeet the temperature goals of the Paris
Agreement. It is therefore absolutely
crucial that the Facilitative Dialogue
in 2018 addresses the need and theopportunities for significantly enhanced
action pre-2030, including by assistingand informing countries in urgently
strengthening their NDCs.

In order to inspire the process of strengthening NDCs, this2017 Emissions Gap Report addresses a number of key
opportunities for closing the 2030 emissions gap, including:• A systematic review of the mitigation potential of alarge number of sector actions. The results here areunambiguous: technologies and institutional innovations
are available to bridge the emissions gap, and at
reasonable cost.
• A detailed assessment of global developments in thecoal sector that also examines the options and barriers
for a gradual coal phase-out.
• Opportunities offered by limiting emissions of SLCPs.
Reducing these pollutants will limit the rate of shortterm warming, and when sustained and combined with
CO2 reductions, help limit long-term warming, which is
the ultimate aim of closing the emissions gap.
• Options for both biological and technological carbon
dioxide removal: some of the former come with decadesof experience, while many of the latter are still in
their infancy.

10. The emissions reduction potential by2030 at costs <US$100/tCO2e, comparedto the current policy trajectory, issufficient to close the emissions gap in
2030 under all cases assessed. It could in
addition provide many benefits for otherimportant environmental, social andeconomic goals.
The systematic review presents estimates of the global
emission reduction potentials that could be achieved in 2030
in six key sectors: agriculture, forestry, buildings, energy,

industry and transport. For all sectors, the main categories
of emissions reduction for 2030 are identified.
The focus is on the socio-economic potential, meaningthat the numbers presented refer to the total emissions
reductions that can be achieved using all technologies
available in a given future year. The potential is defined by
all reductions that can be achieved at a cost of no morethan US$100/tCO2e, using social, not private, paybacktimes. Most of the potential, however, can be achieved at a
cost significantly below US$100/tCO2e.
There are important uncertainties related to technology
development assumptions and implementation rates, suchas how rapidly solar photovoltaic energy production can bescaled up, or the rate at which buildings can be retrofitted.
Most of the underlying analysis introduces some degree of‘realism’ to the assessment and its respective assumptions.
In general, the potentials can be achieved if countries
around the globe are willing to establish necessary policies
that enable the available solutions to be implemented andbarriers to be addressed.
The total of all emission reduction potentials in theassessment amounts to 35–41 GtCO2e/year in 2030, withdetails shown in table ES.1. However, there are someareas where estimates of potentials are fairly new, and it
is uncertain whether it is indeed feasible to realize themby 2030. Leaving out these areas will reduce the emission
reduction potential to 30–36 GtCO2e, which is still morethan double the 2030 emissions gap for the 2°C goal.
An important question is of course what are the policies,
measures and costs required to implement a substantial
part of these emission reduction options? Althoughanswering in full is beyond the scope of the current
assessment, some first comments are made in Chapter 4.
It is remarkable that a large part of the potential consistsof just six relatively standardized categories: solar andwind energy, efficient appliances, efficient passenger
cars, afforestation and stopping deforestation. These six
measures sum up a potential of 15–22 GtCO2e, making up
over 40 percent of the total potential. All these measures
can be realized at modest or even net-negative incremental
costs, and in most of the cases there are proven policies
that can be replicated.
For both current and evolving technologies, the assessment
reported here are at the global level. Further work will beneeded to disaggregate by region and design appropriate
mitigation plans for each country. Countries will need toundertake more specific assessment of the key options
relevant to their own circumstances as part of thecollective effort to boost the global mitigation ambitions.
It will be important to ensure that international technicaland financial support is available to facilitate action indeveloping countries.

The Emissions Gap Report 2017 – Executive summary

xixTable ES.1: Overview of emission reduction potentials in 2030 (GtCO2e per year).
SectorAgriculture

Category

Emission reduction potential
in 2030 (GtCO2e)

Cropland management

0.74

Rice management

0.18

Livestock management

0.23

Grazing land management

0.75

Restoration of degradedagricultural land

0.5 - 1.7

Peatland degradation andpeat fires

1.6

Biochar

Buildings

Energy sector

Forestry

Industry

Transport

Other

0.2

Shifting dietary patterns

0.37 - 1.37

Decreasing food loss andwaste

0.97 - 2

New buildings

0.68 - 0.85

Existing buildings

0.52 - 0.93

Renewable heat - bio

0.39

Renewable heat - solar

0.21Lighting

0.67

Appliances

3.3

Solar energy

3-6Wind energy

2.6 - 4.1

Hydropower

0.32

Nuclear energy

0.87

Bioenergy

0.85

Geothermal

0.73

CCS

0.53

Bioenergy with CCS

0.31

Methane from coal

0.41

Methane from oil and gas

1.78

Restoration of degraded forest

1.6 - 3.4

Reducing deforestation

3

Energy efficiency - indirect

1.9

Energy efficiency - direct

2.2

Renewable heat

0.5

Non-CO2 greenhouse gases

1.5

CCS

1.22

Heavy Duty Vehicles potential(efficiency, mode shift)

0.88Light Duty Vehicles potential(efficiency, mode shift, electricvehicles)2.0

Shipping efficiency

0.7

Aviation efficiency

0.32 - 0.42

Biofuels

0.63 - 0.81

Landfill gas recovery

0.4

Enhanced weathering
measures0.73 - 1.22

Total basic emission reduction potential

Category

Sectoral aggregate potential(GtCO2e)Basic

3 (2.3 - 3.7)

Additional

3.7 (2.6 - 4.8)

1.9 (1.6 - 2.1)
Basic

Basic (indirect emissions)See energy sector
potential

Basic

10 (9.3 – 10.6)

Additional

0.3 (0.2 - 0.4)

Basic

2.2 (1.7 - 2.6)

Basic

5.3 (4.1 - 6.5)

Basic (indirect emissions)See energy sector
potential

Basic

5.4 (4.2 - 6.6)

Basic

4.7 (4.1 - 5.3)

Basic

0.4 (0.3 - 0.5)

Additional

1 (0.7 - 1.2)
33 (30 - 36)

Total emissions reduction potential including additional
38 (35 - 41)
measuresNote: Although for many emission reduction categories a single point estimate is given, there are always uncertainties, assumed to be ±25 percent. For the categories
peatland degradation and peat fires, biochar and energy efficiency, the potential in 2030 is more uncertain. Therefore, a higher uncertainty range of 50 percent isapplied to these categories. In the final column, the categories are aggregated to the sectoral level. The numbers in the third column are not corrected for overlap
between measures. The numbers in the final column are corrected for overlap, and this is also reflected in the total potential. Therefore, the total is smaller than thesum of the individual potentials in the third column. The aggregate potentials for indirect emission reductions in buildings and industry are reflected in the electricity
sector potential.

xx

The Emissions Gap Report 2017 – Executive summary

11. Avoiding building new coal-fired power
plants and phasing out existing ones is
crucial to closing the emissions gap. This
will require careful handling of issues
such as employment impacts, investor
interests, grid stability and energy accessto achieve a just transition.
Many of the sectoral mitigation options presented above
will, if implemented at scale, bring significant changes to
the global energy sector, especially in growing but quickly
decarbonizing electricity capacity. For this to happen, it
will be important to also reduce the fossil-based electricity
capacity already in place and under construction and avoidplanning new coal plants. A gradual phase-out of coal isneeded, recognizing that coal-based power generation willremain significant for a number of both developing andindustrialized countries until at least 2030.
Today, there are an estimated 6,683 operating coal-fired
power plants in the world, with a combined installed capacityof 1,964 GW. If these plants were operated until the end of
their lifetime and not retrofitted with carbon capture andstorage (CCS), the stock of operating power plants would
emit an accumulated amount of around 190 GtCO2.
Without additional policy interventions, the number of coalfired power plants will continue to increase. As of early 2017,
across the globe there were additional 273 GW of coalfired capacity in construction and 570 GW at the planningstage. Ten countries make up approximately 85 percent of
the entire coal pipeline, with 700 GW being built or plannedin China, India, Turkey, Indonesia, Vietnam, Japan, Egypt,
Bangladesh, Pakistan and the Republic of Korea alone. As
shown in table ES.2, these new plants, if operated until
the end of their assumed lifetime of 40 years, would leadto additional accumulated emissions of approximately
150 GtCO2. In comparison, the total remaining carbon budget
is approximately 1,000 GtCO2 for staying below 2°C andless than 600 GtCO2 for staying below 1.5°C. On a positivenote, in 2016 a large number of planned coal-fired power
plants— particularly in China and India — were shelvedor cancelled, and globally there was a slower rate of coal
expansion generally.
Large-scale phase-out of coal will pose very different
challenges and solutions for individual countries, and withrespect to existing plants, recently built plants and those in
the pipeline.
Chapter 5 discusses experiences with possible market andnon-market-based policy instruments and how these could
be used to incentivize a transition away from coal. A set ofcountry assessments presents the challenges a transition
would have for the largest coal-using and exporting
countries. One example, from India, illustrates some of thesechallenges by showing that coal production, transport, usage
and ash disposal employ almost one million people. Coalmining is the second largest employer in India — the largest
being the railroads, which again has coal transporting as its
number one product and revenue source.
The country examples show that if a transition is to succeed,
it will need to be carefully managed, ensuring that impacts
on workers, coal owners, industry and energy users are, as
far as possible, addressed up front and that compensation
measures are developed in consultation with these
key stakeholders. Failing to address the interests of thepotential “losers” in any transition process has made manysocietal or industrial transitions fail or created political andsocial unrest.

Table ES.2: Committed carbon dioxide emissions for coal-fired power plants, in GtCO2, by status and region.
RegionAnnounced

Pre-permitted

Permitted

Construction

Operating

Total

East Asia

12.19

12.34

6.30

30.41

126.41

187.66South Asia

6.21

9.87

5.89

8.28

27.42

57.67

South-East Asia

7.00

5.78

2.63

5.21

8.95

29.60

European Union

0.60

0.66

0.17

1.14

7.22

9.79

Non-EU Europe

4.86

5.30

1.70

0.44

3.56

15.87

Middle East and Africa

5.83

1.16

1.94

2.14

2.46

13.52

Latin America

0.61

0.17

0.28

0.37

1.74

3.18

Eurasia

1.65

0.00

0.00

0.20

2.69

4.54

North America

0.00

0.00

0.15

0.00

8.85

9.01

Australia and New
Zealand

0.00

0.00

0.00

0.00

1.14

1.14

Total

38.97

35.28

19.08

48.20

190.44331.97Note:• The figures take into account the remaining lifetimes of existing plants.
• A lifetime of 40 years is assumed for newly constructed power plants.
• European Union data refers to the current 28 Member States. North America refers to both Canada and the United States.
• It is assumed that not all permitted, pre-permitted and announced power plants come online.
Source: Edenhofer et al. (2017) and Shearer et al. (2017)

The Emissions Gap Report 2017 – Executive summaryxxi

12. Reductions in SLCP emissions can be an
13. Carbon dioxide removal from theimportant part of global mitigation efforts
atmosphere can provide an additionaland contribute to the achievement of
mitigation element to conventional
a number of Sustainable Development
emission abatement strategies. Biological
Goals. Significant potential, beyond
CO2 removal through afforestation,
existing commitments, is achievable withreforestation, forest management,
proven technologies, but dedicated policy
restoration of degraded lands, soil carbon
action to establish legal frameworks
enhancement and biochar application in
and institutional capacity is required toagriculture can play an immediate role,
unlock it.
and can also significantly contributeto achieving several other Sustainable
SLCPs are agents that have a relatively short lifetime in
Development Goals.
the atmosphere — from a few days to a few decades —and a warming influence on climate. The main SLCPs areblack carbon, methane and tropospheric ozone, and somehydrofluorocarbons are also included. Although some SLCPs,
particularly black carbon, are not greenhouse gases andnot included under the UNFCCC and its Paris Agreement,
most SLCPs are considered in evaluations of pathways
towards the temperature targets. Reducing these pollutants
will limit the rate of short-term warming and, whensustained and combined with CO2 reductions, will help limit
long-term warming, which is the ultimate aim of closing theemissions gap.

Carbon dioxide removal refers to a cluster of technologies,
practices and approaches that remove and sequester carbon
dioxide from the atmosphere. Despite the common featureof removing CO2, these technologies and approaches arevery different. In generic terms, they can be distinguished as
biological or engineered options. For biological options suchas afforestation, reforestation or soil carbon management,
experience has been accumulated over decades. On theother hand, engineered options such as bioenergy combinedwith carbon capture and storage, or certainly direct air
capture, have large potential but are still in the early stagesof development.

A complete separation between these pollutants and CO2
reductions is also not possible, as decarbonization strategies
will lead to reductions in some SLCPs, including black carbon,
about a third of which originates from fossil fuel sources,and energy efficiency improvements can reduce all types ofemissions. SLCP reductions have the potential to decrease
the rate and degree of warming in the next few decades, due
to the rapid effect of their mitigation on temperature.

As indicated in the sectoral mitigation options presented intable ES.1, the potential for significant contributions to close
the gap exists in the agricultural and forestry sectors. Chapter 7
presents a more detailed assessment of some of these
options, along with some of the more recent technologicalapproaches to capturing and storing CO2.

Studies have estimated that mitigation of SLCPs has thepotential to avoid up to 0.6°C of warming by mid-century
and in this way, to reduce impacts that are related tocumulative heat uptake, helping ensure a steady and lower
temperature trajectory towards the temperature goals of
the Paris Agreement. In addition, there will be a number ofother benefits associated with a reduced emissions pathway,
notably improved air quality.

Land-based carbon removal options, including forests,
wetlands and soils have been managed by humans formany years and as such, there is a wealth of knowledge
that can be readily applied today with confidence. In
addition, these approaches present opportunities to meetother global sustainability goals, such as improved water
quality, ecosystem restoration, biodiversity preservation andimproved crop yields. The total annual reduction potential
is in the order of 4 to 12 GtCO2e, with relatively wide ranges
for the various options; some studies indicate a significantly
higher potential.

Successful cooperation on the individual building blocks of
the international climate regime, such as the Climate andClean Air Coalition or the Montreal Protocol, will build thetrust and confidence required to help accelerate progress onsome of the bigger elements of the Paris Agreement.
In many NDCs it is usually difficult or impossible to identify
particular compounds, as targets are given in CO2e often
without specific targets for methane, hydrofluorocarbons
or black carbon. Instead the NDCs provide a broad list of
sectors and actions where mitigation action is planned. Fourcountries specifically address black carbon in their NDCs—
Mexico, Chile, Nigeria and Canada—with Mexico specifying
a target.

xxii

The Emissions Gap Report 2017 – Executive summary

For these land-based options to contribute to carbon removal
at the gigatonne scale, large land areas and ecosystems mayneed to be engaged in new ways. There are substantial
uncertainties regarding effective carbon removal rates,
possible volumes and duration of effective sequestration,and implications for ecosystem services and food production
currently associated with these land areas.
The chapter presents a detailed assessment of one specific
set of options that has briefly been addressed in previous
Emissions Gap Reports—bioenergy with carbon captureand storage. This option warrants a specific focus, because
it forms an integral part of the solutions considered withinmany integrated assessment models, and its components are
already applied at a large scale. Most scenarios that aim toFigure ES.3: Major strategies for negative emission technologies.

NATURALFOR
REST
ESTRYY / AGRICULTURE

COMBINED

NATURAL + TECHNOLOGICALTECHNOLOGICAL

ENERGY / IND
DUSTRYAﬀorestation/
Reforestation
Tree growth takes up CO₂
from the atmosphere

Biochar
Partly burnt biomass is added
to soil absorbing additional CO₂

Soil Carbon Sequestration
Land management changes
increase the soil carbon
content, resulting in a net
removal of CO₂ from theatmosphere

Accelerated Weathering
Natural minerals react with
CO₂ and bind them in newminerals
Direct Air Capture
CO₂ is removed fromambient air and stored
underground

Bioenergy with
Carbon Capture andStorage (BECCS)
Plants turn CO₂ into
biomass that fuels
energy systems; CO₂from conversion isstored underground

Ocean Alkalinity
Enhancement
Alkaline materials areadded to the ocean toenhance atmosphericdrawdown and negate
acidiﬁcation

Other Land-Use/Wetlands
Restoration or construction ofhigh carbon density, anaerobic
ecosystems

CO2 to Durable Carbon
CO₂ is removed from theatmosphere and bound inlong-lived materials

Less costly
Closer to deployment
More vulnerable to reversal

More costly
Greater R&D needs
Less vulnerable to reversal

Note: This figure includes the major strategies that have been discussed in the literature so far (Minx et al., 2017).

keep global warming below 2°C, and especially those aiming
for below 1.5°C, include contributions from this option at thegigatonne scale. Achieving these reductions, however, would
entail significant land-use and water-resource requirements
and substantial investment; the question of whether themodel assumptions are realistic is therefore a relevant one.
In addition, while bioenergy and carbon capture and storage
are relatively mature technologies individually, there is very
little deployment of them in combination, especially at alarge scale. Whether the combined option can thus be scaled
up promptly to help achieve the ambitious climate targets
remains uncertain. Mitigation action in other sectors should
therefore not be delayed.

As for engineering options, the chapter provides anassessment of emerging options, such as direct air capturecombined with carbon storage, accelerated weathering ofmaterials, ocean alkalinity enhancement and conversion of
CO2 into long-lived products. Most of these options are at
early piloting stage, so it is hard to judge the technical andeconomic potential in the short term, and the chance of
these technologies making a real contribution to closing the2030 gap seems unrealistic. Beyond 2030, these technologies
may show additional important reduction potential. When
global emissions need to move towards net zero by around
2050, CO2 removal may offer some welcome flexibility and,as with other technologies, cost and performance will likely
improve with increased deployment.

The Emissions Gap Report 2017 – Executive summary

xxiii

xxiv

The Emissions Gap Report 2017 – Foreword

Chapter 1

Scoping the Emissions
Gap Report 2017
Lead authors: Anne Olhoff and John Christensen, UNEP DTU Partnership

1.1 Moving towards implementationof the Paris Agreement: 2018 as a
critical juncture
The adoption of the Paris Agreement at the 2015 Conferenceof the Parties to the United Nations Framework Convention
on Climate Change (UNFCCC) marks a milestone ininternational efforts to establish a universal foundation
for ambitious climate change action. The Agreementbuilds on national plans and contributions submitted byalmost all Parties to the Convention during 2015: theIntended Nationally Determined Contributions (INDCs).
The Agreement entered into force on November 4, 2016,
following a very rapid ratification process. As of 15 October
2017, 168 of the 197 Parties to the Convention have ratified
the Agreement, thereby turning their Intended Nationally
Determined Contributions into Nationally Determined
Contributions (NDCs). This report consequently refers to
NDCs, unless specifically mentioning a country that has not
yet ratified the Agreement.
The Paris Agreement’s long-term goal of “holding theincrease in the global average temperature to well below 2°C
above pre-industrial levels and to pursue efforts to limit thetemperature increase to 1.5°C above pre-industrial levels”(UNFCCC, 2015:22) accentuates the urgency of enhanced
and immediate mitigation action. In 2015 and 2016, the UN
Environment Emissions Gap Reports undertook thoroughassessments of the aggregate effects of the NDCs on global
greenhouse gas emissions in 2025 and 2030 – the years
referred to in the NDCs (UNEP, 2015; 2016). The overall
conclusion of these assessments was that although NDCs
represent an increase in ambition compared with global
greenhouse gas emission levels resulting from a projectionof the impacts from the current policies, these contributions
are far from the level of ambition required for an emissions
pathway consistent with staying below a 2°C, let alone a
1.5°C, temperature increase. Currently, the NDCs cover onlyaround one third of the emission reductions needed by 2030.

Recognizing this significant gap and the urgent need tobridge it, Article 4 of the Paris Agreement specifies that
“Each Party shall communicate a nationally determined
contribution every five years” and furthermore that “EachParty’s successive nationally determined contribution will
represent a progression beyond the Party’s then current
nationally determined contribution and reflect its highest
possible ambition” (UNFCCC, 2015a:22). The successive
NDCs are to be informed by the global stocktakes, which
are specified in Article 14 of the Paris Agreement (UNFCCC,2015). These stocktakes will take place every five years,
starting from 2023, to assess the collective progress towards
achieving the objective of the Agreement and its longterm goal.
However, as an important precursor to the global stocktakes,
a Facilitative Dialogue will take place during 2018. In linewith the subsequent global stocktakes, the purpose of the
Facilitative Dialogue is “to take stock of the collective effortsof Parties in relation to progress towards the long-term goal
and to inform the preparation of nationally determined
contributions” (UNFCCC 2015:4).
During 2017, there have been extensive consultations with
Parties on the organization of the Facilitative Dialogue, witha view to reporting their findings to the 23rd Conference of
the Parties (COP23) taking place in November 2017. Initial
feedback indicates that the dialogue is likely to consist ofa preparatory and political phase, with the preparatory
phase starting officially at the intersessionals in Bonn in
May 2018 and continuing until the 24th Conference of theParties (COP24) in December 2018. The preparatory phasewill include absorbing the information from the 2018 special
report on the impacts of global warming of 1.5°C above preindustrial levels and related global greenhouse gas emission
pathways that the Intergovernmental Panel on Climate
Change (IPCC) was invited to produce in the decision to
adopt the Paris Agreement (UNFCCC, 2015). The politicalphase, which is expected to take place at the 24th Conference

The Emissions Gap Report 2017 – Scoping the Emissions Gap Report 20171

of the Parties, will focus in particular on how to strengthen
the next NDCs (UNFCCC, 2017).
The year 2018 and the Facilitative Dialogue will be a criticaljuncture for countries to identify and pursue opportunities tostrengthen their mitigation action and raise the ambition of
their NDCs by 2020. Indeed, the outcome of the Facilitative
Dialogue and the 2020 submission of new or updated NDCs
are likely to determine whether it will be feasible to bridge
the emissions gap by 2030.
Time lags between implementing policies and actions andthe resulting mitigation benefits imply that by delaying thestrengthening of NDCs until after the global stocktake in2023, the opportunity to bridge the emissions gap by 2030
will be lost.

1.2 The Emissions Gap Reports and new
aspects included in 2017
The 2017 Emissions Gap Report is the eighth assessment
undertaken by UN Environment to provide countries withan independent scientific assessment of how actions andpledges by countries affect the global greenhouse gas
emissions trend, and how this compares to emissions
trajectories consistent with the long-term goal of the Paris
Agreement. The difference has become known as the‘emissions gap’. The reports additionally provide information
on options to achieve the emissions reductions necessary
to bridge the gap. Based on requests by countries, UN
Environment has prepared this eighth Emissions Gap Report
to inform the political process, as we move towards full
implementation of the Paris Agreement.
In line with previous years, the report provides an updateon the progress of G20 members in achieving their Cancun
Pledges for 2020 and an overview of global emission trends(Chapter 2). This is followed by an update of the estimatedgap between countries’ mitigation actions and NDCs for2030 and the emission levels consistent with pathways thatare aligned with the long-term temperature goal of the Paris
Agreement (Chapter 3). New for 2017 are brief assessmentsof the potential implications on the gap of the Kigali
Amendment to the Montreal Protocol, and the new global

2

market-based Carbon Offsetting and Reduction Scheme forInternational Aviation (CORSIA) under the auspices of theInternational Civil Aviation Organization (ICAO).
In addition, and to inspire the process of strengthening the
NDCs, this 2017 Emissions Gap Report assesses a number ofthe issues that will be central to bridging the 2030 emissions
gap. Firstly, the report provides a systematic review ofthe sectoral mitigation potential by 2030. The results are
positive and unambiguous: technologies and institutionalinnovations are available to bridge the emissions gap by
2030 at reasonable cost (Chapter 4). Secondly, the report
includes a detailed assessment of global developments inthe coal sector that also examines the options and barriers
for a gradual coal phase-out (Chapter 5). Thirdly, the report
looks into the opportunities offered by limiting emissionsof short-lived climate pollutants (SLCPs). Reducing thesepollutants will limit the rate of short-term warming and,
when sustained and combined with CO2 reductions, will help
limit long-term warming, which is the ultimate aim of closing
the emissions gap (Chapter 6). Finally, options for land-based
and technological carbon dioxide removal that will become
increasingly critical over this century to stay within the Paris
goals are assessed (Chapter 7).
As in previous years, the 2017 report is based on anassessment approach and has been prepared by a wide rangeof scientists from around the world. This year, 63 scientists
from 49 institutions in 23 countries have contributed to
the report.
The assessment builds on all available information, includingthat reviewed by the IPCC in its fifth assessment report,
as well as more recent scientific studies. The assessment
production process has been transparent and participatory,
involving two rounds of external reviews and overseen bya steering committee. The governments of the countries
with specific mention in the report have been invited tocomment on the specific assessment findings during the
production process.

The Emissions Gap Report 2017 – Scoping the Emissions Gap Report 2017

Chapter 2

Pre-2020 action: trends and progress
Lead authors: Michel den Elzen (PBL Netherlands Environmental Assessment Agency), Taryn Fransen (World Resources Institute), Takeshi
Kuramochi (NewClimate Institute)
Contributing authors: Jasmin Cantzler (Climate Analytics), Hanna Fekete (NewClimate Institute), Jos Olivier (PBL Netherlands Environmental
Assessment Agency), Paola Yanguas Parra (Climate Analytics)

2.1 Introduction

2.2. Trends in current global emissions

This chapter provides an update, based on the latest
available scientific literature, on trends in global emissions
and progress towards the G20 members meeting their
Cancun Pledges. These trends give key indications of pre2020 mitigation progress and action.

Total global greenhouse gas emissions continue to increase,although the rate of growth has decreased over the past
few years. Total global greenhouse gas emissions, including
emissions from land use, land-use change and forestry(LULUCF), were estimated at about 51.9 GtCO2e/year in2016 (Olivier et al., 2017)1. Often, greenhouse gas emissions
from LULUCF are accounted for separately, because theyshow large inter-annual variation and are very uncertain(see Grassi et al., 2017). Considering total global greenhousegas emissions excluding LULUCF (thus also excluding forest
fires), reveals a slowdown in growth in the past three years.
They reached 47.8 billion tonnes of CO2-equivalent in 2016
following increases of 0.9 percent in 2014, 0.2 percent in2015, and 0.5 percent in 2016 (Olivier et al., 2017)2. Taking
into consideration that 2016 was a leap year, and thus
0.3 percent longer than other years, the growth in total
global emissions in 2015 and 2016 is the slowest since theearly 1990s, except for years of global economic recession.

In light of the Paris Agreement, enhanced pre-2020
mitigation action is more urgent than ever: studies indicatethat holding the increase in global average temperature well
below 2°C above pre-industrial levels, and pursuing efforts tolimit the temperature increase to 1.5°C above pre-industrial
levels, requires that global greenhouse gas emissions peak
before 2020. Moreover, enhancing pre-2020 action would
facilitate the implementation and strengthening of the
Nationally Determined Contributions (NDCs), as well as thetransition to the stringent long-term emissions reductions
that are required to reach the temperature target of theParis Agreement.
To assess whether emissions show signs of peaking, section 2.2
provides an overview of current trends in total global
emissions of greenhouse gases, and of energy- and industryrelated carbon dioxide (CO2) emissions as a major driver of
total global greenhouse gas emissions. This is followed by an
update on the extent to which G20 members are on track
to meet their Cancun Pledges (section 2.3). This updateis based on an assessment of current policy portfolios of
the G20 members and plausible assumptions regarding
macroeconomic trends and offsets. The chapter ends byreiterating the urgency of immediately enhancing mitigation
action to facilitate the transition towards least-cost emission
reduction trajectories after 2020 that are aligned with the
2°C and 1.5°C temperature goals.

1

2

The greenhouse gas emissions estimates in EDGAR 4.3.2 (Olivier et al., 2017)
for recent years have decreased compared to the earlier greenhouse gas
emission estimates presented in UNEP (2016; 2015). Apart from revisions
due to revised statistics (for example, for China), also the use of more detailed
emission factors (for example, for cement clinker) and sometimes a change indata source for other sources than fuel combustion (for example, gas flaringand LULUCF emissions including biomass burning emissions), led to a lower
level of CO2 emissions. Likewise, replacing so-called Fast Track estimates forCH4 and N2O emissions by more detailed and recent statistics and improved
information on emission factors and abatement (for example, CH4 in fossil
fuel production) led to lower calculated emissions. Combined, this leads tototal greenhouse gas emissions that are about 1 GtCO2e lower for recent
years than presented in recent Emissions Gap Reports.
The data presented here have been calculated using the new EDGAR 4.3.2
dataset (Olivier et al., 2017), which provides emissions per source andcountry for the period 1970–2012 (Janssens-Maenhout et al., 2017). This was
extended for CO2 using international statistics through 2016, and for othergreenhouse gases using statistics through 2014 (FAO), 2017, 2016 (IEA 2017,
BP 2017), and other data sources such as CDM projects through 2016 (forexample, reductions of CH4, N2O and HFC-23).

The Emissions Gap Report 2017 – Pre-2020 action: trends and progress3

Figure 2.1.a: Global greenhouse gas emissions for top six emitting
countries and regions (excluding land use, land-use change andforestry), international transport emissions, and land use, landuse change and forestry emissions.

Figure 2.1.b: Global carbon dioxide emissions per region fromfossil fuel use, cement production and other processes, and frominternational transport.

Global greenhouse gas emissions

Global CO₂ emissions

GtCO₂e/year
60

GtCO/year
60

50

50

40

40

30

30

20

20

10

10

0
1970

1980

1990

2000

2010 2016

1970

1980

1990

2000

Land-use change emissions (net CO₂)

China

EU-28

Russian Federaon

Other G20 countries

Land-use change fires (CH₄, N₂O)

USA

India

Japan

Other countries

2010

0
2016

Internaonaltransport

Note: Other G20 countries include Argentina, Australia, Brazil, Canada, Indonesia, Mexico, Republic of Korea, Saudi Arabia, South Africa and Turkey. The greenhousegas total are expressed in terms of billions of tonnes of global annual CO2 equivalent emissions (GtCO2e/year). CO2 equivalent is calculated using the Global Warming
Potentials (GWP-100) metric of UNFCCC as reported in the IPCC Second Assessment Report, similar as has been done in the IPCC Fifth Assessment Report.
Source: EDGAR v4.3.2 FT2016 (Olivier et al., 2017).

Figure 2.1 shows the trends in total global emissions forthe period 1970–2016. Trends in global greenhouse gas
emissions are illustrated in Figure 2.1a, while Figure 2.1bshows the development in global carbon dioxide (CO2)emissions from fossil fuel combustion, cement production
and other processes. It should be noted that the time series
data for total global greenhouse gas and CO2 emissions used
for the Emissions Gap Reports have been updated sincethe 2016 report. This affects the numbers presented in the2016 report, where the updated estimate for total global
greenhouse gas emissions in 2014 is 51.7 GtCO2e, and theestimate for global total CO2 emissions in 2015 is 35.6 GtCO2.
Carbon dioxide emissions from fossil fuel combustion,
cement production and other processes3 are the major
source of total global greenhouse gas emissions. Currently
they account for about 70 percent of total global greenhousegas emissions and were estimated at a total of 35.8 GtCO2
for 2016 (Olivier et al., 2017)4. Given their share of total
greenhouse gas emissions, it is relevant to look more closely
at their trend. As Figure 2.1b indicates, global CO2 emissions
from fossil fuel use and cement production remained stable
for the second year in a row in 2016, against a backdrop of
3
4

4

Including flaring of waste gas during gas and oil production, feedstock andother non-energy uses of fuels, and several other small sources.
This is slightly lower than the 2015 emissions estimate of 36.2 GtCO2,
as presented last year, due to regular annual statistical revisions of fuelconsumption in International Energy Agency and British Petroleum statistics
as well as revisions and some full updates, including emission factors, forseveral other sources (gas flaring, cement production, solvent use, ammonia
production, urea and lime application) (Olivier et al., 2017).

relatively stable economic growth. Reduced growth in coaluse since 2011, primarily in China and secondarily in the
United States, plays a key role in the recent slowdown ingrowth in global CO2 emissions (Olivier et al., 2017; Peters
et al., 2017). Growing renewable power generation has
also contributed, but has had a less significant impact thaneconomic factors and energy efficiency (Peters et al., 2017).
These findings are in line with other studies on trends inglobal energy-related CO2 emissions until 2016 (BP, 2017;
IEA, 2017; Jackson et al., 2016).
A number of studies provide detailed analysis of key drivers
for the development in CO2 emissions from fossil fuel use andcement production at the country level (Olivier et al., 2017;
Peters et al., 2017). In China, CO2 emissions have decreased
since 2015, following a slowdown in annual growth of
China’s CO2 emissions since 2012. The decrease since 2015
is mainly caused by reduced coal use, but is also due tostructural changes in the country’s economy and energy mix.
The European Union has consistently reduced CO2 emissions
since 1979, mainly driven by continual improvements inenergy intensity and carbon intensity combined with lower
economic growth since the global financial crisis. In the
United States of America, energy-related CO2 emissions
have decreased over the last 10 years. This decrease has
mainly occurred in the power sector, due to a shift fromcoal to natural gas use in electricity generation, but also
from increased use of renewables and a somewhat slower
economic growth. In contrast, India’s emissions have grownsteadily over the past decade.

The Emissions Gap Report 2017 –Pre-2020 action: trends and progressBox 2.1: Greenhouse gas emissions development: how have G20 members
performed collectively?
G20 members have made more efficient use of energy resources: total greenhouse gas emissions from G20 countries
grew by 34 percent between 1990 and 2014, while GDP grew by nearly 117 percent during the same period. Per capita
energy-related CO2 emissions seem to have peaked and there are signs of an absolute decoupling of economic growthand greenhouse gas emissions.
Current levels of effort are, however, not enough. Climate Transparency (2017) concludes that current efforts are
sufficient neither in speed nor in depth to keep global warming to the limit set in the Paris Agreement. One area that
requires major effort is the power sector, given that the carbon intensity of electricity has not improved for the last
25 years, because the electricity mix has continued to be dominated by coal and other fossil fuels.
Figure 2.2 Key indicators on the G20 transition to a low-carbon economy: trends between 1990 and 2014.
% G20 annual variaon
120

GDP PPP100
80
60

Energy-related
CO₂ emissions

40

GHG

GHG emissions

20

Energy-related CO₂
emissions per capita

0

Carbon intensityof the energy sector
Carbon intensityof the economy

- 20
- 40
1990

1995

2000

2005

2010

2014

Energy intensityof the economy

Source: Climate Transparency (2017)

Focusing on emissions and energy and carbon intensitiesof the G20 members, box 2.1 describes the trends of key
indicators on the transition to a low-carbon economy
observed between 1990 and 2014 for G20 members (Climate
Transparency, 2017).
In summary, global greenhouse gas emissions continue togrow, although the slowdown in growth of global greenhousegas emissions and the apparent stabilization of global levelsof CO2 emissions from fossil fuels and industry over the past
two to three years is very encouraging. However, it is still too
early to say whether it is likely to be permanent, and boththe speed and depth of mitigation efforts require significant
scaling up to enable a transition towards mitigation
pathways consistent with the long-term temperature goal of
the Paris Agreement.

the Cancun Pledges, focusing on the G20 members5.
Thirteen of the members have pledges for 2020 (counting
the EU members France, Germany, Italy and UK as one
member) and three do not have pledges. These economies
collectively generate around three quarters of total global
greenhouse gas emissions6. Although it is critical that all
countries advance as far as possible towards achieving their
Cancun Pledges, the role of the highest-emitting economies
is particularly critical to achieving the Paris Agreement
mitigation goals.

52.3. Progress towards achieving the Cancun
Pledges: G20 members
In line with last year’s Emissions Gap Report, this section
provides an update on the progress towards achieving

6

The members of the G20 are Argentina, Australia, Brazil, Canada, China,
France, Germany, India, Indonesia, Italy, Japan, Mexico, Republic of Korea,
Russia, Saudi Arabia, South Africa, Turkey, the UK, the USA, and the EU. In
our analysis, the EU including all its Member States (regardless of G20 status)
is considered as a single Party, and EU Member States are not considered
individually. In general, evaluating the pledges of other countries is limited
by a lack of data. Aggregate measures for the G20 do not double count EU
members that are also G20 members as individual countries.
In 2012, these parties accounted for 77 percent of global emissions excluding
LULUCF and 75 percent of global greenhouse gas emissions including LULUCF(WRI CAIT, 2017).

The Emissions Gap Report 2017 – Pre-2020 action: trends and progress5

Box 2.1: Assumptions of the assessment of progress towards the Cancun Pledges
For each G20 member, estimates of 2020 emissions are compared under three cases:
1. Pledge case (official data): Identifies the maximum level of greenhouse gas emissions that each member could emitin 2020 and still meet its pledge – without considering the use of offsets. Where available, the 2020 emission leveldescribed by the member as the pledge level is used; alternatively, these levels are calculated working from official
base-year or baseline data. The sources of official country data are provided in Table 2.1.
2. Current policy trajectory case (official data): Identifies most recent, publicly available official estimates of 2020
emissions, considering projected economic trends and current policy approaches. The sources of official country
data are provided in Table 2.1.
3. Current policy trajectory case (independent analysis): Identifies estimates of 2020 emissions, considering the best
current estimates of projected economic trends and current policy approaches, including policies at least through2015, based on independent analysis rather than official data. Estimates are drawn from the Climate Action Tracker(CAT) (2017g) and PBL (den Elzen et al., 2016a; Kuramochi et al., 2016b; PBL, 2017) for all countries, as well asother, country-specific sources where noted. The independent analysis of current policy trajectories supplements
the official sources described in point two by providing data that targets consistency across countries andpolitical independence.
Source: Adapted from UNEP (2015)
To assess the progress of G20 members towards their Cancun
Pledges, this section compares current emissions trajectories
with the trajectories associated with the achievement of thepledges of these members. In line with previous Emissions
Gap Reports, three cases are considered: a pledge case,

based on official data; a current policy trajectory case,
based on official data; and a current policy trajectory case,
based on independent analysis. These three cases are briefly
described in box 2.1.

Table 2.1: Studies used to estimate the emissions in 2020 under the pledge case and current policy trajectory case for G20 members
Country

2020 pledge case

Current policy trajectory

Official data

Official data

Independent estimates

Argentina

No pledgea

Ministry of the Environment andSustainable Development, Argentina(2015)CAT

Australia

Government of Australia (2016)

Government of Australia (2016)

CAT, PBL, RepuTex (2016)

BrazilGovernment of Brazil (2010)

N/A

CAT, PBL

CanadaGovernment of Canada (2016)

Government of Canada (2016)

CAT, PBL

China

N/Ab

N/A

CAT, PBL, Sha et al. (2017)

EU28

EEA (2014)

EEA (2016b)

CAT, PBL

India

Planning Commission Government ofIndia (2011, 2014)

Indonesia

BAPPENAS (2015)

N/A

CAT, PBL

Japan

Government of Japan (2016)

N/A

CAT, PBL

MexicoNCCS (2013)(Government of Mexico, 2012b; NCCS,
2013)

CAT, PBL

RussiaGovernment of Russia (2014)

Government of Russia (2015)

CAT, PBL

Saudi Arabia

No pledge

N/A

CAT

South Africa

Department of Environmental
Affairs, Republic of South Africa (2011a,
2011b)

N/A

CAT, PBL

Republic of
Korea

Republic of Korea (2016)

N/A

CAT, PBL

TurkeyNo pledgea

Republic of Turkey, Ministry ofEnvironment and Urbanization (2016)

CAT, PBL

USAUS Department of State (2016)

US Department of State (2016)

CAT, PBL

a

CAT, PBL, Mitra et al. (2017)

Note:aArgentina, Saudi Arabia and Turkey have not proposed greenhouse gas reduction pledges, and here we assume current policies.
bChina has no official estimate for the 2020 pledge, and here we assume the 2020 emissions estimate for China’s 2020 pledge based on the average outcome of fourglobal studies (PBL, Climate Action Tracker, LSE and University of Melbourne (see Chapter 3).

6

The Emissions Gap Report 2017 –Pre-2020 action: trends and progress

Pledge Range

Figure 2.3: Greenhouse gas emissions of G20 members and the group of non-G20 countries (also includes the international bunker
emissions) for the 2020 pledges and current policies scenario.

2010
Inventories

Current
Policies

Official
CancunPledges010

20

Argenna

BrazilChina

Australia

Canada

EU28

30
Japan
MexicoIndia
Indonesia

40
50
60
Greenhouse gas emissions (GtCO₂e/year)
RussiaSaudi Arabia

South Africa
Republic of Korea

TurkeyUSA

non-G20 andinternaonal
bunker

Source: Table 2.1.

Collectively, G20 countries are on track to achieving the midrange of the Cancun Pledges, but several countries will needto accelerate action to meet their Cancun Pledge by 2020(see Figure 2.4). Seven G20 members (Australia, Brazil, China,
the EU, India, Japan, and Russia) are on track to meet their
Cancun Pledges according to most or all available analyses.
Five members (Canada, Mexico, the Republic of Korea, South
Africa and the United States) are likely to require further
action or to have to purchase offsets — or a combinationof the two — to meet their pledges. (The Republic of Korea
has not rescinded its pledge communicated to the UNFCCC,

but has amended the Green Growth Basic Act to replace the2020 pledge with the NDC target for 2030.) Better data arenecessary to adequately track progress in some countries,
including Indonesia, where there is currently insufficient
information to assess whether the country is on track to meetits pledges. The three remaining G20 members (Argentina,
Saudi Arabia and Turkey) have no Cancun Pledges. Further
details are provided in Box 2.2, which highlights the threeimportant caveats that should be kept in mind whenassessing country progress towards the Cancun Pledges.

Box 2.2: Assessing progress towards achieving the Cancun pledges: three caveats
1. Pledges do not necessarily demand the same level of effort to achieve. In other words, a country currently on trackto achieve its pledge has not necessarily made a greater effort to mitigate emissions than a country not yet on track.
2. Projections are subject to uncertainty associated with macroeconomic trends, such as changes in gross domestic
product (GDP) and population trends, as well as the impact of each country’s climate policy action.
3. The potential impact of using offsets to achieve pledges is not quantified for the emission trajectories considered.
If offsets are traded internationally, and are stemming from actions that are not really additional or if offsets arecounted twice (towards the pledges of both buying and selling parties), the global impact of the pledges will be
weakened. Most countries have not clarified their intentions concerning their use of offsets to meet their 2020
pledges. Australia, Brazil, Canada, the European Union, and the United States have explicitly not excluded thepossibility; other members have not formally commented (WRI, 2015).
Source: UNEP (2015)

The Emissions Gap Report 2017 – Pre-2020 action: trends and progress

7

G20 members that are on track to meet their
Cancun Pledges
According to all available analyses, four G20 members —China, the EU, India, and Japan — are on track to meettheir pledges with currently implemented policies withoutpurchasing offsets. Australia is on track based on the carbon
budget approach. Two more countries — Brazil and Russia —are also on track according to most estimates.
China, which pledged a reduction of 40–45 percent in CO2emissions intensity, is projected by several studies to be
on track to achieve a reduction of at least 42 percent (IEA,
2015; Sha et al., 2015; den Elzen et al., 2016b; Climate
Action Tracker, 2017c; Sha et al 2017). China also pledges
to increase the share of non-fossil fuels in primary energy
consumption to around 15 percent by 2020 and to increase
forest coverage and forest stock volume. The Climate
Action Tracker update of May 2017 (Climate Action Tracker,
2017c) has made a downward revision of economy-wide
greenhouse gas emissions (excluding LULUCF) under current
policies for China. Projections are now 11.9-12.2 GtCO2e/year
instead of the 12.2-12.5 GtCO2e/year projected in the 2016
update. This compares to the pledged emission level of 13.213.5 GtCO2e/year excluding LULUCF, taking into accountboth CO2 intensity and non-fossil fuel targets (Climate Action
Tracker, 2017c). Some analysts have argued that structuralshifts in the economy in recent years make much steeper
reductions in the CO2 intensity of GDP likely; Green and Stern(2017) include an illustrative pathway where CO2 intensity ishalved from 2005 to 2020.
Regarding the EU pledge to reduce its greenhouse gas
emissions by 20 percent from 1990 levels, official data for2014 shows that this pledge has already been met and, infact, exceeded (EEA, 2016a).
India pledged to reduce its emissions intensity of GDP,
excluding the agriculture sector, by 20–25 percent below
2005 levels by 2020. Independent studies project that India
will meet its pledge by a narrow margin through the policies
that are currently implemented (Climate Action Tracker,
2017d; Mitra et al., 2017; PBL, 2017). The Climate Action
Tracker update of May 2017 has made a small downward
revision of current policies projections for India for economywide greenhouse gas emissions (excluding LULUCF) from 3.6
to 3.5 GtCO2e/year in 2020. Meanwhile Mitra et al. (2017)
project 2.9 GtCO2e/year, considering the impacts of five key
policies and excluding the agriculture and land-use sectors.
Japan pledges to reduce its greenhouse gas emissions by
3.8 percent from 2005 levels by 2020. This pledge assumes
the same electricity mix as 2012, which was fossil fueldominant following the Fukushima nuclear accident. Recent
studies (Climate Action Tracker, 2017e; Kuramochi et al.,2016b) project that Japan will overachieve its 2020 pledge
due to lower-than-expected end-use energy demand andconsiderable increase of renewable electricity generation
following the introduction of a feed-in-tariff scheme in 2012.
Official projections reflecting current policies are unavailable.
In accordance with the Kyoto Protocol accounting rules,
Australia uses a carbon budget approach that accounts for8

cumulative emissions over the 2013–2020 period in order toassess progress towards its pledge. Australia’s latest official
projections find that for the budget period (2013–2020),
Australia is now on track to overachieve its 2020 pledge by
97 MtCO2e (cumulative), excluding a 128 MtCO2e carry-overfrom its first commitment period under the Kyoto Protocol(Government of Australia, 2016). Independent studies
consider the year 2020 in isolation, and find a differenceof about 63 MtCO2e between Australia’s projected 2020
emissions and its pledge level for that year (Kuramochi et al.,2016b; PBL, 2017; Reputex, 2016), which is higher than the
37 MtCO2e difference of Australia’s latest official projections(Government of Australia, 2016). The former do not factor in
the most recent official projections.
Brazil pledged to reduce its emissions including LULUCF by
between 36.1 percent and 38.9 percent by 2020, compared
to a business as usual (BAU) scenario. Independent analysis
estimates emission projections under current policies atwell below the 2020 Cancun Pledge (Climate Action Tracker,
2017b; Kuramochi et al., 2016b; PBL, 2017).
Russia pledged a 25 percent reduction from 1990 levels,
excluding LULUCF. According to official data, Russian
emissions are projected at about 2.4 GtCO2e/year for 2020
(Government of Russia, 2014), which is below the pledge
level of 2.5 GtCO2e/year (Government of Russia, 2015).
Independent estimates show a similar emission projection.
G20 members that are likely to require further action orpurchased offsets
Five countries — Canada, Mexico, the Republic of Korea,
South Africa and the United States — are likely to require
further action and/or to have to purchase offsets in order
to meet their pledges, according to government andindependent estimates.
Canada’s Cancun Pledge aims to reduce emissions by
17 percent below 2005 levels by 2020. However, according
to official projections, Canada’s emissions are expected toreach 731 MtCO2e/year in 2020 (Environment and Climate
Change Canada, 2017), well above the pledged level of
620 MtCO2e/year (Government of Canada, 2016).
Independent analysis also suggests that Canada is set to missits 2020 pledge by a wide margin (Climate Action Tracker,
2017g; PBL, 2017).
Mexico’s Cancun Pledge to reduce its greenhouse gas
emissions by 30 percent below BAU levels including LULUCF
is conditional on the provision of adequate financial andtechnological support from developed countries as part of a
global agreement (UNFCCC, 2011). Under its current policies,
Mexico is not on track to meet its pledge. This conclusion isbased on official estimates by the Government of Mexico(2012a), adjusted per the National Climate Change Strategy(NCCS, 2013), and independent estimates (Climate Action
Tracker, 2017g; PBL, 2017).
Independent estimates of the Republic of Korea’s 2020
emissions are well above the level implied by its pledge.
Although the country has not rescinded its pledge
communicated to the UNFCCC, it amended the GreenThe Emissions Gap Report 2017 –Pre-2020 action: trends and progress

Growth Basic Act to replace the 2020 pledge with the NDC
target for 2030 (The Law National Information Center, 2016).
South Africa’s Cancun Pledge includes a reduction ingreenhouse gas emissions, including LULUCF, of 34 percent
below BAU by 2020. Independent studies translate thispledge to a range of 400–600 MtCO2e/year in 2020
(Climate Action Tracker, 2017f; Kuramochi et al., 2016b). An
independent current policy scenario projection that covers
LULUCF (Kuramochi et al., 2016b) indicates that South Africa
is slightly short of reaching the upper end of this range.
The United States submitted a pledge to reduce greenhousegas emissions levels to 17 percent below 2005 levels by
2020. The most recent official projections, produced before
the current Administration took office, indicated that theUnited States was on track to achieve its 2020 pledge,
assuming full implementation of planned measures as of
mid-2015 (US Department of State, 2016). However, more
recent independent analysis that takes a range of possible
policy changes into account raises questions as to whether
the United States will meet its 2020 pledge (Climate Action
Tracker, 2017a; Climate Advisers, 2017; Climate Interactive,
2017; Hafstead, 2017; Rhodium Group, 2017).
Other G20 members
Insufficient information is currently available to determine
whether Indonesia is on track to meet its pledge.
Indonesia’s Cancun Pledge includes an unconditional
26 percent below BAU and a conditional 41 percent
reduction below BAU by 2020, both including LULUCF.
There is considerable uncertainty regarding the pledge
emission level; the unconditional pledge is translated as 2.2
GtCO2e/year when using the BAU projection from the First
Biennial Update Report, and 1.3 GtCO2e/year when using
the BAU projection consistent with the one reported inIndonesia’s NDC (BAPPENAS, 2015). Recent assessments(Kuramochi et al., 2016b; WRI, 2016) project greenhousegas emissions, including LULUCF, ranging between 1.65 and1.81 GtCO2e/year in 2020.

Three G20 member states — Argentina, Saudi Arabia andTurkey — have not proposed greenhouse gas reduction
pledges for 2020. However, all three countries have submitted
post-2020 pledges to the UNFCCC as part of their Nationally
Determined Contributions. In addition, Turkey has submitteda Biennial Report which includes its projected emissionsfor 2020 (Republic of Turkey, Ministry of Environment and
Urbanization, 2016). In all four countries, the emissions
are projected to increase towards 2020 and beyond undercurrent policies (Kuramochi et al., 2016b).

2.4. Amplified urgency of enhanced
pre-2020 action
As the previous sections have demonstrated, mitigation
action shows several encouraging signs. However, theprogress of G20 countries towards decarbonization has beenslow, as illustrated in Box 2.1. The projected emissions undercurrent policies for 2020 are still far from what is required to
improve the starting point for reaching the emission levels
in 2030 consistent with pathways aligned with the long-term
temperature goal of the Paris Agreement (see Chapter 3).
The 2020 emissions under current policies are estimatedto be in the mid-range of the Cancun Pledge scenario (seesection 2.3), and any further delay in strengthened shortterm action will decrease the chance of keeping global
warming well below 2°C and will make the 1.5°C target
increasingly unattainable.
The UNFCCC and its Parties need to seriously consider thegrowing number of science-based policy targets and roadmaps
that have recently been proposed to strengthen shortterm action to meet the Paris Agreement’s long-term goals(Figueres et al., 2017; Kuramochi et al., 2016a; Rockström etal., 2017). Box 2.3 presents an action proposal by Figueres etal. (2017), which focuses on pre-2020 ambition. As Figueres
et al. suggest, concerted global effort is required to scale up
existing solutions rapidly and to encourage optimism.

The Emissions Gap Report 2017 – Pre-2020 action: trends and progress

9

Box 2.3: Mission 2020’s six-point plan
In collaboration with knowledge leaders and several think tanks, the Mission 2020 initiative convened by Christiana
Figueres, the former Executive Secretary of the UNFCCC, developed a six-point plan to enhance pre-2020 action toachieve the Paris Agreement’s long-term goals (Figueres et al., 2017):
1. Energy• renewable electricity: increase renewable energy from 23.7 percent of the world’s electricity supply in 2015 to atleast 30 percent in 2020;• coal-fired power plants: do not approve any new plants beyond 2020 and retire all existing ones;
2. Infrastructure• fully decarbonize buildings and infrastructure by 2050 with US$300 billion in annual funding. Cities are alreadyupgrading their building stock to zero- or near-zero emission structures at a rate of 3 percent per year;
3. Transport• electric vehicles: at least 15 percent share in new car sales globally, up from the current less than 1 percent share;• doubling of mass-transit use in cities;• heavy duty vehicles: 20 percent increase in fuel efficiency;• aviation: 20 percent reduction in greenhouse gas emissions per kilometre travelled;
4. Land use• deforestation and land use change: net zero emissions within the 2020s;• enhanced afforestation and reforestation;
5. Industry• heavy industry: strengthen action in line with halving emissions well before 2050;
6. Finance• mobilize US$1 trillion per year for climate action, mostly from the private sector through, for example, a tenfold
increase in green bonds compared with their current level (US$81 billion in 2016).
Figueres et al. also proposes three necessary steps to enable the achievement of the aforementioned sectorspecific goals: (1) use science to guide decisions and set targets, (2) scale up existing solutions rapidly, and(3) encourage optimism.

10

The Emissions Gap Report 2017 –Pre-2020 action: trends and progressChapter 3

The emissions gap and its implications
Lead authors: Michel den Elzen (PBL Netherlands Environmental Assessment Agency), Niklas Höhne (NewClimate Institute), Kejun Jiang(Energy Research Institute, China)
Contributing authors: Jasmin Cantzler (Climate Analytics), Philip Drost (UN Environment), Taryn Fransen (World Resources Institute),
Hanna Fekete (NewClimate Institute), Takeshi Kuramochi (NewClimate Institute), David Lee (Manchester Metropolitan University), Kelly
Levin (World Resources Institute), Joeri Rogelj (International Institute for Applied Systems Analysis), Fu Sha (National Center for Climate
Strategy and International Cooperation), Michiel Schaeffer (Climate Analytics) and Zoi Vrontisi (E3M-Lab)

3.1 Introduction
The Paris Agreement aims to limit global average temperature
increase to well below 2°C relative to pre-industrial levels
and to pursue efforts to further limit it to 1.5°C. In 2015,
almost all countries submitted national climate actionplans and commitments for 2025 or 2030: their Intended
Nationally Determined Contributions (INDCs). These form
the foundation of the Paris Agreement, which entered into
force on 4 November 2016. For the 168 countries that haveto date (24 October 2017) ratified this Agreement, the INDCs
have become Nationally Determined Contributions (NDCs).
This chapter provides an update on the mitigation challenge
associated with the global temperature goal of the Paris
Agreement, and the estimated global emission levels undervarious assumptions regarding the implementation ofcurrent policies and NDCs or INDCs (hereafter referred to as
NDCs, unless specifically mentioned in relation to a country
that has not ratified the Paris Agreement) (section 3.2 and
3.3). It also assesses the additional impact of the Kigali
Amendment and the International Civil Aviation Organization(ICAO) Agreement (section 3.3), before further exploring the
projected impact up to 2030 of the current policies and NDCs
on emissions for each G20 member and considering how theambition of NDCs can be compared across countries (section
3.4). Finally, the chapter provides an update on recent
estimates of emission reduction potentials by subnationaland non-state actor action (section 3.5).

3.2 Scenarios considered in the emissions
gap assessment
3.2.1 Overview of scenariosof the emissions gap draws on six scenarios (Rogelj et al.,2016). These comprise:• Two reference scenarios:- No-policy baseline scenario, which projects global
greenhouse gas emissions based on the assumptionthat no new climate policies are put into place from2005 onwards.
- Current policy scenario, which provides best estimatesof future global emissions taking all currently adopted
and implemented policies1 into account, but assumingthat no additional mitigation action is taken beyond
these policies.
• Two NDC scenarios2:- Unconditional NDC scenario, where Parties with NDCs
are assumed to implement only the portions of theirtargets that are without conditions, while Parties thatsolely have a conditional target are assumed to follow
a current policy scenario.
- Conditional NDC scenario, where all Parties with NDCs
in addition to their unconditional targets are assumed
to implement their conditional targets, and Parties
that only have an unconditional target are assumed to
implement that target.
• Two scenarios that limit global warming to below 2°C
and 1.5°C, respectively:- 2°C scenario, which is based on global emission
scenarios that assume limited action until 2020 andleast-cost emission reduction pathways from 2020,
and are consistent with a greater than 66 percent

1
2

In line with the 2016 Emissions Gap Report, the assessment

These are defined as legislative decisions, executive orders, ortheir equivalent.
In both the unconditional and conditional NDC cases, it is assumed that forany traded international offsets, each unit is counted towards the NDC ofa single country only – either the buyer or the seller – to avoid issues ofdouble counting.

The Emissions Gap Report 2017 – The emissions gap and its implications

11

chance of limiting global warming in 2100 to below 2°C
above pre-industrial levels.
- 1.5°C scenario, which is based on global emission
scenarios that assume limited action until 2020 andleast-cost emission reduction pathways from 2020,
and are consistent with a 50-66 percent chance oflimiting global warming in 2100 to below 1.5°C above
pre-industrial levels.
The assessment draws on multiple individual scenarios
from the published literature. Each scenario is global inscope, reflecting possible actions by all countries (for further
details, see Appendix A, available online). It should be notedthat the two NDC scenarios assume full implementation of
the conditional and unconditional NDCs for all countries,
including the United States of America, as the NDC of theUnited States of America has not yet been officially repealed.
Section 3.3 discusses the impact of a possible withdrawal of
the United States of America from the Paris Agreement.
In line with the 2016 Emissions Gap Report (UNEP, 2016)
and as indicated above, the 2017 assessment mainly draws
on 1.5°C scenarios that assume least-cost pathways startingfrom 2020 and return global warming to below 1.5°C in
2100 with a lower (50–66 percent) probability than forthe 2°C scenarios (greater than 66 percent probability)(see box 3.1 for additional information about thesescenarios). New studies are emerging that provide leastcost pathways from 2020 consistent with a greater than66 percent chance of limiting global warming in 2100 to
below 1.5°C. The preliminary findings of these new studies
and their implications for the 2030 global emission levels
are summarized in section 3.2.3. More studies are under
way and will be fully integrated into the gap assessment
next year, as current estimates may still change during thereview process of the studies. Box 3.1 provides a discussionof the extent to which the 1.5°C and 2°C least-cost pathways
are informed by the growing damages that increasingly arebeing attributed to early impacts of climate change.
Table 3.1 provides an overview of the projected global
emission estimates under the six scenarios considered forthe assessment in this report, showing the median global
emission levels for 2025 and 2030 — the years countries use
in their NDCs.

Box 3.1 How are recent extreme events reflected in the 1.5°C and 2°C pathways used in the
Emissions Gap Report?
With drought in Africa, floods in South Asia and repeated hurricanes in the Caribbean, 2017 will probably prove to havebeen a record year for the human, social and economic cost of extreme weather events. Although it would be a mistaketo attribute all extreme weather events to the impact of climate change, there is growing evidence that climate change
may be contributing to the their increasing frequency and severity.
It would be logical to think that the damage caused by climate change should affect the least-cost pathways that are at
the core of the analysis in this report: the earlier and more severe the damage, the stronger the case for early action to
reduce emissions.
Some models, such as the Dynamic Integrated Climate-Economy (DICE) model, do indeed incorporate damage functions(Nordhaus, 2017). These are a subset of Integrated Assessment Models that combine physical and economic elements
and are termed ‘cost-benefit Integrated Assessment Models’. These cost-benefit studies monetize the impacts of climatechange and then balance the economic implications of mitigation and climate damages to identify the optimal trajectoryof emissions reductions that will maximize total welfare (see box 6.1 in Clarke et al., 2014). However, since by design
such scenarios do not achieve a specific climate goal, they are less directly useful as a benchmark to assess pathways
towards achieving the long-term temperature goal set in Paris.
For this reason, the Emissions Gap Report makes use of a different class of Integrated Assessment Models, termed ‘costeffectiveness’ models (see Weyant (2017) for a discussion of all types of Integrated Assessment Models). These models
distribute the emission reductions across regions, sectors and gases in such a way that the global discounted reduction
costs are minimized over time, and the climate target is achieved ( Rogelj et al., 2016; Clarke et al., 2014). In practice, theEmissions Gap Report selects pathways that aim to limit global mean temperature increase to either 1.5°C or 2°C relative
to pre-industrial levels, with varying levels of probability. This means that, unless decision makers decide to make theglobal climate target even more ambitious, the benchmark pathways used in the Emissions Gap Report will not change
in response to the impact of extreme weather events.
It does not follow that decision makers can ignore the impact of extreme weather. The events of 2017 reinforce the casefor early and sustained action to reduce emissions.

12

The Emissions Gap Report 2017 – The emissions gap and its implications

Table 3.1: Global total greenhouse gas emissions in 2025 and 2030 under different scenarios (median and 10th to 90th percentile range).
Emissions estimates (GtCO2e/year) (rounded to the nearest gigatonne)
Scenario

Global total emissions in 2025

Global total emissions in 2030

Number of scenarios in set

No-policy baseline

61.0 (56.7–64.3)

64.7 (59.5–69.5)

179

Current policy trajectory

55.4 (53.5–56.8)

58.9 (57.6–60.7)

4

Unconditional NDCs

53.8 (50.6–55.3)

55.2 (51.9–56.2)

10

Conditional NDCsa

52.2 (49.3–54.0)

52.8 (49.5–54.2)

10 (6+4)

2°C pathways (more than 66% chance 2°C,
least-cost from 2020)b

47.7 (46.2–50.2)

41.8 (30.6–43.5)

10

1.5°C pathways(50- 66% chance 1.5°C, least-cost from2020)c44.5 (43.1–45.5)d36.5 (32–37.7)d,e

6

Note:
Ranges are computed as described in Rogelj et al. (2016). In cases where estimates are based on less than 10 scenarios, the minimum-maximum range is provided. The
row of “Conditional NDCs” is only provided for information, as a direct comparison with the “Unconditional NDCs” ranges is not possible, due to arbitrary model sampling
differences. The emissions range for 1.5°C is smaller than for 2oC, as fewer studies for 1.5°C are available. Source: adjusted from Rogelj et al. (2016).
aAssuming full implementation of both unconditional and conditional NDCs. Six studies provided an estimate for the conditional NDC case. The median estimate ofinfluence derived from these six studies is used to adjust the unconditional NDC estimate of the four remaining studies that did not include conditional NDC estimates.
The estimated improvement of moving from the unconditional to the conditional case is in the range of 2.4 (1.2–3.0 GtCO2e/year, full range).
bAs in UNEP (2015): greater than 66 percent probability of limiting global average temperature increase to below 2°C in 2100 (probabilities never drop below 60 percent
during the entire century).
cAs in UNEP (2016): 50 percent to 66 percent probability of limiting global average temperature increase to below 1.5°C in 2100 (allowing median global averagetemperature to temporarily exceed the 1.5°C limit before 2100).
d
These numbers have been harmonized to the same 2010 emissions levels as the 2°C pathways.
eForthcoming peer-reviewed research indicates that this median value is broadly consistent with results for scenarios that assume a middle-of-the-road future socioeconomic development (cf. SSP2 Fricko et al., 2017). At the same time, recent research suggests that the ranges, however, could be extended further at the lower end(Rogelj et al., 2017a), that is 32-34 GtCO2e/year.

Box 3.2 The impact of uncertainties
Additional research is necessary, as the uncertainty ranges overlap for many countries and since the number of studies
available for the current policy trajectory case and the NDC cases vary significantly. A recent study (Rogelj et al., 2017a)
explores six dimensions that contribute to uncertainties in the assessment of emissions outcomes of NDCs. Thesecomprise (i) variations in overall socioeconomic conditions, such as Gross Domestic Product and population growth,(ii) uncertainties in historical emission inventories, (iii) the conditionality of certain NDCs, (iv) the definition of NDC targets
as ranges instead of single values, (v) the way in which renewable energy targets are expressed, and (vi) the way in which
traditional biomass use is accounted for, as renewable energy or otherwise. They find that depending on assumptions inthese six dimensions, NDC estimates can range from 47 to 63 GtCO2e/year in 2030, which is a wider range than the 50
to 56 GtCO2e/year combined unconditional and conditional NDC scenario range of this report (table 3.1). Uncertainties
in socioeconomic developments are the dominant driver, accounting for more than half of the uncertainty, followedby uncertainties in the way renewable energy targets are expressed. These uncertainties are not fully accounted for in
the range of this study, as this is based on the central estimates of all studies that individually make implicit or explicit
assumptions on the above-mentioned uncertainties.
Another issue is the accounting of land-use-related mitigation, which has been identified as an important source of
uncertainty (Forsell et al., 2016; Grassi et al., 2017; Rogelj et al., 2016), but is not explored explicitly in Rogelj et al.
(2017a). Grassi et al. (2017) find a current ±3 GtCO2e/year difference in global LULUCF net emissions between country
reports (data submitted to UNFCCC, such as greenhouse gas inventories and national communications) and scientificstudies (as reflected in Intergovernmental Panel on Climate Change (IPCC) reports). Among the many possible reasonsfor these differences, Grassi et al. suggest that a key factor, which deserves further analysis, relates to what is considered‘anthropogenic sink’.
Finally, there is some additional uncertainty around the impact of Global Warming Potentials. There is no consistency inthe historical data and the future projections across the studies in the use of Global Warming Potentials. Some studies
use the Global Warming Potentials from the IPCC Second Assessment Report (AR2) consistently for all countries, whereas
others use the Global Warming Potentials from the IPCC Fourth and Fifth Assessment Reports (AR4 and AR5), dependingon the NDC information. With regard to the magnitude of uncertainty related to the choice of Global Warming Potentials,
global total greenhouse gas emissions for 2014 are reported to be 3 percent higher when the IPCC Fourth Assessment
Report (AR4) Global Warming Potentials are used, compared to when the IPCC Second Assessment Report (AR2) Global
Warming Potentials are used (Gütschow et al., 2017). The difference can be larger at a country level when, for example,
the share of Methane (CH4) emissions in total greenhouse gas emissions of a country is larger than the global average.

The Emissions Gap Report 2017 – The emissions gap and its implications

13

The studies from which the current policy trajectory
scenario and the NDC scenario are drawn differ in a numberof respects, such as their treatment of conditional versus
unconditional NDCs; assumptions regarding non-covered
sectors and gases; treatment of land use, land-use change
and forestry (LULUCF) and surplus emission units; different
bases for calculating Global Warming Potentials. These
differences are further described in the 2016 Emissions
Gap Report, which also provides a fuller discussion of thesix scenarios. The methodological differences between thestudies cannot be fully harmonized, which leads to someuncertainty as indicated in the results presented in section
3.3, where the implications of the differences between
studies are also further explored (see also box 3.2).

1.5°C pathways and the 2°C pathways3. More specifically,
the global emissions in 2010 of the 1.5°C pathways includedin the 2016 Emissions Gap Report were about 3 GtCO2e
higher than the median 2010 levels of the 2°C pathways.
This resulted in higher global emissions by 2020 for the 1.5°C
pathways compared to the 2°C pathways. The harmonization
brings the 2010 global emission estimates to the samelevel for the assessed 1.5°C pathways and 2°C pathways,
and leads to comparable 2020 emission levels for the twopathways. This harmonization further affects the projected
global emission levels in 2030, lowering them by arounda further 2 GtCO2e. The estimated global emission level isabout 5 GtCO2e lower than the central estimate for the 2°C
pathways, as shown in table 3.1.

3.2.2 Updates to the assessment

3.2.3 Emerging studies on pathways with agreater than 66 percent chance of limiting
global warming to below 1.5°C

The emissions estimates presented in table 3.1 are based on
the 2016 Emissions Gap Report (UNEP, 2016), but updates
have been made in a number of cases.
There are no updates to the no-policy baseline scenario
compared to the 2016 report. However, the current policies
projections at the global level have been updated, drawing
on data from the Climate Action Tracker (CAT, 2017), theJoint Research Centre (Kitous et al., 2017), PBL Netherlands
Environmental Assessment Agency (den Elzen et al., 2016a;
Kuramochi et al., 2016; PBL, 2017), and the International
Energy Agency (IEA, 2016).
The global emissions projections of the two NDC scenarios
have also been updated with data from the four abovementioned modelling studies, and with updated data from
Climate Interactive (2017).
The estimates for the 2°C pathways with higher than66 percent probability in 2100 remain unchanged since the2016 Emissions Gap Report.
The estimates for the 1.5°C pathways with 50-66 percent
probability in 2100 have been updated, resulting in 2030
global emission estimates that are around 3 GtCO2e lower
than those in the 2016 Emissions Gap Report. The updateis based on: (a) the inclusion of new data that have become
available from scenarios generated with updated or othermodelling frameworks, and (b) the harmonization of the
1.5°C pathways with the same global 2010 emissions as
for the 2°C pathways. The new data considered lower the2030 emission estimates by around 1 GtCO2e and have also
expanded the emissions range. Under the assumption ofcontinued historical socioeconomic trends, Rogelj et al. (2017a)
find emissions in 2030 in the range of 35-37 GtCO2e/year,
whereas when assuming enhanced efforts to limit energy
demand and a shift towards sustainable consumption
patterns, cost-optimal emission levels in 2030 are estimatedat 32-34 GtCO2e/year.
The harmonization has been undertaken to resolve a
discrepancy between the global emissions in 2010 of the

14

The strengthened temperature targets of the Paris
Agreement and the forthcoming 2018 Special Report on
the impacts of global warming of 1.5°C above pre-industrial
levels and related global greenhouse gas emissions pathways
by the IPCC have generated substantial interest in scenariosthat assume least-cost pathways starting from 2020 and thathave a higher than 66 percent probability of returning global
warming to 1.5°C in 2100.
For the 2016 Emissions Gap Report, no such scenarios wereavailable. Therefore the report focused on the least-cost
pathways starting from 2020 that had a lower probability(50 percent) of returning global warming to below 1.5°C in
2100, based on a review by Rogelj et al. (2015) of earlier
published scenarios (Luderer et al., 2013; Rogelj et al.,2013a; Rogelj et al., 2013b).
However, new scenarios are now emerging that assume
least-cost pathways starting from 2020 that can returnglobal warming to below 1.5°C in 2100 with at least
66 percent probability. These are reported in the ADVANCE
project’s policy briefs (Luderer et al., 2016; Vrontisi et al.,2016) and its forthcoming paper (Vrontisi et al., 2017). At
the ninth meeting of the research dialogue at the Subsidiary
Body for Scientific and Technological Advice (SBSTA) in Bonn,
May 2017, Rogelj et al. (2017b) also presented the first draftof least-cost 1.5°C pathways starting from 2020 based on amulti-model comparison study and the framework of the
Shared Socioeconomic Pathways (Riahi et al., 2017)4.
These higher probability 1.5°C scenarios have extensive
implications for 2030 global emission levels. Vrontisi et al.
(2016) reported scenarios from various models that assume
least-cost pathways starting from 2020 that can return global
warming to below 1.5°C in 2100 with at least 66 percent
probability. Emission levels in 2030 for 1.5°C scenarios are
estimated at 24 (range: 19–34) GtCO2e, which is about
3
4

The Emissions Gap Report 2017 – The emissions gap and its implications

The harmonization is based on the average outcome of adopting the threeharmonization methods from the literature (Rogelj et al., 2011).
These scenarios represent an extension of the set of ‘Representative
Concentration Pathways’ (RCPs) towards scenarios that limit end-of-century
forcing to 1.9 W/m2.

18 GtCO2e lower than the central estimate for the 2°C
pathways (table 3.1).

agreements outside the UNFCCC: the Kigali Amendment andthe International Civil Aviation Organization Agreement.

3.3 The emissions gap in 2030 and urgencyof action

3.3.1 The effect of NDCs on global greenhouse gas
emissions and the resulting emissions gap

This section updates the 2030 emissions gap from previous
reports (section 3.3.1) and examines the implications of theestimated emission levels associated with the NDC scenarios
for peaking of emissions, depletion of the carbon budget
and global average temperature increase by the end of
the century (section 3.3.2). It then assesses the potential
positive effects on the 2030 emissions gap of two important

This section presents the emissions gap for 2030, drawing
on the estimated global total greenhouse gas emission levels
in 2030 under the six scenarios described in section 3.2 andprovided in table 3.1. As in previous reports, the emissions
gap in 2030 is defined as the difference between global total
greenhouse gas emissions from least-cost scenarios that areconsistent with the below 2°C and 1.5°C temperature target

Figure 3.1: Global greenhouse gas emissions under different scenarios and the emissions gap in 2030 (median estimate and 10th to 90th
percentile range).

Annual Global Total Greenhouse Gas Emissions (GtCO₂e)70

Baseline

60

Current policy trajectory
Uncondional
NDC case

40

Purple area shows pathways
liming global temperature
increase to below 1.5°C by 2100
with 50 to 66% chance

Remaining gap
to stay within
2°C limit

GtCO2e19
GtCO2e16
GtCO2eMedian esmateof level consistent
with 2°C:
42 GtCO₂e(range 31-44)

Remaining gap
to stay within
1.5 °C limit

Uncond. NDC case

2°C
°C
range
e

Blue area shows pathways
liming global temperature
increase to below 2°C by
2100 with > 66% chanceCond. NDC case

GtCO2e13.5

Cond. NDC case

1150

Uncond. NDC case

Condional
NDC case

Median esmateof level consistent
with 1.5°C:
36 GtCO₂e(range 32-38)

1.5°C
range
70
Baseline

60

30
2015

2020

2025

Current policy trajectory2030

Uncondional NDC case
Condional NDC case50

Note: the emissions range for 1.5°C is smaller than for 2°C, as a smaller
number of studies for 1.5°C are available. For current policy, the minimum–
maximum across all assessed studies are provided.

40

2°C
range

30

1.5°C
range

20

10

0
2010

2020

2030

2040

2050

The Emissions Gap Report 2017 – The emissions gap and its implications

15

and the expected global total greenhouse gas emissions
implied if NDCs are fully implemented. Findings regarding
the aggregate effect of full implementation of the NDCs on
global total greenhouse gas emissions in 2025 and 2030 are
also compared to the emissions implied by the no-policy
baseline scenario and the current policy scenario.
The results are illustrated in figure 3.1, which shows that theemissions gap in 2030, compared with least-cost pathways
limiting global warming to below 2°C with a greater than66 percent chance, ranges from 11-13.5 GtCO2e for the full
implementation of the conditional and the unconditional
NDCs respectively. These estimates are slightly lower
than those made in 2016 (12-14 GtCO2e), due to updated
information from five global studies resulting in lower
emission projections for the NDCs. The emissions gap in
the case of least-cost pathways limiting global warming to
below 1.5°C with 50–66 percent chance is 16-19 GtCO2e
for conditional and unconditional NDCs respectively. This ishigher than the estimates made in 2016 (15-17 GtCO2e) due
to the updated 1.5°C pathways (see section 3.2). As indicatedby the emerging new studies, the gap would be significantly
larger if a higher probability (>66 percent) of limiting global
temperature increase to 1.5°C in 2100 was considered.
It is apparent from figure 3.1 that current policies leadto emissions that are markedly lower than the baseline,
which assumes that no additional climate policies are put
in place from 2005. This indicates that the baseline will
become increasingly less useful as a reference case. The
current policies projections have lowered by about 1 GtCO2e
compared with the estimate made in 2016, mainly due tolower current policy projections from China.
Figure 3.1 shows that full implementation of theunconditional NDCs will reduce annual global greenhousegas emissions in 2030 by 9 GtCO2e5 (range: 8–13) relative tothe median no-policy baseline, and by 4 GtCO2e (range: 2–7)
relative to the median current policy trajectory. Comparing
these cost-optimal 2°C and 1.5°C scenarios with theunconditional NDC projections shows a large discrepancy.
More specifically, there is a gap in 2030 of 13.5 GtCO2e(range: 10–15) between the unconditional NDC scenario
and the median 2°C scenario. Comparing the unconditional
NDC scenario with the median global emissions pathway
consistent with meeting 1.5°C with a 50–66 percent chanceleads to a gap of 19 GtCO2e (range: 15-21), which is 2 GtCO2e
higher than the gap in the 2016 report, due to the lower
1.5°C emissions pathways.
In comparison, if countries were to also fully implement
the conditional NDCs, estimated global greenhouse gas
emissions would be about 2.4 GtCO2e (range: 1.2–3.0) lower
in 2030 compared with the unconditional NDC scenariocase. This leaves a gap in 2030 of 11 (range 8–12) GtCO2e

between the conditional NDC scenario and the mediancost-optimal 2°C scenario. Comparing the conditional NDC
scenario with the median 1.5°C scenarios (50–66 percent
chance) increases the gap to 16 GtCO2e (range: 13–18).
It should be noted that the two NDC scenarios assume full
implementation of the conditional and unconditional NDCs
submitted by all countries. Considering the announcementof the United States of America regarding its withdrawal
from the Paris Agreement and policy changes in the
United States of America, section 3.4 also discusses recent
studies estimating possible effects on the United States ofAmerica’s emissions.
The gap calculations assume that there is no double countingof reductions. In other words, transferred reductions are
only counted towards the achievement of one country’s
NDC, not towards both the country buying and selling. The
Paris Agreement provides for voluntary use of “internationaltransferred mitigation outcomes”, such as trading of offset
credits, on the basis that parties shall avoid double counting.
If, in a theoretical scenario, all Parties were to freely double
count (contrary to the provisions of the Paris Agreement),
this could increase the global emissions by 2030 by
0.8 GtCO2e in the case of both unconditional andconditional NDCs6.

3.3.2 The implications on peaking, carbon budget
and temperature

Global total greenhouse gas emissions (covering all sectors
and gases) are expected to increase and not peak before
2030 under both the NDC scenarios and the current policy
scenario. New actions would be necessary to change this.
In contrast, the 2°C and 1.5°C least-cost pathways assume
that global total greenhouse gas emissions peak no later
than in 2020. This stresses the urgency of strengthening
mitigation action as well as NDCs before 2020, as Chapter 2
also concludes.
Another indication of the urgency of action concerns theimplications of projected global total CO2 emissions forthe carbon dioxide (CO2) budget. The CO2 budget indicates
the total cumulative CO2 emissions that can be emitted fortemperatures to stay below 2°C and 1.5°C7. If the NDCs are
fully implemented, they will result in cumulative emissions of
750-800 GtCO2 during the 2011–2030 period, which is about
80 percent of the remaining CO2 budget of 1,000 GtCO2(range: 750-1,400) for limiting global warming to below 2°C
with more than 66 percent probability. The available global
carbon budget for 1.5°C with 50-66 percent probability will
already be well depleted by 2030. A recently published paper(Millar et al., 2017) suggests that the available budget for 1.5°C

6

7
5

16

The gap numbers and ranges in the text are rounded to the nearest Gt.

The Emissions Gap Report 2017 – The emissions gap and its implications

Consistent with the earlier analysis of double counting in the UN Environment
2014 Emissions Gap Report, for the NDC cases it is assumed that internationalemission offsets could account for 33 percent of the difference between
current policies trajectory and emission levels for the NDC cases by 2030
for the OECD countries. This is an arbitrary, conservative estimate, as many
parties have yet to specify any limits on the use of transferable units.
Box 2-1 (UNEP, 2014) explains how cumulative CO2 emissions are influenced
by various factors, such as the transient climate response to cumulative
carbon emissions and non-CO2 greenhouse gases.

Figure 3.2: Comparison of projected emissions by 2030 and all-time 1.5°C and 2°C
carbon budgets.
Cumulave CO₂ emissions 2011–2030 [GtCO₂]
1,400

1,300

1,200

1,100

All-mebudget

2 °C

1,000

(>66%
chance)
range

900

800

700

All-mebudget600

1.5 °C
500(>50%
chance)
range

400

300

200

Emied from 2011-2015
100

0

CO2 emissions implied unl 2030 by...
... current
policies... uncondional NDC... condional
NDC

Note: The figure shows cumulative global total CO2 emissions for the conditional NDC case, the unconditional NDC
case and the current policies scenario, and carbon budgets from the Fifth Assessment Report of the IPCC (IPCC AR5)
(IPCC, 2014a). The carbon budget ranges show the values based on the range of scenarios assessed by Working GroupIII (IPCC, 2014b). The solid horizontal line at 1,000 GtCO2 shows the estimate based on complex Earth-System Models,assessed by Working Group I (IPCC, 2014a). Historical emissions until 2015 are based on Le Quéré et al. (2015).

The Emissions Gap Report 2017 – The emissions gap and its implications

17

might be bigger. However, criticism on the study points tothe fact that using different global average temperature data
sets in the calculations would not lead to higher budgets8.
Finally, the urgency of action and enhanced ambition
becomes unquestionable when the global averagetemperature implications of the NDCs are taken into
consideration. Estimates of the level of global averagetemperature increase associated with the implementationof the NDCs depend on the assumptions made about what
will happen after 2030, and the probability assigned to theglobal average temperature increase. Previous Emissions
Gap Reports adopt the approach of Rogelj et al. (2016),
which assumes that, as a minimum, the level of climate
mitigation effort implied by the NDCs is continued after
2030, until the end of the century. As reported in the 2016
Emissions Gap Report, full implementation of unconditional
NDCs and comparable action afterwards is consistent with a
global average temperature increase of about 3.2°C (median,range: 2.9–3.4°C) relative to pre-industrial levels with greaterthan 66 percent probability by 2100. Full implementation of
the conditional NDCs would lower the projection by about
0.2°C by 2100.

3.3.3 Impact of the Kigali Amendment

The Kigali Amendment to the Montreal Protocol aims to phasedown production and imports of hydrofluorocarbons (HFCs),
thereby reducing hydrofluorocarbon emissions, which isin the spirit of the Paris Agreement to reduce greenhousegas emissions to net zero. It solidifies the international
efforts and provides more certainty that national measures
to reduce these emissions will be implemented. Against a
no-action baseline, the reductions could be in the order of
0.7 GtCO2e/year in 2030 (Höglund-Isaksson et al., 2017).
The Kigali Amendment may have a lower additional impact
against the NDCs, but one that is uncertain as countries are
not clear about the extent to which such reductions are
already covered by the NDCs. Most countries set targets
for all greenhouse gases including the hydrofluorocarbons.
For them, implementing the commitments of theKigali Amendment will not necessarily lead to lower
hydrofluorocarbon emissions than implementing the
NDC. Some, most notably China, have not included theseemissions in their NDC. For them, the implementation of
the Kigali Amendment would lead to lower emissions than
implementing the NDC and would, therefore, narrow theemissions gap.
The long-term impact of the Kigali Amendment is assessed in
Chapter 6, which shows that it can be substantial.

3.3.4 Impact of the International Civil Aviation
Organization Agreement

The International Civil Aviation Organization is the United
Nations body responsible for international civil aviation
emissions of CO2 under Article 2.2 of the Kyoto Protocol.
Although international aviation is not explicitly identified
under the Paris Agreement, it is assumed that theInternational Civil Aviation Organization will continue to takeresponsibility for international emissions.
The International Civil Aviation Organization adopted a targetof ‘Carbon Neutral Growth from 2020’, that is no increase ofinternational aviation emissions of CO2 from 2020 onwards.
In order to achieve this, the International Civil Aviation
Organization agreed a global market-based measure, the‘Carbon Offsetting and Reduction Scheme for International
Aviation’ (CORSIA) at the 39th International Civil Aviation
Organization Assembly (Resolution A39-3) in 2016. The
Carbon Offsetting and Reduction Scheme for International
Aviation relies on emissions offsetting and work is currently
ongoing on agreeing a monitoring, reporting and verification
system and defining the emissions units and registries to be
used. In addition, the International Civil Aviation Organization
is working on implementing technical measures to increase
efficiency or the use of sustainably sourced low-carbon fuels
to also contribute to the target of ‘Carbon Neutral Growthfrom 2020’.
As of 2015, total emissions of aviation CO2 are estimatedto be of the order of 0.9 GtCO2e (International Energy
Agency data)9, around 62 percent of which are international.
Domestic emissions fall under the reporting and reductionplans of States. International aviation emissions are
expected to grow from 0.5 GtCO2e in 2017 to around
1.1 GtCO2e in 2030 with increasing traffic demand overthe coming decades, despite emission reductions fromoperational improvements, aircraft technology andutilization of sustainable alternative fuels. If growth after2020 is compensated by offsets, emissions of the order of
0.3 GtCO2e/year in 2030 could be saved over the reference
development. This is consistent with the International Civil
Aviation Organization’s own estimate10.
Given that participation in the first phases of the Carbon
Offsetting and Reduction Scheme for International
Aviation is voluntary, that certain developing countries
are permanently exempt, and that its actual effectiveness
depends on its implementation by States, the impact of the
Carbon Offsetting and Reduction Scheme for International
Aviation is still uncertain. So far, around 70 States havedeclared their commitment to join the Carbon Offsetting
and Reduction Scheme for International Aviation.

9

8

18

https://www.carbonbrief.org/factcheck-climate-models-have-not-exaggerated-global-warming ; http://www.realclimate.org/index.php/archives/2017/09/is-there-really-still-a-chance-for-staying-below-1-5-c-global-warming/

Here, aviation CO2e emissions are effectively CO2 emissions alone, the sector
having no significant emissions of methane, Nitrous Oxide (N2O) etc. Aviation
does have non-CO2 impacts, however, from emissions of particles, nitrogenoxides (NOx) and water vapour that impact on ozone (O3), reduce methane,
and affect cloudiness but these are not estimated in CO2e since the scientificuncertainty of doing so in terms of Global Warming Potential 100 is stillrather large (Fuglestvedt et al., 2010; Lee et al., 2009; Lee et al., 2010).
10 https://www.icao.int/environmental-protection/Pages/A39_CORSIA_FAQ3.
aspx estimates range from 0.288-0.376 GtCO2 per year in 2030.

The Emissions Gap Report 2017 – The emissions gap and its implications

Whether the offsetting under the Carbon Offsetting andReduction Scheme for International Aviation reduces theemissions gap (between the NDCs and what is needed
for the Paris Agreement long-term goals) also depends
on the quality of the offsets that are allowed under the
Carbon Offsetting and Reduction Scheme for International
Aviation regime. The gap (as defined in this report) would
be narrowed if only offsets that reduce emissions beyond
the NDC of the country that was selling the offsets wereallowed. The gap would not be narrowed if credits wereallowed that were already counted towards meeting thecountries’ NDCs. This would be the case, for example, for
Clean Development Mechanism (CDM) projects initiatedseveral years ago that keep operating regardless of whether
or not the Clean Development Mechanism credits are sold,
and whose reductions are included in the current emission
trajectory of the country selling the offsets (Schneider et al.,2017). Whether the offsetting under the Carbon Offsetting
and Reduction Scheme for International Aviation reduces
the emissions gap also depends on the level of participation.
Hence, the International Civil Aviation Organization
Agreement to reduce greenhouse gas emissions fromaviation may have an impact of between 0 and 0.3 GtCO2e
on closing the emissions gap in 2030.

3.4 Understanding the current emission
trends of G20 members
3.4.1 A comparison of current emission trends of
G20 members

This section presents a comparison of country-specificfindings for the G20 members. To assess these, figure 3.3
shows the projected impact up to 2030 of the NDCs andcurrent policies on greenhouse gas emissions for each G20
member. As mentioned in Chapter 2, these economies
collectively generate around three quarters of global
greenhouse gas emissions. Therefore their success in
implementing (or exceeding) their NDCs will have a major
impact on the achievement of global climate goals.

The calculation is based on the same data as the 2016
Emissions Gap Report was (UNEP, 2016), but updates havebeen used for: the current policies and the NDC projections
from the Climate Action Tracker (CAT, 2017); the International
Energy Agency (IEA, 2016); the Joint Research Centre (Kitous
et al., 2017); PBL Netherlands Environmental Assessment
Agency (den Elzen et al., 2016a; Kuramochi et al., 2016; PBL,
2017); updated NDC projections from Climate Interactive(2017); and some updated national and official studies(Reputex, 2016; Sha et al., 2017) (see Appendix A available
online). More specifically, the data is sourced from: (i) the
official estimates included in the NDCs (UNFCCC, 2015a);(ii) calculations based on the NDCs and on other documents
submitted by countries to the UNFCCC (such as national
greenhouse gas inventories, national communications,biennial reports, and biennial update reports); (iii) estimatespublished in country-specificstudies; and (iv) eight11
independent global analyses . These are described infurther detail in Appendix A, which is available online.
The results of this assessment are presented for all G20
members in figure 3.3 (with the 28 European Union members
represented collectively instead of by the four Member
States, who are individual G20 members), noting that data
are not available for all countries for all studies. By comparing
the current policy scenarios and the NDC scenarios, thefigure provides an indication of whether or not a country
needs to implement policies additional to the current policy
trajectory to meet its NDC target. The figure does not indicate
the level of ambition of the NDC targets. Box 3.3 considers
possible principles for assessing and comparing the ambition
of NDCs across countries. It is also important to note that thecurrent policy trajectory scenarios, which attempt to reflect
the most recent mitigation policies, differ from the baselineor ‘business as usual’ (BAU) scenarios employed by somecountries, which typically assume that no new policies are
adopted or implemented after a given cut-off year.

NDCs are not static or one-off commitments; countries havethe obligation to strengthen them regularly. The assessment
conducted in this section is on current NDCs, acknowledging
that they can be revised in the future.
For each of the G20 members, median emission projections
resulting from the current policies and full implementation of
the NDCs is calculated. As described in box 2.2 in Chapter 2,
current policies projections from independent analyses
presented in Chapter 2 cover the main energy and climate
policies implemented as of a recent cut-off date and do
not consider prospective policies that are being debatedor planned.

11 The UNFCCC synthesis report and the Danish Energy Agency (DEA) study are
excluded here, as these studies do not provide national estimates.

The Emissions Gap Report 2017 – The emissions gap and its implications

19

Figure 3.3: Greenhouse gas emissions (all gases and sectors) of the G20 members by 2030.
Figure 3.3 a
Emissions (GtCO₂e/year)
20
18

1990
2010

16

Naonal BAU reported in NDC

14Current policies (naonal studies)
Current policies (all studies)

12

Uncondional NDC (all studies)

10

Condional NDC (all studies)

8
6
4

4

2
0

China

EU-28

2 5 10 -1 3 6 -

Number of studies

India

USA*

- 4 7 8

1 5 9 -* For the US, the unconditional NDC is for 2025.
Note: Greenhouse gas emissions (all gases and sectors) of the G20 members by 2030 for the BAU emissions projection from the NDC submission (third bar), forthe current policies scenario from official and national studies (fourth bar), from all studies, including official, national and global model studies (fifth bar), for theunconditional NDC scenario (sixth bar), and for the conditional NDC scenario (seventh bar). For current-policy and NDC scenarios respectively, the minimum–maximum
and 10th–90th-percentile range across all assessed studies are provided. The uncertainty ranges are explained in the main text. For reporting reasons, the emissions
projections for China, European Union, India and United States of America are shown in panel (a), and the other countries in panel (b), with different vertical axis. The
figure also shows the number of studies underlying the estimate (if available) for the last four bars: current policies (national studies), current policies (all studies) andthe unconditional NDC and conditional NDC (all studies).

Figure 3.3 shows that for many countries the implementationof their NDC would lead to lower emissions than the current
policies scenario, or in other words that additional policies
would have to be implemented to meet the NDC target.
For some countries the NDC is above the current policies
scenario, indicating that it should be possible to enhance
ambition quite easily. For eight G20 members, the NDC isabove 2010 emission levels.
Recent studies suggest that Brazil, China, India and Russia
are likely to – or are roughly on track to – (over)achieve
their (unconditional) 2030 targets through their currently
implemented policies.
Argentina, Australia, Canada, the European Union, Indonesia,
Japan, Mexico, South Africa, Republic of Korea and theUnited States of America are likely to require further actionin order to meet their NDCs, according to government andindependent estimates.

20

From the existing studies, it is not possible to determine
whether Saudi Arabia and Turkey are on track to meettheir NDCs.
Figure 3.3 furthermore illustrates that the progress on
cutting down greenhouse gas emissions varies across theG20 countries. For 11 of the 16 G20 members (counting the
28 European Union members as one), emission projections
based on current policies are higher than their 2010 emission
levels. More specifically, for some non-OECD Member States(Argentina, China, India and Saudi Arabia) as well as forsome OECD Member States (Australia, Mexico, Republic ofKorea and Turkey), currently implemented policies do notstop annual emissions from increasing until 2030. Annual
emissions in other countries are projected to remain stable
at about 2010 levels (including in Canada, Russia and theUnited States of America), or to decrease further (such as in
the European Union with a 7–32 percent reduction compared
to 2010 levels), under current policies. The following section
provides more detail on each of the G20 members.

The Emissions Gap Report 2017 – The emissions gap and its implications

Figure 3.3 b
Emissions (GtCO₂e/year)
4.0
1990

3.5

2010
Naonal BAU reported in NDC

3.0

Current policies (naonal studies)
2.5

Current policies (all studies)
Uncondional NDC (all studies)

2.0

Condional NDC (all studies)

1.5
1.0
0.5
0

Argenna Australia

BrazilCanada Indonesia

Japan

MexicoRussiaSaudi
Arabia- 2 3 3- 3 6 -

1 4 6 -

- 4 7 - - 3 4 4
Number of studies

1 3 6 -

1 3 3 - 1 5 - 4

1 4 5 -

- 3 4 5South Republic
Africa** of Korea- 3 6 -

Turkey- 3 3 -** South Africa’s NDC is based on an emissions trajectory with an emissions range of 398–614 MtCO2e including LULUCF over the period 2025-2030.

The Emissions Gap Report 2017 – The emissions gap and its implications

21

Box 3.3 Comparing the ambition of countries’ NDCs
When countries put forward their NDCs for the Paris Agreement, they were asked to explain why these are ambitious.
These explanations can be used to derive metrics to compare countries’ actions.
The literature on assessing the ambition of NDCs is growing. It compares different energy and climate indicators
between countries and analyses what would be necessary in terms of national ambition to be compatible with the Paris
Agreement (Aldy et al., 2016; Climate Transparency, 2017; Höhne et al., 2017). Höhne et al. (2017) argue that only acomprehensive approach that covers all perspectives can be used to assess the ambition of national climate policy. Many
principles could be used by countries to assess ambition, including (based on Höhne et al. 2017):• A country’s reduction of emissions since 1990 (or any other base-year): the standard perspective for developed
countries used since 1992, also used in the Kyoto Protocol – the metric used by the European Union, for example.
• Change in recent trend in emissions: a country would do more than before – the main argument in the proposal by
the United States of America. This can also be measured as a deviation from a BAU scenario.
• Time and level of peaking emissions per capita: countries go through different levels of development with first rising,then peaking and then declining emissions – the metric chosen by China.
• Comparison with equity-based effort-sharing calculations: There is a long history of scientific studies that use ‘effortsharing’ principles to calculate ‘fair’ emission targets for countries. The principles include responsibility (for example
those who emitted more in the past now have to reduce more) or capability (for example those with higher per capita
income levels should do more), equality (that is equal emission rights per capita), cost-effectiveness (total abatement
cost per Gross Domestic Product), as well as combinations.
• Comparison with benchmarks of decarbonization indicators: A number of indicators can be used to describe
countries’ circumstances and developments, for example at the national level, emissions per Gross Domestic Product,emissions per capita, energy use per capita or the energy mix. At the sectoral level it could be emissions per kilometre
travelled or per tonne of cement or steel produced. Indicators can measure activity (for example vehicle kilometrestravelled) or intensity (emissions per vehicle kilometre) (see also the data portal of the Climate Action Tracker).
• In line with globally cost-effective model pathways: Modelling exercises can identify the country reductions required
to minimize the aggregated global costs of emission reductions. As a result, reductions are required in those sectors
and countries where they are least-cost from a global perspective.
• Comparison with best practice policy package or policy menu: A comparison can be made on the extent to whicha country has implemented supporting policies, addresses barriers, or has counterproductive policies in place. A
contribution can be regarded as ambitious if it includes many policies that are considered good practice, while it would
be less ambitious if the country were not to implement the policies that most of its peers had already successfully
implemented (see also climate policy database12, Climate Transparency 2017).
Comprehensive studies that evaluate diverse metrics are not yet available. However, their inclusion would be very
useful in future Emissions Gap Reports, as well as for the further processes under the UNFCCC, including the Facilitative
Dialogue in 2018 and the global stocktake in 2023.

3.4.2 NDCs and emission trends of individual
G20 members

China’s NDC includes four major targets: (1) an intention
to peak CO2 emissions around 2030, making best eﬀorts
to peak earlier, (2) to reduce the carbon intensity of Gross
Domestic Product by 60–65 percent from 2005 levels by
2030, (3) to increase the share of non-fossil fuels in primaryenergy consumption to around 20 percent by 2030, and (4)to increase the forest stock volume by around 4.5 billion m3
from 2005 levels by 2030. For the first two targets, the NDC
does not clarify which sectors are covered (Damassa et al.,2015). Recent independent studies (Climate Action Tracker,
2017a; den Elzen et al., 2016b; IEA, 2016; Sha et al., 2015)12	
www.climatepolicydatabase.org, https://newclimate.org/2015/12/01/goodpractice-policies/

22

suggest that China’s emissions under currently implemented
policies would roughly be in line with what the NDC targets
would mean for overall emissions, but do not provide strong
indication that CO2 emissions would peak before 203013. Total
greenhouse gas emissions are projected to keep on growing
up to 2030, albeit at a much lower rate than previously
observed, which is also concluded in the analysis of Jiang etal. (2017). Several studies have revised their projection for2030 downward compared to last year’s projection.
Driven by air pollution control action policies (State Council,2013), China started to control coal use and promote clean
energy use in 2012. Together with economic structural
13 Some analysts have argued that structural shifts in the economy in recent
years make likely much steeper reductions in the CO2 intensity of Gross
Domestic Product. Fergus and Stern (2017) include an illustrative pathway
wherein intensity is halved from 2005 to 2020, and the result is a peak in CO2emissions between 2020 and 2025.

The Emissions Gap Report 2017 – The emissions gap and its implications

changes, this resulted in a slowdown of most energyintensive production, a peak in coal consumption in 2013 inphysical unit and in 2014 in standard coal equivalents, andcontinued decline from 2014. Coal consumption reduced by
4.7 percent in 2015, and 3.7 percent in 2016 (China Statistic
Year Book, 2017). Due to the increase in natural gas andpetroleum production, the total CO2 emissions have started
to decline after 2014. Based on the energy use data, energy
related CO2 emissions are around 450 MtCO2 lower in 2016
than in 2014, which amounts to 5 percent of total CO2
emissions from energy activities. Despite a small increase inemissions from clinker manufacture, CO2 emissions in 2016
are still 430 MtCO2/year lower than in 2015 (China Statistic
Year Book, 2017).
In the last two years, newly installed capacity on wind power,
solar power, and hydropower has increased to more than
120 GW, which together with 11 GW newly installed capacity
for nuclear has dominated the global newly installed capacity
for low-carbon power. Low-carbon power accounts for morethan 40 percent of global newly installed capacity in the last
two years (CEC, 2017; REN21, 2017).
Due to structural change in the industry sector, energy
demand increase is projected to be quite low, with energy
demand by 2020 much lower than that projected ingovernment planning. Based on scenario analysis, theincrease in energy demand in the near future could be
provided by renewable energy, nuclear and natural gas.
Given the recent trends, coal use decline could continue.
Taking into account these recent developments, CO2
emissions may already have peaked, or may not increasein the future (Green and Stern, 2017), a development thatis not yet included in the studies cited above and may bevisible in future Emissions Gap Reports.
Meanwhile, the European Union’s NDC contains acommitment of a 40 percent reduction in domestic
emissions by 2030 compared to 1990. Recent independentstudies (CAT, 2017; Kitous et al., 2016) and the European
Environment Agency (EEA) Trends report (EEA, 2016) suggestthat the European Union will fall slightly short of its NDC
target under existing policies.
India’s NDC commits to, by 2030, reduce its emissions
intensity of Gross Domestic Product by 33–35 percent below
2005 levels, increase the share of non-fossil energy in total
power generation capacity to 40 percent, and create an
additional cumulative carbon sink of 2.5–3 GtCO2e throughadditional forest and tree cover. In figure 3.3, unconditional
NDCs assume either current policies or only the intensity
target, while conditional NDCs assume full implementationof the NDC, including the non-fossil fuel target. Independentstudies project that the emission level under the intensity
target would be overachieved, but it is uncertain whatemission level would be reached under all three targets
combined (Climate Action Tracker, 2017a; Mitra et al.,2017; PBL, 2017). Recent policy developments include theDraft Electricity Plan published in December 2016 (Central
Electricity Authority, 2016). Although this is currently not

an official policy and is in a draft stage, the analysis in the
document forecasts that no new coal-fired power capacity
would be required during the period 2022–2027, in contrast
to around 50 GW of additional capacity expected for theperiod 2017–2022 (Central Electricity Authority, 2016). As aresult, the share of renewables in total installed capacity inthis scenario is projected to increase to around 43 percent
in 2027 (Central Electricity Authority, 2016). Overall, theassessment suggests that the positive development provides
ample room for India to strengthen its NDC.
The INDC communicated by the United States of America in2015 indicated an intent to reduce greenhouse gas emissions
by between 26 and 28 percent below 2005 levels in 2025,
which translates to 4.6-4.8 GtCO2e/year (national estimate,in the IPCC Fourth Assessment Report (AR4) Global Warming
Potential terms). In June 2017, President Donald Trump
announced that the United States of America intended
to withdraw from the Paris Agreement and would cease
implementation of the NDC. The United States of America
subsequently communicated its intent to the United Nations
Secretary-General (The Representative of the United Statesof America to the United Nations, 2017). The earliest that
United States of America withdrawal can take effect is in
2020, four years after the Paris Agreement entered into
force. Seven studies to date estimate that 2025 emissions
under the new Administration’s policies will range from
5.7-6.8 GtCO2e/year, in contrast to 5.0-6.6 GtCO2e/year
under the previous Administration’s policies (Chai et al.,2017; Climate Action Tracker, 2017a; Climate Advisers, 2017;
ClimateInteractive, 2017; Hafstead, 2017; Rhodium Group,
2017a, b). The impact of current and upcoming action bysubnational and non-state actors may also be significant(Kuramochi et al., 2017).
Argentina presented a revised NDC at the COP 22 in
November 2016 (Government of Argentina, 2016). This new
NDC includes an unconditional absolute emissions targetof 483 MtCO2e/year by 2030 and a conditional target of369 MtCO2e by 2030, both including LULUCF. The revised
NDC is significantly more ambitious than the previous one interms of absolute emissions (about 190 MtCO2e/year lower
for the unconditional target), which is partially attributable
to the revised methodology for quantifying the historicalemissions data. The Climate Action Tracker concludes in its
latest analysis (Climate Action Tracker, 2017b) that the 2030
emissions projections, previously assessed to be on track
to meet the unconditional target (Kuramochi et al., 2016),
would not reach the revised NDC targets.
Australia committed to a 26–28 percent reduction ofgreenhouse gas emissions by 2030 below 2005 levels,
including LULUCF. Government projections indicate thatemissions are expected to reach 592 MtCO2e/year in 2030
(Government of Australia, 2016), in contrast to the targetedrange of 429-440 MtCO2e/year. Independent analyses(Kuramochi et al., 2016; Reputex, 2016) confirm that theemissions are set to far exceed its Paris Agreement NDC
target for 2030. The Emissions Reduction Fund, which
the Government of Australia considers to be a key policy

The Emissions Gap Report 2017 – The emissions gap and its implications

23

measure to reduce emissions alongside other measures
such as the National Energy Productivity Plan and targets forthe reduction of hydrofluorocarbons (85 percent by 2036),
does not set Australia on a path to meeting its targets.
Brazil has put forward an absolute emissions reduction
target, committing to reduce emissions to 1.3 GtCO2e/yearby 2025 and 1.2 GtCO2e/year by 2030, which is equivalent
to 37 percent and 43 percent below 2005 emissions levels
including LULUCF. Recent independent studies suggest
current policy projections to be in line with the NDC targets(CAT, 2017; Kuramochi et al., 2016; PBL, 2017). Uncertainty
nevertheless remains about the future of emissions growth;for example, the LULUCF emissions reduced by 86 percent
between 2005 and 2012 (Ministry of Science and Technologyof Brazil, 2016), but recent data and analyses suggest thatthe decreasing trend on deforestation and the resulting
emissions reductions have slowed down or even stopped(SEEG, 2017).
Canada’s NDC commits to emissions reductions of 30 percent
from the 2005 level by 2030. Government projections indicatethat emissions are expected to reach 742 MtCO2e/year
in 2030, in contrast to the targeted level of 523 MtCO2e/year(excluding LULUCF) (Environment and Climate Change
Canada, 2017). Independent studies (Climate Action
Tracker, 2017h; PBL, 2017) also agree that Canada will missits NDC target under current policies by a large margin(610–820 MtCO2e/year compared to the NDC target of
510–580 MtCO2e/year in 2030).
Indonesia’s NDC includes an unconditional target of
29 percent below BAU and a conditional 41 percent
reduction below BAU with sufficient international support
by 2030, both including LULUCF. The NDC includes emissions
due to deforestation and peat land destruction, which are
the country’s largest sources of greenhouse gas emissions.
Studies covered in figure 3.3 show that Indonesia is close tobeing on track to achieving its unconditional NDC, which isbased on new independent analyses (CAT, 2017; Kuramochi
et al., 2016; PBL, 2017) that show a range of emission
projections under current policies for 2030, although theupper end of the projection range is not expected to achieve
the unconditional NDC target.
Japan aims to reduce its greenhouse gas emissions by
26 percent below 2013 levels by 2030 under its NDC. Recent
analyses (CAT, 2017; PBL, 2017) show that the target could
possibly be reached with currently implemented policies,
although there is still a great deal of uncertainty regarding
the future role of nuclear and coal power. It is worth notingthat the government has started the process to formulate a
new Basic Energy Plan, in which a revised future electricity
mix target for 2030 and subsequent years would be laid out.
Mexico aims, in its NDC, to reduce its greenhouse gas
emissions by between 22 percent (unconditional) and
36 percent (conditional) from BAU by 2030. Under its current
policies, Mexico is not on track to meet its NDC target.
Independent studies (Climate Action Tracker, 2017c; PBL,

242017) agree that Mexico will fall short of its unconditional
NDC target (759 MtCO2e/year) by 20–160 MtCO2/year under
its current policies.
The Republic of Korea committed under its NDC to reduce
its greenhouse gas emissions by 37 percent below BAU by
2030. Recent independent analyses (CAT, 2017; PBL, 2017)indicated that the emissions projections under current
policies would fall short of the NDC emission level. However,it should be noted that the new President Moon Jae-in
recently announced that the Republic of Korea will reduce
its dependency on coal-fired and nuclear power generation(Cheong Wa Dae, 2017; MOTIE-MOE-MOLIT, 2017), while
increasing renewable electricity. No official government
document has been published.
Russia’s INDC aims to limit its greenhouse gas emissions
to 70–75 percent of 1990 levels by 2030. Independent
estimates on the INDC emission level vary significantly(2.4–2.7 GtCO2e/year including LULUCF), mainly due todifferent interpretations on the accounting of LULUCF
emissions (Government of Russia, 2014). The emission
levels under current policies projected by independent
analyses are approximately 2.0–2.4 GtCO2e/year (including
LULUCF) in 2030 and reach the lower end of Russia’s INDC
range (Kuramochi et al., 2016). The latest current policies
projections for 2030 excluding LULUCF by the Climate Action
Tracker (Climate Action Tracker, 2017d) have been revised
downward by 0.2–0.3 GtCO2e/year compared to the 2016assessment. Our assessment suggests that there is ample
room for Russia to strengthen its NDC.
Saudi Arabia’s NDC aims to achieve mitigation co-benefits of
up to 130 MtCO2e avoided annually by 2030 through actions
and plans outlined to contribute to economic diversification
and adaptation. The country has not yet defined a baseline,
which the NDC states will be determined based on
differently weighted combinations of two scenarios, which
differ in terms of their assumptions on the allocation ofoil: produced for either domestic consumption or export.
Among independent studies, PBL Netherlands Environmental
Assessment Agency and the European Commission’s Joint
Research Centre project that Saudi Arabia will achieve
its NDC (Kitous et al., 2017), whereas Climate Action
Tracker projects it to miss the NDC target (Climate Action
Tracker, 2017e).
South Africa’s NDC consists of a peak, plateau and decline
in the greenhouse gas emissions trajectory range, which
gives a range of 398–614 MtCO2e/year between 2025 and2030, reaching a peak between 2020 and 2025 and a plateau
for the following decade, before starting to fall. All studies(Climate Action Tracker, 2017f; Kitous et al., 2017; PBL, 2017)agree that South Africa will not achieve its NDC range undercurrent policies by a margin of 50 MtCO2e/year to nearly
400 MtCO2e/year in 2030.
Turkey’s NDC sets an economy-wide greenhouse gas
emission reduction target of up to 21 percent below BAU
in 2030. Among independent studies, PBL Netherlands

The Emissions Gap Report 2017 – The emissions gap and its implications

Environmental Assessment Agency and the European
Commission’s Joint Research Centre project that Turkey will
overachieve its NDC considerably by 370–410 MtCO2e/year(Kitous et al., 2017; PBL, 2017; van Vuuren et al., 2017;
Vandyck et al., 2016) while Climate Action Tracker projects it
to miss the NDC target, based on the government projection(Climate Action Tracker, 2017g).

Analysis of the extent to which individual subnational andnon-state actors or initiatives meet their stated objectives
is still scarce. Chan et al. (2016) find that not all initiatives
deliver on their promises. Graichen et al. (2017) provide apreliminary assessment of the actual emission reductionsof an initiative compared to its potential. Based on suchanalysis, several studies (Graichen et al., 2016; Michaelowa
and Michaelowa, 2017) have identified criteria for initiatives
to be effective:

3.5 Subnational and non-state actions tonarrow the gap• Permanent funding and secretarial support•	Inclusion of Non-Govermental Organizations in thedesign and implementation of the initiative• Definition of mitigation targets including baseline• Regular monitoring, reporting and verification

In line with previous Emissions Gap Reports, this report findsthat subnational and non-state actions could possibly makea significant contribution to narrowing the gap (figure 3.4).
The aggregate impact of the initiatives could be in the orderof a few GtCO2e in 2030 beyond the current NDCs, if theinitiatives reach their stated goals and if these reductions do
not displace actions elsewhere. Since the 2016 report, only
updates on earlier studies (Compact of Mayors 2015; CDP
and We Mean Business, 2016; The Climate Group, 2016;
Graichen et al., 2017), but no significantly new aggregation
reports, have become available.

The process around and following the COP 21 in Paris in2015 has brought about much higher recognition andinstitutionalization of the role of non-state actors in theintergovernmental climate change process. This processcontinued at COP 22 in Marrakech in 2016, where theMarrakech Partnership for Global Climate Action was

Figure 3.4: Illustration of the potential impact of international cooperative initiatives in 2030.
Current individual commitments and/or iniaves goals

Global emissions (GtCO₂e/year)

Cies
Increasing coverageof iniaves
Regions
Companies
Cross-sectoral

17
GtCO₂eTh
em
Co

Current
policies

60

pa

ct

of

M
ay
Cl
or
im
s(
a
20
W
te
15
e
G
& M
r
)
ou
CD ea
p
n
P B
(
20
Ro (20 us
16
16 ine)et elfs
)
s
s
em
a
l. a
Gr
(2
ai
01
ch
5)
en
et
al
.(
20
17
)

70

NDCs

2°C
range
1.5°C
°C
range
e

2020

GtCO₂e

2°C

40

30
2010

Remaining
gap to staywithin
2°C limit

NDCs Gap

NDCs

Current Policies Gap

11-13.5502030

Note: The arrows showing the emission reductions potential start at different levels because the individual studies use different baselines (the last study explicitly
estimated the impact additional to NDCs).

The Emissions Gap Report 2017 – The emissions gap and its implications

25

launched14. It provides guidance on how the UNFCCC process
will catalyse and support climate action by Parties andnon-Party stakeholders in the period up to 2020, in line withthe arrangements of the Paris Agreement. It also promotes
an assessment of the compatibility of commitments withregard to the long-term objectives of the Paris Agreement,
and seeks to increase the coherence with the Sustainable
Development Goals.
A number of new cooperative initiatives involving non-state
actors were launched at COP 22 in Marrakech. The ‘2050
Pathways’ platform intends to build a bridge to long-term
decarbonization scenarios and strategies and brings together
both state and non-state actors15. The Global South waswell represented in new initiatives such as the Marrakech
Investment Committee for Adaptation Fund, the Initiativefor Renewable Island Energy and the Marrakech Pledge for
Fostering Green Capital Markets in Africa. A host of otherinitiatives were launched in various areas, including forests,
water, energy, human settlements, oceans, transport andagriculture16. However, there was little information on the
progress regarding the non-state initiatives launched in Paris.

Actions by subnational and non-state actors have thepotential to reinforce each other (Andonova et al., 2017) andcould make the Paris Agreement more robust. Even if Parties
announce the withdrawal of their support from implementing
the Paris Agreement, other actors in the same country could
step in to reaffirm their commitment. For example, following
the announcement of the Trump Administration to withdraw
from the Paris Agreement, the United States of America has
seen a number of new initiatives driven by subnational andnon-state actors, such as America’s Pledge on Climate19, We
Are Still In20, Climate Mayors21 and the US Climate Alliance22.
If backed by action, these initiatives have the potential to
make up for the withdrawal (Kuramochi et al., 2017).
Jerry Brown, governor of California, announced23 in July
2017 that the State of California will convene representatives
from subnational governments, businesses, investors andcivil society in San Francisco, California, in September 2018
for a Global Climate Action Summit24. The meeting aims
to demonstrate the groundswell of innovative, ambitious
climate action, highlight the economic and environmental
transition already under way and spur deeper commitment
from all parties, including national governments.

The number of non-state commitments and actions includedin the Non-State Actor Zone for Climate Action17 platform,
where the UNFCCC captures and recognizes climate
commitments from non-state actors, continued to growto over 12,000 (mostly individual) commitments in 2016,
compared to 10,000 in 2015. The Non-State Actor Zone for
Climate Action also aims to assess the progress in thesecommitments, but so far there is little data available. UN
Environment’s Climate Initiatives Platform18, which provides
the Non-State Actor Zone for Climate Action with data on
important cooperative non-state climate initiatives, has also
started collecting this information.

14 http://unfccc.int/files/paris_agreement/application/pdf/marrakech_
partnership_for_global_climate_action.pdf
15 http://newsroom.unfccc.int/unfccc-newsroom/high-level-climatechampions-launch-2050-pathways-platform/
16 http://newsroom.unfccc.int/climate-action/non-state-actors-partner-withgovernments-to-boost-climate-action/
17 http://climateaction.unfccc.int/
18 http://climateinitiativesplatform.org/

26

19
20
21
22
23
24

The Emissions Gap Report 2017 – The emissions gap and its implications

https://www.americaspledgeonclimate.com
http://www.wearestillin.com
http://www.climatemayors.org
https://www.usclimatealliance.org
https://www.gov.ca.gov/news.php?id=19866
https://globalclimateactionsummit.org/

Chapter 4

Bridging the gap - sectoral
greenhouse gas emission reduction
potentials in 2030
Lead authors: Kornelis Blok (Ecofys), Angélica Afanador (Ecofys), Detlef van Vuuren (PBL Netherlands Environmental Assessment Agency)
Contributing authors: Tom Berg (Ecofys), Christian Breyer (Lappeenranta University of Technology), Oreane Edelenbosch (PBL Netherlands
Environmental Assessment Agency), Ann Gardiner (SQ Consult), Danny Harvey (University of Toronto), Atul Kumar (TERI University),
Roberto Schaeffer (Universidade Federal do Rio de Janeiro), Pete Smith (University of Aberdeen), Lynn Price (Lawrence Berkeley National
Laboratory), Irina van der Hoorn (Ecofys), Paul Waide (Waide Strategic Efficiency), Hans Joosten (Greifswald University)

4.1 Introduction
This chapter explores two central questions: Can theemissions gap in 2030 be bridged, and what are the mostpromising options to do so? As presented in Chapter 3,
the estimated emissions gap in 2030 is 11 to 13.5 GtCO2e
for the below 2°C target (>66 percent ‘likely’ chance), and
16 to 19 GtCO2e for the 1.5°C target (50-66 percent ‘medium’
chance). Chapter 3 furthermore assessed the difference in2030 between emissions under the current policy scenario
and the emission levels consistent with a likely chance ofstaying below 2°C and a medium chance of staying below
1.5°C of about 17 and 22.5 GtCO2e respectively (table 3.1). To
be sufficient to bridge the gap, emission reduction potentials
in 2030 need to be of a comparable magnitude.
The chapter provides a detailed review of greenhouse gas
emission reduction potentials in 2030 for key economic
sectors (section 4.2). Sectoral emission reduction potentials,
also called bottom-up potentials, provide detailed estimatesof the level of emission reductions that is feasible within acertain sector or for a specific emissions category up to acertain marginal cost level. When added up, and adjusting
for any overlaps, these estimates give an indication of thetotal potential for reducing global greenhouse gas emissions
in 2030. The total potential can then be compared to thegap, to determine whether it can be bridged (section 4.3).
In addition, the estimates provide policy makers with a clear
and granular view of where important emission reduction
options exist, that is, how the gap can be bridged. The
sectoral estimates are then compared to emission reduction
options provided by integrated assessment models(section 4.4).
Previous Emissions Gap Reports have provided both sectoral
emission reduction potential estimates and estimates basedon integrated assessment models (see UNEP, 2014; 2013;2012; 2011). However, most of the previous assessments
provide estimates of emission reduction potentials for
2020, and the most recent assessments of sectoral emission
reduction potentials date from more than six years ago.
These include UNEP (2011) for 2020, IPCC (2007) for 2020
and 2030, and McKinsey (2010) for 2030. Assessments thatare more recent include IPCC (2014) and IEA (2017), butthese do not include a sector-by-sector assessment of thefull emission reduction potential in 2030.

4.2 Assessment of emission reduction
potentials by sector in 2030
Drawing on a detailed review of recent studies, this section
presents estimates of the global emission reduction
potentials that are technically and economically feasible in
2030. The focus is on six main sectors: agriculture, buildings,
energy, forestry, industry, and transport (sections 4.2.1
to 4.2.6). However, some promising options for emission
reductions are difficult to allocate under one sector. These
are considered in section 4.2.7. For all sectors, the maincategories of emission reductions for 2030 are identified.
The focus of the analysis is on the socio-economic potential.
This means that the potentials presented here refer to thetotal of emission reductions that can be achieved using
all technologies available in a given future year, which areeconomically attractive from a social cost perspective (IPCC,
2001). This potential is defined as all reductions that can beachieved at a marginal cost of no more than US$100/tCO2e,
at current prices, which is the cost level often assumed tobe necessary by 2030 for achieving ambitious reduction
pathways (IPCC, 2014; IEA, 2016). There are important
uncertainties related to assumptions regarding technology
deployment and implementation rates, including, for

The Emissions Gap Report 2017 – Bridging the gap - sectoral greenhouse gas emission reduction potentials in 2030

27

example, how rapidly solar photovoltaic energy production
can be scaled up, and the rate at which buildings can be
retrofitted. The underlying analysis introduces some degreeof ‘realism’ in the assessment and its respective assumptions.
In general, it is assumed that the potentials can be achieved,
if countries around the globe are willing to set policies thatenable the implementation of the available solutions.
The potentials are assessed against a current policy scenario,
which provides a reference level in 2030 against which thegreenhouse gas emission reductions could be achieved. The
current policy scenario emissions projected for 2030 amountto 61.1 GtCO2e. If emissions from peat degradation and peat
fires are excluded, projected emissions are 59.2 GtCO2e
which corresponds well with the 58.9 GtCO2e current policy
projection listed in Chapter 3, where peat-related emissions
are excluded in 3 out of the 4 underlying scenarios. Details
on the current policy scenario are included in Appendix B,
available online. The following gases are included in theanalysis: carbon dioxide (CO2), methane (CH4), nitrous oxide(N2O), perfluorocarbons (PFCs), hydrofluorocarbons (HFCs)
and sulfurhexafluoride (SF6). Black carbon is not included in
the assessment (for impacts on global warming of short-lived
climate pollutants, including black carbon, see Chapter 6).
The potentials are adjusted to be in line with the current
policy scenario used for this chapter. Emission factors are
based on the average global emission intensities for 2030
from the World Energy Outlook 2016 (IEA, 2016). For theelectricity sector the average emission intensity of fossil-fuelbased power plants is used. Finally, interactions between
mitigation measures (for example, efficient appliances
versus power sector decarbonisation) are taken into accountand handled on a case-by-case basis.

4.2.1 Emission reduction options and potential in
the agriculture sector

Studies of emission reduction potentials for the agriculture
sector vary widely. Since IPCC AR5, studies that reportmitigation potentials in the agriculture sector with carbon
prices up to US$100/tCO2 provide annual reductions of
between 0.26 to 4.6 GtCO2e (Smith et al., 2014)1. Theseestimates exclude demand-side options. However, demandside mitigation options are included in the assessment
below. While net carbon emissions from soils are negligiblein current policy trajectories, Smith et al. (2007) argue
that around 90 percent of the mitigation potential can be
attributed to carbon sequestration in soils, like cropland,grazing land and the restoration of degraded land. In addition,
non-CO2 greenhouse gases from enteric fermentation andrice cultivation can be avoided. Finally, a large share of peatrelated emissions can be avoided.
Regarding cropland management, Smith et al. (2008) cite amitigation potential of 0.74 GtCO2e in 2030, with 90 percentof the potential coming from CO2, while long-term biophysicalpotentials of 2.6 GtCO2e/year are reported (Smith, 2016).
The non-CO2 component is more or less in line with the128

Lower range figure only concerns non-CO2 GHGs and thus excludes soil
Carbon sequestration where the largest share of the potential lies.

0.04 GtCO2e from USEPA (2013), presenting a range ofoptions to reduce the emissions originating from crop
farming. The estimate is established through a combinationof no-tillage and residue management, agronomy andnutrient management, which are all three applied on
one-third of global croplands. Recently, there has been
discussion on no-tillage measures, for example in Dimassi
et al. (2014), who argue that an increase in the soil-carbon
stock may be the result of a redistribution of carbon
between soil layers. However, this would not affect thepotential from Smith et al. (2008), since the area to which
no-tillage measures are applied can be substituted withmeasures that have a more or less similar potential fromthe other cropland management categories, like agronomy
and nutrient management (Smith et al., 2008). We therefore
maintain the estimate potential of 0.74 GtCO2e in 2030 for
cropland management.
Grazing lands are typically managed less intensively thancroplands, leaving significant potential for enhanced removals
and emission reduction. Grazing land measures suggested
by Smith et al. (2008) include: adjusting grazing intensity
and allowing for more biomass growth, increasing land
productivity by reducing nutrient deficiencies, using more
precise nutrient additions resulting in savings in fertilizer, fire
management (reducing frequency and fire intensity in fireprone areas), and species introduction, for example of grass
species with higher productivity from associated nitrogen
inputs (Smith et al., 2008). Together, these measures havethe potential to sequester an additional 0.75 GtCO2 in 2030,
if measures under US$100/tCO2 are adopted.
Degraded wetlands, drained for agricultural use, contributedisproportionally to global greenhouse gas emissions fromthe land-use sectors, with approximately 25 percent of allland-use emissions originating from degraded peatlands(Bonn et al., 2014). When peatlands are drained, organic
matter in soils starts oxidizing and releases significant
volumes of carbon dioxide emissions, until drainage isreversed or all peat is lost (Bonn et al., 2014). Currently,
global greenhouse gas emissions from peatland degradationand peat fires are in the order of 2.2 GtCO2e/year and are
expected to decrease to 1.9 GtCO2e/year in 2030. Smithet al. (2008) provides 2030 mitigation potentials for the
restoration of cultivated organic (peaty) soils of 1.3 GtCO2e,
but excludes mitigation from fires. In practice, peat fires canonly be prevented when an economic value is attributed tothe peatlands, or when they are rewetted effectively (Joosten
et al., 2012). Taking the substantial cost of peat fires into
account and considering measures of up to US$100/tCO2, it
is assumed that emissions from peat fires can be reduced tozero for the majority of the peat sites in the world (World
Bank, 2016; Wichtmann et al., 2016). Remaining emissions
from peat fires in the current policy scenario are 0.3 GtCO2.
Emission reductions from peatland degradation and peat
fires combined would therefore amount to 1.6 GtCO2 in 2030.
Based on a simulation of alternative rice management
scenarios using varying management techniques, USEPA(2013) estimates an emissions reduction potential of

The Emissions Gap Report 2017 – Bridging the gap - sectoral greenhouse gas emission reduction potentials in 2030

0.18 GtCO2e in 2030, a reduction of nearly 25 percent
compared to emissions under the current policy scenario.
The scenarios include measures such as adjusting theflooding regime, applying no-tillage, and using various
fertilizer alternatives.
Recently, biochar has gained attention as a potential carbon
removal option in agricultural lands, mainly cropland.
Biochar is produced by heating biomass under anaerobic
conditions, and can under the right conditions enhance soil
fertility and improve soil’s water retention properties while
enhancing the soil organic carbon content. Woolf et al.
estimate that after 15 years, a reduction of about 0.2 GtCO2e
can be realized (Woolf, et al., 2010).
Although current-policy emissions from enteric fermentationand manure management make up a significant part of
total emissions in agriculture, the mitigation potential fromlivestock management is limited. Based on country-level
livestock populations from USEPA (2012), and livestock
production and market price projections from Nelson etal. (2010), a global mitigation potential at costs below
US$100/tCO2 in 2030 of 0.23 GtCO2e is estimated (8 percent
of current policy scenario emissions). The mitigation options
with the highest cost-effective potentials are waste andmanure digesters, anti-methanogens (vaccines that suppress
methane production in the rumen), intensive grazing,and improved feed conversion and propionate precursors(animal feed addition that converts more of the producedhydrogen into propionate instead of methane).
Based on a combination of intensive restoration projects on
agricultural lands (15 million hectares) and farmer-managed
natural regeneration projects2 (135 million hectares), theGlobal Commission on the Economy and Climate estimatesthat an emission reduction of 1.1 GtCO2e/year can beachieved by 2030 (GCEM, 2015). These estimates are scaled
up from case-study results in China and Niger respectively,
and an uncertainty range of 0.5 to 1.7 GtCO2e is applied.
Turning to demand-side mitigation options, efforts canbe made to lower the carbon footprint of the average
diet. Stehfest et al. (2013) model the impact of shifting
food patterns to a diet recommended by the World
Health Organization, which sets recommendations on the
consumption of animal products and fat, and compare
this impact using two different economic models: theInternational Food Policy Research Institute’s (IFPRI)International Model for Policy Analysis of Agricultural
Commodities and Trade (IMPACT) and the so-called LEITAP
model from the Global Trade Analysis Project (GTAP). Bothmodels were coupled to the integrated assessment model
IMAGE. As a result of less agricultural demand from lessland- and resource-intensive diets, total greenhouse gas
emissions decrease by 0.37 to 1.37 GtCO2e/year in 2030
(Stehfest et al., 2013).

2

Stehfest et al. (2013) also studied the effect of reducing
food waste, utilising the same methods as described in
the previous paragraph. Within the agricultural supply
chain, significant losses can be identified when factors
such as harvesting inefficiency, bad harvesting conditions,deterioration during storage, and consumer behaviour are
considered. Estimates of total losses vary considerably,
between 30 to 50 percent (Nelleman et al., 2009; Lundqvist,2009), and the effect of waste reduction is modelled at a
15 percent reduction in the amount of food needed to meetsimilar nutrition levels, which requires a 45–75 percent
reduction in the amount of wasted food. Modelled impacts
on greenhouse gas emissions are somewhat higher thanshifting dietary patterns, with IMPACT reporting 2030
potentials of 0.79 GtCO2e/year and LEITAP of 2 GtCO2e/year.
Combining the potentials of all the measures discussed leads
to an emission reduction potential of 3 GtCO2e/year in 2030
(uncertainty range 2.3 – 3.7 GtCO2e), if uncertain measures
like biochar, peat-related emission reductions, and demandside measures are excluded. These three measures add up
to an additional potential of 3.7 GtCO2e (uncertainty range
2.6 – 4.8 GtCO2e) in 2030, after correction for overlap withother measures.

4.2.2 Emission reduction options and potential in
the buildings sector

Under the current policy scenario, buildings accountfor annual energy-related greenhouse gas emissions of
12.6 GtCO2 in 2030. Of these emissions, 29 percent are direct,
mainly from space heating and hot water production, and71 percent are indirect, mainly from electric appliances andlighting. Improvements in energy efficiency is an importantemission reduction option for all energy uses. In addition,
renewable energy can play a role.
In many countries, policy measures and legislation are
already addressing the energy efficiency potential of newbuildings. Concepts like net-zero buildings, insulation, smart
glazing, and building automation are of increasing interest.
While developing new buildings with energy-efficienttechnologies is an important step in reducing emissions fromthe sector, retrofitting of existing buildings is also essential.
Based on the method used by the Climate Action Tracker
it is estimated that for new buildings between 0.68 and0.85 GtCO2/year could be avoided in 2030 (Climate Action
Tracker, 2016). This would require that all new buildings inOECD countries are near-zero energy from 2020 onwards,
and from 2020 to 2025 onwards also in non-OECD countries.
It is assumed that near-zero energy buildings have 90 percent
lower emissions than the current standard. This figure isconsistent with Blok et al. (2015) who based on an analysis ofseveral studies estimated a potential from ambitious energy
efficiency standards for new buildings of 0.7 to 1.3 GtCO2/year
in 2030. This is also consistent with C40 (2014), which reports
a reduction potential of 0.9 GtCO2/year in 2030 for heating
efficiency in new buildings.

A land restoration method using living tree stumps or roots in crop fields,
grazing pastures, woodlands or forests that have proven to have co-benefits
in combating poverty and hunger (Haglund et al., 2011).

The Emissions Gap Report 2017 – Bridging the gap - sectoral greenhouse gas emission reduction potentials in 2030

29

For the thermal retrofit of existing buildings, the estimatedemission reduction potential is 0.52 to 0.93 GtCO2/year
in 2030 using the same method as in the Climate Action
Tracker (2016). The lower range requires annual renovation
rates of 3 percent in OECD and non-OECD countries from2020 onwards, with 75 percent direct emissions reduction
per retrofit (GBPN, 2013). The higher range requires annual
renovation rates from 2020 onwards of 5 percent in OECD
countries and of 3 percent in non-OECD countries, with
90 percent direct emissions reduction per retrofit (GBPN,
2013). This emission reduction potential is consistent
with C40 (2014), which forecasts a reduction potential of
0.8 GtCO2/year for existing buildings in 2030.
According to IRENA (2016) and Wagner (2017) heat fromrenewable sources can grow by 5.4 EJ for solid, liquid andgaseous biofuels and by 2.9 EJ for solar energy comparedto the current policy scenario. This equals an emission
reduction potential of 0.39 GtCO2/year in 2030 from biomass
and 0.21 GtCO2/year for solar heat.
For electric appliances (excluding lighting) in households andthe service sector, an assessment of the emission reduction
potential is calculated based on Molenbroek et al. (2015),
leading to an estimate of 3.3 GtCO2/year in 2030. This is inline with the estimation of adopting the world’s best end-use
equipment technology by CLASP (2011). For energy efficient
lighting, a report by UN Environment (UNEP, 2014) estimatesenergy savings of 4.4 EJ, equivalent to 0.92 GtCO2/year in
2030. Molenbroek et al. (2015) reports emission reductions
from lighting of 0.67 GtCO2/year in 2030. We will use thisfigure, which is slightly lower than the older estimate in
CLASP (2011).
The total emission reduction potential for directemissions from buildings is 1.9 GtCO2/year (uncertainty
range 1.6 – 2.1 GtCO2) in 2030 after correction for overlap
between energy efficiency and renewable energy measures.
The reduction potential for indirect emissions is included in
the energy sector potential.

4.2.3 Emission reduction options and potential in
the energy sector

In the current policy scenario, energy sector emissions
amount to 21.3 GtCO2 in 2030, of which 16.3 GtCO2 comesfrom power generation (IEA, 2016, USEPA, 2012). Main
options for reducing emissions in the energy sector are windand solar energy. In addition, hydro, nuclear, carbon captureand storage and bioenergy combined with carbon captureand storage can contribute. Emission reductions from the oiland gas sector and coal mining are also discussed.
The installed global wind capacity was 487 GW by the endof 2016 (REN21, 2017). Wind energy capacity can grow to
between 2,110 and 3,064 GW in 2030 (GWEC, 2016; Teske
et al., 2015), compared to 940 GW in the current policy
scenario. This represents an emission reduction of between
2.6 and 4.1 GtCO2 in 2030. Reaching these potentials
would require an annual growth of installed capacity of30

11 to 15 percent per year. For comparison, the growth in thepast decade amounted to 21 percent per year.
Solar power capacity can reach 3,725 GW in 2030 (Teske
et al., 2015), compared to 708 GW in the current policy
scenario, which represents an emissions reduction of
3.0 GtCO2/year in 2030. The installed global solar capacity
by the end of 2016 amounted to 303 GW (REN21, 2016).
Reaching these potentials would require an annual growthof installed capacity of 14 to 20 percent per year (Teske etal., 2015). For comparison, the growth in the past decade
amounted to 48 percent per year. Creutzig et al. (2017)find that many models have consistently underestimateddeployment of solar photovoltaics. However, some newer
studies provide higher potentials. A recent analysis by
Breyer et al. (2017) estimate a potential of 7,100 – 9,100 GW.
This potential would require a growth of the installed solar
photovoltaics capacity of 26 to 29 percent per year andwould lead to avoided emissions of 5.5 to 7.2 GtCO2/year3.
For a more electrified energy system, Breyer et al. reporta potential of 12,000 GW. An Ecofys study done for Sitra,
showed that, by scaling up the solar photovoltaics energy
strategy of Germany to the whole world, the potential global
increase in solar photovoltaics could be in the range of
3,885 to 8,722 GW in 2030. This is equivalent to a potential
emission reduction of 2.49 to 6.17 GtCO2e/year in 2030
(SITRA, 2015; Afanador et al., 2015)4. Based on the large
variation of numbers presented here, and leaving out thehighest ones, we come to a potential of 3 to 6 GtCO2/year
avoided through solar photovoltaics.
Other electricity production options also have potential toreduce emissions in the energy sector in 2030. Comparedto emission levels under the current policy scenario,
biomass has a potential of 0.85 GtCO2/year and geothermal
has a potential of 0.73 GtCO2/year (Teske et al., 2015).
For hydro power and nuclear energy, the IEA (2016) in its
450 scenario indicates a potential increase of 147 GW
and 154 GW compared to the current policy scenario. The
emission reduction potentials are estimated at 0.32 and0.87 GtCO2 /year in 2030, respectively.
The total emission reduction potential for carbon capture andstorage (CCS) is estimated by IEA (2017) at 2.03 GtCO2/year
in 2030, which is slightly lower than the estimation of Mac
Dowell and Fajardy (2017) of 2.5 GtCO2, based on an earlier
IEA study. This includes a reduction of 0.8 GtCO2/year in 2030
for CO2 for enhanced oil recovery and 0.1 GtCO2/year in 2030
for carbon capture and utilisation in 2030. This reduction
potential can be allocated either to the energy sector or to
the industry sector. Based on the allocation in IEA (2016),
67 percent is allocated to the industry sector and 33 percent
to the energy sector. The amount of carbon dioxide avoided
is smaller than the amount of carbon dioxide captured,
3
4

Given the high penetration of solar photovoltaics, we use average emission
factors here instead of marginal emission factors.
According to the study, the level of uncertainty of the estimation is about
20 percent, due to data limitations at the country level. The study scales up
the solar photovoltaics case of Germany in each individual country and thenaggregates them to a global potential. In cases where country data was notavailable, the authors used regional data.

The Emissions Gap Report 2017 – Bridging the gap - sectoral greenhouse gas emission reduction potentials in 2030

because it consumes energy to operate CCS. This ratio is 70
to 90 percent (Herzog et al., 2005). Therefore, a 20 percent
discount is applied to correct for the stored CO2 that isreported. In the industrial sector, a correction of 10 percent
is applied since the CO2 in these sectors is often emitted
at higher purity. The above leads to a reduction potentialof 0.53 GtCO2/year in 2030 for the energy sector and1.22 GtCO2/year in 2030 for the industry sector5.
Bioenergy with CCS has a reduction potential of
0.31 GtCO2/year in 2030 (IEA, 2017). There is uncertainty
about whether bioenergy with CCS exceeds the costs of
US$100/tCO2. Several studies provide cost estimations
ranging from above to under the US$100/tCO2. Arasto et al.
(2014) estimate costs at US$100-200/tCO2, while McGlashan
et al. (2012) estimate the average costs for bioenergy
with CCS to be US$80-90/tCO2, and Johnsen et al. (2014)
estimates that bioenergy with CCS applied on biofuels
production in 2030 will cost €25 – 175/tCO2. Since there arestudies with estimations under and above US$100/tCO2, thepotential for bioenergy with CCS is allocated to the energy
sector category as an additional option.
This chapter does not include the shift from coal to gas,
since natural gas declines in the World Energy Outlook
450 scenario compared to the current policy scenario (IEA,
2016). However, within certain regions the shift from coal
to gas can play a role in the reduction of emissions from theenergy sector. In the World Energy Outlook 450 scenario,
only a small increase is visible in India (0.3 EJ) and South
Africa (0.04 EJ) (IEA, 2016). Given the small size, this is notincluded in the potentials.
The total emission reduction potential in the power sector
is large. It makes up about 70 percent of the power sector
emissions in the current policy scenario, without considering
overlaps. Adding electricity savings from the buildings andindustry sector implies that power sector emissions in 2030
could be reduced by more than 100 percent comparedwith the current policy scenario, which is obviously notpossible unless bioenergy with CCS is applied on a large
scale. However, there will be increasing interaction between
the different emission reduction options long before the
100 percent is reached, making the total potential smaller
than the sum of the individual options. In the assessment,
it is assumed that total emissions in the power sector are
reduced by a maximum of 57 to 65 percent, which are thelargest percentages found in the literature (Deng et al.,2012; Teske et al., 2015)6. This will lead to total emission
reductions of 9.3 to 10.6 GtCO2/year in 2030, which indicatesthe ‘basic’ potential. However, given the large potentials forthe individual categories, power sector decarbonization
may develop faster (see, for example, Breyer et al., 2017).
Implementing large shares of intermittent renewablesources would require the use of flexibility options such as
56Compared with Chapter 7, this chapter considers different groupings ofemission reduction options, timeframes and cost levels. For this reason,
estimates are not directly comparable across chapters.
For comparison, the recent Energy Technology Perspective reports (IEA,
2016; IEA, 2017), give reductions of 35 percent and 48 percent compared tothe current policy scenario.

demand response, flexibility of supply, network optimizationand expansion, and storage to match supply and demand.
For an overview of flexibility options, see Papaefthymiou etal. (2014).
Outside the power sector, methane emissions from the
distribution of gas and the production and transmissionof oil and gas can be reduced by 1.78 GtCO2/year in 2030
(Klimont and Höglund-Isaksson, 2017). This is 75 percentof the current policy scenario emissions from the oil andgas industry. These reductions can mainly be achieved by
implementing measures for the recovery and utilization ofvented gas and the reduction of leakages.
Methane emissions from coal mining can be reduced by
0.41 GtCO2e/year in 2030, which is a reduction of 56 percent
compared to the current policy scenario (Klimont and
Höglund-Isaksson, 2017). Measures implemented in this
scenario include pre-mining degasification measures andthe installation of ventilation air oxidizers.
Combining the potentials of all the electricityrelated measures discussed, also in buildings and industry,leads to a potential of 10.0 GtCO2e (uncertainty range 9.3–
10.6 GtCO2e/year) in 2030. Bioenergy with CCS could provide
an additional potential of 0.3 GtCO2e in 2030 (uncertainty
range 0.2 – 0.4 GtCO2e). Emission reductions from the oil andgas sector and coal mining are 2.2 GtCO2e/year (uncertainty
range 1.7 – 2.6 GtCO2e).

4.2.4 Emission reduction options and potential in
the forestry sector

Since IPCC AR5, studies of mitigation potentials in the forestry
sector with carbon prices up to US$100/tCO2 report values
between 0.2—13.8 GtCO2e/year, largely depending on thetypes of models used (Smith et al., 2014). There are twomain options for reducing emissions in this sector: halting
deforestation, and restoration of degraded forest land.
Emission reduction potentials from halting deforestation
come with great uncertainty. These uncertainties relate, forexample, to the degree to which decreased deforestation
leads to lowered degradation and associated carbon
emissions, but also depend on the baseline used (GCEM,
2015). We assume a global potential in 2030 of 3 GtCO2e(based on Clarke et al., 2014). This central estimate assumes
that the current policy scenario emissions remain stablefrom current levels.
Global commitments on restoration of degraded forests,
such as commitments to the Bonn Challenge and the New
York Declaration on Forests, aim to bring a total of 350 million
hectares of degraded and deforested land under restoration(Messinger and DeWitt, 2015). Reaching this target by
2030 would yield emission reductions in the order of 1.6–
3.4 GtCO2/year, with a central estimate of 2.3 GtCO2/year
in 2030 (Verdone et al., 2015).

The Emissions Gap Report 2017 – Bridging the gap - sectoral greenhouse gas emission reduction potentials in 2030

31

Combining the potentials of the measures discussed
leads to a total contribution from the forestry sector of
5.3 GtCO2e/year (with an uncertainty range of 4.1 – 6.5 GtCO2e).

4.2.5 Emission reduction options and potential in
the industry sector

Industry sector greenhouse gas emissions are 19.3 GtCO2e
in 2030 under the current policy scenario. The two main
sources of industrial greenhouse gas emissions are direct
and indirect (via electricity consumption) use of fossil fuels.
There are also smaller sources of greenhouse gas emissions,
including ‘non-energy’ use of fossil fuels (for example, fossil
fuels as feedstock for chemical processes) and emissions
from industrial processes (for example, carbonizationin the cement process and several sources of non-CO2
greenhouse gases). By applying a broad set of mitigation
options (Fischedick, 2014), the industry sector can achieve
substantial emission reductions by 2030, mainly fromenergy efficiency, non-CO2 measures and CCS, with a smaller
contribution from renewable heat.
For energy efficiency, the emission reduction potential
for 2030 is estimated at 4.1 GtCO2/year compared to thecurrent policy scenario. This estimate is based on data from
ClimateWorks Foundation and the World Bank (Akbar et al.,2014), scaled up from six major regions to the entire world
and correcting for measures other than energy efficiency.
The emission reduction implies a nearly 30 percent reduction
compared to the current policy scenario. This is compatible
with the estimate by Worrell and Carreon (2017) (seealso Saygin et al. (2011), who estimated a static potential of
27 ± 9 percent). It should be noted that the potentials
vary by sector and by region. For example, it is estimatedat 9 - 30 percent for iron and steel, 4-7 percent for primaryaluminium, for cement the estimate is 20-25 percent, forpetrochemicals 23-7 percent, and for ammonia production
11-25 percent (Worrell and Carreon, 2017). Based on theshare in current policy emissions, a 2.2 GtCO2/year emission
reduction is allocated to direct emissions and a 1.9 GtCO2/year
is allocated to indirect emissions.
Renewable energy use in the form of solid, liquid and gaseous
biofuels, solar thermal energy and geothermal can generate
9.7 EJ (IRENA 2016), which is an additional 7.8 EJ comparedto the current policy scenario. This will reduce emissions by
0.5 GtCO2/year in 2030.
Carbon capture and storage in the manufacturing industry
is associated with an emission reduction potential of
1.22 GtCO2/year in 2030 (see the discussion of the option in
the section on the energy sector).
For non-CO2 greenhouse gases, the largest reduction isfrom HFCs, which can be reduced by 1.5 GtCO2e/year in
2030 (Purohit and Höglund-Isaksson, 2017)7. USEPA (2013)
estimates an additional reduction potential for non-CO2732Note that these estimates do not consider the emission reduction impacts
associated with implementing the Kigali Amendment to the Montreal
Protocol. Taking these impacts into account would lower the estimate (seeChapters 3 and 6).

greenhouse gas emissions of 0.2 GtCO2e/year in 2030, where
0.12 GtCO2e comes from nitric and adipic acid production
and the rest from perfluorocarbons from primary aluminium
production and sulphur hexafluoride from electric powersystems and magnesium production.
Based on the above, the emission reduction potential forindustry for direct emissions is 5.4 GtCO2e/year in 2030
(uncertainty range 4.2 – 6.6 GtCO2e). No correction foroverlap is needed, as many industrial plants are so largethat energy efficiency measures can be combined with CCS
or renewable energy. The reduction potential of indirectemissions is already accounted for in the potential for theenergy supply sector.

4.2.6 Emission reduction options and potential in
the transport sector

In the current policy scenario, total emissions for transport
are 9.7 GtCO2 in 2030, of which 9.42 GtCO2 are directemissions and 0.28 GtCO2 indirect emissions for electricity
use. The emission reduction potential differs per mode oftransport, but is most significant for light-duty vehicles andheavy-duty vehicles, with other contributions coming fromshipping, aviation and biofuels.
In the automobile sector, fuel efficiency measures could
potentially reduce emissions by 0.88 GtCO2/year (heavy
duty vehicles) and by 2.0 GtCO2/year (light duty vehicles)by 2030 (ICCT, 2012). These numbers include modal shifts.
A shift to more electric vehicles is also included. ICCT (2012)
assumes that electric-drive vehicles will form a small, but
not insignificant, share (up to 9 percent) of new-vehicle sales
by 2030. This is in line with the estimations of IRENA (2016)(10 percent) and Bloomberg New Energy Finance (2017)(7 percent). Note that substantial emission reductions due
to fuel economy standards for passenger cars are alreadyincluded in the current policy scenario.
Aviation can reduce emissions with up to 0.32 (ICCT2012) or up to 0.42 (ICAO 2013) GtCO2/year in 2030 byusing alternative fuels, improved infrastructure use andtechnical improvements.
Several studies indicate an emission reduction for shipping(Alvik et al., 2010; Faber et al., 2011; Eide et al., 2011;
Hoffmann et al., 2012) ranging from 0.39 to 0.99 GtCO2. The
studies contain several measures focused on fuel efficiency.
The most recent study, from Bouman et al. (2017), reports
an emission reduction potential of 0.70 GtCO2/year in 2030.
The numbers for aviation and shipping are in the same orderas those in the study from New Climate Economy (GCEM,
2015), which shows a reduction potential between 0.60 and
0.90 GtCO2 per year.
Biofuels is another measure that is relevant for the transport
sector. ICCT (2012) provides no potential for biofuels in 2030
due to the high uncertainty. IRENA (2016) does provide anestimate for biofuels to cover 10 percent of the sector’s total
fuel use in 2030. Taking into account that greenhouse gas

The Emissions Gap Report 2017 – Bridging the gap - sectoral greenhouse gas emission reduction potentials in 2030

emissions from biofuels are 70 percent to 90 percent lower
than those of conventional fuels (BLE, 2016; Ecofys, 2017
forthcoming) an emission reduction potential of 0.63 to
0.81 GtCO2e/year in 2030 can be calculated.
Based on the above, the total emission reduction potential
for the transport sector is 4.7 GtCO2/year in 2030 (with anuncertainty of 4.1 – 5.3 GtCO2). No overlap correction isneeded, as biofuels can be used as drop-in fuels.

4.2.7 Other promising emission reduction options
and potential

Some options for emission reduction are difficult to allocate
to one of the sectors assessed in the previous sections. Thismay be because it is still unknown in which sector it can best
be implemented, or because the option can be applied tomultiple sectors. Some promising mitigation measures aredescribed below.
Methane constitutes some 90 percent of greenhouse gas
emissions from the waste sector. Landfill gas recovery andutilization is one option for reducing methane emissions.
USEPA (2013) estimates that landfill gas recovery can reduce
emissions by 0.4 GtCO2e/year in 2030, which represents
42 percent of the emissions in the current policy scenario.
Enhanced weathering measures aim to draw carbon fromthe atmosphere via, among others, the natural chemical
weathering process of silicates (other processes elaborated
in Chapter 7). Preliminary global estimates using wastematerial only, for example from cement and iron and steel
manufacturing, arrive at 0.73—1.22 GtCO2/year in 2030,
excluding stockpiled waste (Renforth et al., 2012).

There are other measures that are not included in thischapter. In April 2017 the book, Drawdown, was publishedcontaining the 100 most substantive solutions to reverse
global warming (Hawken, 2017). Comparing the top 20 of
Drawdown with this analysis, two high-ranked measures are
missing in this chapter: educating girls and family planning.
It is expected that the quantitative impact of such measures
is mostly beyond 2030.

4.3 Can the gap be bridged: total emission
reduction potential in 2030
An overview of the estimated total emission reduction
potentials in 2030 assessed in the previous sections isprovided in table 4.1. The table shows that estimates
based on proven technologies and relatively precautionary
assumptions regarding potentials in 2030 (the ‘basic’potential in table 4.1), leads to a total emission reduction
potential in 2030 of 33 GtCO2e/year (uncertainty 30 –36 GtCO2e). The basic emission reduction potential in 2030
is also shown in figure 4.1. If, in addition, areas where
estimates of potentials are relatively new, and the feasibilityof realizing these in 2030 is more uncertain, are considered(the ‘additional’ potential in table 4.1), the potential is
38 GtCO2e/year (uncertainty range 35 – 41 GtCO2e).
Importantly, even if only the basic emission reduction
potential for 2030 is considered, the estimated total
potential listed here is sufficient to bridge the emissions
gap in 2030 for 2°C (>66 percent chance) and 1.5°C (50 to66 percent chance). It exceeds the estimated difference in2030 between emissions under the current policy scenario
and the emission levels consistent with a likely chance ofstaying below 2°C and a medium chance of staying below

Figure 4.1: Total emission reduction basic potentials compared to the current policy scenario in 2030.

Annual Global Total Greenhouse Gas Emissions (GtCO₂e)

Sectoral emission reducon potenals in 2030

70

EnergysectorIndustry60

Forestry
Emission
reduc onpoten al(2030)- basic
opons50

Transport

Agriculture

Current
policy scenario

Buildings

Other
40

2015

2020

2025

2030

2035

0

2

4

6

8

10

The Emissions Gap Report 2017 – Bridging the gap - sectoral greenhouse gas emission reduction potentials in 2030

1233

1.5°C of about 17 and 22.5 GtCO2e respectively, as indicatedin the introduction to this chapter.
An important question is what the efforts and costs ofrealizing these emission reductions are. Although it is beyond
the scope of the current chapter to answer this question in
full, a number of observations can be made. It is remarkablethat a large part of the potential consists of just six categories,that is, solar and wind energy, efficient appliances, efficientpassenger cars, afforestation and stopping deforestation.
These six categories sum up a potential of 18.5 GtCO2e in
2030 (range: 15-22 GtCO2e), making up more than half of thebasic potential. Equally important, all these measures can berealized at modest cost, and are predominantly achievablethrough proven policies:• Solar photovoltaics and wind energy. Many countries
around the world have targets for renewable energy andhave policies in place to stimulate its adoption. The mostdominant policy instruments are feed-in tariffs or feed-in
premiums, which have been implemented in 75 countries
and 29 states or provinces in the world, providing
long-term power purchase agreements with a specified
price or premium price per kWh for a renewable energy
technology (REN21, 2017). An instrument with increasing
popularity is competitive bidding or auctioning, especiallyfor large scale developments, where the renewableenergy market is mature and governments have alreadyachieved a degree of success with renewable installation
through feed-in-tariffs (REN21, 2017). Costs of electricity
from solar and wind electricity have already declined
to levels comparable with fossil-fuel based electricity(Lazard, 2016), and auctions have accelerated this trend(IRENA, 2017). Continuation of feed-in policies and/or a shift to auctions are a straightforward and cheap
approach to rapid decarbonization of the power sector.
• Energy efficient appliances and cars. A combination oflabelling and minimum energy performance standards
are the dominant policies to stimulate the uptake ofefficient appliances. Over 60 countries have adopted orpledged to adopt policies to shift to more energy-efficient
lighting (UNEP, 2014). Under the United for Efficiency(U4E) public-private-partnership, UN Environment
is supporting developing countries and emerging
economies to move their markets to energy-efficient
appliances and equipment (UNEP, 2017). In terms of
performance standards for cars, several countries have
opted to implement fuel economy standards in miles per

34

gallon or CO2 emission standards in gCO2 per km; thesestandards exist in Brazil, the EU, India, Japan, Mexicoand the USA (ICCT, 2017). Typically, energy efficiency
standards are implemented in such a way that life-cycle
costs are minimized, hence leading to net negative costs
for the consumer. Similar policies are in place in many
countries for new building construction (UNEP, 2016).
Further continuation of these policies, scaling themup to more countries while raising ambitions is a way
forward to limit the growth of energy use and hence
reducing emissions.
• Stopping deforestation and restoration of degraded
forests. There are several examples of policies
successfully stopping deforestation, the most largescale being the Brazilian ‘Action Plan for Prevention andControl of Deforestation in the Amazon’, consisting of(1) territorial and land-use planning, (2) environmental
control and monitoring, and (3) fostering sustainableproduction activities. The programme led to a reductionof the rate of deforestation by more than 80 percent.
Costs are found to be US$13/tCO2e on average (Afanador
et al., 2015; Sitra, 2015). For reforestation of degraded
forests, the scale of operations is not of that size, but
promising examples are available for China (Chen et al.,2016), Costa Rica (Afanador et. al 2015), and the Republicof Korea (Kim and Zsuffa, 1994). Costs are comparablewith the costs of stopping deforestation.
These are examples of a few of the options that can be
implemented at relatively low cost and based on significant
existing experience. Together they represent more thanhalf of the basic potential identified. Previous Emissions
Gap Reports provide many more examples of scaling up
of existing policies and programmes, as do other studies,including the study Green to Scale (Sitra, 2015).
Although the available studies prevent an explicit, economic
assessment of all emission reduction options, there is arelatively high degree of confidence that all options included
in table 4.1 have costs below US$100/tCO2e avoided. In
many cases, this is explicit in the source documents. For
some, however, it is not clear whether the costs will be
below US$100/tCO2e. For example, some electricity sources
may show costs above US$100/tCO2e, as there are large
variations in costs (Lazard, 2016). However, given that there
are abundant options in the electricity sector, leaving out
these options will not affect the total potential.

The Emissions Gap Report 2017 – Bridging the gap - sectoral greenhouse gas emission reduction potentials in 2030

Table 4.1: Overview of emission reduction potentials.
SectorAgriculture

Category
Cropland management

0.74

Rice management

0.18

Livestock management

0.23

Grazing land management

0.75

Restoration of degradedagricultural land

0.5 - 1.7

Peatland degradation andpeat fires

1.6

Biochar

Buildings

Energy sector

Forestry

Industry

Transport

Other

Emission reduction potential
in 2030 (GtCO2e)

0.2

Shifting dietary patterns

0.37 - 1.37

Decreasing food loss andwaste

0.97 - 2

New buildings

0.68 - 0.85

Existing buildings

0.52 - 0.93

Renewable heat - bio

0.39

Renewable heat - solar

0.21Lighting

0.67

Appliances

3.3

Solar energy

3-6Wind energy

2.6 - 4.1

Hydropower

0.32

Nuclear energy

0.87

Bioenergy

0.85

Geothermal

0.73

CCS

0.53

Bioenergy with CCS

0.31

Methane from coal

0.41

Methane from oil and gas

1.78

Restoration of degraded forest

1.6 - 3.4

Reducing deforestation

3

Energy efficiency - indirect

1.9

Energy efficiency - direct

2.2

Renewable heat

0.5

Non-CO2 greenhouse gases

1.5

CCS

1.22

Heavy Duty Vehicles potential(efficiency, mode shift)

0.88Light Duty Vehicles potential(efficiency, mode shift, electricvehicles)2.0

Shipping efficiency

0.7

Aviation efficiency

0.32 - 0.42

Biofuels

0.63 - 0.81

Landfill gas recovery

0.4

Enhanced weathering
measures0.73 - 1.22

Category

Sectoral aggregate potential(GtCO2e)Basic

3 (2.3 - 3.7)

Additional

3.7 (2.6 - 4.8)

Basic

1.9 (1.6 - 2.1)

Basic (indirect emissions)See energy sector
potential

Basic

10 .0 (9.3 – 10.6)

Additional

0.3 (0.2 - 0.4)

Basic

2.2 (1.7 - 2.6)

Basic
Basic (indirect emissions)

5.3 (4.1 - 6.5)
See energy sector
potential

Basic

5.4 (4.2 - 6.6)

Basic

4.7 (4.1 - 5.3)

Basic

0.4 (0.3 - 0.5)

Additional

1 (0.7 - 1.2)

Total basic emission reduction potential

33 (30 - 36)

Total emissions reduction potential including
additional measures

38 (35 - 41)

Note: Although for many emission reduction categories a single point estimate is given, there are always uncertainties, assumed to be ±25 percent. For the categories
peatland degradation and peat fires, biochar and energy efficiency, the potential in 2030 is more uncertain. Therefore, a higher uncertainty range of 50 percent isapplied to these categories. In the final column, the categories are aggregated to the sectoral level. The numbers in the third column are not corrected for overlap
between measures. The numbers in the final column are corrected for overlap, and this is also reflected in the total potential. Therefore, the total is smaller than thesum of the individual potentials in the third column. The aggregate potentials for indirect emission reductions in buildings and industry are reflected in the electricity
sector potential.

The Emissions Gap Report 2017 – Bridging the gap - sectoral greenhouse gas emission reduction potentials in 2030

35

4.4 Comparison with results from Integrated
Assessment Models
In this section, the results of the bottom-up sector-by-sector
assessment is compared with the sectoral emissions asreported by a range of state-of-the-art integrated assessment
models. This is relevant because integrated assessment
models provide information on how a given climate target
can be achieved in a “least-cost” way through a full costcomparison across all sectors, and by taking account of theinteractions between the different reduction options and theinteractions with the wider economy. Since the scenarios bydefinition stay within the 2°C or 1.5°C target, they bridge theemissions gap in 2030 and the difference between emissions
levels associated with the current policy scenario and theemissions in line with the 2°C and 1.5°C target. Hence, thepackage of mitigation measures identified in the scenarios
can be viewed as successful examples of how to close thegap. Moreover, the scenarios of the integrated assessment
models also provide the foundation for the gap analysis inother chapters of the Emissions Gap Report. Details regarding
the baseline scenarios for the integrated assessment models
used are provided in Appendix B, available online.
Figure 4.2 compares the emission reduction potentials of
the sector-by-sector technology-based analysis with the
mitigation activities in the integrated assessment model set
for the 2°C scenario, noting that the integrated assessment
models assume a slightly higher total 2030 emission level
as described in Appendix B, available online. The average
total mitigation in 2030 in the integrated assessment model
scenarios is 23 GtCO2e, with a full range of 5 - 42 GtCO2e. The
wide range across the integrated assessment models is causedby different reduction strategies over time and different
baseline assumptions. Overall, the integrated assessment
model range of reductions are lower than the total emission
reduction potential found in the sector-by-sector analysis,
which supports the technical feasibility of the integrated
assessment model scenarios. The sectoral breakdown
shows that in the electricity sector, emission reductions are

Figure 4.2: Comparison of mitigation in the integrated assessment models under a 2°C pathway with the emission reduction potentials
found in the sector-by-sector analysis.

Avoided Emissions (GtCO₂e/yr)
0Category

CO₂

2

4

6

8

10

12

Electricity produconIndustry
Transport
Buildings
Other
Deforestaon/landuse change

N₂O and
CH₄

Emissions from staonary
and mobile combuson
Energy supply emissions
Agriculture

Burning of agricultural residues, savanna
burning and open burning of forest clearing
Waste
Other

HFCs

Substutes for OzoneDepleng SubstancesBoom-Up Sector by Sector

2 °C IAM

2 °C IMAGE

1.5 °C IMAGE

Note: The integrated assessment model results show the results of six models, in terms of the mean and the range (15-85th range, thus each time exlcuding the twomost extreme models). The red dots indicate the reduction in the integrated assessment model IMAGE for both 2 °C and 1.5 °C (in some cases the IMAGE numbers areoutside the indicated range of IAM model results.)

36

The Emissions Gap Report 2017 – Bridging the gap - sectoral greenhouse gas emission reduction potentials in 2030

comparable, although the integrated assessment models
show a very wide range for this sector. This is also true for theunderlying contribution of increased use of renewable andnuclear power, fossil fuel and CCS, fuel switch and bioenergy
and CCS. Typically, however, integrated assessment models
show a relatively high contribution of bio-energy and fossil
fuel CCS technology, certainly also for the long-term. Thishighlights the importance of research and developmentwith respect to negative emission options, even though
their role might still be limited in the short-term. Chapter 7
further discusses this. For the various end-use sectors, theintegrated assessment models show considerably lower
emission reductions than the sector-by-sector estimates.
In the literature, this is explained by 1) the relatively large
implementation barriers complicating emission reductionsin these sectors, and 2) the possible predominant focus
of integrated assessment models on energy supply. While
the sectoral, bottom up assessment finds energy efficiency
improvements much more important than fuel switching in
the end-use sections, integrated assessment models results
show both measures to be equally important. The emission
reduction potential of biological carbon removal by meansof reforestation and increasing carbon in agricultural soil isalso less in integrated assessment models than in the sectorby-sector assessment. It should be noted, however, that ingeneral integrated assessment models do not consider the
option of increasing carbon in agricultural soils. Finally, for
non-CO2 greenhouse gases, a similar picture emerges: theemission reduction in the integrated assessment model 2°C
scenarios is smaller than the total potential of the sector-bysector analysis.
It is not possible to compare the sector-by-sector analysis
with the integrated assessment models for 1.5°C, because
most of these integrated assessment model scenarios are
yet to be published (see Chapter 3). However, focusing on
the results of one integrated assessment model, the IMAGE
model, figure 4.2 shows the IMAGE results for both 2°C and
1.5°C. The figure shows that moving to the more ambitious
target requires scaling up emission reductions in several
sectors, including the electricity sector and most enduse sectors.
In conclusion, the emission reductions of the integrated
assessment model 2°C scenarios as well as the IMAGE 1.5°C
are typically within the overall sector specific potentialof the bottom up assessment. The electricity sector is an
exception – but here it should be noted that the current
policy emissions in the bottom up assessment were lower
than for the integrated assessment models. The analysis alsosuggests that predominantly further emission reductionsin the integrated assessment model scenarios could beachieved via energy efficiency and biological carbon
removal options.

4.5 Conclusions
The assessment presented confirms that the total emission
reduction potential is more than sufficient to bridge theemissions gap in 2030, with measures that are technicallyand economically feasible, and at a marginal cost of no
more than US$100/tCO2e. The total potential exceeds
the difference between the current policy trajectory in2030 and the emission levels consistent with a 2°C (>66
percent chance) and a 1.5°C (50 to 66 percent chance)
temperature target.
All sectors present substantial emission reduction potentials
that add up to a total of 33 GtCO2e/year in 2030 (range:
30 – 36). This does not include emission reduction potentials
of fairly new measures (such as direct capture of atmosphericCO2, decreasing food loss and waste, and biochar) because it
is uncertain whether these emission reductions potentials
could be realized by 2030.
Notably, six specific categories of measures have thepotential to reduce emissions between 15 to 22 GtCO2e/year
in 2030, which is more than half of the total emission
reduction potential. This is comparable to the estimateddifference in 2030 between the current policy trajectory
and the emissions consistent with the 2°C and 1.5°C target.
These six categories include solar and wind energy, efficient
appliances, efficient passenger cars, afforestation andstopping deforestation. All these measures can be realized
at modest costs, and countries around the world havealready established policies to implement many of them. By
scaling up these measures that are relatively cheap and easy
to implement, the world could collectively get on track tobridge the emissions gap by 2030.
To realize the full emission reduction potential, countries needto implement ambitious policies immediately, to enable andaccelerate the implementation of the full socio-economic
potential of available measures and technologies. Most of
the studies used for the bottom-up assessment of sectoral
emission reduction potentials assume that implementationof measures start immediately, underscoring the urgency of
pre-2020 mitigation action (see also Chapter 2).

The Emissions Gap Report 2017 – Bridging the gap - sectoral greenhouse gas emission reduction potentials in 2030

37

Chapter 5

Bridging the gap – Phasing out coal
Lead authors: Amit Garg (Indian Institute of Management Ahmedabad), Jan Christoph Steckel (Mercator Research Institute on Global Commonsand Climate Change)
Contributing authors: Jesse Burton (University of Cape Town), Julio Friedmann (Energy Futures Initiative), Frank Jotzo (Australian National
University), Gunnar Luderer (Potsdam Institute for Climate Impact Research), Pao-Yu Oei (German Institute for Economic Research /Berlin Technical University), Michiel Schaeffer (Climate Analytics), Samantha Smith (Just Transition Centre), Fabby Tumiwa (Institute for
Essential Services Reform), Adrien Vogt-Schilb (Inter-American Development Bank), Paola Yanguas-Parra (Climate Analytics), Xianli Zhu(UNEP DTU Partnership)

5.1 Introduction
If the temperature increase is to be kept well below
2°C by 2100, the global economy must undergo rapid
decarbonization. The power sector holds a critical role, given
the widely available and relatively cheap decarbonization
options in the sector (Kriegler et al. 2014; Luderer et al.
2017; Sachs et al. 2014; Williams et al. 2012). In most of
the scenarios consistent with limiting warming to below 2°C
in the Intergovernmental Panel on Climate Change’s (IPPC)
Fifth Assessment Report (Clarke et al. 2014), unabated coalfired power not equipped with carbon dioxide capture andstorage (CCS)1 declines rapidly, and is almost completely
phased out by mid-century2 (Audoly, Vogt-Schilb, andGuivarch 2014; Kriegler et al. 2014; Luderer et al. 2017;
Rogelj et al. 2015; Williams et al. 2012) (Chapter 3). In the
scenarios consistent with a 1.5°C increase in global mean
temperature by 2100, the decline of the power sector’s
carbon emissions has to be even faster (Rogelj et al. 2015),
leading to a faster phase-out of power production fromcoal3. The longer the world continues to use coal, the greater
the need for negative emissions technologies in the second
half of the century (Luderer et al. 2013; Riahi et al. 2015)4.
There are currently an estimated 6,683 coal-fired power
plants in operation worldwide, with a combined installedcapacity of 1,964 GW. Emissions from coal alone were
responsible for a major share of past emissions. If run until
the end of their lifetime, and not retrofitted with CCS5,
the stock of operating power plants would emit around
190 GtCO2. Furthermore, they would use a large share of theavailable carbon budget for internationally agreed climate
targets figure 5.1 and table 5.1).
Coal-based power generation is the single most importantcause of carbon lock-in (Bertram, Johnson, et al. 2015;
Davis, Caldeira, and Matthews 2010)6. Without additional
policy interventions, the number of coal-fired power plants
would likely continue to increase. In early 2017, across
3

1

2

38

Carbon capture, (transport) and storage (CCS) consists of three stages,
beginning with capturing CO2 from large stationary emitters, such as coal
power plants or industrial facilities, then transporting it to an undergroundstorage site, before compressing it in suitable geological formations.
Scenarios by the IPCC (2014) projected large-scale CCS utilization, particularly
given its potential to provide negative emissions when used in combination
with biomass plants (see also Chapter 6).
Coal is the most carbon-intensive fossil fuel, responsible for about
46 percent of global carbon emissions from fossil fuels (Olivier et al. 2016). It
is commonly categorized as steam coal (5,811 Mt; 75 percent market share),metallurgical or coking coal (1,090 Mt; 15 percent market share) and lignite(807 Mt; 10 percent market share), based on its material properties and end
use (IEA/OECD 2016). This chapter and most policies focus on steam coal andlignite, which are primarily used for generating electricity.

4
5

6

The Emissions Gap Report 2017 – Bridging the gap – Phasing out coal

Without large-scale deployment of CCS, achieving climate targets would also
involve a large transformation of the upstream coal sector (Meinshausen
et al. 2009; Bauer et al. 2016). Between 82 percent and 88 percent
of current coal reserves are considered ‘unburnable’, compared with
33 percent–35 percent of oil and 49 percent–52 percent of gas reserves(McGlade and Ekins 2015, see also box 5.1).
See also Chapter 7 of this report for a detailed discussion.
Today, there are 17 large-scale CCS projects operating worldwide, mostly
in combination with enhanced-oil recovery (EOR), which inject a total of
22 MtCO2/y. Two of the 17 large-scale CCS projects operating worldwide arecoal power retrofits: Boundary Dam in Saskatchewan and Petra Nova in Texas.
Each of these projects captures and stores >1M tonnes/year, and effectively
decarbonizes a unit by 90 percent. The Petra Nova project costs (‘all in’) areroughly US$100/tonne, with analysts anticipating second and fourth project
costs for the same technology at US$80/tonne and US$60/tonne respectively.
Although some countries have very little CO2 storage resources, overall there
does not appear to be a shortage of such resources (GCCSI 2017).
Coal power plants have a long economic lifetime, often over forty years,
meaning that every new coal-fired power commits a large amount of CO2
emissions if run over its economic lifetime (Davis and Socolow 2014).

the globe there were an additional 273 GW of coal-fired
capacity in construction, and 570 GW in pre-construction(Shearer et al. 2017). Ten countries make up approximately
85 percent of the entire coal pipeline, with 700 GW being
built or planned in China, India, Turkey, Indonesia, Vietnam,
Japan, Egypt, Bangladesh, Pakistan and the Republic ofKorea alone (Shearer et al. 2017). While a large amount ofplanned power plants were shelved or cancelled in 2016 —particularly in China and India (with reductions of 54 percent
and 52 percent, respectively, compared to 20157) — othercountries, such as Indonesia, Japan, Egypt, Bangladesh
and Pakistan, announced new investments in 2016 (withincreases of 40, 60, 784, 40 and 100 percent, respectively,
compared to 2015) (Edenhofer et al. 2017). If run until theend of their assumed lifetime of 40 years, the plants currently
under construction (273 GW) and those planned (570 GW)
would lead to emissions of approximately 150 GtCO2, of
which 50 GtCO2 can be attributed to those currently underconstruction (figure 5.1 and table 5.1).

To meet international emissions targets, further lock-ins
should be avoided (box 5.1). Nonetheless, this would
not suffice, as existing stocks and plants currently underconstruction would still commit approximately 240 GtCO2
over their lifetime. Closing the emissions gap requires thatthese plants run with lower capacity rates, and are phasedout before the end of their lifetime, and/or retrofitted with
CCS facilities.

Figure 5.1: Committed emissions to the atmosphere from coal-fired power plants (existing, under construction and planned) and othereconomic sectors, by region.

Commied emissions (GtCO₂)
1,400

1,200

Carbon budget

2 °C

1,000

(>66% chance
range)

800

Carbon budget

600

1.5 °C( >50% chance
range)

400

200

Emitted from2011-2015

0

All Sectors
without Coal(2010)
Non-OECD
Asia

Exisng

Middle East
and Africa

Under Construcon
CoalLan America
and Caribbean

PlannedEconomies
in TransionOECD 1990

Uncertainty

Note:• Regional breakdowns are consistent with Representative Concentration Pathways, as defined in IPCC (2014).
• Uncertainty ranges indicate differing lifetimes (between 30 years and 50 years), and coal-fired power plants’ capacity factors (between 37 percent and 80 percent as
per IEA (2016).
• Emission factors are specific to the power plants.
• For the calculation of “all sectors”, medium lifetimes of infrastructure are as reported by Davis and Socolow (2014).
Source: Figure based on Edenhofer et al. (2017). Data from: Davis and Socolow (2014) and Shearer et al. (2017).

7

The slowdown of China and India is significant because together the twocountries accounted for 86 percent of all new capacity between 2006 and2016. Both countries face a marked slowdown in the anticipated domestic
demand for new coal power, due to overcapacity in China and a downturn insolar prices in India (Shearer et al. 2017, see also section 5.3).

The Emissions Gap Report 2017 – Bridging the gap – Phasing out coal39

Table 5.1: Committed carbon dioxide emissions for coal-fired power plants, in GtCO2, by status and region
Scenario

Announced

Pre-permitted

Permitted

Construction

Operating

Total

East Asia

12.19

12.34

6.30

30.41

126.41

187.66South Asia

6.21

9.87

5.89

8.28

27.42

57.67

South-East Asia

7.00

5.78

2.63

5.21

8.95

29.60

European Union

0.60

0.66

0.17

1.14

7.22

9.79

Non-EU Europe

4.86

5.30

1.70

0.44

3.56

15.87

Middle East and Africa

5.83

1.16

1.94

2.14

2.46

13.52

Latin America

0.61

0.17

0.28

0.37

1.74

3.18

Eurasia

1.65

0.00

0.00

0.20

2.69

4.54

North America

0.00

0.00

0.15

0.00

8.85

9.01

Australia and New Zealand

0.00

0.00

0.00

0.00

1.14

1.14

Total

38.97

35.28

19.08

48.20

190.44331.97Note:• The figures take into account the remaining lifetimes of existing plants.
• A lifetime of 40 years is assumed for newly constructed power plants.
• European Union data refers to the current 28 Member States. North America refers to both Canada and the United States.
• It is assumed that not all permitted, pre-permitted and announced power plants come online.
Source: Edenhofer et al. (2017) and Shearer et al. (2017).

Phasing out coal can have important societal benefits, going
beyond climate change mitigation. Key among these are
improved air quality, especially reduced particulate matterand reduced emissions of sulphur dioxide and nitrogenoxides (IEA/OECD 2016 and West et al. 2013) (Chapter 6),
and increased water availability (Zhou et al. 2016). However,a transition away from coal can be expected to be politicallydifficult (Vogt-Schilb and Hallegatte 2017). Meanwhile, cobenefits and rapidly decreasing costs of alternatives8 might
not suffice to achieve a transformation of the scale, and at
the speed, that is required to meet international climate
targets. Investment into coal can also be attractive, as it can
support other societal goals, such as cheap energy supply,
energy security or energy access (Jakob and Steckel 2016).
There is also limited evidence that long-term climate targets
alone are impacting current investment decisions. Climate
policy may not be viewed as credible by fossil fuel investors,
for whom returns on continued investment may be assured

840

by (i) lobbying (Dolphin, Pollitt, and Newbery 2016; Kim,
Urpelainen, and Yang 2016), (ii) market design, or (iii) limited
implementation of domestic policies to meet emission
reduction targets (Nemet et al. 2017). Without credible
additional policies, coal will likely remain attractive in many
countries, due to its technological maturity, wide availability
and relatively low price (ignoring externalities) (Edenhofer et
al. 2017; Steckel, Edenhofer, and Jakob 2015).
If climate policies are to be implemented, they will need tobe supported to ease the social and economic burden of
adjustment (Trebilcock 2014). For example, distributional
effects that might result from such policies, be it by increasingenergy prices (Sterner 2012) or potential job losses in theindustry (Arent et al. 2017), can be a major stumbling block
for a transition away from coal.

In particular, the costs of renewable energy have fallen significantly and fasterthan previously expected (Creutzig et al. 2017). In some places, the costs ofrenewable energy (on a levelized cost of electricity (LCOE) basis) are now
lower than those of their fossil alternatives (depending on geography andavailable finance).

The Emissions Gap Report 2017 – Bridging the gap – Phasing out coalBox 5.1: Stranded assets
The term ‘stranded assets’ is used to describe various situations (Caldecott 2017):• Assets that are lost because of the impact of climate change itself.
•	Man-made capital that has to be retired prematurely or is underutilized, because of direct or indirect climate policies(such as coal power plants that become unprofitable after a carbon price is implemented) (Guivarch and Hood 2011;
Wynn 2016), or which can simply no longer compete against the falling costs of alternative technologies (BNEF 2017;
IEA-RETD 2016).
•	Fossil fuel resources that cannot be burned if a given climate target is to be reached, also called ‘unburnable carbon’(McGlade and Ekins 2015).
A number of studies have shown that the 2°C target requires early retirement of coal power plants (Guivarch and Hood2011; Pfeiffer et al. 2016; Rogelj et al. 2013), and that the longer ambitious mitigation action is delayed, the more therate of retirement increases (Bertram, Johnson, et al. 2015; Johnson et al. 2015; Luderer et al. 2017). Iyer et al. (2015)
estimate that catching up with 2°C-consistent pathways would involve stranding about 1,500 GW of coal and gas power
plants worldwide after 2030, while Johnson et al. (2015) estimate that a carbon price consistent with the 2°C target
would strand at least US$165 billion worth of coal plants worldwide.
Furthermore, stringent emission reductions translate into substantial upstream unburnable carbon assets, where theemissions embodied in fossil fuel reserves already exceed extraction budgets consistent with 1.5°C or 2°C (McGladeand Ekins 2015), while OCI (2016) have calculated that developed coal reserves (that is, current mining areas) alreadyexceed the budget for the 1.5°C target. The lower capital intensity of coal (compared to oil and gas) means lower
costs of stranding, but does point to both loss of value invested in coal producers (about US$800 billion according to
IRENA (2017b), and potential wasted capex in mining (worth US$177 billion) if climate policies are later implemented
successfully (Carbon Tracker Initiative 2015). Investor-owned firms hold lower reserves than state-owned companies
and nation states, thus state-owned companies and nations may pose a greater risk to exceeding the carbon budget(Heede 2014; Heede and Oreskes 2016), equity considerations notwithstanding (see also section 2.2).

Market-based instruments

5.2	Incentivizing and managing
a smooth transition
Policy instruments will be needed to incentivize the transition,
both with respect to avoiding lock-ins, and facilitating thephase-out of existing stocks, including retrofitting them with
CCS where feasible9.

5.2.1 Policy instruments

Global climate policies in general can be organized along
different metrics: market-based economic instruments(notably taxes and subsidies, tradable allowances or credits,
and border tax adjustments) (Kolstad et al. 2014), regulatory
non-market-based approaches (such as standards, andnon-compliance penalties), and complementary policy
instruments (notably government provision of goods andservices) (Oei and Mendelevitch 2016). It is increasingly
acknowledged that a transition to a low-carbon economy will
require adjustment to a variety of fiscal and normative rulesthat have an impact on investment decisions (OECD 2017).
This section assesses possible policy interventions, and how
their introduction can be managed in a socially balanced
way. Coal phase-out would have different requirements indifferent geographies for existing coal plants, recently built
coal plants, and those in the pipeline. Therefore, a different
combination of these instruments might be necessary.

9

The economically efficient approach to cutting global coaluse (without CCS), as part of an overall drive to reducecarbon emissions, would have governments remove coalsubsidies, enforce Pigouvian taxes on local air pollution,and use a carbon price to internalize the global warming
impacts of burning coal. A carbon price creates incentives
for markets to use all available levers to reduce emissions,and should theoretically result in a broadly cost-effective
overall emissions reductions outcome (Cramton et al. 2017;
Nordhaus 1991; Pearce 1991; Pigou 1920). Pricing carbon
strongly disincentivizes the use of coal, as it is the mostemissions-intensive fossil fuel.
Many countries have emissions trading and other formsof carbon pricing schemes in place that, in 2016, covered
13 percent of global greenhouse gas emissions (World Bankand Ecofys 2016). However, the resulting carbon prices are
typically much lower than the social cost of carbon (theestimated monetized negative impact of climate change
caused by greenhouse gas emissions) and lower than therates required to achieve significant reductions in coal use.
Instead of being taxed, in many countries fossil fuelconsumption and production are subsidized, with fiscal
subsidies to fossil fuel production and use being estimatedto be over US$300 billion, or around 0.4 percent of global

Note that application of CCS in the coal sector might result in a prolonged
usage of coal and therefore allow for a longer transition period.

The Emissions Gap Report 2017 – Bridging the gap – Phasing out coal41

gross domestic product in 2015 (Coady et al. 2016)10.
Most of these fiscal subsidies were for oil and gas, with
only a relatively small amount for coal. The picturechanges dramatically once the lack of taxation of negative
externalities of fossil fuel use is accounted for. Comparing
actual taxes on coal with the estimated damage to society
from air pollution reveals an implicit global subsidy to coalof US$2,400 billion in 2015, or US$3,100 billion (half oftotal implicit to all fossil fuels) if the damage to climate isaccounted for (Coady et al. 2016).
In the absence of full implementation of carbon prices, coaltaxes could potentially reduce carbon leakage (Collier and
Venables 2014), provide credible long-term price signals, andreduce (or even avoid) carbon lock-ins (Lazarus, Erickson,
and Tempest 2015). When coordinated among major coalproducing countries, they could raise global coal prices andlower global coal consumption, and hence reduce emissions(Mendelevitch, Richter, and Jotzo 2015).

Non-market-based instruments
Implementing carbon prices that are sufficiently high might
not be politically feasible (section 2.2). Hence, complementing
a carbon price — or even temporarily substituting it —with alternative policy instruments such as performancestandards, feebates, or targeted financial instruments(such as subsidized loans) that apply only to new, clean
power plants can avoid early retirement of existing plants,
thus preserving vested interests, and ease the phase-out(Bertram, Johnson, et al. 2015; Rozenberg, Vogt-Schilb, andHallegatte 2017). Preventing the construction of new assets
is especially vital in countries that currently invest in coal(figure 5.1 and table 5.1). In contrast to a high carbon price,
standards, mandates or feebates on new power plants do
not prompt current producers to underutilize existing coalplants. While they would avoid stranded assets (box 5.1),
they would likely redirect new investments towards greener
options. Stated differently, the stock of coal power plants
would stop increasing, and instead decrease progressively as
plants aged and were retired (Rozenberg, Vogt-Schilb, andHallegatte 2017).
Another policy option in this direction is to enact a
moratorium (a ban) on new coal power plants or coal mines
beyond a specific timeline (Bertram et al. 2015; Pfeiffer et al.
2016; Rozenberg, Vogt-Schilb, and Hallegatte 2017). Those
approaches can have advantages in political economy terms,
in that they impact owners of existing coal power plants
and mines less, and hence reduce resistance to change(Rozenberg, Vogt-Schilb, and Hallegatte 2017). When a highcarbon price is not feasible, typically due to political economy
considerations, a low price coupled with a moratorium andother complementary policy instruments, such as support
for low-carbon electricity generation capacities, could
indeed help make progress towards the 2°C target, while
drastically limiting stranded assets (Bertram et al. 2015).

10 We added together ‘pre-tax subsidies’ and ‘foregone consumption tax
revenue’ from IMF figures to calculate this total, which we call ‘fiscal subsidy’.
The IMF adds the failure to internalize externalities related to fuel usage toarrive at its headline ‘fossil fuel subsidy’ figure.

42

Complementary instruments
Even if complemented with non-market-based instruments,
carbon prices alone would fail to overcome other market
failures, notably network externalities or imperfections in
the capital market. While usually assumed to play a key rolein future electricity supply, renewable energy technologies,
such as wind or solar power, require additional infrastructure
to provide a reliable electricity supply (IPCC 2014)11. To
support their increased deployment, governments caninvest in improved grid infrastructure and storage facilities toaddress variable availability (Hirth, Ueckerdt, and Edenhofer,2015). Smart grids, including bidirectional power flows andmetering at the individual level, could further enhancesystem efficiency, in turn increasing the market share ofclean technologies (Iqtiyanillham, Hasanuzzaman, andHosenuzzaman 2017; Meadowcroft et al. 2017; Rifkin 2011).
Being more capital-intensive than coal, low-carbon
technologies are sensitive to perceived investor risks, both
political and financial, and to other capital market constraints.
For example, regional differences in the weighted averagecosts of capital play a more important role in evaluating
investments in renewable energy technologies than differing
natural conditions, such as differences in solar irradiation orwind potentials (Ondraczek, Komendantova, and Patt 2015,
for photovoltaic technologies). These differences can lead tocarbon prices alone being unable to trigger a transition awayfrom coal (Hirth and Steckel 2016).
To address the existing investor risks, and improve theattractiveness of alternatives to new coal investments,
instruments for de-risking clean investment are suggested
for all financial institutions and governments across theworld. These include, for example, support for policy
design, identification and removal of regulatory hurdles,
improvement of institutional capacity, and provision ofbridging investment subsidies. Such financial de-risking
instruments can transfer risk from private investors to public
actors. A range of ‘private sector instruments’, such as
guarantees, subordinated debt or equity, is already available(Torvanger et al. 2016). National or multilateral developmentbanks could employ public financing to mobilize private
investments, which contribute to a declared development
target. Concessionary climate finance can also be used
to de-risk low-carbon investments (Steckel et al. 2017),
while coal investment could also be made less attractive.
In 2016, public finance by G20 countries for coal projects
outstripped financing for renewable projects by four to one
internationally (Chen 2017).

11 Additional infrastructure investments would also be necessary for increasing
the deployment and use of CCS. Recent trends suggest that a large-scaleutilization of CCS as decarbonization technology for the electricity sector isunlikely, as the combination of renewables with storage and demand-side
technologies provides the cheaper alternative (Breyer et al. 2017; Löffler et
al. 2017). Nevertheless, large-scale power storage technologies to matchdemand–supply mismatches is still a technological challenge and requires
additional research (Annaluru and Garg 2017; Park and Lappas 2017).
Critically, the ministers of 26 countries agree that without overt policy
support (as has been provided in the past to renewable, nuclear, and power
storage technology), CCS will encounter challenges entering the market andachieving emissions reductions.

The Emissions Gap Report 2017 – Bridging the gap – Phasing out coal

5.2.2 Managing the transition

Some of the stakeholders negatively impacted by thetransition away from coal, including workers, coal owners,
and energy users relying on low prices, may have the power
to veto proposed reforms (Arent et al. 2017; Kern andRogge 2016; Sovacool et al. 2016; Trebilcock 2014). As one
example, governments that have tried to pass fossil fuelsubsidy reforms on the grounds of technical soundness andadministrative feasibility, without taking into account thepolitical economy of reforms, have often failed (Bazilian andOnyeji 2012; Rentschler and Bazilian 2016; Sdralevich, Sab,
and Zouhar 2014).
A review of previous experience with reforms in the energy
sector provides guidance on measures to navigate thepolitical economy of phasing out coal (Fay et al. 2015; Louieand Pearce 2016; Sovacool et al. 2016; Vogt-Schilb andHallegatte 2017)12. These include managing the impact onworkers, coal owners, industry and energy users, as well as
the role of communication.

Managing impacts on workers
A transition away from coal affects many different groups ofworkers. Historically, transitions away from coal have often
left workers and communities to bear the brunt of job losses
and deindustrialization (Caldecott, Sartor, and Spencer
2017; Trebilcock 1981). While macroeconomic analyses ofthe employment impact of switching to more renewableenergy usually find net job creation (Cameron and van der
Zwaan 2015; Perrier and Quirion 2016; Ragwitz et al. 2009;
Wei, Patadia, and Kammen 2010), they may mask job losses
in other locations, and might hence be a poor indicator fora just transition13. Indeed, case-by-case analyses are often
needed to assess the kinds of jobs created, their wages andconditions, the skills required by these jobs, and whether
they can be accessed by roughly the same populationgroup affected by a coal phase-out (Miller, Richter, andO’Leary 2015).
Support, such as wage subsidies (to encourage hiringin expanding sectors) and unemployment insurance fordisplaced workers, can help effectively mitigate most of thelosses at generally modest costs (Louie and Pearce 2016;
Porto 2012). More generally, research on past transitions
shows that social dialogue, social protection and economic
diversification are instrumental in ensuring just transitions(Caldecott, Sartor, and Spencer 2017; Galgóczi 2014;
Healy and Barry 2017). This can be expected to be morechallenging in developing countries, where resources andinstitutional capacities are scarcer and the mining workforce
is semi- or unskilled.

Managing impacts on coal owners and industry
A coal phase-out would lead to a devaluation of existingcoal assets (section 5.1 and box 5.1). In a situation in which
12 Including energy taxation, energy subsidy removal, and carbon taxes, as wellas adjustment packages for, and re-training of, energy sector workers.
13 The International Labour Organization has produced the Guidelines for a Just
Transition Towards Environmentally Sustainable Economies and Societies for
All (International Labour Organization 2015), which are explicitly recognizedin the Paris Agreement (United Nations 2015).

the competitiveness of other industries was reduced, forexample following a potential increase in energy prices
associated with a coal phase-out process (Branger andQuirion 2014), the prospects of successfully completing acoal phase-out process would be compromised14. Model
analyses find that losses incurred by coal owners could
be compensated by governments redistributing a fractionof the carbon rent15 (Arent et al. 2017; Bauer et al. 2016;
Goulder and Schein 2013; Kalkuhl and Brecha 2013). Several
countries or regions, such as Alberta in Canada, have coalphase-out agreements, to ensure an efficient, progressive,and politically acceptable reduction in coal power
generation (Jordaan et al. 2017)16. In the United Kingdom,compensatory subsidies were given to support the industry
in its efforts to compete in the reformed electricity market(Oosterhuis and Brink 2014).

Managing impacts on energy users
The negative impacts of a coal phase-out on poor andmiddle-class energy users, notably through increased
electricity prices, can also challenge the political feasibilityof reforms, regardless of the progressivity or regressivityof increased coal prices on consumers (Lindebjerg, Peng,and Yeboah 2015; Arze del Granado, Coady, and Gillingham
2012). Compensatory redistributive policies can mitigate
the distributional impacts to a large extent, especially if afraction of revenues is recycled into transfers to poor andmiddle-class households (Brenner, Riddle, and Boyce 2007;
Burtraw, Sweeney, and Walls 2009; Callan et al. 2009; Coady,
Parry, and Shang 2017; Gonzalez 2012; Liang and Wei 2012;
Rausch, Metcalf, and Reilly 2011; Symons, Proops, and Gay
1994). This can be done through different instruments thatspecifically target the subset of the population that is directly
affected. For example, direct cash transfers can be used ascompensatory measures, where appropriate systems exist(Rentschler 2015; Robles, Rubio, and Stampini 2015; WorldBank 2015). Alternatively, compensation can be offeredthrough in-kind measures, such as electrification in poorand rural areas, distributing efficient light-bulbs, improving
public transport, or eliminating fees at government-run
schools (Coady, Parry, and Shang 2017; Fay et al. 2015; Garg
et al. 2017).
Redirecting resources, from coal use to the provision of
public goods, helps governments garner support for coalphase-out plans (Stiglitz and Stern 2017). For instance,
governments can use revenues from taxation or savings fromavoided fossil fuel subsidies to invest in public infrastructure(Jakob et al. 2016, 2015), energy infrastructure17, or social
assistance (Hallegatte et al. 2016). Governments can also
14 These kinds of dislocations played a role in the 2016 US elections, whereloss of coal jobs over the past 20–30 years affected entire communities andstates, leading to massive shifts in voting behaviour.
15 The ‘carbon rent’ describes the economic value of being allowed to emit,
which would be captured by governments implementing a carbon price, thatis a tax or an emissions trading scheme.
16 To do so, the government of Alberta committed to “provide transition
payments to the companies which were originally slated to operate theircoal-fired units beyond 2030”. These payments “represent the approximate
economic disruption to their capital investments” (Government ofAlberta 2015).
17 See, for example, the case study on India, in Section 5.3.

The Emissions Gap Report 2017 – Bridging the gap – Phasing out coal43

use those savings to reduce income taxes and payroll taxes,
to correct impacts on those consumers who do pay taxes(Metcalf 1999).
Cash transfers (to directly affected communities) and tax
reductions (benefiting all citizens) are not necessarily
mutually exclusive (Parry and Williams 2010). Indeed, acombination of transfers and a reduction of distortive taxes
funded by energy taxes could foster more progressive income
distribution patterns, and drive a reduction in low-cost coalusage (Bach et al. 2002).

Communicating policy packages
Communicating potential benefits and involving stakeholders
is an essential precondition for a successful transition awayfrom coal (Healy and Barry 2017). Coady et al. (2017),
comparing 32 energy pricing reforms, found that theabsence of an effective communication strategy was decisivein unsuccessful past reforms.

5.3 Country studies
This section presents policies, measures and instruments
being used by major coal users and producers aroundthe world, to highlight the challenges and opportunities
associated with coal phase-out. Success rates differ andmajor gaps need to be bridged for a quicker phase-out.
However, the breadth of positive experiences is enough tooffer a buoyant outlook on the overall direction.

5.3.1. Australia: coal exports and policy challenges

In Australia, which has relied heavily on its abundant coalreserves for domestic electricity production, transitioning
away from coal is likely to pose significant policy challenges.
It is widely anticipated that the number of coal-fired power
plants will continue to decline, as plants come towards theend of their planned lifetimes. A number of older coal-fired
power plants have been shut down, and new coal-fired
capacity is now widely seen as ‘uninvestable’ by the private
sector, due to carbon risks and because renewable energy is
rapidly gaining a cost advantage (Morgan 2017).
Being the world’s second largest coal exporter18, the evenbigger question is the future of coal exports. Thermal coalexports, which are directly dependent on other countries’
climate change policies, currently stand at around
200 million tonnes per year (Australian Government 2017),
almost double the volume from a decade ago. Large-scale
expansion of coal mining for export from inland areas ofnorth-eastern Australia is under discussion.

Australia is the only country that introduced a full-scalecarbon pricing scheme (in 2012) and then abolished it (in2014). Policy uncertainty is deep-seated in the energy sector,
stifling investment (Jotzo, Jordan, and Fabian 2012).

5.3.2 China: slowly turning the wheel

Being the world’s largest consumer of coal (BP, 2017), andrelying largely on coal in its energy supply, China has (in its
Nationally Determined Contribution) committed to achievea peak in coal emissions by 2030, and eventually diversify its
energy supply. Since 2013, coal consumption seems to havestalled, with some claiming that the period of major growthin China’s coal consumption is already over (IEA 2016) or that
China’s coal consumption has already peaked (Green andStern 2017; IEA 2016).
While it is too early to interpret current developments,
China is adopting a wide range of cross-sectoral policies andmeasures to reduce its coal production and consumption,
largely motivated by the need to tackle local air pollution(Chong et al. 2015; Hao et al. 2016). Specific policies include
phasing out coal in key cities and regions to improve air
quality, improving the efficiency of coal-fired power plants
and industrial boilers and furnaces, mandatory closure of old
and inefficient coal mines, as well as coal-fired power plants,
and industrial facilities. For instance, during the 2011–2014
period, 24 GW of coal-fired power plants and 473 million
tonnes of coal production capacity were closed (Hart,
Bassett, and Johnson 2017; NDRC 2016). The Government
also promotes the development of low-carbon energy
sources, for example by feed-in tariffs for renewable energy
and granted grid access. The newly introduced carbon
dioxide emissions trading scheme can also be expected
to make coal consumption relatively unattractive (Swartz2016). In addition, to address the overcapacity of industries
and power generation, the Government has also halted
the approval of new capacity19, although it remains to be
seen how many of these projects will be cancelled or justpostponed until after 2020. To soften the social side effects ofclosing insolvent, polluting and inefficient state-owned coalmines, an Industry Adjustment Fund has provided Chinese
Yuan100 billion (approximately US$15 billion) to manage
unemployment in the steel and coal sectors (NDRC 2016).

There is currently no policy to accelerate the phase-out
of coal in domestic use, and no systematic framework toease the transition away from coal in regions where large
coal-based infrastructure exists, or where coal is mined.
Australia’s experience with climate policy has been adifficult one, with the issue heavily politicized, and emission
reduction policy instruments the subject of political contest.

Despite those developments, China still added 14 GW of
new coal-fired power generation capacity during the firsthalf of 2017. Even though this increase is 52 percent smaller
than that during the same period in 2016 (CEC 2017), at the
beginning of 2017 there were still 280 GW in the pipeline,of which 145 GW were under construction (Shearer et al.
2017). Facing a marked slowdown in new coal capacity
in the country, the central government has encouraged
Chinese coal enterprises to seek opportunities outside thecountry (Bal Kishan Sharma 2016). In recent years, China
has become a major player in developing coal-fired power
plants abroad, including providing the funding, equipment
and labour. By the end of 2016, China had been involved in
the construction of a total capacity of 250 GW of coal-fired

18 Note that Australia is the largest exporter of coal when also accounting formetallurgical coal.

19 In the second half of 2016, 120 GW acronym of power plant capacity underconstruction and planned were halted (Zhang 2017).

44

The Emissions Gap Report 2017 – Bridging the gap – Phasing out coalcapacity at different stages (that is, from the planning phase
to plants that were operational in 2016) across the globe(Ren, Liu, and Zhang 2017).

address a transformation might also negatively impact future
approaches to European Union climate policy (Marcinkiewicz
and Tosun 2015).

5.3.3. Europe: Learning from past experiences

5.3.4. India: balancing multiple objectives

In terms of managing a coal phase-out, trends in European
countries are diverging, roughly along an east/west divide.
Most Western European countries have either alreadyphased out coal (Belgium, Cyprus, Luxembourg, Malta, andthe Baltic countries), agreed on a phase-out path within
the next 10 years (Portugal, Finland, the United Kingdom,
Denmark and Austria), or are currently discussing pathways
with declining coal demand in the medium term (Germany,
France, Spain, Italy and the Netherlands) (Graichen, Kleiner,
and Buck 2016). Lessons from these experiences can be
drawn to design future coal phase-out pathways. The closureof most steam coal mines in Western Europe (located mainlyin the United Kingdom and Germany) at the end of the20th century was based on economic reasoning. Public
subsidies were granted with the aim of securing supply
and easing the social impact of reduced coal production(Fothergill 2017; Galgóczi 2014; Matthes et al. 2015). Local
supplies were at first replaced by steam coal imports, andeventually also by natural gas. The latter was supported
by European Union policies, in combination with national
measures such as the introduction of a carbon dioxide pricefloor and emission performance standards in the United
Kingdom (Fothergill 2017; Matthes et al. 2015).
Public financial support in Western Europe has been shiftingfrom conventional technologies such as coal (or nuclear)
towards renewables. Energy transitions, as seen in countries
such as Denmark (Danish Energy Agency 2017; Gerdes 2016)
and Germany (Matthes 2017; Renn and Marshall 2016), havebeen facilitated by cooperation between unions, employers,
governments and research institutions, in a continuous
process spanning several decades (Sovacool 2017).
In Eastern Europe, countries (most notably Poland) continue
to support coal-fired electricity with the aim of backing
up their domestic coal production. Energy security andenergy prices are major political concerns, while European
Union climate policy and the German “transition towards
sustainable energy” are regarded rather critically acrosspolitical parties (Bouzarovski and Tirado Herrero 2017;
Marcinkiewicz and Tosun 2015; Szulecki et al. 2016). As
a consequence, coal mining companies, under economic
pressure due to the plummeted global coal prices, aregiven (indirect) state subsidies or are renationalized (Jonek
Kowalska 2015; Widera, Kasztelewicz, and Ptak 2016).
Debates on potential coal phase-out scenarios are met withgreat scepticism, due to previous negative experiences with(coal sector) restructuring programmes having resulted inhigh unemployment, as they failed to create jobs in othersectors (Suwala 2010; Szpor 2017). However, missing theopportunity to start the necessary structured phase-out
process might result in difficulties to transform the industry
in a socially balanced way, risking much bigger complicationsin the future for the regions involved. In turn, in somecountries, ongoing lock-ins and related unwillingness to

India’s starting point is the urgent need for poverty alleviationand more energy for development: in 2016, 21.9 percent ofIndians lived below the national poverty line, while morethan 240 million people lacked access to electricity (ADB
2017; IEA 2016). The country, in line with many others, faces
a dilemma in addressing its developmental goals: it needs to
respond to demands in poverty reduction, energy access andurbanization, while reconstructing its development pathway
towards a cleaner energy system that has been coupled
historically with fossil fuel use (Arent et al. 2017).
Coal has remained the mainstay of India’s electricity
generation, contributing 61 percent of total national
generation capacity (Central Electricity Authority
Government of India 2016). With the goal of providing
power more efficiently to more people, India is investing inmodernizing its power plant fleet. Since 2006 the country has
added 151 GW of new coal power, making a total of 218 GW
as of June 2017, with about 75 percent of this capacity being
subcritical (Shearer et al. 2017). Coal-based power plants
closed or declared non-functional due to their inefficiency
and pollution amounted to 18.5 GW in 2013–2014, 23 GW
in 2014–2015, 26.8 GW in 2015–2016, and 30.5 GW in
2016–2017) (Ministry of Power, Government of India, n.d.).
There are plans to shut down about 37 GW of antiquated,heavily polluting subcritical coal plants in the near future(Singh 2016).
Coal use in India is subject to a form of carbon tax. Total
collections of around US$ 9 billion until June 2017 are mainly
used to support renewable energy programmes. India
plans to install 175 GW of renewable power by 2030, which
includes 100 GW of solar photovoltaic power (GoI 2015).
4 GW of solar-powered capacity was added to the gridin 2016, that is double the addition of the previous year
(IEA 2017).
Energy security concerns are often presented as a major
barrier for India to quickly and decisively turn away fromdomestic coal (Garg and Shukla 2009). In addition, coalproduction, transport and usage and ash disposal employ
almost one million people20. Income from coal royalties
constitutes almost 50 percent of total earning of statessuch as Chhatisgarh, Jharkhand and Odisha (Mondal 2017),
which are some of the least developed large Indian states.
Therefore, and perhaps more so than in other countries, coaluse policies have strong socio-economic and sociopoliticallinkages. A successful energy transition in India hence
requires a broader perspective that includes economic
development and measures that balance the associatedsocial transformation, notably protecting displaced workers(Khosla et al. 2015; Reddy 2016).

20 Coal mining is the second largest employer in India (the largest is the railroads,
which ship coal as their number one product and revenue source).

The Emissions Gap Report 2017 – Bridging the gap – Phasing out coal45

5.3.5. Indonesia: covering increasing demand withdomestic resources

In 2015, Indonesia was the world’s fifth largest coal producer
and the largest steam coal exporter in the world, exporting
mainly to neighbouring countries, such as China, India, Japan,
the Republic of Korea, and the Philippines (IEA/OECD 2016).
In the last two decades, coal production has accelerated
sharply, but the most recent years have seen a decreasein both production and exports, particularly to China andJapan. Coal contributes to 2.4 percent of Indonesia’s grossdomestic product (GDP), and in 2014 led to US$22 billion inexports (PWC Indonesia and ICMA 2016).
With Indonesia increasingly using its coal for domestic
purposes, it is now also the world’s eighth largest coalconsumer. About 27 GW of coal capacity provide more thanhalf of the electricity generated in the country (MEMR 2016).
Existing power plants are comparably inefficient and have
low environmental standards, leading to high emissions of
nitrogen oxides, sulphur dioxide, and particulate matter(Centre for Science and Environment 2017).
Indonesia’s electricity demand is expected to increase
rapidly, as millions will gain access to electricity (Enerdata
2015). The country aims to provide an increasing share ofenergy by domestic sources, including coal, although due
to lower-than-expected economic growth rates, 7 GW ofplanned coal-fired power plants were recently deferred in
Sumatra and Java. The state-owned utility (PLN) neverthelessestimates that, in the next decade, 77 GW of additional
capacity will be needed, of which 32 GW are planned to becovered by coal plants (MEMR 2017). Building those would
cause coal use for electricity generation to triple by 2025. To
secure domestic supply, the country has announced in its
National Energy Plan that it will regulate exports.
Indonesia is also rich in other energy sources. The country
is a large producer and exporter of natural gas, and haslarge potential for renewable energy, not only in solar,
wind and biomass, but also hydropower and geothermal
power, the latter of which could, in some cases, produce
power at a relatively low cost (IRENA 2017a). There areplans for exploration and possible significant expansion ofhydropower and geothermal power, but implementation
tends to face significant practical hurdles.

5.3.6. South Africa: political lock-in

The lock-in of interests, institutions, and infrastructure may
slow down the process of coal phase-out in South Africa,
despite economics favouring low-carbon alternatives.
South Africa is a good example of how the politics of acountry may make incentivizing a transition away fromcoal substantially more difficult. The country depends oncoal for the production of 90 percent of its electricity, in asector dominated by the state-owned, vertically integrated
monopoly Eskom (Eskom 2017).

and Eskom is building, new coal-fired capacity at costs thatare approximately 40–50 percent higher than the prices
achieved for wind and solar photovoltaic in recent renewableenergy auctions (CSIR 2016). Independent power producers
will receive 30-year power purchase agreements andguaranteed minimum off-take (Baker and Burton, in press).
A regulated electricity price, state subsidies, and guarantees
on Eskom’s debt have offset the large cost and time overruns
at plants under construction. Stated differently, although
new coal-fired capacity is no longer competitive, as thestate-owned monopoly Eskom is not subject to competitiveelectricity markets, investors in new coal plants are
essentially guaranteed returns on their investments throughthe institutional arrangements in the electricity sector.
Furthermore, the grid operator Eskom is able to limit a rapidtransition, as it compares long-term prices for new capacity
against the fuel costs of depreciated coal plants, without aclear differentiation in the market between overall systemefficiency and Eskom’s financial interests.

5.3.7. United States of America: cheap alternatives

A dramatic reduction in coal use by United States power
utilities was facilitated by several factors. First and foremost
was the availability of abundant low-cost natural gas, andsome expectation that costs would remain low indefinitely.
Two major studies (DoE 2017b; Houser, Bordoff, andMarsters 2017) support this view, stating that low-cost gas
drove the majority of coal-to-gas fuel changes. Additional
factors included conventional pollution controls (such as
regulations to reduce mercury emissions), concern overcarbon liability (notably through the Clean Power Plan,
but also through shareholder votes), and the age of many
shuttered plants (some over 60 years old). This suggeststhat access to sustained low-cost gas can accelerate a coalto-gas transition. Similarly, in regions where gas is scarce or
expensive, that transition would be slower (Citi GPS 2015).
It should be noted that further closures will continue, butwill likely plateau as the oldest, dirtiest, and least efficientplants close.
Recently, a number of policy proposals have emerged
to incentivize the deployment of CCS. One of the more
promising approaches concerns a production tax credit
for CCS, which pays operators for tonnes stored or used(the FUTURE Act (US Senate 2017)). By guaranteeing afully refundable tax credit for 12 years of US$50 for saline
formation and US$30 for carbon dioxide use (including
Enhanced Oil Recovery), its goal is to create markets for
CCS technology and projects such that project financing ispossible. Additional proposed policies include a combinationof production and investment tax credits (White House 2016,2015), changing renewable portfolio standards to clean
energy portfolio standards (Great Plains Institute 2016),
building CCS pipeline infrastructure (DoE 2017a), providing
access to master limited partnerships (Coons 2015), and taxexempt debt financing (Portman 2017).

In scenarios compatible with the 2°C target, coal-fired
electricity is phased out before 2050 (Burton et al. 2016).
Nonetheless, independent power producers are planning,

46

The Emissions Gap Report 2017 – Bridging the gap – Phasing out coal

5.4. Synthesis and policy discussions
Phasing out coal consumption in the power sector (without
CCS) is an indispensable condition for achieving international
climate change targets, but one that is at odds with recent
developments. At the global scale, the stock of coal-fired
power plants is increasing, as are emissions related to coal.
The existing stocks, in combination with what is currently
planned and built (assuming standard lifetimes and usage
rates), will account for a significant share of the available
carbon budget for a 2°C target, and would make a 1.5°C target
probably infeasible. Avoiding further lock-ins is therefore amajor and urgent requirement, as is phasing out existing coaluse gradually.
Coal is mainly used in the power sector, where cleaner andmature technological alternatives are available at increasingly
lower costs. However, the low price (ignoring externalities)of coal, wide domestic availability, and path dependencies
under a business-as-usual scenario could make coal an
ongoing large investment. Its negative externalities, suchas air pollution, land degradation and airborne emissions,are regularly not priced in, leading to economic incentive
structures that favour the extraction and use of coal overclean alternatives. Particularly where energy demand isincreasing rapidly, investments in coal are still attractive.
While case studies suggest that new coal plants are being
considered increasingly risky and new investment growth isslowing down, stronger policy interventions are needed toturn the tide.
With regard to a transition away from coal, it is hence
pivotal to price in the negative side effects of coal throughappropriate mechanisms. Increasing prices would affectthe current stock as well as future investments, by making
current plants as well as future investments less attractive
than other alternatives. Subsidies for coal, where they
apply, should be phased out immediately. On the other
hand, a carbon price, or pricing coal directly (for example
in coal-producing countries) needs to be phased in verysoon. This would generate revenues that in turn could
help ease the transition, for example by financing public
infrastructure, social security systems or investments in clean
energy infrastructure.
Even though getting the prices right is highly important, atransformation will likely need to be backed by a set ofcomplementary policy instruments. Their implementation
can be expected to be politically challenging. Even though
they increase global welfare, policies necessary to phaseout coal will negatively affect a society’s important interest
groups; not only producers and owners of coal, but also
workers that are employed in the industry, and households
or energy-intensive industry that benefit from current
low energy prices. These groups might have the power toveto measures necessary to trigger the transformation.
Therefore, for a transformation to be successful, theirinterests need to be taken into account and addressed byadditional measures, be it compensation for higher prices orlost business models, training for workers or the provisionof alternative employment options. Examples for successfultransformations include introducing phase-out agreements
between important stakeholders in a country, phasing out
inefficient plants first, reducing coal subsidies and promoting
renewable energy.
Scenarios that achieve temperature stabilization well below
2°C do not envisage any further room for new investments
into coal. Given the difficulty of retiring or phasing out coalonce plants are built, it is even more important to ensurethat no new coal-fired power plants are constructed, andthat carbon lock-in from coal is reduced to a minimum.
Financial institutions worldwide should realize that financing
coal is quickly becoming riskier, as these investments
would become stranded. Energy investments are, however,required to tackle energy poverty in many developing
countries, and to upgrade energy infrastructure even in
many developed countries, which will need to move towards
alternatives. Countries should ensure that alternatives
can enter the market easily. This requires investments inthe smart grid infrastructure and storage capacities thatfacilitate the integration of variable, low-carbon alternatives.
Additionally, investments in alternatives to coal (such as
renewable sources of energy) should be supported, forexample by de-risking investments for investors.
Considering the very recent developments of the coalpipeline (that is, power plants that are planned or underconstruction) gives some reason for hope. The pipeline
decreased significantly in 2016 (compared with 2015) andmany power plants that were planned have been shelved
or even cancelled. Important emerging economies that arelargely dependent on coal, such as China and India, haveannounced policies that address coal consumption fromvarious angles, including price mechanisms and policies thatcan socially support a transformation.
However, despite the coal pipeline shrinking, there are stilllarge investments in new coal capacities. Some countries
have recently announced that they will invest more heavily
in coal (often alongside large investments in renewableenergy), primarily to cover their increasing energy demands.
A transition away from coal will only be successful if poor,
fast-growing countries seek low-carbon alternatives tocover their rapidly increasing energy demand. Making
those alternatives viable will require strong policies aroundthe globe. Developing and newly industrializing countries
will likely need support from the international community
to design and implement the policies that are neededto achieve multiple societal objectives, including energy
provision and achieving climate change mitigation targets.

The Emissions Gap Report 2017 – Bridging the gap – Phasing out coal47

Chapter 6

Bridging the gap – The role ofshort-lived climate pollutants
Lead authors: Zbigniew Klimont (International Institute for Applied Systems Analysis), Drew Shindell (Duke University)
Contributing authors: Nathan Borgford-Parnell (UN Environment), Lena Höglund-Isaksson (International Institute for Applied Systems
Analysis), Steffen Kallbekken (CICERO Center for International Climate Research), Johan Kuylenstierna (Stockholm Environment Instituteat York), Luisa Molina (Molina Center for Energy and the Environment/ Massachusetts Institute of Technology), Leena Srivastava (TERI
University), Shu Tao (Peking University), Chandra Venkataraman (Indian Institute of Technology Bombay)

6.1 The contribution of SLCPs to climatechange – Introduction and framing
This chapter outlines the opportunities to reduce theemissions gap afforded by limiting emissions of short-lived
climate pollutants (SLCPs). This is a topic that has not been
included in previous Emissions Gap Reports.
Greenhouse gas (GHG) emission reduction policies
contribute to varying degrees to reducing emissions of SLCPs:
while methane sources are covered, black carbon sources
are only partially covered (for example, through policies
to regulate emissions from diesel engines). In light of this,and given that SLCPs have a relatively short residence timein the atmosphere, implementing targeted SLCP reduction
measures can provide rapid reductions in global warming.
For this reason, this chapter focuses on measures that are
specific to SLCPs.
Anthropogenic climate change is largely driven by humaninduced changes in the composition of the atmosphere,
including long-lived GHGs (that have lifetimes ofapproximately eight years or more) and short-lived climate
pollutants (that have lifetimes of approximately 20 years
or less) (Myhre et al., 2013)1. The most recent assessment
report by the Intergovernmental Panel on Climate Change(IPCC) found that increases in carbon dioxide (CO2) were thelargest single contributor to climate change. However, othercompounds also play large roles and, for this reason, it isstandard practice to include all climate drivers in analysesof historical and projected trends2. In sum, although some
SLCPs — particularly black carbon — are not explicitly part
1
2

48

These groupings of pollutants by lifetime are consistent with the IPCCs Fifth
Assessment Report (AR5), and methane is included within both groups.
This extends to allowable carbon budgets, for which the IPPC’s Fifth
Assessment Report presented analyses for both CO₂ alone and all
climate drivers.

of the Paris Agreement, which targets long-lived GHGs
only, SLCPs are routinely included in analyses aimed to
identify emission trajectories that are consistent withtemperature targets.
This report defines the ‘emissions gap’ as the difference
between the emission trajectories resulting from
implementation of Nationally Determined Contributions(NDCs), and the trajectories associated with emission
scenarios that are consistent with temperature targets, suchas the 2°C target. For some SLCPs, however, such a definition
is problematic. For example, emissions of black carbon can
increase relative to current policies under a 2°C pathway,
due to a greater reliance on biofuels, or growing numbers ofdiesel vehicles without particulate filters and/or stringent fuelquality standards. In light of this, the definition of ‘emissions
gap’ that applies to this chapter is “the difference between
emission levels that are consistent with emission trajectories
resulting from NDC implementation, and the lowest emission
levels achievable using current mitigation technologies andpolicies”. For methane and hydrofluorocarbons, results
are presented in CO2 equivalents (CO2e). Additionally, thetemperature response associated with mitigation measurescovering all SLCPs is presented3.
Strategies to reduce SLCPs will typically target methane,
tropospheric ozone, black carbon and hydrofluorocarbons.
Other short-lived climate forcers, such as sulphur dioxide
and organic carbon, lead to cooling and are therefore nottargeted. These SLCP reduction strategies will sometimes
affect only a single pollutant, for example intermittent
rice irrigation affects methane alone. Nonetheless, moststrategies to reduce SLCPs will affect multiple pollutants.
It follows that an evaluation of mitigation measures must
3

The Emissions Gap Report 2017 – Bridging the gap – Phasing out coal

The analysis presented in this chapter cannot assess the emissions gap interms of national pledges, as most countries pledged reductions in CO₂e.

examine emissions of both long-lived GHGs and all SLCPs, toassess the net impact on warming.
Sustained SLCP reduction strategies can help limit long-termwarming, especially when combined with CO2 reduction, andtherefore contribute to closing the emissions gap. A complete
separation between SLCP and CO2 reductions is not possible
for two reasons. Firstly, decarbonization strategies willlead to a reduction of some SLCPs, including black carbon,
about one third of which originates from fossil fuel sources(Bond et al., 2013; Klimont et al., 2017). Secondly, efficiency
increases can reduce all types of emissions, but many SLCP
mitigation strategies are distinct from strategies to reduce
CO2, especially in the near term, as many decarbonization
measures require lengthy structural changes.
Reductions in SLCPs have the potential to decrease the rateand degree of warming in the next few decades, with SLCP
mitigation having a rapid effect on temperature. In contrast,
reducing CO2 (and associated emissions, which often include
cooling agents such as sulphur dioxide or nitrogen oxides)
tends to reduce warming more slowly. Hence, the climate
impact of mitigating SLCPs is not equivalent to reducing CO2,
which is a much longer-lived GHG, owing to the differing
temporal evolution of the radiative forcing response tothese emissions (Myhre et al., 2013). It has been estimatedthat SLCP mitigation has the potential to avoid up to 0.6°C
of warming by mid-century (for example Hu et al., 2013;
Rogelj et al., 2014; Shindell et al., 2012), while aggressive
CO2mitigation in a comparable scenario leads to less than half
as much near-term reduction in warming (Hu et al., 2013).
SLCPs will also affect long-term global mean temperatures.
In that context, the impact of sustained emissions changes
of SLCPs can be usefully compared with pulse emission
changes of long-lived GHGs (Allen et al., 2016). Furthermore,existing air quality and CO2 mitigation policies will reduce
emissions of sulphate and nitrogen oxides, which will drive
up warming in the near term (despite improving air quality).
Enhancing SLCP mitigation measures can help counteract
this unmasked warming.
When considering opportunities to reduce the emissions
gap, it is also important to consider how the measures andstrategies adopted to cover the temperature gap will affectsocieties, human well-being and health, as well as ecosystems.
The text of the Paris Agreement commits the world toan ambitious long-term temperature target (Article 2aand 4.1), but places this ambition within the context of“sustainable development and efforts to eradicate poverty.”
Through the lens of sustainable development, the path thatthe world choses to reach the long-term climate target is
as important as achieving the target itself, particularly for
those that are already suffering from the impacts of climatechange (Shindell et al., 2017a).
In this context, near-term mitigation of SLCPs is perhaps
even more important. In addition to the fast temperature
response, reductions of SLCPs would contribute to reducing
climate change impacts that are based on cumulative heatuptake (for example, sea-level rise, and glacier and ice

sheet melting). They would also help reduce the likelihoodof passing irreversible thresholds and triggering large
positive feedbacks. In doing so, they would strengthen otherclimate change mitigation efforts (Shindell et al., 2017a; Xu
and Ramanathan, 2017). SLCP reductions also improve air
quality, with benefits for human health, agricultural yields,
rainfall stability and other environmental and social policy
goals (section 6.5).
Finally, cutting levels of black carbon and other SLCPs
delivers short-term benefits, which may help governments
to increasingly view collective action on climate change as
feasible (Victor et al., 2015). Capitalizing on efforts such as
the Climate and Clean Air Coalition or the Montreal Protocol
on Substances that Deplete the Ozone Layer can increase
the momentum for climate change mitigation (Sabel andVictor, 2015).

6.2 Recent SLCP emissions trends andoutlook towards 2030
Efforts to estimate emissions of SLCPs and their future
trends have intensified, following a global assessment ofemission trends for black carbon and tropospheric ozone
precursors (UNEP/WMO, 2011). Many recent studies havefocused on improving the understanding about emissions
from poorly quantified sources4, with a secondary focus onlarge emitting regions5.

6.2.1. Historical estimates

Recent work has led to revised global estimates of SLCP
emissions (Crippa et al., 2016; Höglund-Isaksson, 2017;
Höglund-Isaksson et al., 2017; Klimont et al., 2017; Purohitand Höglund-Isaksson, 2017; Wang et al., 2014), and to there-estimation of historical emissions of SLCPs that wereused to develop the Representative Concentration Pathways(Lamarque et al., 2010) and Shared Socio-Economic
Pathways (Rao et al., 2017)6. While estimates of SLCP
emissions remain uncertain, the revised historical estimates
are higher than previously assumed (Hoesly et al., 2017;
Klimont et al., 2017). This is especially important with regard
to black carbon, where the inclusion of emissions fromkerosene lamps, open burning of waste, gas flaring, andregional data on coal use in China results in emission levels
that are over a million tonnes (over 15 percent) higher in2010 than in the integrated assessment models used in the

4

5
6These include black carbon from kerosene lamps (Jacobson et al., 2013;
Lam et al., 2012), gas flaring (Conrad and Johnson, 2017; Stohl et al., 2013;
Weyant et al., 2016), brick manufacturing (Cardenas et al., 2012; Maithel etal., 2012; Weyant et al., 2014), open burning of residential waste (Christian
et al., 2010; Wiedinmyer et al., 2014), open burning of agricultural residues(Stockwell et al. (2016), and methane from the oil and gas industry (HöglundIsaksson, 2017).
Notably China, India, Russia and the Arctic (Evans et al., 2017, 2015; Huang etal., 2015; Kholod et al., 2016; Kondo et al., 2011; Kurokawa et al., 2013; Lu etal., 2011; Shen et al., 2012; Winiger et al., 2017).
See Hoesly et al. (2017) for additional details concerning past trends onanthropogenic emissions of reactive gases and aerosols.

The Emissions Gap Report 2017 – Bridging the gap – The role of short-lived climate pollutants

49

Representative Concentration Pathways and Shared SocioEconomic Pathways scenarios7.
Asia’s role in emissions of black carbon and methane isever-increasing, while North America and Europe (including
Russia) combined represented nearly one third of global
methane emissions in 2010, primarily via emissions from theoil and gas sector. Although sectoral structures of emissions
vary greatly across pollutants, a few sectors tend to
dominate. For black carbon, residential combustion (cooking
and heating in solid fuel stoves) has been a key source ofemissions, with transport and industry gaining importancein recent years (Hoesly et al., 2017).

6.2.2. Projected emissions (including NDCs)

Within Nationally Determined Contributions (NDCs),
identifying particular compounds is usually difficult or
impossible. This is because emissions reduction targets
are expressed in CO2e, often without specific targets formethane, hydrofluorocarbons or black carbon, but rather
providing a list of target sectors. Only Mexico, Chile,
Nigeria and Canada name SLCPs (black carbon) in their
NDCs (and only Mexico specifies a target)8. It follows that
NDCs are unsuited to analyses of SLCP projections. For thisreason, the assessment below relies upon air pollutant
and GHG emissions modelling that provides pollutantspecific estimates.
Recent projections of black carbon emissions indicate achange in trends (figure 6.1), driven by legislation developed
to address primarily the health impacts of particulate matter9.
Following the introduction of diesel particulate filters, black
carbon emissions from diesel engines in OECD countries
have continued to decline since about 2005. A similar impact
is expected in developing countries, where comparable
legislation has been recently introduced (DieselNet, 2015;
GOI, 2014; MoRTH, 2016) in addition to measures to reducesmoke exposure among rural populations cooking withbiomass and using kerosene for lighting (Venkataraman
et al., 2010). Finally, China’s policy to reduce coal use inhouseholds and small industries is likely to play an importantrole in near-future emissions of black carbon.
Recent scenarios reflect these policies to curb emissionsof black carbon. figure 6.1 shows how projected emissionsof black carbon (and methane and hydrofluorocarbons)

7

8

9

50

A recent study by Höglund-Isaksson (2017) reports a considerably higher
release of methane and ethane from global oil and gas systems for the period
1980 to 2012, with oil production emerging as a much larger contributor
than natural gas production. The results of this study show much closer
consistency between bottom-up and top-down estimates of global ethane
emissions from fossil sources than existing bottom-up inventories (EC-JRC/
PBL, 2013; US EPA, 2012).
By 2030, Mexico aims to achieve a 51 percent reduction in emissions ofblack carbon, compared to the country’s emissions levels in 2013. Thisis an ambitious goal, requiring significant reductions in transport (over70 percent), residential combustion (nearly 60 percent), and industry(50 percent), and the enforcement of a ban on open burning of residues(INDC-Mexico, 2015). Beyond developing the strategy, the government
issued new legislation regarding the transport sector requiring improved
efficiency and emission standards.
Reductions in emissions of black carbon is an ancillary benefit of policies
aimed to curb particulate matter emissions.

compare with Shared Socio Economic Pathways scenarios10.
In addition to the three Shared Socio-Economic Pathways
scenario ranges, an ‘updated policy’ pathway is shown,reflecting the latest policy assessments11. In the period prior
to 2030, this pathway is consistent with all the Shared SocioEconomic Pathways trajectories associated with a radiative
forcing of 2.6 Watts/m2 (which corresponds to a 2°C increasein global mean temperature at the end of this century).
After 2030, the ‘updated policy’ pathway is consistent with
Shared Socio-Economic Pathway – narrative 3 trajectories
associated with a radiative forcing of 3.4 Watts/m2. Unlike
recent estimates, the Shared Socio-Economic Pathway –narrative 3 (reference - no mitigation) scenario does notinclude the most recent policies in the transport sector.
Considering the latest developments with respect to diesel
engines (notably stricter standards, bans in cities, andthe development of alternative propulsion systems), theprojected decline in emissions from diesel engines over the
next decades appears plausible. Finally, it is worth notingthat the estimated near-term baseline developments do notconsider some of the ongoing discussion that could bringfurther commitments to reduce SLCP emissions12.

10 The figure shows projected emission ranges for three Shared Socio-Economic
Pathways scenario groups. Shared Socio-Economic Pathway – narrative 3(reference - no mitigation) assumes a focus on national and regional policies,
slow economic growth, lack of collaboration, large population remaining
in poverty, and low priority for environmental policies, leading to strong
environmental degradation in some regions. Shared Socio-Economic Pathway– narrative 3 (3.4 Watts/m2) assumes the same socio-economic pathways,
except that they include aggressive policies to curb climate change. Shared
Socio-Economic Pathways 1-5 (2.6 Watts/m2) trajectories are consistent withthe 2°C target that is achieved for all Shared Socio-Economic Pathways except
Shared Socio-Economic Pathway – narrative 3 (reference – no mitigation)(Rao et al. 2017; Riahi et al. 2017).
11 Updates include recent emission legislation (as of 2015) and updated energy
projections, as described in IEA (2016).
12 Four commitments are especially significant:• The member states of the Arctic Council have pledged to reduce black
carbon emissions by between 25 percent and 33 percent of 2013 levels
by 2025.
• Black carbon is covered by the Gothenburg Protocol to the United
Nations Economic Commission for Europe’s Convention on Long-Range
Transboundary Air Pollution. While no specific target is set, the Convention
requires parties to prioritize important sources of black carbon emissions intheir strategies to reduce emissions of particulate matter.
• The International Maritime Organization is considering options to reduce
emissions of black carbon from the maritime industry.
• Thirty-eight partner countries to the Climate and Clean Air Coalition havepledged to develop or refine inventories of black carbon (55 countries are
now partners in the coalition, which targets SLCPs, including black carbon).
Other non-state actors have also made commitments, with the state ofCalifornia in the United States adopting specific legal targets for reductionsof each of the major SLCPs.

The Emissions Gap Report 2017 – Bridging the gap – The role of short-lived climate pollutants

Figure 6.1: Global annual emissions of methane, black carbon (including forest and savannah fires) and hydrofluorocarbons.
Methaneemissions

GtCO₂e

GtCO₂e(GWP100)(GWP20)

12

40
35

10

30

8

25

6

20

4

15
10

2
0

Black carbon
emissions

Mt

GtCO₂e(GWP20)

10

30

2020

2030

2040

0
2050

6

20

3

5

0

2010

2020

2030

2040

Current policy
Mitigation for 'Current policy'
Updated policy
Mitigation for 'Updated policy'
SSP3 (3.4 W/m2)

10
8
6

2

10
2

Current policy
Updated policy
Maximum reduction

SSP3 (Reference)(GWP20)

12

25

15

GtCO₂e

5

8

4

HFC
emissions(GWP100)

4

5
2010

GtCO₂e

0
2050

4
1
0

2
2010

2020

2030

2040

0
2050

Current policy
Updated policy (incl. Kigali Amendment)
Maximum reduction

SSP1-5 (2.6 W/m2)

Note: For black carbon, values are shown in million tonnes and also based upon conversion to CO2e using 20-year global warming potentials (Bond et al., 2013). For
methane and hydrofluorocarbons, the values shown are based upon conversion to CO2e using both 100-year (left axis) and 20-year (right axis) global warming potentials,
to highlight the dependence of comparisons between SLCPs and CO2 on the choice of metric. Note that a 100-year global warming potential of 21 is used for methane,for consistency with prior issues of the ‘emissions gap report’, even though current studies and IPCC assessments use values more than 60 percent higher (Gasser et al.,2017; Myhre et al., 2013).
Source: The figures were developed using data from Shared Socio Economic Pathways database (https://tntcat.iiasa.ac.at/SspDb/dsd), Riahi et al. (2017) and datafor policy and mitigation scenarios from the GAINS model (http://gains.iiasa.ac.at) documented in Klimont et al. (2017); Stohl et al. (2015), and Purohit and HöglundIsaksson (2017).

For methane and hydrofluorocarbons, the baseline
trajectories (labelled ‘current policy’ in figure 6.1) relying
on near-term energy projections (IEA, 2016; Purohit and
Höglund-Isaksson, 2017) appear similar to the Shared SocioEconomic Pathway – narrative 3 trajectories. Numerous
parties to the United Nations Framework Convention on
Climate Change (including the top three global consumers ofhydrofluorocarbons, China, the United States and European
Union) are already taking action to reduce emissions throughnational policies and legislation. In their Intended Nationally
Determined Contributions INDCs/NDCs, 99 countries
pledged to reduce emissions of hydrofluorocarbons13.

6.2.3. Impact of the Kigali Amendment

A 2015 study found that phasing down hydrofluorocarbons
could avoid between 4.0 GtCO2e and 5.3 GtCO2e per
year by 2050, compared to a reference scenario (Velders
et al., 2015). A related study from 2017, which uses
13 Three sets of initiatives are worth noting:•
In May 2014, as part of an action plan to implement the energy conservationand emission reduction targets of its 12th five-year plan, the State Council ofChina announced that it would strengthen emission reduction requirements
for hydrofluorocarbons, and accelerate their phase-out and replacement.
In its INDC/NDC, China has stated that it will completely phase outhydrofluorocarbon-123.
•
The European Union’s regulation 842/2006 on fluorinated greenhousegases, which entered into effect on 1 January 2015, envisages that, by 2030,
hydrofluorocarbon levels will have reduced by 79 percent of the levels
registered in the period between 2009 and 2012.
•
The United States considered federal-level measures to reduce the
manufacture and use of hydrofluorocarbons. In August 2017, a court struck
down part of a 2016 decision by the country’s Environmental Protection
Agency, which sought to revoke approval for several of the most potent
hydrofluorocarbons. However, it is unclear how much impact this ruling will
have, as it returned the decision to the Agency, for further justification. In
parallel, several state administrations in the United States are regulatinghydrofluorocarbons. For example, California has set a new emissions
reductions target for hydrofluorocarbons (a 40 percent reduction to 2013
levels by 2030).

more up-to-date assumptions about emission reduction
policies and a revised reference scenario, found that fullcompliance with the Kigali Amendment to the Montreal
Protocol could reduce global hydrofluorocarbon emissions by
0.7 Gt CO2e per year by 2030, and up to 2.7 Gt CO2e per yearby 2050 (Höglund-Isaksson et al., 2017). This would avoid
cumulative emissions of 39 GtCO2e between 2018 and 2050
(figure 6.1)14. Strengthening phase-down efforts (that is,pursuing a reduction in emissions that goes beyond thatafforded by the implementation of the Kigali Amendment
and that seeks to reach the maximum potential) could
provide about 30 percent greater cumulative benefits(figure 6.1), while avoiding additional future emissions by
precluding a build-up of storage hydrofluorocarbon banks(Velders et al., 2014).
In addition to efforts to avoid direct emissions ofhydrofluorocarbons, additional indirect CO2e mitigation
is likely through parallel improvements in the energy
efficiency of refrigeration and air-conditioning appliancesand equipment. Past phase-outs under the Montreal
Protocol have catalysed significant improvements in theenergy efficiency of appliances — up to 30 percent in somesubsectors (US EPA, 2002). Höglund-Isaksson et al. (2017)
found that full compliance with the Kigali Amendment
could reduce global electricity consumption by between

14 These estimates are based on a 100-year global warming potential.

The Emissions Gap Report 2017 – Bridging the gap – The role of short-lived climate pollutants

51

0.2 percent and 0.7 percent over the period 2018 to 2050, due
to the adoption of more energy-efficient technologies15,16.

6.3 SLCP mitigation potential
Some of the reduction potential for black carbon identifiedin early studies (Shindell et al., 2012; UNEP/WMO, 2011) is
expected to be realized in the updated baselines (Section 6.2).
Nonetheless, significant additional opportunities exist,
which could reduce black carbon emissions by about
70 percent by 2030 (and more, in the longer term)(figure 6.1). Provided that strong targeted SLPC policies are
introduced, these reductions in emissions could be achieved
quickly17. While the illustrated potential was estimated foran energy scenario with CO2 emission levels similar to the
Shared Socio-Economic Pathway – narrative 3 trajectory, theshown potential appears comparable with, or even larger
than, the strict climate mitigation strategies that assume
significant structural changes in the energy system. However,these strict climate policy scenarios are not compatible
with the socio-economic developments associated with
Shared Socio-Economic Pathway – narrative 3. Therefore,
the intermediate climate target scenario results (reaching a
3.4 Watts/m2 forcing level, or approximately a concentrationof 550 ppm of CO2) were added. These results illustrate theco-benefits of climate policies on black carbon emissions.
Indeed, under this scenario emissions are reduced by about
30 percent by 2050, compared to the Shared Socio-Economic
Pathway – narrative 3 trajectory.
Any further mitigation of black carbon emissions would
require either tightened air quality standards, and/or
strengthened development policy. These are included in
the SLCP mitigation case, and in the strict climate policies
case (as shown in the 2.6 Watts/m2 scenarios). By 2030, very
limited reduction is demonstrated in this scenario, contrary
to the SLCP mitigation case, where effective technologicalsolutions and tested policy approaches afford much larger
emission reduction potentials. In general, the new global
set of scenarios (Shared Socio Economic Pathways) shows afairly large span of emissions, even within the same Shared
Socio Economic Pathways (Rao et al., 2017). This differs fromthe Representative Concentration Pathways data set, whereassumptions that economic growth automatically leads todecreases in pollution were uniformly used across all themodels for projecting changes in emissions of air pollutants,
including SLCPs (Amann et al., 2013).

15 This would result in a cumulative reduction of about 5.5 GtCO₂e due toelectricity savings when using country-specific emission factors that take into
account country-specific transformation and distribution losses (Brander etal., 2011).
16 A 2015 study suggested that, in the air conditioning sector alone, improving
the energy efficiency of equipment by 30 percent, while simultaneouslytransitioning to alternatives with low global warming potential, could provide
cumulative mitigation of nearly 100 GtCO₂e by 2050 (Shah et al., 2015).
17 Past experience on a regional and local scale exists, demonstrating fastand effective implementation, provided that appropriate enforcement
mechanisms are set in place along the regulation; several examples areprovided in, for example, Coaen (2012); Klimont et al. (2017); Kodjak (2015);
Saikawa (2013); Shindell et al. (2012).

52

In the Shared Socio-Economic Pathway – narrative 3
scenarios, the global technical mitigation potential formethane is estimated at about 45 percent by 2030, provided
that an appropriate policy environment is introduced18.
Most of the emission reduction opportunities are in the
exploration and distribution of coal, oil and gas, and in thewaste sector19. The reductions available are comparable withthose in the deep climate mitigation scenarios (figure 6.1). In
general, policies to reduce emissions of CO2 will effectively
cover a large portion of methane emissions.
Technical measures could bring about fast and significant
reductions in emissions of black carbon and methane (forexample Amann et al., 2013; Höglund-Isaksson, 2012;
Klimont et al., 2017)20. However, introducing such measures
has proven problematic in some instances. For example,
programmes that focus on substituting cooking stoves withclean alternatives have often had disappointing results,
with declining penetration rates over time (Aggarwal
and Chandel, 2004; Pine et al., 2011; Ruiz-Mercado et al.,2011; Venkataraman et al., 2010; Wickramasinghe, 2011)21.
Nevertheless, some other types of programmes havebeen successful, including emissions reduction strategies
for motor vehicles, such as those focused on diesel
particulate filters or emissions standards (CAI-Asia, 2011;
Chambliss et al., 2013; Coan, 2012; Kodjak, 2015; Saikawa,
2013; US EPA, 2017).
This chapter presents estimates of technical mitigation
potentials, since they are more widely used, and therefore
more abundant, than estimates of economic mitigation
potentials. Notwithstanding, it is acknowledged that
economic potentials may be more relevant with regard tounderstanding the political feasibility of mitigation actions22.

18 In figure 6.1 this is coded ‘maximum reduction’, and represented by thefollowing symbol: .
19 The emissions reduction potential associated with rice and anaerobic
digestion is only significant in certain regions.
20 Emission reduction rates would be faster than those brought about by
transformational changes associated with low CO₂ strategies.
21 Nonetheless, locally tailored projects, often embedded in a larger scale policy
process, and coupled with awareness-raising efforts, have proven successful(GACC, 2015; Sinton et al., 2004; Thomas et al., 2015). Political feasibility
depends strongly on the design of the programme, its local sustainability, thestrong involvement of local stakeholders, and on the incentives for national
governments to act.
22 The economic potential of SLCP mitigation differs substantially from thetechnical potential of CO₂ mitigation for two main reasons: (i) the total
benefits of SLCP mitigation are typically larger, because they include nonclimate benefits; and (ii) with SLCP mitigation, a large share of the benefits isnationally appropriable, in particular for black carbon. Shindell et al. (2017b)
estimate that the social cost of methane (that is, the monetized societal
damages resulting from a tonne of emissions incorporating climate and air
quality related impacts) is 50 to 100 times greater than the correspondingsocial cost of CO₂. Estimates of the net benefits that are nationallyappropriable are not yet available in the literature. Research programmes are
ongoing to bridge this research gap.

The Emissions Gap Report 2017 – Bridging the gap – The role of short-lived climate pollutants

6.3.1 Methane

The technical mitigation potential identified through the
integrated assessment models used to develop Shared SocioEconomic Pathways scenarios draws primarily on the workof United States Environmental Protection Agency (US EPA,
2013). The estimates for methane have been further updated(Höglund-Isaksson, 2012; UNEP/WMO, 2011) to include
explicit consideration of unconventional gas production,
new regional characteristics for oil and gas production(Höglund-Isaksson, 2017), and waste management. For coalproduction, a structural update was made, to allow for the
separate estimation of emissions and mitigation potentials
from pre-mining operations (de-gasification), mining
operations (ventilation air methane oxidation), and postmining activities. Finally, current model implementation
includes impacts of animal feed and manure management
options as described in FAO (2013), but does not include
changes in consumer preferences or behaviour, which could
add mitigation potentials in the agricultural sector throughreduced consumption of meat (especially beef) and reduced
food waste generation (Stehfest et al. (2009) (Chapter 4).
Figure 6.2 shows regional estimates of ‘Current policy’

emission trajectories and reduction potentials in the coming
decades. These estimates are consistent with International
Energy Agency projections of energy use (IEA, 2012), andintegrate the refinements highlighted above23.
Mitigation potentials vary across regions, and are often
characterized by a dominating source sector24. Nonetheless,solid waste separation and treatment offers opportunities
across all regions. In Europe and Brazil, reduction
potentials are smaller, as agriculture is the dominating
methane source, and there are relatively limited technicalmitigation opportunities. The comparison with the ‘Climate
policy’ scenario (based on the IEA (2012) 450 ppm CO2
mitigation strategy) shows that most of the near-termemissions reduction potential appears to require dedicated
SLCP measures.

23 In terms of CO₂ emission levels, the International Energy Agency’s scenario iscomparable to Shared Socio-Economic Pathway – narrative 3 (reference - no
mitigation) and ‘Current policy’, shown in figure 6.1.
24 For example, capturing ventilation air methane from coal mines represents
the key mitigation opportunity in China.

Figure 6.2: Regional baseline methane and black carbon [shaded background] emissions and mitigation potential by 2030 [Mt per year].
China
Methane (Mt)

100

India

Black carbon (Mt)

2.5

50

80

2.0

40

60

1.5

30

40

1.0

20

20

0.5

10

Methane (Mt)Black carbon (Mt)

1.2
1.0
0.8
0.6

0

2000

2010

USA

2020

0

2030

Methane (Mt)

50

2000

2010

2020

2030

0.2
2000

EU-28

Black carbon (Mt)

0.5

0

0.4

25

2010

2020

2030

Methane (Mt)

0

0.4

20

0.4

30

0.3

15

0.3

20

0.2

10

0.2

10

0.1

5

0.1

2000

Brazil2010

2020

Methane (Mt)

25

2030

0

2000

2010

2020

2030

2000

MexicoBlack carbon (Mt)

0.25

0

25

2010

2020

Methane (Mt)

2030

0

0.20

20

0.20

15

0.15

15

0.15

10

0.10

10

0.10

5

0.05

5

0.05

0

2000

2010

2020

Current policy
Mitigation (Current policy)

2030

0

2000

2010

2020

2030

0

2000

2010

2020

2000

2030

0

2020

2030

2010

2020

2030

Black carbon (Mt)

0.25

20

2010

Black carbon (Mt)

0.5

40

0

2000

2000

2010

2020

2030

Climate policy (450 ppm)
Mitigation (Climate policy)

Source: The figures were developed using data from the GAINS model (http://gains.iiasa.ac.at) and scenarios documented in Höglund-Isaksson (2012, 2017); Klimont etal. (2017); Stohl et al. (2015), with underlying energy scenarios from IEA (2012).

The Emissions Gap Report 2017 – Bridging the gap – The role of short-lived climate pollutants

53

6.3.2 Black carbon

Figure 6.2 gives estimates of mitigation potentials forblack carbon in a number of world regions. The estimatesreflect updates referred to above (Klimont et al., 2017;
Stohl et al., 2015). With regard to black carbon, key updates
include improved characterisations of the gas flaring
sector, kerosene lighting, diesel generators, and the brickmanufacturing sector.
The ‘Current policy’ trajectory varies greatly between
regions, depending on the structure of emissions and current
policies. Consequently, the mitigation potential varies too.
For the European Union and the United States, a strong
decline is observed (owing to strict transport legislation),
which explains the limited mitigation potential that remains.
In China, the transformation in the coke sector, ever-more
stringent policies in transport, and reductions of coal use in
the residential sector lead to significant reductions relative tothe reference scenario emission levels. Therefore, mitigation
potential is larger in China than in the European Union andthe United States. In some of the other regions with a large
share of emissions from biomass cooking (notably India),significant opportunities exist.
While the overall global potential by 2030 was estimatedat over 70 percent (figure 6.1), the regional potentials
vary from about 40 percent to over 80 percent. In regions
where solid fuel cooking and heating dominates emissionsof black carbon, the emissions reduction potential increases
significantly beyond 2030 (not shown)25.

6.3.3 Hydrofluorocarbons (HFCs)

Full compliance with the Kigali Amendment would achieve a
61 percent decrease in hydrofluorocarbon emissions in the
period between 2018 and 2050, compared to the emission
levels in a reference scenario (Höglund-Isaksson et al., 2017).
Transitioning to available low global warming potential
alternatives faster and more thoroughly than contemplatedby the Kigali Amendment represents a major opportunity to
reduce emissions of hydrofluorocarbons. Such accelerated
transition is feasible. In countries with high ambient air
temperatures, almost 70 percent of sectors currently
using hydrochlorofluorocarbons can leapfrog past highglobal warming potential hydrofluorocarbon refrigerants,
directly to low global warming potential alternatives withequal or better energy efficiency (Zeiger et al., 2014). The
same study notes that other low global warming potential
alternatives are in development, and expected to be readyto replace the remaining uses by 2025. Höglund-Isaksson
and colleagues (2017) report that the maximum technicalabatement potential, relying on existing technologies,
is 85 percent below the reference scenario emission
levels (in the period between 2018 and 2050) (figure 6.1).
They further note that, towards the end of the period,
the mitigation potential could represent as much as
98 percent of the annual reference scenario emission
levels. Interestingly, most of the model realizations of the
Shared Socio-Economic Pathways scenarios consistent
with the 2.6 W/m2 trajectories assume even faster andsteeper reductions than the Kigali Amendment (figure 6.1).

6.4 Implications for the emissions gap
Compared to the Shared Socio-Economic Pathway –narrative 3 trajectories, assessments of the impact of
updated policies show weaker growth or, depending on thepollutant, greater decreases in emissions of methane, black
carbon, organic carbon, and sulphur dioxide (and CO2). These
trends can be translated into likely changes in temperature26.
Recent policies lead to roughly 0.09 ± 0.04°C less warming
due to methane, 0.04 ± 0.02°C less warming due to CO2, and0.17 ± 0.11°C less cooling due to sulphate in 203027. These
results evidence that, in the near term, the net warming due
to reductions in CO2 and co-emissions (primarily sulphur
dioxide) is roughly offset by reductions in SLCP, primarily
methane. Modelling results highlight that SLCP holds a
substantial additional emission reductions potential, as
described in section 6.3.

Table 6.1: Warming mitigation resulting from SLCP emission reductions
Additional SLCP mitigation

Change in temperature (°C)
2030

2050

All SLCPs (HFCs following the Kigali Amendment)

0.22 ± 0.11

0.59 ± 0.27

Methane0.09 ± 0.03

0.30 ± 0.12

HFCs following Kigali Amendment

0.005 ± 0.002

0.07 ± 0.02

HFCs Maximum Feasible Reduction

0.02 ± 0.01

0.10 ± 0.03

Black carbon-rich sources

0.1 ± 0.1

0.2 ± 0.2

Note: The estimates in the table represent departures from the estimates associated with the International Energy Agency’s ‘current policies’ scenario (see the main
text for details). HFCs stands for hydrofluorocarbons. HFCs Maximum Feasible Reduction includes Kigali Amendment.
Source: Own elaboration.

25 This is due to the assumptions made about the effectiveness of cooking
stove programmes, and the large increases in diesel vehicle emissions insome regions.

54

26 To do so, we used the complementary analyses described in Shindell et al.
(2017b) that included:•a simple energy-balance calculation, incorporating climate response
functions based on the CMIP5 models (Geoffroy et al., 2013);•
estimate of the impact of emissions on the carbon cycle (Gasser et al., 2017);•
updated radiative forcing for methane, including shortwave absorption(Etminan et al., 2016).
27 Smaller changes due to other pollutants are not reported here.

The Emissions Gap Report 2017 – Bridging the gap – The role of short-lived climate pollutants

Figure 6.3: Temperature trajectories from 2015-2050 in response to historical emissions and post-2017 projections
Global mean surface temperature change (°C)
1.4
1.2

Reference-SSP3-Ref

1.0

GAINS-IEA-updated
policies

0.8
0.6

Migaon (SLCP);
no Kigali Amendment+ Kigali Amendment+ Maximum reduconpotenal HFC

0.4
0.2
0
2015

2020

2030

2040

2050

Source: Own elaboration.

Additional SLCP mitigation could avert a large fraction ofprojected warming over the near term (figure 6.3 and table
6.1). By 2050, methane reductions contribute the largest
share (table 6.1). Realizing the maximum emission reduction
potentials for emissions of hydrofluorocarbons, thus going
beyond what is envisaged in the Kigali Amendment to
the Montreal Protocol, would lead to fourfold additionalsavings by 2030 (figure 6.1)28. The remaining half to
one third of the benefits stem from the net impactof the measures targeting black carbon-rich sources.
Figure 6.1 illustrates the near-term mitigation potential forblack carbon using 20-year global warming potentials. By
2030, such near-term mitigation potential is roughly threequarters that of methane. As noted, however, understanding
the full impact of measures to mitigate black carbon
requires an assessment of the impact of all pollutants
affected. Compared to methane, changes in emissionsof black carbon lead to faster changes in concentrationsof black carbon. When the effects of organic carbon andcarbon monoxide from black carbon-rich sectors are taken
into account, the net impact on 2030 temperatures isalso about three quarters that of methane. This fraction
decreases over time, as methane concentrations adjust
more fully to emissions changes. By 2050, the black carbon
mitigation potential is approximately two thirds thatof methane, but the temperature response is just over
50 percent (again, including co-emissions of black carbon).
This shows that mitigation potentials using 20-year global
warming potentials can be a useful, but only rough, guideto near-term temperature impacts. For the longer term,
the 2030 additional mitigation potential for methane isabout 3 GtCO₂e per year (using a 100-year global warming

28 With hydrofluorocarbons, emissions reductions are phased in early: in 2050,
additional gains would reach about 30 percent, which represents a much
more moderate rate in reductions, compared to those achievable by 2030.

potentials of 21), and roughly 5 GtCO2e per year (using
updated 100-year global warming potentials of 34)29.
The relatively large near-term warming mitigation potentials
presented above are similar to those in several prior studies.
Excluding hydrofluorocarbons, they are similar to theresults presented in (UNEP/WMO, 2011) and Shindell etal. (2012). Warming mitigation values are slightly larger in
2050, consistent with the inclusion of additional mitigation
measures in this analysis, along with the extension of
SLCP mitigation through 2050, which offset the decrease
in benefits associated with the later start in mitigation.
Including hydrofluorocarbons, values for 2050 are similar to
those reported elsewhere (Xu et al., 2013)30.

29 A reduction of that magnitude, sustained for 100 years, would be equivalent
to reducing CO₂ emissions by 170 GtCO₂ in one year (Allen et al., 2016).
30 Other research found smaller warming mitigation from SLCPs, althoughcompared to reference cases with reduced SLCP emissions. For example,
Smith and Mizrahi (2013) used a model that assumed that (i) all control
measures with a negative cost automatically happen based on ‘rational
economic behaviour’, and (ii) projected increases in wealth worldwide lead
to automatic adoption of strict emission control standards. Therefore, in
essence this study calculated benefits of additional efforts to remove SLCPs
after many of the available emissions control had already happened. Anotherstudy explored many possible reference cases, unsurprisingly reporting
smaller SLCP-related benefits in comparison to reference cases with relatively
low SLCP emissions, and similar values in comparison with high-SLCP emission
reference cases akin to those seen in the detailed modelling presented
above (Section 6.2) (Rogelj et al., 2014). In comparison with reference cases
incorporating stringent climate mitigation policies focused on CO₂, thatstudy found a substantial decrease in the mitigation potential for SLCPs. This
reflects the overlap mentioned previously between stringent CO₂ controlsthat transition away from fossil fuel use (covering energy-related methane
emissions and diesel-related black carbon emissions). Those results are
consistent with the drop in black carbon emissions under the Shared SocioEconomic Pathway – narrative 3 3.4 W/m2 scenario relative to the Shared
Socio-Economic Pathway – narrative 3 reference scenario shown in figure 6.1,
although such scenarios also include structural changes (for example, withregard to renewable sources of energy, energy access or electric vehicles),and increased energy access for the poor, which may be more difficult torealize than technical SLCP control measures, and would likely take longer
to materialize.

The Emissions Gap Report 2017 – Bridging the gap – The role of short-lived climate pollutants

55Given the potential for enhanced SLCP reductions to reduce
warming substantially in the near term, relative to current
policies, such reductions could clearly help to close theemissions gap defined by long-term global mean annual
average temperature. They could also help offset near-termwarming caused by CO₂ mitigation strategies. Near-term
SLCP mitigation is also a critical lever for slowing the rateof change in the next few decades, which is particularly
important for reducing cumulative climate impacts, such as
sea-level rise. Hu et al. (2013) found that curbing emissionsof SLCPs immediately can reduce the rate of sea-level riseby approximately 18 percent by 2050, while immediate
reductions in CO2 would yield minimal benefits with regard
to sea-level rise. Delaying SLCP mitigation by 25 years
could decrease the impact of both CO2 and SLCP mitigation
on sea-level rise by approximately 30 percent. Not least,
reducing near-term warming can also decrease risks of lowprobability, high-impact climate change effects (Xu andRamanathan, 2017).

6.5 Implications for the Sustainable
Development Goals and other policy goals
This chapter assesses the role of SLCPs, including black
carbon (a component of particulate matter) and methane, inbridging the emissions gap. In addition to the climate change
mitigation benefits associated with curbing emissions of
SLCPs, a reduction in emissions of these pollutants would
contribute significantly to the achievement of several of theUnited Nations’ Sustainable Development Goals (SDGs)31.
The SDGs capture key human and planetary needs andchallenges, and achieving them by 2030 requires coordinatedactions on diverse fronts. Implementing SLCP mitigation
measures can clearly contribute to the achievement ofmultiple SDGs, because of the impact of SLCPs on climatechange and air pollution32.
Residential combustion of solid fuels in traditional cooking
stoves and the use of kerosene for lighting in the AsiaPacific and African regions results in very high levels ofindoor air pollution (Karekezi et al., 2006). The World HealthOrganization has estimated that indoor and ambient air
pollution cause 6.5 million premature deaths, recognizing
it as “the single most important environmental health risk
factor worldwide”, and noting that it is driving a global healthemergency (WHO, 2016). The provision of modern andclean energy forms for meeting these basic requirements,
particularly those of rural households, would not only help
reduce the emissions gap, but would also help achieve SDG 3
on ensuring healthy lives and promoting well-being, SDG 4

31 The majority of black carbon emissions are accounted for by the AsiaPacific region (including China), followed by Africa. Emissions come largely
from residential combustion of fuels and diesel burning in the transport
sector. Sources of black carbon also emit a large proportion of precursors of
tropospheric ozone globally. Methane is another significant precursor of theincreasing background levels of ozone.
32 SLCP mitigation is also complementary to CO₂ mitigation: many SLCP
mitigation strategies can yield CO₂ mitigation co-benefits, and vice versa(Haines and et al., under review).

56

on ensuring inclusive education, SDG 5 on empowering womenand girls, and SDG 15 on sustainable forests (Griggs et al., 2014).
Tropospheric ozone is also harmful to human health. Recent
estimates show that the significance of this pollutant as acause of premature mortality is higher than had previously
been estimated (Malley et al., 2017). In addition, troposphericozone is the pollutant that causes the most significant crop
yield losses. Therefore, early action on sources of SLCPs could
lead to a rapid reduction in these adverse impacts.
Another key area of global concern is the increasing levels ofpollution in urban areas. Urbanization is a global megatrend,
and it is expected that nearly 70 percent of the world’s
population will be living in urban areas by 2050 (comparedwith 54 percent in 2014). The major causes of urban air
pollution, namely transportation and industrial activity, arealso major contributors to SLCP emissions. Improving fueland technology choices in the transport sector, banning
the open burning of biomass and waste in urban areas, andimproving energy efficiencies, all contribute to reducing
SLCPs. In doing so, these initiatives would also contribute toachieving several SDGs (Cherian, 2015): SDG 2 on sustainableagriculture, SDG 3 on health, SDG 7 on energy, SDG 11 on
inclusive and sustainable cities, and SDG 12 on sustainableproduction and consumption.
Actions to reduce SLCP emissions can be synergistic withefforts to improve energy efficiency. For example, whencoupled with energy efficiency policies, measures tophase out hydrofluorocarbon-based refrigerants can save
between 340 GW and 790 GW of peak power load globally,
while also avoiding about 98 Gt of CO₂ emissions by 2050
(Shah et al., 2015).
Despite widespread efforts to reduce emissions of several air
pollutants, especially sulphur dioxide, nitrogen oxides, andparticulate matter, in several regions air pollution will not
improve enough to reduce the burden on human health (IEA,
2016). On the contrary, regional demographics, rising energy
use and urbanization may lead to growth in the number ofpremature deaths due to outdoor air pollution, especially in
Asia. However, introducing efficient reduction measures in
the power sector, industry, and transport, and accelerating
access to clean energy for cooking — measures that arecompatible with an SLCP mitigation strategy — could reduce
the number of premature deaths significantly (IEA, 2016).
These results are consistent with those of Schmale et al.
(2014), who estimated that, by halving the concentrations of
SLCPs in the atmosphere, more than 40 million deaths from
respiratory and cardiovascular diseases could be avoided
by 2030.
Compared to introducing policies to mitigate SLCPs,
introducing policies to implement the SDGs is often morefeasible politically. For this reason, the latter can be used to
exploit the opportunity of reducing emissions of SLCPs.

The Emissions Gap Report 2017 – Bridging the gap – The role of short-lived climate pollutants

Reductions in emissions of SLCPs offer significant potential
to slow the rate of near-term warming, contribute to theachievement of the long-term Paris Agreement temperaturetargets, improve well-being via improved air quality, andfacilitate the achievement of several SDGs. Althoughtechnical control measures already exist and have been
demonstrated, scaling up those measures to their fullpotential would require dedicated policy efforts beyond
those embodied in either current policies or low-carbon
policies. Ideally, by aggressively reducing both SLCPs andCO₂, policies would optimize the societal welfare associatedwith efforts to curb climate change, improve air quality andachieve sustainable development.

6.6 Key messages
Large reductions in emissions of short-lived climate pollutants(SLCPs) are an important part of mitigation efforts in virtually
all scenarios that meet the 2ᵒC target, and especially thosethat meet the 1.5ᵒC target.
Reductions in SLCP emissions cannot be considered
equivalent to reductions in long-lived greenhouse gases, asmany impacts are not directly proportional to global mean
temperature change at a given point in time. For this reason,climate change mitigation policies need to consider thesetwo classes of emissions separately.

Significant SLCP mitigation potential, beyond existingcommitments, is available via proven technologies. However,to unlock that potential requires dedicated policy action tostrengthen legal frameworks and institutional capacities.
This is because many SLCP mitigation strategies are distinct
from strategies to reduce CO2 emissions.
Over the period 2018–2050, stringent SLCP reductions
based on existing, demonstrated technical measures could
reduce warming by between 0.3ᵒC and 0.9ᵒC relative tocurrent emissions projections. Roughly half of the mitigation
potential is associated with methane, one third with black
carbon, and the remainder with hydrofluorocarbons. As
some policies that reduce CO2 emissions also reduce SLCP
emissions, a substantial portion of SLCP reductions could
be achieved through CO2 mitigation efforts. However,compared with policies specifically targeting SLCP controls,
the reductions in SLCP emission resulting from CO2 mitigation
efforts would be slower.
Reduction of SLCP emissions, specifically black carbon, mightplay an important role in mitigating the regional impacts ofclimate change.

Early reductions in SLCP emissions would provide substantial
health benefits, limit the short-term rate of climate change,
slow self-amplifying feedbacks, and facilitate the achievementof the Paris Agreement’s long-term temperature target.

The Emissions Gap Report 2017 – Bridging the gap – The role of short-lived climate pollutants

57

Chapter 7

Bridging the Gap – Carbon
dioxide removal
Lead authors: Pete Smith (University of Aberdeen), Julio Friedmann (Carbon Wrangler, LLC)
Contributing authors: Sabine Fuss (Mercator Research Institute on Global Commons and Climate Change), Noah Deich (Center for Carbon Removal), Giana Amador (Center for Carbon Removal), Jan Minx (Mercator Research Institute on Global Commons and Climate
Change), Mark G. Lawrence (Institute for Advanced Sustainability Studies, Potsdam), Mercedes Bustamante (Departamento de Ecologia,
Universidade de Brasília), Omar Masera (Institute for Ecosystem Research and Sustainability, Universidad Nacional Autónoma de Mexico),
Annette Cowie (New South Wales Department of Primary Industries/University of New England), Oliver Geden (German Institute forInternational and Security Affairs)

7.1 Introduction
Carbon dioxide removal (sometimes called carbon removal
or CDR) refers to a cluster of technologies, practices andapproaches that remove and sequester carbon dioxidefrom the atmosphere. Despite the common denominatorof removing carbon dioxide, these technologies can bevery different. To put it simply, one can distinguish between
biological and engineered options. For some of the

Figure 7.1: Major strategies for negative emission technologies.

NATURALFOR
REST
ESTRYY / AGRICULTURE

COMBINED

NATURAL + TECHNOLOGICALTECHNOLOGICAL

ENERGY / IND
DUSTRYAﬀorestation/
Reforestation
Tree growth takes up CO₂
from the atmosphere

Biochar
Partly burnt biomass is added
to soil absorbing additional CO₂

Soil Carbon Sequestration
Land management changes
increase the soil carbon
content, resulting in a net
removal of CO₂ from theatmosphere

Accelerated Weathering
Natural minerals react with
CO₂ and bind them in newminerals
Bioenergy with
Carbon Capture andStorage (BECCS)
Plants turn CO₂ into
biomass that fuels
energy systems; CO₂from conversion isstored underground

Other Land-Use/Wetlands
Restoration or construction ofhigh carbon density, anaerobic
ecosystems

Less costly
Closer to deployment
More vulnerable to reversal
Note: This figure includes the major strategies that have been discussed in the literature so far (Minx et al., 2017).

58

The Emissions Gap Report 2017 – Bridging the gap – The role of short-lived climate pollutants

Direct Air Capture
CO₂ is removed fromambient air and stored
underground
Ocean Alkalinity
Enhancement
Alkaline materials areadded to the ocean toenhance atmosphericdrawdown and negate
acidiﬁcation
CO2 to Durable Carbon
CO₂ is removed from theatmosphere and bound inlong-lived materials

More costly
Greater R&D needs
Less vulnerable to reversal

former (such as afforestation, reforestation or soil carbon
management), experience has been accumulated overdecades. Conversely, experience is limited with regard to
the latter (notably direct air capture, or bioenergy combinedwith carbon dioxide capture and storage). Some approaches
would be more difficult to implement than others, forexample, using the ocean as a common-pool resource,which would require coordination on an international scale.
The leading technologies and approaches considered here
are shown in figure 7.1.
Importantly, carbon dioxide removal is not the same as solar
radiation management (Royal Society, 2009). This distinction
is critical and was emphasized by the United States National
Academy of Sciences, which has reviewed approaches tosolar radiation management (USNAS, 2015a) and to carbon
dioxide removal (USNAS, 2015b). While solar radiation
management may prove important for mitigating climatechange in the future (Keith et al., 2017), it is not the subjectof this chapter. Instead, this chapter focuses on reducing
carbon dioxide concentrations in the atmosphere throughactive management.
Carbon dioxide removal options have become a common
feature in climate change mitigation scenarios that areconsistent with the goals of the Paris Agreement (Clarke etal., 2014; van Vuuren et al., 2013; Fuss et al., 2014). Given
that carbon budgets are tight and rapidly being depleted(Rogelj et al., 2016; IPCC, 2014), carbon dioxide removal

options are more widely used to compensate for temporary
budget overshoot.
Carbon dioxide removal and the deployment of negativeemissions approaches must be employed in addition to othermitigation options (such as those discussed in Chapter 4).
Stated differently, carbon dioxide removal is concernedwith the management of overshoot, even in the event that
all mitigation options are pursued. For example, limiting
deforestation and improving forest management are key
undertakings to reduce current emissions and avoid future
emissions. However, necessary as they are, these practices
are quite different to afforestation, which is the practice ofadding forests to areas where there are none today.
In many scenarios, net negative emissions occur in thesecond half of the 21st Century. However, negative emissions
are introduced much earlier, and to a greater extent, in thosescenarios. This is done to compensate for residual emissions
that are too difficult or too expensive to reduce at thelevel of climate policy ambition that the scenario seeks tocharacterize. Taken together, both climate dioxide removal
options represent the total or gross negative emissions
required in a particular scenario (figure 7.2).
From a wider portfolio of mitigation options, integrated
assessment models select negative emissions technologies
based on cost-minimization considerations1. Naturally,
the deployment of negative emissions technologies varies

Figure 7.2: The role of carbon dioxide removal in climate change mitigation.
GHG emissions (GtCO₂e/year)
80
70
60

Gross posive GHG emissions
CO₂ from fossil fuels, industry
and land use changes
CH₄, N₂O and F-Gases
al
usu
s as
s
e
in
Bus

50

other
GHG

40
30

Be

low

2°

Migated
GHG emissions

Examples of associated technologies

Convenonal
abatement technologies

C

CO₂

20

Net zero
GHG emissions

10

Emingtechnologies

0
-10
-20

Net negave
GHG emissions

Gross negave
CO₂ emissions
2010

2020

2030

2040

2050

2060

2070

2080

2090

Carbon removal
technologies

2100

Note: This figure shows emission reductions from conventional mitigation technologies combined with carbon dioxide removal. This exemplary scenario is consistent
with an at least 66 percent chance of keeping warming below 2°C relative to pre-industrial levels. Emission reductions are shown against a business-as-usual scenario
without any additional climate policies. Global net emissions levels turn to net negative towards the very end of the century, but carbon dioxide removal is already being
deployed much earlier. Some residual greenhouse gas emissions remain at the end of the century, as they are too difficult to mitigate in the scenario. Note that the
scenario used is different from the scenarios used in Chapter 3, which leads to small variations in emission levels and timing of negative emissions.
Source: Jérôme Hilaire (Mercator Research Institute on Global Commons and Climate).
1

Specifically, integrated assessment models determine the least-cost pathway
for the global economy to meet a given climate target (before additional
benefits are accounted for). They do so on the basis of assumptions about
technology costs and availability, alongside other macroeconomic factors (forexample, demand for energy and food).

The Emissions Gap Report 2017 – Bridging the Gap – Carbon dioxide removal

59

greatly from one scenario to the next, due to differencesin scenario design and the specifications of the particularmodel. Nevertheless, some robust patterns emerge acrossclusters of scenarios:• Scenarios consistent with the 1.5°C target dependon the large-scale availability of negative emissions
technologies. There are no scenarios available that cankeep warming below 1.5°C by 2100 without removing
carbon from the atmosphere via negative emissions
technologies (Fuss, 2017; Minx et al., 2017).
• In general, the deployment of negative emissions
technologies in the second half of the century occurs ona large scale, and with a very rapid scale-up to 8 GtCO2
per year by 2050 (range 5–15). By 2100 the median(2010–2100) removal of carbon dioxide via negativeemissions technologies is 810 GtCO2 (range 440–1,020).
This corresponds to about 20 years of global emissions atcurrent emission rates.
˚ In the 2°C scenarios with immediate climate action, themedian (2010–2100) deployment of negative emissions
technologies is considerably lower: 670 GtCO2 (range
320–840). In addition, the scale-up towards mid-century
is much slower.
• Delay in adequate near-term climate action swiftly
locks 2°C pathways deeply into negative emissions.
To limit warming to 2°C, current Nationally
Determined Contributions lead to pathways that are
fundamentally dependent on the large-scale availabilityof negative emissions technologies (like 1.5°C pathways
today, and with similar deployment rates and technology
upscaling requirements).
• Compared to emissions pathways that are less efficientin energy use, 1.5°C and 2°C emissions pathways thatfeature aggressive energy savings are less dependent on
negative emissions technologies.
It is worth noting that a few scenarios can meet the 2°C target
without the deployment of negative emissions technologies.
If the models select these technologies, it is because they
represent a cheaper mitigation option overall. This meansthat even in scenarios that are consistent with the 2°C
target, there is scope to considerably limit the deploymentof negative emissions technologies, compared to what we
see in economic optimization scenarios.

7.2. Land-based carbon dioxide
removal options
Land-based carbon dioxide removal involves technologies,
practices and approaches that harness the carbon removal
potential of land-based ecosystems, including forests,
wetlands, agricultural land and soils. As these systems
have been managed by humans for many years, there isa wealth of knowledge that can be readily applied todaywith confidence. In addition, these approaches present
opportunities to meet other global sustainability goals,
such as improved water quality, ecosystem restoration,
biodiversity preservation, food and nutrition security, job
creation and improved crop yields.

60

For these land-based options to contribute to carbon removal
at the scale of gigatonnes, new management approaches
that impact large land areas and ecosystems will be requiredin some cases. In others, traditional, sustainable practices
such as agroforestry may need to be applied2.
Many substantial uncertainties exist regarding effective
carbon dioxide removal rates, the volumes stored, theduration of effective sequestration under a changing climate
and the implications for ecosystem services provided
by the land in question. In this regard, carbon dioxide
removal in these systems may prove very different to othercurrent efforts. Ultimately, each option has its strengths,
uncertainties and constraints.

7.2.1 Afforestation and reforestation

Afforestation refers to planting trees on land not afforested inrecent history (usually 50 years or longer), while reforestationrefers to the replanting of trees on more recently deforested
land (Hamilton et al., 2010). Agroforestry practices entail the
integration of trees into agricultural systems, in combination
with crops, livestock or both. Afforestation, and reforestation,
and agroforestry projects form part of several voluntary andmandatory carbon-offset trading schemes worldwide (Diazet al., 2011; Miles and Sonwa, 2015).
Globally, the carbon dioxide removal potential forafforestation and reforestation options is quite significant—it has been estimated at between 4 and 12 GtCO2 per year
(Smith et al., 2016), with other recent estimates even higher,
at up to 28 GtCO2 per year (Griscom et al., 2017). Preparationand deployment can be done at a relatively modest cost3,
with the potential for co-benefits. The existence of various
projects today, and the experience of forest managers
worldwide, provide a high level of technical readiness forafforestation and reforestation options4. As such, afforestation
and reforestation are considered established carbon dioxide
removal options and projects could feasibly be launched soon.
Ultimately, achieving large carbon removal rates and volumes
would require very large tracts of land (Houghton et al.,2015; Kriedenweis et al. 2016) and potentially huge volumesof water (Trabucco et al., 2008), although vegetation density
is positively correlated with the strength of precipitation
sheds and has a moderating effect on the volatility of water
availability—in this regard, distant effects might be different
and as such, more research is required. Competition forland and water used for food production is a development
concern, but could be minimized through agroforestry5 or
careful selection of appropriate land areas for afforestation
and reforestation. There are significant uncertainties around
2

3
4
5

While agroforestry is widely present in the tropics, there are manyagroforestry systems in temperate and even boreal regions. For example,
according to Aertsens et al. (2013), 90 percent of Europe’s mitigation
potential in the agriculture sector stems from agroforestry.
For example, Nielsen et al. (2014) report that, within the United States ofAmerica, up to 730 MtCO2 per year might be sequestered at a carbon pricebelow US$50 per tonne of carbon.
Political and planning readiness varies between countries.
Such competition is avoided in agroforestry systems, which allow integrated
management of agricultural landscapes for food production and the deliveryof ecosystem services (Zomer et al., 2016; Kimaro et al., 2011; WilliamsGuillén et al., 2008).

The Emissions Gap Report 2017 – Bridging the Gap – Carbon dioxide removal

the impacts on non-carbon dioxide greenhouse gases(Benanti et al., 2014), albedo (Kirschbaum et al., 2011;
Zhao and Jackson, 2014), evapotranspiration, emissions ofvolatile organic compounds and other issues6. Obstacles may
also arise with regard to monitoring, sustaining sequesteredcarbon in the long term due to sink saturation, changing
practices among forest managers and farmers, and creating
market and policy contingencies. Despite these uncertainties
and obstacles, experience with managing forests stands inour favour for adopting these options, which, as previously
mentioned, also have the potential to contribute to otherglobal sustainability goals.

7.2.2 Other ‘natural’, land-based solutions

Other natural, land-based carbon dioxide removal solutions
rely on the restoration or construction of high carbon density,
anaerobic ecosystems, including “inland organic soils
and wetlands on mineral soils, coastal wetlands including
mangrove forests, tidal marshes and seagrass meadows,
and constructed wetlands for wastewater treatment”(IPCC, 2014). Hereinafter, these solutions are referred toas wetlands. It is increasingly critical to not only preserve
existing wetlands, but also to restore and construct theseecosystems for use as carbon dioxide removal solutions.
Peatlands and coastal wetlands store up to 44 to 71 percentof the world’s terrestrial biological carbon pool (Zedler andKercher, 2005). While the carbon stocks in peatlands andcoastal wetlands are now vulnerable to reversal (Parish etal., 2008), these ecosystems also have significant carbon
sequestration capacity (Page and Hooijer, 2016).
Compared to afforestation and reforestation options, muchless is known about wetlands. Roughly one third of global
wetland ecosystems had been lost by 2009 (Hu et al., 2017),
suggesting there are a number of locations where work could
begin. Long-term sequestration rates in wetlands range from
0.1 to 5 tonnes of carbon per hectare and per year, a ratethat significantly improves when emissions avoided from(previously degraded) restored wetlands are counted (Parish
et al., 2008; Mitsch et al., 2012; Smith et al., 2008). However,estimating global rates and volumes is challenging. Carbon
dioxide abatement costs for wetland restoration range from
US$10 to US$100 per tonne of carbon dioxide (Worrall etal., 2009), suggesting potential low-cost options for projects.
Little is known about the total land and water requirements
needed to achieve substantial and sustainable levels ofcarbon dioxide removal through wetlands. However, noncarbon dioxide greenhouse gases represent a substantial
risk. While wetlands store significant amounts of carbon inabove- and below-ground biomass, and in soil, they havealso historically been a significant source of methane, withestimates ranging from 20 to 25 percent of global methane
emissions (Mitsch et al., 2012). As such, restoring somewetlands could induce a short-term net warming effect(Mitsch et al., 2012) due to increased emissions of methane
6

These uncertainties could be reduced or better characterized through a
dedicated science programme aimed at understanding the issues acrossecosystems, latitudes and climate zones.

and nitrous oxide7. In addition, while some sites may besuitable for early remediation, in other instances, sites offormer wetlands have been converted to ports, industrialsites and other high-value capital assets, which limits
the extent to which they can be used for carbon dioxide
removal. Griscom et al. (2017) estimate that avoided coastal
wetland impacts, avoided peat impacts and peat restoration
could deliver 0.3, 0.7 and 0.8 GtCO2 per year, respectively, by2030. As with forest management, wetlands and peatlands
have been managed by humans for many years, which
provides an opportunity to capitalize on existing knowledge
and on the readiness to implement measures (Griscom etal., 2017). There is also the added potential to contributeto other global sustainability goals such as improved water
quality, ecosystem restoration, biodiversity preservation andjob creation.

7.2.3 Soil carbon sequestration

Soil carbon sequestration occurs when a change in land
management practices increases the carbon content of soil,
thus resulting in a net removal of carbon dioxide from theatmosphere. Since the level of carbon in the soil is a balanceof carbon inputs (for example, from litter, residues, roots
or manure) and carbon losses (mostly through respiration,
which is increased by soil disturbance), practices that either
increase inputs or reduce losses can promote soil carbon
sequestration. Lal (2011, 2013) and Smith et al. (2008, 2014)cite a large number of land management practices that canpromote soil carbon sequestration, some of which can also
promote carbon sequestration in above-ground biomass.
Soil carbon sequestration uses agricultural and land
management practices that are generally well known by
farmers and land managers, and for the most part, does not
require additional machinery or infrastructure. It therefore
represents a readily available option to be implemented.
Rates for soil carbon sequestration vary considerably,
depending on land management approaches, soil typeand climate region (Smith, 2012; Lal, 2013). When scaled
globally, the technical potential for soil carbon sequestration
is estimated at 4.8 GtCO2e per year (Smith, 2016)8. Assuming
unit costs between US$20 and US$100 per tonne of carbon,
the global carbon emissions mitigation potential of soil
carbon sequestration ranges between 1.5 and 2.6 GtCO2e
per year (Smith et al., 2008; Smith, 2016). It is worth notingthat for some systems, such as croplands and grazing lands,
soil carbon sequestration costs range from minus US$45 toplus US$10 per tonne of carbon (Smith, 2016), suggesting
there are revenues and cost savings to be made from some ofthese practices9. Smith (2016) estimated that carbon dioxide
removal through soil carbon sequestration at a rate of

7
8
9

Dedicated and sustained research is needed to resolve or reducethese uncertainties.
Other estimates range between 0.4 GtCO2e per year (Powlson et al., 2014)
and 11.4 GtCO2e per year (Lal, 2011; Lal, 2013; Minasny et al., 2017).
Most of the annual estimates are based on sequestration values calculated
over 20 years. Given that sinks saturate, annualized sequestration
estimates should be multiplied by 20 to derive the total cumulative
sequestration potential.

The Emissions Gap Report 2017 – Bridging the Gap – Carbon dioxide removal

61

2.6 GtCO2e per year would save US$7.7 billion, comprising
US$16.9 billion of savings and US$9.2 billion of costs.
Although the apparent energy costs for soil carbon
sequestration appear low, and in many cases, soil carbon
sequestering practices would benefit soil ecosystems andagribusinesses, implementing these practices involves asignificant range of potential land requirements (Smith et al.,2010). While emissions from methane may be limited, soil
carbon sequestration may result in emissions of nitrous oxide(Smith, 2016). As for wetlands, dedicated and continued
research on these uncertainties and challenges could help
reduce risks and improve performance.
Barriers to implementation include lack of knowledge
among farmers, lack of policy incentives, monitoring andverification of practices and costs and crucially, reversibilityof stored carbon. Dedicated pilot projects and programmes
could help to identify the measures required to overcome
these barriers, with an emphasis on learning-by-doing andresolving key uncertainties through data acquisition anddevelopment of practices. Since soils have been managed formillenniums, there is a high level of knowledge and readiness,with the potential to contribute to other global sustainability
goals such as improved water quality, ecosystem restoration,
biodiversity preservation, job creation and increased yields
and food security.

7.2.4 Biochar

Biochar is produced through pyrolysis of biomass into astable, long-lived product, such as charcoal. Biochar is
resistant to decomposition (Lehmann et al., 2015) and canstabilize organic matter added to soil (Weng et al., 2017).
It can form long-term carbon pools in the soil and provide
a range of soil fertility and soil quality co-benefits, suchas improved water and nutrient retention, increased soil
porosity and higher crop yields.
While biochar can be applied at high rates (Genesio et al.,2012; Zhang et al., 2010), the net benefits of biochar are likely
to be higher if applied in low volumes in the most responsive
soils10. The carbon dioxide removal potential throughbiochar is high: it has been estimated at between 1.8 and
3.3 GtCO2e per year (Woolf et al., 2010). However, theefficacy of biochar for carbon dioxide removal is disputed11.
Costs range between US$18 and US$166 per tonne ofcarbon dioxide-equivalent per year (Woolf et al., 2010),
although economic benefits and revenues could offset partof this cost.
Although biochar is an established technology, it is not
yet widely applied, in part due to costs and the (limited)availability of infrastructure. Additional infrastructure(namely pyrolysis facilities) would be required for large-scale
implementation. Indeed, the quantity of biomass available
for biochar production is a key factor limiting the global
10 Notably after enhancement through co-composting or nutrient addition(Joseph et al., 2013).
11 Interestingly, biochar can reduce non-carbon dioxide greenhouse gases,
notably nitrous oxide (Cayuela et al., 2015).

62

potential for carbon dioxide removal through biochar. Energy
and water are also required to produce the crop feedstocks,
although producing biochar can also produce power andfuels12. While the land use for carbon dioxide removal
through biochar appears relatively modest (between 26 and95 million hectares), estimates are dependent on land andcrop quality. Not least, carbon dioxide-reduction benefits
may be mitigated by albedo reduction (Bozzi et al., 2015).
Although the risks of reversibility and difficulty of monitoring
are lower than for soil carbon sequestration, barriers suchas limited knowledge of practice or policy support remain.

7.3 Combined land/technology-based option:
bioenergy with carbon dioxide captureand storage
Bioenergy with carbon dioxide capture and storage removes
carbon dioxide from the atmosphere through the cultivationof biomass (bioenergy), and stores carbon dioxide fromenergy generation in deep, geological formations (carbon
dioxide capture and storage), providing net carbon removal.
So far, this is the carbon dioxide removal technology that hasfeatured most prominently in the mitigation scenarios by
the Intergovernmental Panel on Climate Change (Fuss et al.,2016; Fuss, 2017).
Many integrated assessment models estimate the availabilityof sustainable bioenergy at 100 exajoules per year (Creutzig
et al., 2015; Slade et al., 2014)13; fewer models accommodate
estimates above 300 exajoules per year.
With regard to carbon dioxide capture and storage, estimatesfor geological storage capacity are well above 5,000 GtCO2.
However, the estimated capacities are not viable in all
locations (Scott et al., 2015; De Coninck and Benson, 2014;
Lassiter and Misra, 2016; Global CCS Institute, 2016).
The combined potentials of bioenergy and carbon dioxide
capture and storage in 2050 are estimated at between 2 and18 GtCO2 per year (Kemper, 2015; USNAS 2015a; McLaren,2012). To achieve this scale, the demands on land use are
significant: a level of carbon dioxide removal consistent withaverage 2°C emissions pathways would require between
0.38 and 0.7 billion hectares of crops purpose-grown forbioenergy with carbon dioxide capture and storage (Smithet al., 2016)14. Under more conservative assumptions, thedemands on land use would be even higher (Monfreda etal., 2008).
Use of agricultural and forest residue as a feedstock forbioenergy does not require competition for land, although
its extraction can adversely impact soil carbon stocks(Smith et al., 2016). The potential competition for land
from widespread use of bioenergy with carbon capture and

12 Net energy balances remain controversial and dependent on process,feedstock and products.
13 Roughly, this represents 15 percent of global primary energy
consumption today.
14 For comparison, global agriculture today, including both farming and grazing,
requires roughly 5 billion hectares of land.

The Emissions Gap Report 2017 – Bridging the Gap – Carbon dioxide removal

storage remains a major issue for large-scale bioenergy withcarbon capture and storage deployment and policymaking.
In a scenario consistent with the 2°C target, infrastructure
investment costs associated with bioenergy with carbon
dioxide capture and storage in 2050 are estimated at
US$138 billion per year for power and US$123 billion
per year for fuels (Smith et al., 2016). Nonetheless, there
are significant variations in unit costs for bioenergy andwith carbon dioxide capture and storage, depending on
assumptions about feedstock, technology, supply chainsand logistics15.
For a level of bioenergy with carbon capture and storage
deployment consistent with a 2°C target, 170 exajoules per
year of energy would be generated from bioenergy withcarbon capture and storage by 2100 (Smith et al., 2016).
Bioenergy with carbon dioxide capture and storage could
have a large impact on water use, requiring about 720 km3
per year or roughly 3 percent of the fresh water currently
appropriated for human use (Smith et al., 2016). Non-carbon
dioxide greenhouse gas impacts are value-chain specific anduncertain, as are global albedo effects (Bright et al., 2015;
Jones et al., 2015). Taken together, these considerations
suggest that (i) over the next 10 to 20 years, carbon reduction
using combined land- and technology-based options will bechallenging; and (ii) there are risks associated with largescale implementation of these options.
Three main barriers stand out with regard to large-scale
implementation of bioenergy with carbon dioxide captureand storage. Firstly, carbon dioxide capture and storage
and bioenergy enjoy little public acceptance (Benson et al.,2012; Upham and Roberts, 2011; Wallquist et al., 2012; deBest-Waldhober et al., 2009). Secondly, whether there aresubstantial, or even any carbon reductions when accounting
for displaced activities is unclear (Havlík et al., 2011; Franket al., 2013; Searchinger et al., 2009; Plevin et al., 2010,
Creutzig et al., 2015; Popp et al., 2012). Thirdly, the lack of
economic incentives and the regulatory barriers related tounderground storage hamper large-scale implementation(De Coninck and Benson, 2014)16.
McLaren (2012) reports a technological readiness level of 4
to 6 for bioenergy with carbon dioxide capture and storage
from combustion and co-firing, and a technological readinesslevel of 5 to 6 for bioenergy with carbon dioxide captureand storage from ethanol fermentation (technologicalreadiness level 6 corresponds to “prototype demonstrationin the ‘relevant’ real-world environment” and technologicalreadiness level 4 to the stage of “component validation”).
Although individually, both bioenergy and carbon dioxide
capture and storage are relatively mature technologies, in
combination they have seen very little demonstration and
15 Estimates of cost per tonne of carbon dioxide range from US$60–250 (Kemper,2015), to US$70–250 (McLaren, 2012), to as little as US$15–45 for bioenergy
and carbon dioxide capture and storage from ethanol fermentation.
16 Current low carbon prices deter investments in bioenergy with carbon dioxide
capture and storage. The withdrawal of public support for these technologies(as was the same effect.

deployment, especially at a large scale. Whether bioenergy
with carbon dioxide capture and storage can thus be scaled
up in the manner required to achieve ambitious climatechange targets remains questionable, given the lag in actual
carbon dioxide capture and storage deployment, comparedto the requirements associated with emissions pathways
that are compatible with the 2°C target (Peters et al., 2017;
Peters and Geden, 2017).

7.4 Technology-based carbon dioxide
removal options
Man-made technologies to remove carbon dioxide from theair have been in use for many years, mostly in submarine,
aerospace and medical applications. Consideration of themas global-scale carbon removal agents is recent (USNAS,
2015a). They offer specific benefits in that they use very
little land or water, they do not emit non-carbon dioxidegreenhouse gases and they have very high levels of certainty
regarding the flux and long-term fate of the carbon dioxide
removed. Some approaches also produce materials that canbe used commercially, for example, cements and aggregates.
However, many approaches are expensive. Most have notbeen deployed at scale and have a low level of technicalreadiness. Investment in developing these options
will likely yield breakthroughs in material science andmanufacturing, and could spur new industries and a circularcarbon economy (McDonough, 2016; Center for Carbon
Removal, 2017), as was true for lithium-ion batteries
25 years ago (The Economist, 2017). Nonetheless, among the
23 countries committed to undertaking large-scale researchand development programmes in this and related areas,
only the United Kingdom has financed technology-basedcarbon dioxide removal programmes, and at a modest levelof £8.6 million (approximately US$11.3 million) per year
(NERC, 2017).
Each option has strengths, uncertainties and constraints. The
low level of readiness facing many technologies is perhaps
the most pressing issue.

7.4.1. Direct air capture

Direct air capture is the practice of separating carbon dioxidefrom ambient air, typically through chemical or physicalseparation (Lackner et al., 1999; Sanz-Peres et al., 2016). Early
approaches to this process have been applied in aerospaceand submarine settings, to provide environmental controls(Keith et al., 2006). To achieve carbon removal and negativeemissions, direct air capture would have to be combinedwith carbon-dioxide capture and storage or carbon dioxide
conversion to long-lived materials (see below)17.
To yield negative emissions, direct air capture combinedwith carbon dioxide capture and storage must be powered
predominantly by zero-carbon energy sources (wind, solar,
17 Several companies have fielded direct air capture units (Marshall, 2017;
Lassiter and Misra, 2016). Most of these produce fresh water as a by-product(American Physics Society, 2011). Niche applications could include the foodand beverage industry, semiconductor manufacturing and remote sites forenhanced oil recovery (Lassiter and Misra, 2016).

The Emissions Gap Report 2017 – Bridging the Gap – Carbon dioxide removal

63

geothermal, hydro and nuclear). Although this approach has
a technical potential above 20 GtCO2 per year, actual global
deployment is likely to result in reductions of between 2 and
5 GtCO2 per year (USNAS, 2015a).
Cost remains the largest barrier to deployment. Since direct
air capture involves separating carbon dioxide from air, andthe partial pressure of carbon dioxide in air is low, costs
can be between US$200 and US$600 per tonne (American
Physics Society, 2011)18. Like bioenergy with carbon
dioxide capture and storage, direct air capture combinedwith carbon dioxide capture and storage would require
functional scale deployment of carbon dioxide capture andstorage, which represents both a potential limit and cause
for renewed commitments to the technology (Center for
Carbon Removal, 2017).
It is worth noting that it is possible to directly separate
dissolved carbon dioxide from ocean water and from air.
This could provide an additional benefit as a local or global
countermeasure to ocean acidification. However, researchon dissolved ocean carbon dioxide is very recent and at very
low technical readiness levels (Willauer et al., 2014)19.

represented in the literature, thus necessitating additional
research in this area.
Since carbon dioxide is bound indefinitely in chemical form,
there is both high confidence in carbon dioxide retention
for many years, and robustness in accounting and validationof carbon storage and removal. For ex situ approaches,revenues from product sales, including agricultural
inputs or aggregate and cement for construction offer
an additional benefit (Monkman and MacDonald, 2015;
CO2Sciences, 2016)21.

7.4.3. Ocean alkalinity enhancement

The addition of alkaline materials to sea water enhances
the amount of carbon stored in the ocean. It draws carbon
dioxide from the atmosphere by shifting the equilibrium
between atmospheric carbon dioxide and dissolved
inorganic carbon in the ocean, which also serves to counter
ocean acidification. While ocean alkalinity enhancement
has received very little attention, compared to other carbon
dioxide removal options, it has the potential “to sequester
hundreds of billions to trillions of tonnes of [carbon]”(Renforth and Henderson, 2017).

7.4.2. Accelerated weathering of minerals

Ocean alkalinity can be enhanced in a number of ways:• Weathering of silicate and carbonate minerals on land,
resulting in the introduction of calcium and magnesium
ions into ocean waters (Hartmann et al., 2013;
Rau et al., 2007).
• Introducing calcium ions into ocean water by adding
calcium oxide or calcium hydroxide to sea water, a
procedure often referred to as ocean liming (Kheshgi,
1995; Renforth and Kruger, 2013).
• Electrolysis of sea water, often referred to aselectrochemical splitting, to increase aqueous sodiumhydroxide (House et al., 2007) or to accelerate thedissolution of calcium carbonate (Rau et al., 2004).

While the technical potential of accelerated weathering
is, in theory, unlimited (IPCC, 2005), the effective technicalpotential is not. This is due to the kinetics of most carbon
dioxide mineral reactions, which are slow and limit the viable
rates for carbon dioxide removal. Not least, the technicalpotential can be limited by the rate at which the groundmaterial can be applied to land (Smith et al., 2016, Taylor
et al., 2016). Global estimates of potential for accelerated
weathering of minerals are in the range of 0.7 and 3.7 GtCO2
per year (Lenton, 2014; Smith et al., 2016).

Few techno-economic assessments of these approaches
exist. Preliminary estimates range from US$10 to US$600
per tonne of carbon dioxide for weathering of silicate andcarbonate minerals, US$72 to US$159 per tonne of carbon
dioxide for ocean liming and US$14 to US$190 per tonne ofcarbon dioxide for electrochemical splitting (Renforth andHenderson, 2017).

It has long been known that natural weathering of mostrocks (silicates, carbonates and oxides) binds carbon dioxidefrom the atmosphere (Chamberlain, 1899; Raymo, 1991).
Accelerated weathering has been proposed as a meansof either drawing carbon dioxide from the air, binding it
permanently, or both (Lackner et al., 1995; Chiang and Pan,
2017). Much of this research proposes using rocks that arevery rich in iron, calcium and magnesium (ultramafic rocks)
as the primary feedstock, and reacting these in situ or ex situ
with carbon dioxide to form carbonate rocks and minerals,
locking away atmospheric carbon dioxide in the process(Kelemen and Matter, 2008).

While kinetics can be improved by grinding, drilling anddeep, in situ injection, adding heat or other energy sources,
or adding chemicals (such as strong acids), these approaches
dramatically increase costs and can increase the carbon
intensity of the overall process20. These estimates are poorly

The availability of suitable minerals close to oceans would
limit deployment. Notwithstanding, environmental concernsand governance considerations may prove to be the primarybarrier to implementation. Regarding the former, theconsequences of increased alkalinity on marine ecosystems
are poorly understood (Henderson et al., 2008)22.
Regarding the latter, the addition of alkaline materials tothe ocean would fall within the remit of the International

18 Specialized companies claim much lower prices today (a maximum of US$500
per tonne) and cost reductions of about 50 percent in the next 10 years.
19 Nonetheless, the United States Senate recently asked the National Academies
to undertake an assessment on the matter (Whitehouse, 2017).
20 Costs would range between US$20 and US$1,000 per tonne of carbon dioxide(USNAS, 2015a).

21 Early niche applications are likely at diamond, base-metal and asbestos
mines with tailings of carbon dioxide-reactive rocks that have already beenprocessed for primary mineral extraction.
22 Note that the addition of alkaline materials would counteract
ocean acidification.

64

The Emissions Gap Report 2017 – Bridging the Gap – Carbon dioxide removal

Maritime Organization, through the London Protocol to
the “Convention on the Prevention of Marine Pollution by
Dumping of Wastes and Other Matter” (also known as the“London Convention”)23.

from carbon dioxide-reduction approaches24. And finally,
they would have to develop international agreements withregard to the transboundary effects of these technologies(Schäfer et al., 2015).

7.4.4. Conversion of carbon dioxide tolong-lived products

There is currently limited discussion on carbon dioxide
removal issues in most subnational and international climate
policy forums. Policymakers might consider giving attention
to the importance of carbon dioxide removal, the risks
and challenges faced by leading carbon dioxide removal
solutions and the policy options for addressing these risks
and challenges (Williamson, 2016). This is because, toachieve the objectives of the Paris Agreement, mobilizing
a rapid reduction of greenhouse gas emissions will beessential. Carbon dioxide removal can play an important rolein meeting these objectives. However, to do so, enabling
actions on carbon dioxide removal will be required, including
more extensive policy discussions and focus on specificbarriers to deployment (Peters and Geden, 2017).

The concept of using carbon dioxide to produce chemicals
and materials was already being developed in the context ofchemical research in the 1970s, long before climate change
and the possibilities for removing CO2 from the atmosphere
entered the public debate (Aresta, 2010; Bruhn et al., 2016).
Most of these technologies have not been developed withlong-term storage of carbon dioxide in mind. In addition,
most materials based on captured carbon dioxide (forexample, polyurethane foams or fuels such as ethanol) only
have limited lifetimes in the context of the timescales thatare relevant to climate change (Aresta, 2013; CLCF, 2011). An
exception to this is carbonates, which are used to produce
cement-like construction materials in which long-term(decades to centuries) sequestration of carbon dioxide canbe achieved (von der Assen, Jung et al., 2013; Bruhn, 2016),
as noted above.
Recently, there has been new research and commercial
activity focused on converting carbon dioxide directly toother long-lived materials, including polymers, carbon fibre
composites, graphene, carbon black and even diamond (ICEF,
2017). Although these companies and research efforts arein their infancy, they have attracted substantial commercial
interest. Due to the early stages of development, it isdifficult to estimate the upscaling potential of the various
approaches. A recent estimate puts the annual market forthese materials between 1 and 7 GtCO2 per year, although
this is contingent on policy- and market-support actions(CO2Sciences, 2016).

Many key uncertainties can be explored using a learning-bydoing approach, notably by undertaking research and smallscale deployment activities (Lomax et al., 2015). All of theapproaches described in this chapter have initiated or caninitiate small- and large-scale pilot projects, from which dataon cost, performance and improvement opportunities canbe drawn (IEA, 2017). Some efforts, such as afforestation
or reforestation projects, have begun under the jurisdictionof United Nations programmes that could be expanded or
rapidly scaled up. Scenarios that show net emissions turning
negative in the second half of the 21st Century can givethe false impression that there is no urgency. However, toachieve those scenarios will require significant amounts ofgross negative emissions by 2030 at the latest (Rogelj et al.,2015; Anderson and Peters, 2016), and advancing techniques
to maturity usually takes decades.

7.6 Conclusions and recommendations

7.5. Governance issues for carbon
dioxide removal
Realizing the potential of carbon dioxide removal would
require large-scale investment in research (to reduce
key uncertainties), and development and deployment
incentives (to reduce costs). Governments can play a keyrole in providing the funding and incentives needed toachieve these investments (Lomax et al., 2015; Peters andGeden, 2017).

Carbon dioxide removal remains an important set ofundertakings following the Paris Agreement, to supplement
immediate and aggressive mitigation action. In order toachieve the goals of the Paris Agreement, to keep the global
mean temperature increase well below 2°C (or even below
1.5°C), carbon dioxide removal is likely a necessary step.

Firstly, government policy can work to protect communities
from any potential, negative side-effects (environmental,
economic, social, political and ethical) associated with largescale deployment of carbon dioxide removal solutions (Buck,2016). Secondly, governments can set consistent standards
for transparency, notably with regard to the measurement
and verification of carbon stored from a given carbon
dioxide removal solution (Zakkour et al., 2014). Thirdly,
they can require that standards accept products arising

Although there is much ongoing work worldwide on this
topic, the field of carbon removal remains very young(particularly for technology-based solutions), with relatively
little scholarship on the direct topic of carbon dioxide
removal. In some cases, efforts aimed at strengthening
approaches to carbon dioxide removal can build on deep
understanding and experience from other industries, forexample, agribusinesses or heavy industry. Nonetheless,specific questions concerning current and future costs ofcarbon dioxide removal options, the longevity of carbon
retention, the environmental consequences of scale-level

23 The London Convention is examining ocean alkalinity enhancement.

24 For example, the International Civil Aviation Organization (ICAO) standards
do not currently accept synthetic fuels made from carbon dioxide derived
from direct air capture.

The Emissions Gap Report 2017 – Bridging the Gap – Carbon dioxide removal

65

deployment of carbon dioxide removal and other key
questions remain largely unexplored. Critically, only one
country in the world (the United Kingdom) has a government
programme aimed explicitly at supporting carbon dioxide
removal (NERC, 2017).
In light of the above, there are four key recommendations
for consideration:• Governments around the world might carefully assess
the potential role of carbon dioxide removal in achieving
the goals of the Paris Agreement. They would benefit
from understanding these technologies and the potential
ancillary benefits they may provide to commerce andtrade, such as improved crop yields.
• Governments and other stakeholders could launch joint
research and development programmes on the many
pathways for carbon dioxide removal. Such programmes
would be appropriate, given that some carbon
dioxide removal options are only at the early stages ofdevelopment, and in light of the role they could play incurbing climate change. Both core scientific undertakings(for example, a decade-long science programme on
the carbon cycle in soil) and technology development
efforts (focused, for example, on novel materials andprocesses for direct air capture) could be included,
possibly structured around pilot programmes and earlydemonstration activities, where progress can be madequickly and early-action opportunities can be identified
and investigated.

66• Carbon dioxide removal presents specific challenges forlife-cycle accounting, which will directly affect accounting
standards, industrial standards, industrial and financial
practice, and regulation. Emissions trading in particularwould be complicated by carbon-negative approaches.
Overt and dedicated analysis and efforts would be
required to develop, refine and incorporate carbon
dioxide removal approaches into these commercial andgovernmental endeavours.
• Some approaches raise questions around global
governance in the near term (for example, ocean
alkalinity enhancement vis-a-vis the London Convention).
In addition, wide deployment of carbon dioxide removal
raises fundamental questions about how to appropriately
stabilize atmospheric carbon dioxide concentrations andhow to manage interests globally and among nations.
Dedicated working groups, perhaps modelled on the
Climate and Clean Air Coalition and their work on shortlived climate pollutants, could be formed and begin
discussing these issues.
• Since the land-based systems relevant for carbon dioxide
removal have been managed by humans for many years,
there is a wealth of knowledge that can be readily applied
today with confidence. Furthermore, these approaches
present opportunities to meet other global sustainability
goals, such as improved water quality, ecosystem
restoration, biodiversity preservation, food and nutrition
security, job creation and improved crop yields.

The Emissions Gap Report 2017 – Bridging the Gap – Carbon dioxide removal

The Emissions Gap Report 201767

References
Chapter 1
UNEP (2016). ‘The Emissions Gap Report 2016’, United Nations Environment Programme (UNEP), Nairobi. Available at: http://www.
google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0ahUKEwiAncDtsfPWAhViQZoKHZt9CrAQFggwMAE&url=http%3A%2F%2Fwedocs.unep.org%2Fbitstream%2Fhandle%2F20.500.11822%2F10016%2Femission_gap_report_2016.pdf&usg=A
OvVaw3gBleyjAH07zqiIjLQw9N2 [Accessed 15 October 2017].
UNEP (2015). ‘The Emissions Gap Report 2015’, United Nations Environment Programme (UNEP), Nairobi. Available at: http://­uneplive.unep.org/media/docs/theme/13/EGR_2015_Technical_Report_final_version.pdf [Accessed 15 October 2017].
UNFCCC (2017). ‘Initial feedback by Fiji and Morocco on the approach to the Facilitative Dialogue 2018 based on their consultations
with Parties’ United Nations Framework Convention on Climate Change (UNFCCC), Bonn Available at: http://unfccc.int/files/na/
application/pdf/preliminary_ideas.pdf [Accessed 20 October 2017].
UNFCCC (2015). ‘The Paris Agreement’, The Conference of the Parties. Available at: https://unfccc.int/resource/docs/2015/cop21/
eng/l09r01.pdf [Accessed 15 October 2017].

Chapter 2
Australian Government (2016) Australia’s emissions projections 2016. http://www.environment.gov.au/system/files/resources/
9437fe27-64f4-4d16-b3f1-4e03c2f7b0d7/files/aust-emissions-projections-2016.pdf: Department of the Environment andEnergy, Australia.
Bappenas (2015) Sekretariat RAN-GRK. Available at: http://apki.net/wp-content/uploads/2015/07/Presentasi-INDC-BAPPENAS-­­
di-KLHK.pptx.
BP (2017) Statistical review of World Energy 2016, British Petroleum, http://www.bp.com/en/global/corporate/energy-economics/
statistical-review-of-world-energy.html.
Climate Action Tracker (2017a) Action by China and India slows emissions growth, President Trump’s policies likely to cause US
emissions to flatten. Policy Brief Climate Analytics, Ecofys and NewClimate institute, Available at: http://climateactiontracker.
org/assets/publications/briefing_papers/CAT_2017-05-15_Briefing_India-China-USA.pdf [Accessed 7 August 2017].
Climate Action Tracker (2017b) Country assessment: Brazil (updated 17 May, 2017). Climate Action Tracker (Climate Analytics,
Ecofys, NewClimate Institute). http://climateactiontracker.org/countries/brazil.html (Accessed 27 August, 2017).
Climate Action Tracker (2017c) Country assessment: China (updated 17 May, 2017). Climate Action Tracker (Climate Analytics,
Ecofys, NewClimate Institute). http://climateactiontracker.org/countries/china.html (Accessed 27 August, 2017).
Climate Action Tracker (2017d) Country assessment: India (updated 17 May, 2017). Climate Action Tracker (Climate Analytics, Ecofys, NewClimate Institute). http://climateactiontracker.org/countries/india.html (Accessed 27 August, 2017).
Climate Action Tracker (2017e) Country assessment: Japan (updated 9 May, 2017). Climate Action Tracker (Climate Analytics, Ecofys, NewClimate Institute). http://climateactiontracker.org/countries/japan.html (accessed on 27 August, 2017).
Climate Action Tracker (2017f) Country assessment: South Africa (updated 6 July, 2017). Climate Action Tracker (Climate Analytics,
Ecofys, NewClimate Institute). http://climateactiontracker.org/countries/southafrica.html (accessed on 27 August, 2017).
Climate Action Tracker (2017g) http://climateactiontracker.org/.
Climate Advisers (2017) Trumpbacktracker. https://www.climateadvisers.com/trumpbacktracker/.
Climate Transparency (2017) Brown to Green: The G20 transition to a low-carbon economy. Climate Transparency, c/o HumboldtViadrina Governance Platform, Berlin, Germany, www.climate-transparency.org.
Climateinteractive (2017) What Slashing Climate Rules Means For the U.S. Pledge to Paris, Available at: https://www.climateinteractive.org/media-coverage/what-slashing-climate-rules-means-for-the-u-s-pledge-to-paris/
Den Elzen, M., Admiraal, A., Roelfsema, M., Van Soest, H., Hof, A. F. & Forsell, N. (2016a) Contribution of the G20 economies to theglobal impact of the Paris agreement climate proposals. Climatic Change, 137, 655-665.
Den Elzen, M. G. J., Fekete, H., Höhne, N., Admiraal, A., Forsell, N., Hof, A. F., Olivier, J. G. J., Roelfsema, M. & Van Soest, H. (2016b)
Greenhouse gas emissions from current and enhanced policies of China until 2030: Can emissions peak before 2030? Energy
Policy, 89, 224-236.

68

The Emissions Gap Report 2017 – ReferencesDepartment Of Environmental Affairs Republic Of South Africa (2011a) South Africa’s Second National Communication under theUnited Nations Framework Convention on Climate Change, Available at: http://unfccc.int/resource/docs/natc/zafnc02.pdf[Accessed 14 October 2016].
Department Of Environmental Affairs Republic Of South Africa (2011b) Explanatory note: Defining South Africa’s Peak, Plateau
and Decline Greenhouse Gas Emission Trajectory. Available at: http://www.climateaction.org.za/cop17-cmp7/sa-governmentposition-on-climate-change [Accessed 24 October, 2017]
EEA (2014) Trends and projections in Europe 2014. European Environment Agency, EEA Report No 6/2016, http://www.eea.europa.
eu/publications/trends-and-projections-in-europe-2014.
EEA (2016a) Total greenhouse gas emissions trends and projections — European Environment Agency [Online]. Available: http://
www.eea.europa.eu/data-and-maps/indicators/greenhouse-gas-emission-trends-6/assessment [Accessed 27 January 2017].
EEA (2016b) Trends and projections in Europe 2016 - Tracking progress towards Europe’s climate and energy targets. European
Environment Agency, EEA Report No 29/2016, https://www.eea.europa.eu/publications/trends-and-projections-in-europe.
Environment And Climate Change Canada (2017) Canadian Environmental Sustainability Indicators: Progress Towards Canada’s
Greenhouse Gas Emissions Reduction Target. https://www.ec.gc.ca/indicateurs-indicators/CCED3397-174A-4F0E-825891DCFE295B34/ProgressTowardsCanadaGHGEmissionsTarget_EN.pdf.
FAO (2017) FAOSTAT Production of live animals, crops, consumption of nitrogen fertilisers, burning – savannah. Available at: “http://
www.fao.org/faostat/en/” \l “data” [Accessed 24 October 2017] Figueres, C., Schellnhuber, H. J., Whiteman, G., Rockström, J.,
Hobley, A. & Rahmstorf, S. 2017. Three years to safeguard our climate. Nature, 546, 593-595, doi:10.1038/546593a.
Government of Canada (2016) Canada’s Second Biennial Report on Climate Change, Environment and Climate Change Canada,
https://www.ec.gc.ca/ges-ghg/02D095CB-BAB0-40D6-B7F0-828145249AF5/3001%20UNFCCC%202nd%20Biennial%20
Report_e_v7_lowRes.pdf.
Government of Japan. (2016) Japan’s Second Biennial Report Under the United Nations Framework Convention on Climate Change,
Available at: http://unfccc.int/files/national_reports/biennial_reports_and_iar/submitted_biennial_reports/application/pdf/
japan_br2_revised.pdf [Online]. [Accessed].
Government of Russia. (2014) First Biennial Report of the Russian Federation [Online]. UNFCCC, Bonn, available at: http://unfccc.
int/files/national_reports/biennial_reports_and_iar/submitted_biennial_reports/application/pdf/1br_rus_unoffical_translation_eng.pdf [Accessed 12 December 2014].
Government of Russia. (2015) Second Biennial Report of the Russian Federation [Online]. UNFCCC, Bonn, available at: http://unfccc.
int/resource/docs/2016/trr/rus.pdf. [Accessed 2015].
Government of Brazil (2010) DECREE No. 7390, 9 December 2010. http://www.planalto.gov.br/ccivil_03/_Ato2007-2010/2010/
Decreto/D7390.htm
Government of Mexico (2012a) Mexico. México quinta comunicación nacional ante la Convención Marco de las Naciones Unidas
sobre el Cambio Climático.: http://unfccc.int/resource/docs/natc/mexnc5s.pdf.
Government of Mexico (2012b) Programas para mitigar el cambio climático, Available at: http://www2.inecc.gob.mx/publicaciones/libros/685/programas2.pdf [Accessed 10 November 2015].
Grassi, G., House, J., Dentener, F., Federici, S., Den Elzen, M. & Penman, J. (2017) The key role of forests in meeting climate targets
requires science for credible mitigation. Nature Clim. Change, 7, 220-226.
Green, F. and Stern, N. (2017) China’s changing economy: implications for its carbon dioxide emissions. Climate Policy, 17, 423-442.
Hafstead, M. (2017) On Trump, Paris, and Greenhouse Gas Emissions. Retrieved August 7, 2017, from Resources for the Future:
http://www.rff.org/blog/2017/trump-paris-and-greenhouse-gas-emissions.
IEA (2015) World Energy Outlook 2016, Paris, France, International Energy Agency.
IEA (2017) IEA finds CO2 emissions flat for third straight year even as global economy grew in 2016, Paris, France, International
Energy Agency, https://www.iea.org/newsroom/news/2017/march/iea-finds-co2-emissions-flat-for-third-straight-year-evenas-global-economy-grew.html.
Jackson, R. B., Canadell, J. G., Le Quere, C., Andrew, R. M., Korsbakken, J. I., Peters, G. P. & Nakicenovic, N. (2016) Reaching peakemissions. Nature Clim. Change, 6, 7-10.
Janssens-Maenhout, G., Crippa, M., Guizzardi, D., Muntean, M., Schaaf, E., Dentener, F., Bergamaschi, P., Pagliari, V., Olivier, J. G. J.,
Peters, J. A. H. W., Van Aardenne, J. A., Monni, S., Doering, U. & Petrescu, A. M. R. (2017) EDGAR v4.3.2 Global Atlas of the threemajor Greenhouse Gas Emissions for the period 1970-2012. Earth Syst. Sci. Data Discuss., 2017, 1-55 (in review).
Kuramochi, T., Höhne, N., Hagemann, M., Sterl, S., El-Laboudy, T., Wouters, K., Deng, Y., Blok, K., Hare, B., Schaeffer, M., Cantzler, J.,
Rocha, M., Deryng, D., Rogelj, J., Sindt, J. & Yanguas Parra, P. (2016a) The ten most important short-term steps to limit warming
to 1.5°C. Climate Analytics, Ecofys and the Potsdam Institute for Climate Impact Research (PIK).
Kuramochi, T., Höhne, N., Sterl, S., Gonzales-Zuñiga, S., Hans, F., Hagemann, M., Hernandez Legaria, E., Den Elzen, M. G. J., Roelfsema, M., Van Soest, H., Forsell, N. & Turkovska, O. (2016b) Greenhouse gas mitigation scenarios for major emitting countries:
Analysis of current and planned climate policies, and mitigation pledges. Cologne, Germany: NewClimate Institute, PBL, IIASA,
http://www.pbl.nl/en/publications/greenhouse-gas-mitigation-scenarios-for-major-emitting-countries.
Ministry of The Environment and Sustainable Development Argentina. (2015) Tercera Comunicación Nacional del Gobierno de la
República Argentina a las Partes de la Convención Marco de las Naciones Unidas sobre Cambio Climático [Online]. Secretaría deAmbiente y Desarrollo Sustentable de la Nación. Available: http://unfccc.int/resource/docs/natc/argnc3s.pdf [Accessed 4 August2016].
Mitra, A., Chitkara, P., Ross, K., Singh, M., Sawhney, S., Keswani, S. & Batra, P. (2017) Pathways for Meeting India’s Climate Goals.
Washington DC, USA: World Resource Institute.
NCCS (2013) National Climate Change Strategy. 10-20-40 Vision. Mexico: Federal Government of Mexico.
Olivier, J. G. J., Peters, J. A. H. W. & Schure, K. M. (2017) Trends in global emissions of CO2 and other greenhouse gases: 2017 Report.
PBL report no. 2674, PBL Netherlands Environmental Assessment Agency, Bilthoven, the Netherlands, http://www.pbl.nl/en/
news/newsitems/2017/greenhouse-gas-emission-levels-continued-to-rise-in-2016.
PBL (2017) PBL Climate Pledge NDC tool, www.pbl.nl/indc. PBL Netherlands Environmental Assessment Agency.

The Emissions Gap Report 2017 – References69

Peters, G. P., Andrew, R. M., Canadell, J. G., Fuss, S., Jackson, R. B., Korsbakken, J. I., Le Quere, C. & Nakicenovic, N. (2017) Key indicators to track current progress and future ambition of the Paris Agreement. Nature Clim. Change, 7, 118-122.
Planning Commission Government of India (2011) Low Carbon Strategies for Inclusive Growth: An Interim Report. Interim Reportof the Expert Group on Low Carbon Strategies for Inclusive Growth, New Delhi, India, http://moef.nic.in/downloads/publicinformation/Interim%20Report%20of%20the%20Expert%20Group.pdf.
Planning Commission Government of India (2014) The Final Report of the Expert Group on Low Carbon Strategies for Inclusive
Growth. Interim Report of the Expert Group on Low Carbon Strategies for Inclusive Growth, New Delhi, India, http://planningcommission.nic.in/reports/genrep/rep_carbon2005.pdf.
Republic of Korea. (2016) Submission by the Republic of Korea: Intended Nationally Determined Contribution [Online]. UNFCCC.
Available:
http://www4.unfccc.int/ndcregistry/PublishedDocuments/Republic%20of%20Korea%20First/INDC%20Submission%20by%20the%20Republic%20of%20Korea%20on%20June%2030.pdf [Accessed 28 July 2017].
Republic of Turkey Ministry of Environment and Urbanization (2016) Sixth National Communication of Turkey. Ankara, Turkey.
Reputex (2016) Framing Australia’s 2030 energy & climate policy mix. The contribution of safeguard sectors to Australia’s 2030
emissions reduction target. http://www.reputex.com/wp-content/uploads/2016/09/0916_RepuTex-White-Paper_FramingAustralias-energy-policy-mix-to-2030.pdf: MARKET UPDATE | September 2016
Rhodium Group (2017) Taking Stock 2017: Adjusting Expectations for US GHG Emissions. Available at: http://rhg.com/reports/taking-stock-2017-adjusting-expectations-for-us-ghg-emissions.
Rockström, J., Gaffney, O., Rogelj, J., Meinshausen, M., Nakicenovic, N. & Schellnhuber, H. J. (2017) A roadmap for rapid decarbonization. Science, 355, 1269.
Sha, F., JI, Z. & Linwei, L. (2015) An Analysis of China’s INDC. Beijing, China: China National Center for Climate Change Strategy andInternational Cooperation.
Sha, F., JI, Z. & Linwei, L. (2017) An Analysis of China’s INDC (Updated analysis 2017) (MILES report). Beijing, China: China National
Center for Climate Change Strategy and International Cooperation.
South Africa. Department of Environmental Affairs (2011) Explanatory note: Defining South Africa’s Peak, Plateau and Decline
Greenhouse Gas Emission Trajectory. Government of Republic of South Africa.: http://www.climateaction.org.za/cop17-cmp7/sagovernment-position-on-climate-change.
The Law National Information Center. (2016) Presidental Decree 27180 of 24 May, 2016 (enforced 1 June, 2016); partial amendmentof the Enforcement Decree of the Framework Act on Low Carbon, Green Growth. The Law National Information Center, Korea[Online]. Ministry of Government Legislation. Available: htp://www.law.go.kr/lsInfoP.do?lsiSeq=183314&efYd=20160601#AJAX[Accessed 16 October 2016].
U.S. Department of State (2016) 2016 second biennial report of the United States of America, under the United Nations Framework
Convention on Climate Change. US Department of State, Washington, DC, https://unfccc.int/files/national_reports/biennial_
reports_and_iar/submitted_biennial_reports/application/pdf/2016_second_biennial_report_of_the_united_states_.pdf.
UNEP (2016) The Emissions Gap Report 2016: A UNEP Synthesis Report [Online]. United Nations Environment Programme (UNEP),
Nairobi. Available: http://www.unep.org/emissionsgapreport2016/ [Accessed 20 October 2017].
UNEP (2015) The Emissions Gap Report 2015: A UNEP Synthesis Report [Online]. United Nations Environment Programme (UNEP),
Nairobi. Available: http://www.unep.org/emissionsgapreport2015/ [Accessed].
UNFCCC (2011) Compilation of information on nationally appropriate mitigation actions to be implemented by Parties not includedin Annex I to the Convention. FCCC/AWGLCA/2011/INF.1, http://unfccc.int/resource/docs/2011/awglca14/eng/inf01.pdf
WRI (2016) CAIT Indonesia Climate Data Explorer - PINDAI [Online]. Available: http://cait.wri.org/indonesia?lng=en [Accessed 31
October 2016].
WRI CAIT (2017) Climate Analysis Indicators Tool: WRI’s Climate Data Explorer. Washington DC, USA: World Resource Institute.

Chapter 3
Aldy, J. E., Pizer, W. A. & Akimoto, K. (2016) Comparing emissions mitigation efforts across countries. Climate Policy, 1-15.
Andonova, L. B., Hale, T. N. & Roger, C. B. (2017) National Policy and Transnational Governance of Climate Change: Substitutes orComplements? International Studies Quarterly, 61, 253-268.
Australian Government (2016) Australia’s emissions projections 2016. http://www.environment.gov.au/system/files/
resources/9437fe27-64f4-4d16-b3f1-4e03c2f7b0d7/files/aust-emissions-projections-2016.pdf: Department of the Environment
and Energy, Australia.
CAT (2017) Climate Action Tracker. Available at: http://climateactiontracker.org/ [Accessed 7 August 2017].
CDP and We Mean Business (2016) The Business End of Climate Change. Available at: https://newclimateinstitute.files.wordpress.
com/2016/06/business-end-of-climate-change.pdf.
CEC (2017) Power Generation Industry Information, CEC (China Electricity Council), Beijing [Online]. [Accessed 08/10/2017].
Central Electricity Authority (2016) Draft National Electricity Plan, Central Elctricity Authority (CEA), Ministry of Power, Governmentof India,, http://www.cea.nic.in/reports/committee/nep/nep_dec.pdf
Chai, Q., Fu, S., XU, H., Li, W. & Zhong, Y. (2017) The gap report of global climate change mitigation, finance, and governance after
the United States declared its withdrawal from the Paris Agreement. Chinese Journal of Population Resources and Environment,
1-13.
Chan, S., Falkner, R., Goldberg, M. & Van Asselt, H. (2016) Effective and geographically balanced? An output-based assessment of
non-state climate actions. Climate Policy, 1-12.
Cheong Wa Dae (2017) Opening remarks by the President Moon Jae-In at the 2nd Annual Meeting of the AIIB Board of Governors,
16 June, 2017, Jeju, the Republic of Korea. Cheong Wa Dae (the President’s Office of the Republic of Korea). http://men.president.go.kr/activity/speeches.php?srh%5Bview_mode%5D=detail&srh%5Bseq%5D=429&srh%5Bdetail_no%5D=4 (accessed 18
July, 2017).

70

The Emissions Gap Report 2017 – References

China Statistic Year Book (2017) China Statistic Year Book 2017, China Statistic Publishing House, Beijing, available at: http://www.
stats.gov.cn/tjsj/ndsj/2016/indexeh.htm.
Clarke, L., Jiang, K., Akimoto, K., Babiker, M., Blanford, G., Fisher-Vanden, K., Hourcade, J.-C., Krey, V., Kriegler, E., Löschel, A., Mccollum, D., Paltsev, S., Rose, S., Shukla, P. R., Tavoni, M., Zwaan, B. V. D. & Vuuren, D. V. (2014) Assessing Transformation Pathways.
In: Edenhofer, O., Pichs-Madruga, R., Sokona, Y., Farahani, E., Kadner, S., Seyboth, K., Adler, A., Baum, I., Brunner, S., Eickemeier,P., Kriemann, B., Savolainen, J., Schlömer, S., Stechow, C. V., Zwickel, T. & Minx, J. C. (eds.) Climate Change 2014: Mitigation of
Climate Change. Contribution of Working Group III to the Fifth Assessment Report of the Intergovernmental Panel on Climate
Change. Cambridge, United Kingdom and New York, NY, USA: Cambridge University Press.
Climate Action Tracker (2017a) Action by China and India slows emissions growth, President Trump’s policies likely to cause US emissions to flatten. Policy Brief Climate Analytics, Ecofys and NewClimate institute, Available at: http://climateactiontracker.org/
assets/publications/briefing_papers/CAT_2017-05-15_Briefing_India-China-USA.pdf [Accessed 7 August 2017].
Climate Action Tracker (2017b) Country assessment: Argentina (updated 17 May, 2017). Climate Action Tracker (Climate Analytics,
Ecofys, NewClimate Institute). http://climateactiontracker.org/countries/argentina.html(Accessed 27 August, 2017).
Climate Action Tracker (2017c) Country assessment: Mexico (updated 6 July, 2017). Climate Action Tracker (Climate Analytics,
Ecofys, NewClimate Institute). http://climateactiontracker.org/countries/mexico.html [Accessed 30 August, 2017].
Climate Action Tracker (2017d) Country assessment: Russian Federation (updated 11 May, 2017). Climate Action Tracker (Climate
Analytics, Ecofys, NewClimate Institute). http://climateactiontracker.org/countries/russianfederation.html (accessed on 27
August, 2017).
Climate Action Tracker (2017e) Country assessment: Saudi Arabia (updated 10 May, 2017). Climate Action Tracker (Climate Analytics, Ecofys, NewClimate Institute). http://climateactiontracker.org/countries/saudiarabia.html (Accessed 27 August, 2017).
Climate Action Tracker (2017f) Country assessment: South Africa (updated 6 July, 2017). Climate Action Tracker (Climate Analytics,
Ecofys, NewClimate Institute). http://climateactiontracker.org/countries/southafrica.html (accessed on 27 August, 2017).
Climate Action Tracker (2017g) Country assessment: Turkey (updated 17 May, 2017). Climate Action Tracker (Climate Analytics,
Ecofys, NewClimate Institute). http://climateactiontracker.org/countries/turkey.html (Accessed 27 August, 2017).
Climate Action Tracker (2017h) http://climateactiontracker.org/.
Climate Advisers (2017) Trumpbacktracker. https://www.climateadvisers.com/trumpbacktracker/.
Climate Transparency (2017) Brown to Green: The G20 transition to a low-carbon economy. Climate Transparency, c/o HumboldtViadrina Governance Platform, Berlin, Germany, www.climate-transparency.org.
Climate Interactive (2017) Climate Scoreboard. US: Climate Interactive.
Climateinteractive (2017) What Slashing Climate Rules Means For the U.S. Pledge to Paris, Available at: https://www.climateinteractive.org/media-coverage/what-slashing-climate-rules-means-for-the-u-s-pledge-to-paris/
Compact Of Mayors (2015) Climate Leadership at the Local Level: Global Impact of the Compact of Mayors. Available at: https://data.bloomberglp.com/mayors/sites/14/2016/01/BR_AggregationReport_Final_SinglePages-FINAL-2016.pdf.
Damassa, T., Fransen, T., Haya, B., Ge, M., Pjeczka, K. & Ross, K. (2015) Interpreting INDCs: Assessing transparency of post-2020
greenhouse gas emissions targets for 8 top-emitting economies. Working Paper. Washington, DC: World Resources Institute.
Available online at http://www.wri.org/publication/interpreting-indcs.
Den Elzen, M., Admiraal, A., Roelfsema, M., Van Soest, H., Hof, A. F. & Forsell, N. (2016a) Contribution of the G20 economies to theglobal impact of the Paris agreement climate proposals. Climatic Change, 137, 655-665.
Den Elzen, M. G. J., Fekete, H., Höhne, N., Admiraal, A., Forsell, N., Hof, A. F., Olivier, J. G. J., Roelfsema, M. & Van Soest, H. (2016b)
Greenhouse gas emissions from current and enhanced policies of China until 2030: Can emissions peak before 2030? Energy
Policy, 89, 224-236.
EEA (2016) Trends and projections in Europe (2016 - Tracking progress towards Europe’s climate and energy targets. European Environment Agency, EEA Report No 29/2016, https://www.eea.europa.eu/publications/trends-and-projections-in-europe.
Environment And Climate Change Canada (2017) Canadian Environmental Sustainability Indicators: Progress Towards Canada’s
Greenhouse Gas Emissions Reduction Target. https://www.ec.gc.ca/indicateurs-indicators/CCED3397-174A-4F0E-825891DCFE295B34/ProgressTowardsCanadaGHGEmissionsTarget_EN.pdf.
Forsell, N., Turkovska, O., Gusti, M., Obersteiner, M., Elzen, M. D. & Havlik, P. (2016) Assessing the INDCs’ land use, land use change,
and forest emission projections. Carbon Balance and Management, 11, 26.
Fricko, O., Havlik, P., Rogelj, J., Klimont, Z., Gusti, M., Johnson, N., Kolp, P., Strubegger, M., Valin, H., Amann, M., Ermolieva, T., Forsell,N., Herrero, M., Heyes, C., Kindermann, G., Krey, V., Mccollum, D. L., Obersteiner, M., Pachauri, S., Rao, S., Schmid, E., Schoepp,
W. & Riahi, K. (2017) The marker quantification of the Shared Socioeconomic Pathway 2: A middle-of-the-road scenario for the
21st century. Global Environmental Change, 42, 251-267.
Fuglestvedt, J. S., Shine, K. P., Berntsen, T., Cook, J., Lee, D. S., Stenke, A., Skeie, R. B., Velders, G. J. M. & Waitz, I. A. (2010) Transport
impacts on atmosphere and climate: Metrics. Atmospheric Environment, 44, 4648-4677.
Government of Argentina (2016) Primera Revisión de su Contribución Determinada a Nivel Nacional, http://www4.unfccc.int/
ndcregistry/PublishedDocuments/Argentina%20First/17112016%20NDC%20Revisada%202016.pdf.
Government of Russia. (2014) First Biennial Report of the Russian Federation [Online]. UNFCCC, Bonn, available at: http://unfccc.int/files/national_reports/biennial_reports_and_iar/submitted_biennial_reports/application/pdf/1br_rus_unoffical_trans­
lation_eng.pdf [Accessed 12 December 2014].
Graichen, J., Healy, S., Siemons, A., Höhne, N., Kuramochi, T., Gonzales Zuñiga, S., Sterl, S., Kersting, J. & Wachsmuth, J. (2017)
International Climate Initiatives – A way forward to close the emissions gap? Initiatives’ potential and role under the Paris Agreement. Berlin: Öko-Institut. Retrieved from https://www.umweltbundesamt.de/sites/default/files/medien/376/publikationen/
climate_change_22_2017.pdf.
Graichen, J., Healy, S., Siemons, A., Höhne, N., Kuramochi, T., Gonzales Zuñiga, S. & Wachsmuth, J. (2016) Climate initiatives, national contributions, and the Paris Agreement. Berlin: Öko-Institut. Retrieved from http://www.oeko.de/oekodoc/2554/2016079-de.pdf.
Grassi, G., House, J., Dentener, F., Federici, S., Den Elzen, M. & Penman, J. (2017) The key role of forests in meeting climate targets
requires science for credible mitigation. Nature Clim. Change, 7, 220-226.

The Emissions Gap Report 2017 – References

71

Green, F. and Stern, N. (2017) China’s changing economy: implications for its carbon dioxide emissions. Climate Policy, 17, 423-442.
Gütschow, J., Jeffery, L., Gieseke, R. & Gebel, R. (2017) The PRIMAP-hist national historical emissions time series (1850-2014). V. 1.1.
GFZ Data Services. http://doi.org/10.5880/PIK.2017.001.
Hafstead, M. (2017) On Trump, Paris, and Greenhouse Gas Emissions. Retrieved August 7, 2017, from Resources for the Future:
http://www.rff.org/blog/2017/trump-paris-and-greenhouse-gas-emissions.
Höglund-Isaksson, L., Purohit, P., Amann, M., Bertok, I., Rafaj, P., Schöpp, W. & Borken-Kleefeld, J. (2017) Cost estimates of the Kigali
Amendment to phase-down hydrofluorocarbons. Environmental Science and Policy, 75, 138-147.
Höhne, N., Fekete, H., Den Elzen, M. G. J., Hof, A. F. & Kuramochi, T. (2017) Assessing the ambition of post-2020 climate targets: acomprehensive framework. Climate Policy, 1-16.
IEA (2016) World Energy Outlook 2016, Paris, France, International Energy Agency.
IPCC (2014a) Climate Change 2014: Synthesis Report. Contribution of Working Groups I, II and III to the Fifth Assessment Report of
the Intergovernmental Panel on Climate Change. In: CORE WRITING TEAM, PACHAURI, R. K. & MEYER, L. A. (eds.). Geneva, Switzerland: IPCC.
IPCC (2014b) Summary for Policymakers. In: Edenhofer, O., Pichs-Madruga, R., Sokona, Y., Farahani, E., Kadner, S., Seyboth, K., Adler,
A., Baum, I., Brunner, S., Eickemeier, P., Kriemann, B., Savolainen, J., Schlömer, S., Stechow, C. V., Zwickel, T. & Minx, J. C. (eds.)
Climate Change 2014: Mitigation of Climate Change. Contribution of Working Group III to the Fifth Assessment Report of theIntergovernmental Panel on Climate Change. Cambridge, United Kingdom, and New York, NY, USA: Cambridge University Press.
Jiang, K.-J., Tamura, K. & Hanaoka, T. (2017) Can we go beyond INDCs: Analysis of a future mitigation possibility in China, Japan, EU
and the U.S. Advances in Climate Change Research, 8, 117-122.
Kitous, A., Keramidas, K., Vandyck, T. & Saveyn, B. (2016) GECO2016. Global Energy and Climate Outlook. Road to Paris. download
at: http://ec.europa.eu/jrc/en/geco: Joint Research Centre.
Kitous, A., Keramidas, K., Vandyck, T., Saveyn, B., Van Dingenen, R., Spadaro, J. & Holland, M. (2017) Global Energy and Climate
Outlook 2017: How climate policies improve air quality. EUR 28798 EN, Publications Office of the European Union, Luxembourg,
2017, ISBN 978-92-79-73864-7, doi:10.2760/474356, JRC107944: Joint Research Centre.
Kuramochi, T., Höhne, N., Sterl, S., Gonzales-Zuñiga, S., Hans, F., Hagemann, M., Hernandez Legaria, E., Den Elzen, M. G. J., Roelfsema, M., Van Soest, H., Forsell, N. & Turkovska, O. (2016) Greenhouse gas mitigation scenarios for major emitting countries:
Analysis of current and planned climate policies, and mitigation pledges. Cologne, Germany: NewClimate Institute, PBL, IIASA,
http://www.pbl.nl/en/publications/greenhouse-gas-mitigation-scenarios-for-major-emitting-countries.
Kuramochi, T., Höhne, N., Sterl, S., Lütkehermöller, K. & Seghers, J.-C. (2017) States, cities and businesses leading the way: a first lookat decentralized climate commitments in the US. NewClimate Institute, the Climate group.
Le Quéré, C., Moriarty, R., Andrew, R. M., Canadell, J. G., Sitch, S., Korsbakken, J. I., Friedlingstein, P., Peters, G. P., Andres, R. J.,
Boden, T. A., Houghton, R. A., House, J. I., Keeling, R. F., Tans, P., Arneth, A., Bakker, D. C. E., Barbero, L., Bopp, L., Chang, J.,
Chevallier, F., Chini, L. P., Ciais, P., Fader, M., Feely, R. A., Gkritzalis, T., Harris, I., Hauck, J., Ilyina, T., Jain, A. K., Kato, E., Kitidis, V.,
Klein Goldewijk, K., Koven, C., Landschützer, P., Lauvset, S. K., Lefèvre, N., Lenton, A., Lima, I. D., Metzl, N., Millero, F., Munro, D.
R., Murata, A., Nabel, J. E. M. S., Nakaoka, S., Nojiri, Y., O’brien, K., Olsen, A., Ono, T., Pérez, F. F., Pfeil, B., Pierrot, D., Poulter, B.,
Rehder, G., Rödenbeck, C., Saito, S., Schuster, U., Schwinger, J., Séférian, R., Steinhoff, T., Stocker, B. D., Sutton, A. J., Takahashi,T., Tilbrook, B., Van Der Laan-Luijkx, I. T., Van Der Werf, G. R., Van Heuven, S., Vandemark, D., Viovy, N., Wiltshire, A., Zaehle, S. &Zeng, N. (2015) Global Carbon Budget 2015. Earth Syst. Sci. Data, 7, 349-396.
Lee, D. S., Fahey, D. W., Forster, P. M., Newton, P. J., Wit, R. C. N., Lim, L. L., Owen, B. & Sausen, R. (2009.) Aviation and global climatechange in the 21st century. Atmospheric Environment, 43, 3520-3537.
Lee, D. S., Pitari, G., Grewe, V., Gierens, K., Penner, J. E., Petzold, A., Prather, M. J., Schumann, U., Bais, A., Berntsen, T., Iachetti, D.,
Lim, L. L. & Sausen, R. (2010) Transport impacts on atmosphere and climate: Aviation. Atmospheric Environment, 44, 4678-4734.
Luderer, G., Kriegler, E., Delsa, L., Edelenbosch, O., Emmerling, J., Krey, V., Mccollum, D., Pachauri, S., Riahi, K., Saveyn, B., Tavoni,M., Vrontisi, Z., Van Vuuren, D., Arent, D., Arvesen, A., Fujimori, S., Iyer, G., Keppo, I., Kermeli, K., Mima, S., Ó , Broin, E., Pietzcker,
R., Sano, F., Scholz, Y., Van Ruijven, B. & Wilson, C. (2016) Deep Decarbonisation Towards 1.5°C - 2°C Stabilisation - Policy findings
from the ADVANCE project (first edition). ADVANCE, http://www.fp7-advance.eu/content/advance-key-findings.
Luderer, G., Pietzcker, R. C., Bertram, C., Kriegler, E., Meinshausen, M. & Edenhofer, O. (2013) Economic mitigation challenges: howfurther delay closes the door for achieving climate targets. Environmental Research Letters, 8, 034033.
Michaelowa, K. and Michaelowa, A. (2017) Transnational Climate Governance Initiatives: Designed for Effective Climate Change
Mitigation? International Interactions, 43, 129-155.
Millar, R. J., Fuglestvedt, J. S., Friedlingstein, P., Rogelj, J., Grubb, M. J., Matthews, H. D., Skeie, R. B., Forster, P. M., Frame, D. J. &Allen, M. R. (2017) Emission budgets and pathways consistent with limiting warming to 1.5°C. Nature Geosci, 10, 741-747.
Ministry of Science And Technology Of Brazil (2016) Third National Communication of Brazil to the United Nations Framework Convention on Climate Change.
Mitra, A., Chitkara, P., Ross, K., Singh, M., Sawhney, S., Keswani, S. & Batra, P. (2017) Pathways for Meeting India’s Climate Goals.
Washington DC, USA: World Resource Institute.
Motie-Moe-Molit (2017) Joint press release by Ministry of Trade, Industry, and Energy (MOTIE), Ministry of Environment (MOE), andMinistry of Land, Infrastructure, and Transport (MOLIT) on the occasion of joint report to the President.
Nordhaus, W. D. (2017) Revisiting the social cost of carbon. Proceedings of the National Academy of Sciences, 114, 1518-1523.
PBL (2017) PBL Climate Pledge NDC tool, www.pbl.nl/indc. PBL Netherlands Environmental Assessment Agency.
REN21 (2017) Renewables 2017: Global Status Report, available at: http://www.ren21.net/gsr-2017/ [Online]. Available: http://
www.ren21.net/gsr-2017/ [Accessed 08/10/2017].
Reputex (2016) Framing Australia’s 2030 energy and climate policy mix. The contribution of safeguard sectors to Australia’s 2030
emissions reduction target. http://www.reputex.com/wp-content/uploads/2016/09/0916_RepuTex-White-Paper_Framing-Australias-energy-policy-mix-to-2030.pdf: MARKET UPDATE | September 2016
Rhodium GROUP (2017a) Taking Stock 2017: Adjusting Expectations for US GHG Emissions. Available at: http://rhg.com/reports/taking-stock-2017-adjusting-expectations-for-us-ghg-emissions.

72

The Emissions Gap Report 2017 – ReferencesRhodium GROUP (2017b) Trump’s Regulatory Rollback Begins, Available at: http://rhg.com/notes/trumps-regulatory-rollback-begins.
Riahi, K., Van Vuuren, D. P., Kriegler, E., Edmonds, J., O’neill, B. C., Fujimori, S., Bauer, N., Calvin, K., Dellink, R., Fricko, O., Lutz,
W., POPP, A., Cuaresma, J. C., KC, S., Leimbach, M., Jiang, L., Kram, T., Rao, S., Emmerling, J., Ebi, K., Hasegawa, T., Havlik, P.,
Humpenöder, F., Da Silva, L. A., Smith, S., Stehfest, E., Bosetti, V., Eom, J., Gernaat, D., Masui, T., Rogelj, J., Strefler, J., Drouet, L.,
Krey, V., Luderer, G., Harmsen, M., Takahashi, K., Baumstark, L., Doelman, J. C., Kainuma, M., Klimont, Z., Marangoni, G., LotzeCampen, H., Obersteiner, M., Tabeau, A. & Tavoni, M. (2017) The Shared Socioeconomic Pathways and their energy, land use, andgreenhouse gas emissions implications: An overview. Global Environmental Change, 42, 153-168.
Rogelj, J., Den Elzen, M., Höhne, N., Fransen, T., Fekete, H., Winkler, H., Schaeffer, R., SHA, F., RIAHI, K. & MEINSHAUSEN, M. (2016)
Paris Agreement climate proposals need a boost to keep warming well below 2°C. Nature, 534, 631-639.
Rogelj, J., Fricko, O., Meinshausen, M., Krey, V., J, Z. & Riahi, K. (2017a) Understanding the origin of Paris Agreement emission uncertainties Nature Communications 8,15748 doi: 10.1038/ncomms15748.
Rogelj, J., Hare, W., Chen, C. & Meinshausen, M. (2011) Discrepancies in historical emissions point to a wider 2020 gap between 2°C
benchmarks and aggregated national mitigation pledges. Environmental Research Letters.
Rogelj, J., Luderer, G., Pietzcker, R. C., Kriegler, E., Schaeffer, M., Krey, V. & Riahi, K. (2015) Energy system transformations for limiting
end-of-century warming to below 1.5°C. Nature Climate Change, 5, 519-527.
Rogelj, J., Mccollum, D. L., O’neill, B. C. & Riahi, K. (2013a) 2020 emissions levels required to limit warming to below 2°C. Nature
Clim. Change, 3, 405-412.
Rogelj, J., Mccollum, D. L., Reisinger, A., Meinshausen, M. & Riahi, K. (2013b) Probabilistic cost estimates for climate change mitigation. Nature, 493, 79-83.
Rogelj, J., Popp, A., Calvin, K. V., Luderer, G., Emmerling, J., Gernaat, D., Fujimori, S., Strefler, J., Hasegawa, T., Marangoni, G., Krey,
V., Kriegler, E., Riahi, K., Van Vuuren, D. P., Doelman, J., Drouet, L., Edmonds, J., Fricko, O., Harmsen, M., Havlík, P., Humpenöder,F., Stehfest, E. & Tavoni, M. (2017b) Transition pathways towards limiting climate change below 1.5°C. Nature Climate Change(under review), http://unfccc.int/files/adaptation/application/pdf/2.9_iiasa_rogelj.pdf.
Schneider, L., Day, T., LA Hoz, S. & Warnecke, C. (2017) Discussion Paper: CDM Supply Potential up to 2020. NewClimate Institute,
the Climate group.
SEEG (2017) The System Study Greenhouse Gas Emissions Estimates (SEEG). [Online]. Available: http://seeg.eco.br/en/ [Accessed
21 July 2017].
Sha, F., Ji, Z. and Linwei, L. (2015) An Analysis of China’s INDC. Beijing, China: China National Center for Climate Change Strategy andInternational Cooperation.
Sha, F., Ji, Z. and Linwei, L. (2017) An Analysis of China’s INDC (Updated analysis 2017) (MILES report). Beijing, China: China National
Center for Climate Change Strategy and International Cooperation.
State CounciL (2013) Air Pollution Prevention Action Plan [Online]. Accessed: 26 October 2017
The Climate Group (2016) Compact of States and Regions - Disclosure report: How leading states, provinces and regions are responding to the Paris Agreement 2016 Edition. Available at: https://www.theclimategroup.org/sites/default/files/compact-ofstates-and-regions-disclosure-report-2015.pdf.
The Representative of The United States of America to the United Nations (2017) Reference: C.N.464.2017.TREATIES-XXVII.7.d (Depositary Notification). United Nations, https://treaties.un.org/doc/Publication/CN/2017/CN.464.2017-Eng.pdf
UNEP (2012) The Emissions Gap Report 2012: A UNEP Synthesis Report. United Nations Environment Programme (UNEP), Nairobi.
Available: http://www.unep.org/emissionsgapreport2012/ [accessed 23 September 2017]
UNEP (2015) The Emissions Gap Report 2015: A UNEP Synthesis Report [Online]. United Nations Environment Programme (UNEP),
Nairobi. Available: http://www.unep.org/emissionsgapreport2015/ [Accessed 23 September 2017].
UNEP (2016) The Emissions Gap Report 2016: A UNEP Synthesis Report [Online]. United Nations Environment Programme (UNEP),
Nairobi. Available: http://www.unep.org/emissionsgapreport2016/ [Accessed 23 September 2017].
UNFCCC (2015) Intended Nationally Determined Contributions (INDCs), http://www4.unfccc.int/submissions/indc/Submission%20
Pages/submissions.aspx.
Van Vuuren, D. P., Stehfest, E., Gernaat, D., Doelman, J., Van Den Berg, M., Harmsen, M., DE Boer, H. S., Bouwman, L., Daioglou, V.,
Edelenbosch, O., Girod, B., Kram, T., Lassaletta, L., Lucas, P., Van Meijl, H., Müller, C., Van Ruijven, B., Van Der Sluis, S. & Tabeau,
A. (2017) Energy, land-use and greenhouse gas emissions trajectories under a green growth paradigm. Global Environmental
Change, 42, 237-250.
Vandyck, T., Keramidas, K., Saveyn, B., Kitous, A. & Vrontisi, Z. (2016) A global stocktake of the Paris pledges: Implications for energy
systems and economy. Global Environmental Change, 41, 46-63.
Vrontisi, Z., Luderer, G., Saveyn, B., Bertram, C., De Boer, H. S., Drouet, L., Fragkiadakis, K., Fricko, O., Fujimori, S., Guivarch, C.,
Keramidas, K., Kitous, A., Krey, V., Kriegler, E., Broin, E., Paroussos, L., Riahi, K., Tavoni, M. & Van Vuuren, D. P. (2016) Reportcontaining an economic analysis of a set of sectoral impacts, Deliverable No. 6.4, ADVANCE, Advanced Model Development
and Validation for Improved Analysis of Costs and Impacts of Mitigation Policies, http://www.fp7-advance.eu/sites/default/files/
documents/WP6/D6.4_deliverable_20170619.pdf.
Vrontisi, Z., Luderer, G., Saveyn, B., Bertram, C., De Boer, H. S., Drouet, L., Fragkiadakis, K., Fricko, O., Fujimori, S., Guivarch, C.,
Keramidas, K., Kitous, A., Krey, V., Kriegler, E., Broin, E., Paroussos, L., Riahi, K., Tavoni, M. & Van Vuuren, D. P. (2017) A multi-model assessment of the effectiveness of Paris pledges towards a 1.5-2°C stabilization, Global Environmental Change (submitted).
Weyant, J. (2017) Some Contributions of Integrated Assessment Models of Global Climate Change. Review of Environmental Economics and Policy, 11, 115-137.

Chapter 4
Afanador, A., Begemann, E., Bourgault, C., Krabbe, O. and Wouters, K. (2015) The potential of scaling up proven low-carbon solutions. Available at: https://media.sitra.fi/2017/02/28142516/Ecofys_2015_potential_of_scaling_up-low_carbon_solutions.pdf[Accessed 24 October 2017].

The Emissions Gap Report 2017 – References

73

Akbar, S., Kleiman, G., Menon, S. and Segafredo, L. (2014) Climate-smart development : adding up the benefits of actions that help
build prosperity, end poverty and combat climate change : Main report Washington, DC : World Bank Group. Available at: http://
documents.worldbank.org/curated/en/794281468155721244/Main-report [Accessed 24 October 2017]
Alvik, S., Eide, M., Endresen, Ø., Hoffman, P., and Longva, T. (2010) Pathways to Low Carbon Shipping-Abatement Potential Towards
2030. DNV De Norske Veritas.
Arasto, A., K. Onarheim, E., Tsupari, and Kärki, J. (2014) ‘Bio-CCS: feasibility comparison of large scale carbon-negative solutions’.
Energy Procedia 63, 6756-6769.
Blok, K., and Gardiner, A. (2015) Climate commitments of subnational actors and business – a quantitative assessment of theiremission reduction impact. Available at: http://www.unep.org/ourplanet/september-2015/unep-publications/climate-commitments-subnational-actors-and-business-quantitative [Accessed 24 October 2017]
Bloomberg New Energy Finance. (2017) Electric Vehicle Outlook 2017. Available at: https://data.bloomberglp.com/bnef/sites/14/2017/07/BNEF_EVO_2017_ExecutiveSummary.pdf [Accessed 24 October 2017]
Bonn, A., Reed, M., Evans, C., Joosten, H., Bain, C., Farmer, J., Emmer, I., Birnie, D.. (2014) Investing in nature: Developing ecosystemservice markets for peatland restoration. Ecosystem Services, 9: 54-65.
Breyer, C., Bogdanov, D., Gulagi, A., Aghahosseini, A., Barbosa, L.S.N.S., Koskinen, O., Barasa, M., Caldera, U., Afanasyeva, S., Child,M., Farfan, J. and Vainikka, P. (2017) On the role of solar photovoltaics in global energy transition scenarios. Progress in photovoltaics: research and applications. 25(8): 727-745.
Bouman, E., Lindstad, E., Rialland, A., Stromann, A. (2017) State-of-the-art technologies, measures, and potential for reducing GHG
emissions from shipping – A review. Transportation Research Part D: Transport and Environment. 52: 408 – 421.
BLE (2016) Evaluations und Erfahrungsbericht für das Jahr 2015, Biomassestrom-Nachhaltigkeitsverordnung and BiokraftstoffNachhaltigkeitsverordnung. Bonn Germany: Bundesanstalt für Landwirtschaft und Ernährung.
C40 (2014) Advancing climate ambition: cities as partners in global climate action. Available at http://c40-production-images.
s3.amazonaws.com/researches/images/25_Advancing_Climate_Ambition.original.pdf?1412878084 [Accessed 24 October
2017]
Chen, X., Luo, Y., Zhou, Y., and Lu, M. (2016) Carbon Sequestration Potential in Stands under the Grain for Green Program in Southwest China. PLoS ONE, 11(3): 1-17.
Clarke, L., Jiang, K., Akimoto, K., Babiker, M., Blanford, G., Fisher-Vanden, K., Hourcade, J.-C., Krey, V., Kriegler, E., Löschel, A., McCollum, D., Paltsev, S., Rose, S., Shukla, P.R., Tavoni, M., Van der Zwaan, B., Van Vuuren, D. (2014) Assessing Transformation Pathways. In: Climate Change 2014: Mitigation of Climate Change. Contribution of Working Group III to the Fifth Assessment Reportof the Intergovernmental Panel on Climate Change. Cambrigde and New York: Cambridge University Press.
CLASP (2011) Opportunities for success and CO2 savings from appliance energy efficiency harmonisation. Available at http://clasp.
ngo/Resources/Resources/PublicationLibrary/2011/Opportunities-for-appliance-EE-harmonization#file [Accessed 24 October
2017]
Climate Action Tracker (2016) 10 Steps: the ten most important short-term steps to limit warming to 1.5°C. Available at http://climateactiontracker.org/assets/publications/publications/CAT_10_Steps_for_1o5.pdf [Accessed 24 October 2017]
Creutzig, F., Agoston, P., Goldschmidt, J., Luderer, G., Nemet, G., and Pietzcker, R. (2017) The underestimated potential of solar
energy to mitigate climate change. Nature Energy (2) doi:10.1038/nenergy.2017.140
Deng, Y., Blok, K., and Leun, K. (2012) Transition to a fully sustainable global energy system. Energy Strategy Reviews, 1(2): 1-13.
Dimassi, B., Mary, B., Wylleman, R., Labreuche, J., Couture, D., Piraux, F., and Cohan, J. (2014) Long-term effect of contrasted tillage
and crop management on soil carbon dynamics during 41 years. Agriculture, Ecosystems and Environment, 136-146.
Ecofys (2017) A role for rapeseed biodiesel in greening EU transport. Utrecht: Ecofys (forthcoming).
Eide, M., Longva, T., Hoffmann, P., Endresen, Ø., and Dalsøren , S. (2011) Future cost scenarios for reduction of ship CO2 emissions.
Maritime Policy and Management, 11-37.
Faber, J., Wang., H., Nelissen, D., Russell, B., and Amand, D. (2011) Marginal abatement costs and cost effectiveness of energyefficiency measures. Institute of Marine Engineering, Science and Technology.
Fischedick. (2014) Industry. New York: Cambridge University Press.
GBPN (2013) What is a deep renovation definition? Available at http://www.gbpn.org/sites/default/files/08.DR_TechRep.low_.pdf[Accessed 24 October 2017]
GCEM (2015) Raising Ambition to Reduce International Aviation and Maritime Emissions. Contributing paper for Seizing the Global
Opportunity: Partnerships for Better Growth and a Better Climate. New Climate Economy, London and Washington, DC. Available
at: http://newclimateeconomy.report/misc/working-papers. [Accessed 24 October 2017]
GCEM (2015) New Climate Economy Technical Note: Abatement Reduction Potential. Available at: http://newclimateeconomy.
report/workingpapers/wp-content/uploads/sites/5/2016/04/NCE-technical-note-emission-reduction-potential_final.pdf [Accessed 24 October 2017]
GWEC (2016) Global Wind Report 2016. Available at http://gwec.net/publications/global-wind-report-2/global-wind-report-2016/[Accessed 24 October 2017]
Hawken, P. (2017) Drawdown: The Most Comprehensive Plan Ever Proposed to Reverse Global Warming. New York: Penguin Random House LLC.
Herzog, H., Smekens K., Dadhich, P., Dooley, J., Fujii, Y., Hohmeyer, O., and Riahi K. (2005) Costs and Economic Potential, in: IPCC
Special Report on Carbon Dioxide Capture and Storage. Cambridge, United Kingdom and New York, NY, USA: Cambridge University Press.
Hoffmann, P., Eide, M., and Endresen, Ø. (2012) Effect of proposed CO2 emission reduction scenarios on capital expenditure. Maritime Policy and Management, 443-460.
ICAO (2013) Environmental Report 2013. Available at http://cfapp.icao.int/Environmental-Report-2013/files/assets/basic-html/index.html#1 [Accessed 24 October 2017].
ICCT (2012) Global Transportation Energy and Climate Roadmap. Availabel at: http://www.theicct.org/publications/global-transportation-energy-and-climate-roadmap [Accessed 24 October 2017].

74

The Emissions Gap Report 2017 – References

ICCT (2017) Technology uptake, costs, and benefits under a next-phase passenger car efficiency program in Brazil. Available at:
http://www.theicct.org/publications/technology-uptake-costs-and-benefits-under-next-phase-passenger-car-efficiency-program [Accessed 24 October 2017].
IEA (2016) World Energy Outlook 2016. Paris: International Energy Agency.
IEA (2017) Enery Technology Perspectives 2017. Paris: International Energy Agency.
IPCC. (2001) Climate Change 2001: Synthesis Report. A Contribution of Working Groups I, II, and III to the Third Assessment Reportof the Integovernmental Panel on Climate Change. Cambrigde and New York: Cambridge University Press.
IPCC (2007) Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Geneva: IPCC.
IPCC (2014) Climate Change 2014: Mitigation of Climate Change. Geneva: IPCC.
IRENA (2016) Roadmap for a Renewable Energy Future. Bonn: IRENA Innovation and Technology Centre.
IRENA (2017) ‘Renewable Energy Auctions: Analysing 2016’. IRENA, Abu Dhabi. Available at http://www.irena.org/DocumentDownloads/Publications/IRENA_REAuctions_summary_2017.pdf
Johnson, N., Parker, N., and J.Ogden. (2014) How negative can biofuels with CCS take us and at what cost? . Energy Procedia 63:
6770 – 6791.
Joosten, H., Tapio-Biström, M.-L., and Tol, S. (2012) Peatlands - guidance for climate change mitigation through conservation, rehabilitation and sustainable use. Available at: http://www.fao.org/3/a-an762e.pdf [Accessed 24 October 2017].
Kim, K., and Zsuffa, L. (1994) Reforestation of South Korea: The history and analysis of a unique case in forest tree improvement andforestry. The Forestry Chronicle, 58-64.
Klimont, Z., and Höglund-Isaksson, L. (2017) Personal communication. IIASA.
Lazard (2016) Levelized Cost of Energy Analysis 10.0. Available at: https://www.lazard.com/media/438038/levelized-cost-of-energyv100.pdf [Accessed 24 October 2017].
Lundqvist, J. (2009) Losses and waste in the global crisis. Rev. Environ. Sci. Biotechnnol., 121-123
Mac Dowell N, and Fajardy, M. (2017) Inefficient power generation as an optimal route to negative emissions via BECCS? Environmental Research Letters 12 (4): 1-11.
McGlashan, N., Workman, M., Caldecott, B., and Shah, N. (2012) Negative Emissions Technologies. Grantham Institute for Climate
Change Briefing paper No 8.
Messinger, J. and DeWitt, S. (2015) Bonn Challenge on track to meet land restoration goal by 2020. Available at: http://www.wri.
org/blog/2015/03/bonn-challenge-track-meet-land-restoration-goal-2020-0 [Accessed 24 October 2017]
Molenbroek, E., Smith, M., Surmeli, N., Schimschär, S., Waide, P., Tait, J., and McAllister, C. (2015) Savings and benefits of global
regulations for energy efficient products. Brussels, Belgium: European Commission.
Nelleman, C., MacDevette, M., Manders, T., Eickhout, B., Svihus, B., and Prins, A. (2009) The environmental Food Crisis – The Environment’s Role in Averting Future Food Crises. A UNEP Rapid Response Assessment. Arendal, Norway: United Nations Environmental Programme, GRID.
Nelson, G., Rosegrant, M., Palazzo, A., Gray, I., Ingersoll, C., Robertson, R., Tokzog S., Zhu T., Sulser T.B., Ringer, C., Mgansi, S. and You,
L. (2010) Food Security, Farming, and Climate Change to 2050: Scenarios, Results, Policy Options. Washington, DC: International
Food Policy Research Institute.
Papaefthymiou, G., Grave, K., and Dragoon, K. (2014) Flexibility options in electricity systems. Available at: https://www.ecofys.com/
files/files/ecofys-eci-2014-flexibility-options-in-electricity-systems.pdf [Accessed 24 October 2017]
Purohit, P., and Höglund-Isaksson, L. (2017) Global emissions of fluorinated greenhouse gases 2005–2050 with abatement potentials and costs. Atmos. Chem. Phys., 17, 2795–2816. doi:10.5194/acp-17-2795-2017
REN21 (2017) Global Status Report. Available at http://www.ren21.net/status-of-renewables/global-status-report/ [Accessed 24
October 2017]Renforth, P., Washbourne, C.-L., Taylder, J., and Manning, D.A.C. (2012) Silicate Production and Availability for
Mineral Carbonation. Environmental Science and Technology, 45 (6), 2035–2041Saygin, D., E. Worrell, M.K. Patel, D.J. Gielen.
(2011) Benchmarking the energy use of energy-intensive industries in industrialized and in developing countries. Energy (36):6661 – 6673.
SITRA (2015) Green to Scale. Available at https://media.sitra.fi/2017/02/28142523/Selvityksia105.pdf [Accessed 24 October 2017].
Smith (2016) Soil carbon sequestration and biochar as negative emission technologies. Global Change Biology, 1315-1324.
Smith, P., Martino, D., Cai, Z., Gwary, D., Janzen, H., Pushpam, K., McCarl, B., Ogle, S., O’Mara, F., Rice, C., Scholes, B., Sirotenko, O.
(2008) Greenhouse gas mitigation in agriculture. Phil. Trans. R. Soc. B, 789-813.
Smith, P. Smith, P., Martino, D., Cai, Z., Gwary, D., Janzen, H., Pushpam, K., McCarl, B., Ogle, S., O’Mara, Frank, Rice, Charles, Scholes,
Bob, Sirotenko, Oleg, (2007) Agriculture. In Climate Change 2007: Mitigation. Contribution of Working Group III to the Fourth
Assessment Report of the, Cambridge: Cambridge University Press.
Smith, P., M. Bustamante, H.Ahammad, H. Clark, H. Dong, E. Elsiddig, H. Haberl, R. Harper, J. House,, M. Jafari, O. Masera, C. Mbow,
N. Ravindranath, C. Rice, C. Robledo, A. Romanovskaya, F. Sperling, F. Tubiello. (2014) Agriculture, Forestry and Other Land Use(AFOLU) In: Climate Change 2014: Mitigation of Climate Change. Contribution of Working Group III to the Fifth Assessment Reportof the Intergovernmental Panel on Climate Change. Cambridge and New York: Cambridge University Press.
Stehfest, E., Van den Berg, M., Woltjer, G., and Westhoek, G. (2013) Options to reduce the environmental effects of livestock production – Comparison of two economic models. Agricultural Systems, 38-53.
Teske, S., Sawyer, S., Schäter, O., Pregger, T., Simon, S., and Naegler, T. (2015) Energy [R]evolution a Sustainable World Energy Outlook 2015. Hamburg: Greenpeace International.
UNEP (2011) Bridging the Emission Gap. Nairobi: United Nations Environment Programme. Available at: https://www.ecofys.com/
files/files/unep_bridging%20the%20emissions%20gap.pdf [Accessed 24 October 2017]
UNEP (2012) The Emissions Gap Report 2012. Nairobi: United Nations Environment Programme (UNEP). http://apps.unep.org/redirect.php?file=/publications/pmtdocuments/-The%20emissions%20gap%20report%202012_%20a%20UNEP%20synthesis%20
reportemissionGapReport2012.pdf [Accessed 24 October 2017]

The Emissions Gap Report 2017 – References

75

UNEP (2013) The Emissions Gap Report 2013. Nairobi: United Nations Environment Programme (UNEP). Available at: http://www.
unep.org/sites/default/files/EGR2013/EmissionsGapReport_2013_high-res.pdf [Acessed 24 October 2017]
UNEP (2014) The Emissions Gap Report 2014. Nairobi: United Nations Environment Programme (UNEP). Available at: http://wedocs.unep.org/bitstream/handle/20.500.11822/9345/-The%20Emissions%20Gap%20Report%202014%3a%20a%20UNEP%20
synthesis%20report-November%202014EGR_2014_Lowres.pdf?sequence=3&isAllowed=y [Accessed 24 October 2017]
UNEP (2014) Green paper Policy Options to Accelerate the Global Transition to Advanced Lighting. Nairobi: United Nations Environment Programme (UNEP).
UNEP (2016) Emission Gap Report 2016. Nairobi: United Nations Environment Programme (UNEP). Available at: https://www.
google.dk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&cad=rja&uact=8&ved=0ahUKEwignN39p4vXAhXpDZoKHdh9BgUQ
FggwMAE&url=http%3A%2F%2Fwedocs.unep.org%2Fbitstream%2Fhandle%2F20.500.11822%2F10016%2Femission_gap_report_2016.pdf&usg=AOvVaw3gBleyjAH07zqiIjLQw9N2 [Accessed 24 October 2017.
UNEP (2017) Accelerating the global adoption of energy-efficient lighting. Available at: http://www.enlighten-initiative.org/Portals/0/documents/global-forum/Green_Paper_FINAL%20reduced.pft [Accessed 24 October 2017]
USEPA (2012) Global Anthropogenic Non-CO2 Greenhouse Gas Emissions: 1990 - 2030. United States: Environmental Protection
Agency.
USEPA (2013) Global Mitigation of Non-CO2 Greenhouse Gases: 2010-2030. United States: Environmental Protection Agency.
Verdone, M., Olsen, N., Wylie, P., Saint Laurent, C., and Maginnis, M. (2015) Making the case for forest landscape restoration. White
paper, initial working draft for future discussion. Post-Bonn Challenge 2.0 Ministerial Event, 20-21 March 2015. IUCN.
Wagner, N. (2017) Personal communication from Mr. N. Wagner, IRENA, September 2017.
Wichtmann, W., Schröder, C., and Joosten, H. (2016) Paludiculture – productive use of wet peatlands. Climate protection − biodiversity − regional economic benefits. Stuttgart: Schweizerbart Science Publishers.
Woolf, D., Amonette, J., Alayne Street-Perrott, F., Lehmann, J., and Joseph, S. (2010) Sustainable biochar to mitigate global climatechange. Nature Communications, 1-56.
Worell, E., and Carreon, J. (2017) Energy demand for materials in an international context. Utrecht: The Royal Society.
World Bank (2016) The Cost of Fire: An Economic Analysis of Indonesia’s 2015 Fire Crisis. Jakarta: World Bank.

Chapter 5
ADB (2017). ‘Poverty in India.’ Basic Statistics. Asian Development Bank. Available at: https://www.adb.org/countries/india/
poverty[Accessed 19 October 2017]
Annaluru, R., and Garg, A. (2017). Managing the Power Grid Ramping Challenges Critical to Success of India’s Renewable Energy
Targets. Working paper No 2017-08-01. Indian Institute of Management Ahmedabad. Available at: https://web.iima.ac.in/assets/snippets/workingpaperpdf/14473831782017-08-01.pdf [Accessed October 19 2017 ]Arent, D., Arndt, C., Miller, M., Zinaman, O., and Tarp, F. (2017). ‘The Political Economy of Clean Energy Transitions.’ Oxford University Press.
Audoly, R., Vogt-Schilb, A. and Guivarch, C. (2014). ‘Pathways toward Zero-Carbon Electricity Required for Climate Stabilization.’
World Bank Policy Research Working Paper 7075.
Australian Government. (2017). ‘Australian Mineral Commodities: Coal.’ Department of Industry, Innovation and Science. Available
at:https://www.industry.gov.au/resource/Mining/AustralianMineralCommodities/Pages/Coal.aspx [Accessed 19 October 2017]
Bach, S., Kohlhaas, M., Meyer, B., Praetorius, B. and Welsch, H. (2002). ‘The Effects of Environmental Fiscal Reform in Germany:
A Simulation Study.’ Energy Policy 30 (9): pp. 803–811.
Baker, L., and Burton, J. in press. ‘The Politics of Procurement and the Low Carbon Transition in South Africa.’ In: Elgar, E. Handbookof the International Political Economy of Energy and Natural Resources.
Sharma, B. K. and Das Kundu, N. (2016). China’s One Belt One Road: Initiative, Challenges and Prospects. Vij Books India Pvt Ltd.
Available at:https://books.google.dk/books?isbn=9385563602 [Accessed 19 October 2017]
Bauer, N., Mouratiadou, I., Luderer, G., Baumstark, L., Brecha, R. J., Edenhofer, O., and Kriegler, E. (2016). ‘Global Fossil Energy
Markets and Climate Change Mitigation–an Analysis with REMIND.’ Climatic Change 136 (1): pp. 69–82.
Bazilian, M., and Onyeji, I. (2012). ‘Fossil Fuel Subsidy Removal and Inadequate Public Power Supply: Implications for Businesses.’
Energy Policy 45: pp. 1–5.
Bertram, C., Johnson, N., Luderer, G., Riahi, K., Isaac, M. and Eom, J. (2015). ‘Carbon Lock-in through Capital Stock Inertia Associatedwith Weak near-Term Climate Policies.’ Technological Forecasting and Social Change 90, Part A (January): pp. 62–72. Bertram,
C., Luderer, G., Pietzcker, R. C., Schmid, E., Kriegler, E., and Edenhofer, O. (2015). ‘Complementing Carbon Prices with Technology
Policies to Keep Climate Targets within Reach.’ Nature Climate Change 5 (3): pp. 235–39.
BNEF (2017). ‘New Energy Outlook.’ Bloomberg New Energy Finance. https://about.bnef.com/new-energy-outlook/
Bouzarovski, S. and Tirado Herrero, S. (2017). ‘Geographies of Injustice: The Socio-Spatial Determinants of Energy Poverty in Poland, the Czech Republic and Hungary.’ Post-Communist Economies 29 (1): pp. 27–50.
Branger, F. and Quirion, P. (2014). ‘Climate Policy and the ‘Carbon Haven’ Effect.’ Wiley Interdisciplinary Reviews: Climate Change 5(1): pp. 53–71. doi:10.1002/wcc.245.
Brenner, M., Riddle, M. and Boyce, J.K. (2007). ‘A Chinese Sky Trust?: Distributional Impacts of Carbon Charges and Revenue
Recycling in China.’ Energy Policy 35 (3): pp. 1771–1784.
Breyer, C., Bogdanov, D., Gulagi, A., Aghahosseini, A., Barbosa, L. S.N.S., Koskinen, O., Maulidi Barasa, M. (2017). ‘On the Role ofSolar Photovoltaics in Global Energy Transition Scenarios.’ Progress in Photovoltaics: Research and Applications 25: pp. 727–745.
doi:10.1002/pip.2885.
Burton, J., Caetano, T., Hughes, A., Merven, B., Ahjum, F. and McCall, B. (2016). ‘The Impact of Stranding Power Sector Assets inSouth Africa: Using a Linked Model to Understand Economy-Wide Implications.’ Cape Town: Energy Research Centre, Universityof Cape Town.

76

The Emissions Gap Report 2017 – References

Burtraw, D., Sweeney, R. and Walls, M. (2009). ‘The Incidence of U.S. Climate Policy: Alternative Uses of Revenues from a Cap-andTrade Auction.’ National Tax Journal 62 (3): pp. 497–518.
Caldecott, B. (2017). ‘Introduction to Special Issue: Stranded Assets and the Environment.’ Journal of Sustainable Finance & Investment 7 (1): pp. 1–13.
Caldecott, B., Sartor, O. and Spencer, T. (2017). ‘Lessons from Previous Coal Transitions: High-Level Summary for Decision-Makers.’
London: IDDRI & Climate Strategies. http://www.iddri.org/Publications/Rapports-and-briefing-papers/COAL_SynthesisReport_
v04.pdf
Callan, T., Lyons, S., Scott, S., Tol, R. S. J. and Verde, S. (2009). ‘The Distributional Implications of a Carbon Tax in Ireland.’ Energy
Policy 37 (2): pp. 407–412.
Cameron, L., and van der Zwaan, B. (2015). ‘Employment Factors for Wind and Solar Energy Technologies: A Literature Review.’
Renewable and Sustainable Energy Reviews 45 (May): pp. 160–172.
Carbon Tracker Initiative. (2015). ‘The $2 Trillion Stranded Assets Danger Zone: How Fossil Fuel Firms Risk Destroying Investor
Returns.’ London. https://www.carbontracker.org/reports/stranded-assets-danger-zone/
CEC. (2017). ‘Briefing on the Power Sector’s Status during January - June 2017.’ China Electricity Council. http://www.cec.org.cn/
guihuayutongji/gongxufenxi/dianliyunxingjiankuang/2017-07-19/171012.html
Central Electricity Authority Government of India. (2016). ‘Draft National Electricity Plan (Volume 1) Generation.’ http://www.cea.
nic.in/reports/committee/nep/nep_dec.pdf
Chen, H. (2017). ‘Why Are G20 Governments Financing Coal Over Renewables?’ National Resources Defense Council (NRDC) Expert
Blog. July 17. https://www.nrdc.org/experts/han-chen/why-are-g20-governments-financing-coal-over-renewables
Chong, C., Ma, L., Li, Z., Ni, W and Song, S. (2015). ‘Logarithmic Mean Divisia Index (LMDI) Decomposition of Coal Consumption in
China Based on the Energy Allocation Diagram of Coal Flows.’ Energy 85 (June): pp. 366–378.
Citi GPS. (2015). ‘Energy 2030: Financing a Greener Future. Financing Green Energy in a Low Fossil Fuel Price World and Managing
Stranded Asset Risk.’ Citi Global Perspectives & Solutions. https://ir.citi.com/BOkALUJBhr6ezsrQxov5ZpfX3D8UkGSU7cyUzHOPU
zfK%2FaozVshGqUWCOwuxH0eFBsfY5BSB8aM%3D
Clarke, L., Jiang, K., Akimoto, K., Babiker, M., Blanford, G., Fisher-Vanden, K. and van Vuuren, D. P. (2014). Assessing Transformation
Pathways. In: Climate Change 2014: Mitigation of Climate Change. Contribution of Working Group III to the Fifth Assessment
Report of the Intergovernmental Panel on Climate Change. Cambridge, New York. Cambridge University Press.
Coady, D., Parry, I., Sears, L. and Shang, B. (2016). ‘How Large Are Global Fossil Fuel Subsidies?’ World Development.
Coady, D., Parry, I. and Shang, B. (2017). ‘Energy Price Reform: A Guide for Policymakers.’ CESifo Working Paper Series No. 6342.
Collier, P., and Venables, A. J. (2014). ‘Closing Coal: Economic and Moral Incentives.’ Oxford Review of Economic Policy 30 (3):pp. 492–512.
Coons, C. (2015). ‘Master Limited Partnership Parity Act Section-by-Section.’ http://www.mlpassociation.org/wp-content/uploads/
2015/09/MLP_Section-by-Section-114th_-Congress.pdf
Cramton, P, MacKay, D. J. C., Ockenfels, A. and Stoft, S. eds. (2017). Global Carbon Pricing: The Path to Climate Cooperation.
Cambridge, MA, USA: MIT Press.
Creutzig, F., Agoston, P., Goldschmidt, J. C., Luderer, G., Nemet, G. and Pietzcker, R. C. (2017). ‘The Underestimated Potential of Solar
Energy to Mitigate Climate Change.’ Nature Energy 2 (9):CSIR. (2016). ‘Least-Cost Electricity Mix for South Africa by 2040: Scenarios for South Africa’s Future Electricity Mix.’ Pretoria: South
Africa: Council of Scientific & Industrial Research (CSIR) Energy Centre.
Danish Energy Agency. (2017). ‘Annual and Monthly Statistics.’ https://ens.dk/en/our-services/statistics-data-key-figures-andenergy-maps/annual-and-monthly-statistics
Davis, S. J., Caldeira, K. and Matthews, H. D. 2010. ‘Future CO2 Emissions and Climate Change from Existing Energy Infrastructure.’
Science 329 (5997): pp. 1330–1333.
Davis, S. J., and Socolow R.H. (2014). ‘Commitment Accounting of CO2 Emissions.’ Environmental Research Letters 9 (8).
DoE. 2017a. ‘Siting and Regulating Carbon Capture, Utilization and Storage Infrastructure.’ Workshop Report. Washington, DC: U.S.
Dept. of Energy.
DoE. 2017b. ‘Staff Report to the Secretary on Electricity Markets and Reliability.’ Washington DC: U.S. Dept. of Energy. https://energy.gov/sites/prod/files/2017/08/f36/Staff%20Report%20on%20Electricity%20Markets%20and%20Reliability_0.pdf
Dolphin, G., Pollitt, M. and Newbery, D. (2016). ‘Political Economy of Carbon Pricing Policies: Insights from a Panel of Countries.’
In Energy: Expectations and Uncertainty, 39th IAEE International Conference, Jun 19-22, (2016). International Association for
Energy Economics.
Edenhofer, O., Steckel, J. C., Jakob, M. and Bertram, C. (2017). ‘Reports of Coal’s Terminal Decline May Be Exaggerated.’ MCC
Working Paper.
Enerdata. (2015). ‘Indonesia Releases Its 35 GW Power Capacity Addition Plan.’ http://www.enerdata.net/enerdatauk/press-andpublication/energy-news-001/indonesia-releases-its-35-gw-power-capacity-addition-plan_32605.html
Eskom. (2017). ‘Integrated Report 2017.’ http://www.eskom.co.za/IR2017/Documents/Eskom_integrated_report_2017.pdf
Fay, M., Hallegatte, S., Vogt-Schilb, A., Rozenberg, J., Narloch, U. and Kerr, T. (2015). Decarbonizing Development: Three Steps to a
Zero-Carbon Future. Washington DC, USA: World Bank Publications.
Fothergill, S. (2017). ‘Coal Transition in the United Kingdom.’ An Historical Case Study for the Project ‘Coal Transitions: Researchand Dialogue on the Future of Coal.’ IDDRI and Climate Strategies. www.iddri.org/Publications/Rapports-and-briefing-papers/
COAL_UK_v04.pdf
Galgóczi, B. (2014). ‘The Long and Winding Road from Black to Green: Decades of Structural Change in the Ruhr Region.’ International Journal of Labour Research 6 (2): pp. 217–240.
Garg, A., Mohan, P., Kankal, B., Shukla, S. and Vishwanathan, S. (2017). High-Impact Opportunities for Energy Efficiency in India.
Copenhagen: Copenhagen Centre on Energy Efficiency, UNEP DTU. ISBN: 978-87-93458-14-7
Garg, A., and Shukla, P. R. (2009). ‘Coal and Energy Security for India: Role of Carbon Dioxide (CO2) Capture and Storage (CCS).’
Energy Journal 34 (8): pp. 1032–1041.
The Emissions Gap Report 2017 – References

77Gerdes, J. (2016). Quitting Carbon: How Denmark Is Leading the Clean Energy Transition and Winning the Race to the Low-Carbon
Future.
GoI. (2017). India’s Intended Nationally Determined Contribution: Working Towards Climate Justice. New Delhi: Government ofIndia. http://www4.unfccc.int/submissions/INDC/Published%20Documents/India/1/INDIA%20INDC%20TO%20UNFCCC.pdf
Gonzalez, F. (2012). ‘Distributional Effects of Carbon Taxes: The Case of Mexico.’ Energy Economics 34 (6): pp. 2102–2115.
doi:10.1016/j.eneco.2012.03.007.
Goulder, L. H., and Schein, A. R. (2013). ‘Carbon Taxes versus Cap and Trade: A Critical Review.’ Climate Change Economics 4 (3):1350010. doi:10.1142/S2010007813500103.
Government of Alberta. (2015). ‘Phasing Out Coal Pollution – Alberta Climate Leadership Plan.’ Edmonton. http://www.alberta.ca/
climate-coal-electricity.cfm
Graichen, P., Kleiner, M. M. and Buck, M. (2016). ‘Energy Transition in the Power Sector in Europe: State of Affairs in 2015: Reviewof the Developments and Outlook for 2016.’ Agora Energiewende.
Arze del Granado, F.J., Coady, D., Gillingham, R. (2012). ‘The Unequal Benefits of Fuel Subsidies: A Review of Evidence for Developing Countries.’ World Development 40 (11): pp. 2234–2248.
Great Plains Institute. (2016). ‘Putting the Puzzle Together: State and Federal Policy Drivers for Growing America’s Carbon Capture &CO2-EOR Industry.’ Great Plains Institute. http://www.betterenergy.org/sites/default/files/PolicyDriversCO2_EOR%20V1.1_0.pdf
Green, F., and Stern, N. (2017). ‘China’s Changing Economy: Implications for Its Carbon Dioxide Emissions.’ Climate Policy 17 (4):pp. 423–442.
Guivarch, C., and Hood, C. 2011. ‘Early Retirement of Coal-Fired Generation in the Transition to Low-Carbon Electricity Systems.’ In:
Climate & Electricity Annual 2011 Data and Analyses. Paris: International Energy Agency.
Hallegatte, S., Bangalore, M., Bonzanigo, L., Fay, M., Kane, T., Narloch, U., Rozenberg, J., Treguer, D. and Vogt-Schilb, A. (2016). ShockWaves: Managing the Impacts of Climate Change on Poverty. Washington DC: World Bank Publications.
Hao, Y., Liu, Y., Weng, J., and Gao, Y. (2016). ‘Does the Environmental Kuznets Curve for Coal Consumption in China Exist? New
Evidence from Spatial Econometric Analysis.’ Energy 114 (November): pp. 1214–1223.
Hart, M, Bassett, L. and Johnson, B. (2017). ‘Everything You Think You Know About Coal in China Is Wrong.’ Issue Brief. Energy andEnvironment. Center for American Progress. https://www.americanprogress.org/issues/green/reports/2017/05/15/432141/
everything-think-know-coal-china-wrong/
Healy, N., and Barry, J. (2017). ‘Politicizing Energy Justice and Energy System Transitions: Fossil Fuel Divestment and a ‘Just Transition.’’ Energy Policy 108 (September): pp. 451–459.
Heede, R. (2014). ‘Tracing Anthropogenic Carbon Dioxide and Methane Emissions to Fossil Fuel and Cement Producers, 1854–
2010.’ Climatic Change 122 (1–2): pp. 229–241.
Heede, R., and Oreskes, N. (2016). ‘Potential Emissions of CO2 and Methane from Proved Reserves of Fossil Fuels: An Alternative
Analysis.’ Global Environmental Change 36: pp. 12–20.
Hirth, L., and Steckel, J.C. (2016). ‘The Role of Capital Costs in Decarbonizing the Electricity Sector.’ Environmental Research Letters
11. doi:doi:10.1088/1748-9326/11/11/114010.
Hirth, L., Ueckerdt, F. and Edenhofer, O. (2015). ‘Integration Costs Revisited – An Economic Framework for Wind and Solar Variability.’ Renewable Energy 74 (February): pp. 925–939.
Hirth, L., Ueckerdt, F. and Edenhofer, O. (2016). ‘Why Wind Is Not Coal: On the Economics of Electricity Generation.’ The Energy
Journal 37 (3).
Houser, T., Bordoff, J. and Marsters, P. (2017). ‘Can Coal Make a Comeback?’ New York, NY: Columbia University. Center on Global
Energy Policy. https://www.eenews.net/assets/2017/04/27/document_gw_06.pdf
IEA. (2016). World Energy Outlook (2016). International Energy Agency. Paris: IEA. http://www.oecd-ilibrary.org/energy/world-­
energy-outlook-2016_weo-2016-en
IEA. (2017). Tracking Progress: Renewable Power. Paris: IEA. https://www.iea.org/etp/tracking2017/renewablepower
IEA/OECD. (2016). Coal Information (2016). Paris, France: International Energy Agency, OECD Publishing. http://www.oecd-ilibrary.
org/energy/coal-information-2016_coal-2016-en
IEA-RETD. (2016). ‘RE-TRANSITION – Transitioning to Policy Frameworks for Cost-Competitive Renewables.’ Utrecht: IEA Technology
Collaboration Programme for Renewable Energy Technology Deployment (IEA-RETD).
International Labour Organization. (2015). Guidelines for a Just Transition towards Environmentally Sustainable Economies andSocieties for All. Geneva: International Labour Organization. http://www.ilo.org/wcmsp5/groups/public/---ed_emp/---emp_ent/
documents/publication/wcms_432859.pdf
IPCC. (2014). Climate Change 2014: Mitigation of Climate Change. Contribution of Working Group III to the Fifth Assessment Reportof the Intergovernmental Panel on Climate Change. Edited by Edenhofer, Ottmar, Ramón Pichs-Madruga, Youba Sokona, Ellie
Farahani, Susanne Kadner, Anna Adler, and Kristin Seyboth. Cambridge, United Kingdom and New York, NY, USA: Cambridge
University Press.
IqtiyaniIlham, N., Hasanuzzaman, M. and Hosenuzzaman, M. (2017). ‘European Smart Grid Prospects, Policies, and Challenges.’
Renewable and Sustainable Energy Reviews 67: pp. 776–790.
IRENA. 2017a. ‘Geothermal Power. Technology Brief.’ Abu Dhabi: International Renewable Energy Agency. http://www.irena.org/
DocumentDownloads/Publications/IRENA_Geothermal_Power_2017.pdf
IRENA. 2017b. ‘Stranded Assets and Renewables: How the Energy Transition Affects the Value of Energy Reserves, Buildings andCapital Stock.’ Abu Dhabi: International Renewable Energy Agency (IRENA). http://www.irena.org/DocumentDownloads/Publications/IRENA_REmap_Stranded_assets_and_renewables_2017.pdf
Iyer, G. C., Clarke, L. E., Edmonds, J.E., Flannery, B. P., Hultman, N.E., McJeon, H. C. and Victor, D. G. (2015). ‘Improved Representation of Investment Decisions in Assessments of CO2 Mitigation.’ Nature Climate Change 5 (5): pp. 436–440.
Jakob, M., Chen, C., Fuss, S., Marxen, A. and Edenhofer, O. (2015). ‘Development Incentives for Fossil Fuel Subsidy Reform.’ Nature
Climate Change 5 (8): pp. 709–712.

78

The Emissions Gap Report 2017 – References

Jakob, M., Chen, C., Fuss, S., Marxen, A., Rao, N. D. and Edenhofer, O. (2016). ‘Carbon Pricing Revenues Could Close Infrastructure
Access Gaps.’ World Development 84 (August): pp. 254–265.
Jakob, M., and Steckel, J.C. (2016). ‘Implications of Climate Change Mitigation for Sustainable Development.’ Environmental
Research Letters 11 (10): 104010.
Johnson, N., Krey, V., McCollum, D. L., Rao, S., Riahi, K. and Rogelj, J. (2015). ‘Stranded on a Low-Carbon Planet: Implications of
Climate Policy for the Phase-out of Coal-Based Power Plants.’ Technological Forecasting and Social Change 90, Part A (January):
pp. 89–102.
Jonek Kowalska, I. (2015). ‘Challenges for Long-Term Industry Restructuring in the Upper Silesian Coal Basin: What Has Polish Coal
Mining Achieved and Failed from a Twenty-Year Perspective?’ Resources Policy 44 (June): pp. 135–149.
Jordaan, S. M., Romo-Rabago, E., McLeary, R., Reidy, L., Nazari, J., and Herremans, I.M. (2017). ‘The Role of Energy Technology
Innovation in Reducing Greenhouse Gas Emissions: A Case Study of Canada.’ Renewable and Sustainable Energy Reviews 78(October): pp. 1397–1409. doi:10.1016/j.rser.2017.05.162.
Jotzo, F., Jordan, T. and Fabian, N. (2012). ‘Policy Uncertainty about Australia’s Carbon Price: Expert Survey Results and Implications
for Investment.’ Australian Economic Review 45 (4): pp. 395–409.
Kalkuhl, M., and Brecha, R.J. (2013). ‘The Carbon Rent Economics of Climate Policy.’ Energy Economics 39: pp. 89–99.
Kern, F., and Rogge, K. S. (2016). ‘The Pace of Governed Energy Transitions: Agency, International Dynamics and the Global Paris
Agreement Accelerating Decarbonisation Processes?’ Energy Research & Social Science 22 (December): pp. 13–17.
Khosla, R., Dukkipati, S., Dubash, N.K., Sreenivas, A. and Cohen, B. (2015). ‘Towards Methodologies for Multiple Objective-Based
Energy and Climate Policy.’ Economic & Political Weekly 50 (49): pp. 49–59.
Kim, S. E., Urpelainen, J. and Yang, J. (2016). ‘Electric Utilities and American Climate Policy: Lobbying by Expected Winners andLosers.’ Journal of Public Policy 36 (2): pp. 251–275.
Kolstad, C. D., Urama, K., Broome, J., Bruvoll, A., Cariño-Olvera, M., Fullerton, D., Gollier, C. (2014). ‘Social, Economic and EthicalConcepts and Methods.’ In: Climate Change 2014: Mitigation of Climate Change, pp. 173–248. Cambridge, United Kingdom and
New York, NY, USA: Cambridge University Press. http://lup.lub.lu.se/record/5104578.
Kriegler, E., Weyant, J.P., Blanford, G. J., Krey, V., Clarke, L., Edmonds, J., Fawcett, A. (2014). ‘The Role of Technology for Achieving
Climate Policy Objectives: Overview of the EMF 27 Study on Global Technology and Climate Policy Strategies.’ Climatic Change
123 (3–4): pp. 353–367.
Lazarus, M., Erickson, P. and Tempest, K. (2015). ‘Supply-Side Climate Policy: The Road Less Taken.’ Stockholm Environment Institute,
Working Paper, No. SEI-WP-2015-13 (October).
Liang, Q. and Wei, Y. (2012). ‘Distributional Impacts of Taxing Carbon in China: Results from the CEEPA Model.’ Applied Energy 92(April): pp. 545–551.
Lindebjerg, E. S., Peng, W., and Yeboah, S. (2015). ‘Do Policies for Phasing out Fossil Fuel Subsidies Deliver What They Promise?
Social Gains and Repercussions in Iran, Indonesia and Ghana.’ United Nations Research Institute for Social Development(UNRISD) Working Paper.
Löffler, K., Hainsch, K., Burandt, T., Oei, P., Kemfert, C. and von Hirschhausen, C. (2017). ‘Designing a Global Energy System Basedon 100% Renewables for 2050 - GENeSYS-MOD: An Application of the Open-Source Energy Modelling System (OSeMOSYS).’ DIW
Discussion Paper, DIW Discussion Paper 1678.
Louie, E. P., and Pearce, J.M. (2016). ‘Retraining Investment for U.S. Transition from Coal to Solar Photovoltaic Employment.’ Energy
Economics 57 (June): pp. 295–302.
Luderer, G., Pietzcker, R. C., Carrara, Bertram, C., Kriegler, E., Meinshausen, M. and Edenhofer, O. (2013). ‘Economic Mitigation
Challenges: How Further Delay Closes the Door for Achieving Climate Targets.’ Environmental Research Letters 8 (3): 34033.
Luderer, G., Pietzcker, R. C., Carrara, S., Sytze de Boer, H., Fujimori, S., Johnson, N., Mima, S. and Arent, D. (2017). ‘Assessment ofWind and Solar Power in Global Low-Carbon Energy Scenarios: An Introduction.’ Energy Economics 64 (May): pp. 542–551.
Marcinkiewicz, K., and Tosun, J. (2015). ‘Contesting Climate Change: Mapping the Political Debate in Poland.’ East European Politics
31 (2): pp. 187–207. doi:10.1080/21599165.2015.1022648.
Matthes, F. C. (2017). ‘Energy Transition in Germany: A Case Study on a Policy-Driven Structural Change of the Energy System.’
Evolutionary and Institutional Economics Review 14 (1): pp. 141–169.
Matthes, F. C., Fabra, N., Newbery, D., Colombier, M., Mathieu, M. and Rüdinger, A. (2015). ‘The Energy Transition in Europe: Initial
Lessons from Germany, the UK and France.’ Centre on Regulation in Europe (CERRE).
McGlade, C., and Ekins, P. (2015). ‘The Geographical Distribution of Fossil Fuels Unused When Limiting Global Warming to 2°C.’
Nature 517 (7533): pp. 187–190. doi:10.1038/nature14016.
Meadowcroft, J., Stephens, J., Wilson, E. and Rowlands, I. (2017). ‘Social Dimensions of Smart Grid: Regional Analysis in Canada
and the United States. Introduction to Special Issue of Renewable and Sustainable Energy Reviews.’ Renewable and Sustainable
Energy Reviews In press.
Meinshausen, M., Meinshausen, N., Hare, W., Raper, S. C. B., Frieler, K., Knutti, R., Frame, D. J. and Allen, M. R. (2009). ‘Greenhouse-­
Gas Emission Targets for Limiting Global Warming to 2°C.’ Nature 458 (7242): pp. 1158–1162. doi:10.1038/nature08017.
MEMR. (2016). ‘Statistik Ketenagalistrikan (Electricity Statistics) 2015.’ Jakarta: Directorate General Electricity Ministry of Energy
and Mineral Resources of Indonesia.
MEMR. (2017). ‘Electric
ity Supply Business Plan (Rencana Umum Penyediaan Tenaga Listrik) 2017 – 2026.’ Jakarta: Directorate General Electricity Ministry of Energy and Mineral Resources of Indonesia.
Mendelevitch, R., Richter, P. and Jotzo, F. (2015). ‘Market Power Rents and Climate Change Mitigation: A Rationale for Coal Export
Taxes?’ Conference Paper.
Metcalf, G. E. (1999). ‘A Distributional Analysis of Green Tax Reforms.’ National Tax Journal 52 (4): pp. 655–682.
Miller, C. A., Richter, J. and O’Leary, J. (2015). ‘Socio-Energy Systems Design: A Policy Framework for Energy Transitions.’ Energy
Research & Social Science 6 (March): pp. 29–40.
Ministry of Power Government of India. n.d. LOK SABHA STARRED QUESTION NO.164 ANSWERED ON 28.07.2016.

The Emissions Gap Report 2017 – References

79

Mondal, D. (2017). ‘Electricity May Get Costlier as States Demand Higher Royalty on Coal: India Ratings.’ ET Energy World.
January 18. http://energy.economictimes.indiatimes.com/news/coal/electricity-may-get-costlier-as-states-demand-higherroyalty-on-coal-india-ratings/56649160
Morgan, E. (2017). ‘Electricity Prices Could Double with New Coal-Fired Stations, Energy Experts Say.’ ABC. http://www.abc.net.
au/news/2017-02-02/coal-power-stations-could-double-the-cost-of-electricity/8234240
NDRC. (2016). ‘First Biennial Update Report on Climate Change of China.’ China’s official submission to the UNFCCC. National
Development and Reform Commission. http://unfccc.int/files/national_reports/non-annex_i_parties/biennial_update_reports/application/pdf/pr_china-_bur-chinese+en.pdf
Nemet, G. F., Jakob, M., Steckel, J. C. and Edenhofer, O. (2017). ‘Addressing Policy Credibility Problems for Low-Carbon Investment.’
Global Environmental Change 42 (January): pp. 47–57. doi:10.1016/j.gloenvcha.2016.12.004.
Nordhaus, W. D. (1991). ‘A Sketch of the Economics of the Greenhouse Effect.’ The American Economic Review 81 (2): pp. 146–150.
OCI. (2016). ‘The Sky’s Limit. Why the Paris Climate Goals Require a Managed Decline of Fossil Fuel Production.’ Oil Change International. http://priceofoil.org/content/uploads/2016/09/OCI_the_skys_limit_2016_FINAL_2.pdf
OECD. (2017). Investing in Climate, Investing in Growth. OECD Publishing, Paris. http://www.oecd-ilibrary.org/economics/investing-in-climate-investing-in-growth_9789264273528-en
Oei, P., and Mendelevitch, R. (2016). ‘European Scenarios of CO2 Infrastructure Investment until 2050.’ The Energy Journal 37: pp.
171-194.
Olivier, J. G. J., Greet Janssens-Maenhout, Marilena Muntean, and Jeroen Peters. (2016). ‘Trends in Global CO2 Emissions: 2016
Report.’ PBL publication number: 2315. JRC Science for Policy Report: 103428. The Hague: PBL Netherlands Environmental Assessment Agency. European Commission, Joint Research Centre.
Ondraczek, J., Komendantova, N. and Patt, A. (2015). ‘WACC the Dog: The Effect of Financing Costs on the Levelized Cost of Solar
PV Power.’ Renewable Energy 75: pp. 888–898.
Oosterhuis, F., and ten Brink, P. eds. (2014). Paying the Polluter: Environmentally Harmful Subsidies and Their Reform. Cheltenham,
UK ; Northampton, MA, USA: Edward Elgar Publishing.
Park, A., and Lappas, P. (2017). ‘Evaluating Demand Charge Reduction for Commercial-Scale Solar PV Coupled with Battery Storage.’ Renewable Energy 108 (August): pp. 523–532.
Parry, I. W. H., and Williams III, R.C. (2010). ‘What Are the Costs of Meeting Distributional Objectives for Climate Policy?’ The B.E.
Journal of Economic Analysis & Policy 10 (2): pp. 1935–1682.
Pearce, D. (1991). ‘The Role of Carbon Taxes in Adjusting to Global Warming.’ The Economic Journal 101 (407): pp. 938–948.
Perrier, Q., and Quirion, P. (2016). ‘La transition énergétique est-elle favorable aux branches à fort contenu en emploi ? Uneapproche input-output pour la France.’ Working Paper 2016.09. French Association of Environmental and Resource Economists(FAERE) http://faere.fr/pub/WorkingPapers/Perrier_Quirion_FAERE_WP2016.09.pdf
Pfeiffer, A., Millar, M., Hepburn, C. and Beinhocker, E. (2016). ‘The ‘2°C Capital Stock’ for Electricity Generation: Committed
Cumulative Carbon Emissions from the Electricity Generation Sector and the Transition to a Green Economy.’ Applied Energy
179 (October): pp. 1395–1408.
Pigou, A. C. (1920). The Economics of Welfare. Macmillan & Co., London.
Portman, R. (2017). ‘Portman, Bennet Introduce Bill to Help Finance Carbon Capture and Storage Projects.’ Press release.
https://www.portman.senate.gov/public/index.cfm/2017/4/portman-bennet-introduce-bill-to-help-finance-carbon-captureand-storage-projects
Porto, G.G. (2012). ‘The Cost of Adjustment to Green Growth Policies: Lessons from Trade Adjustment Costs.’ World Bank Policy
Research Working Paper No. 6237. http://papers.ssrn.com/abstract=2165675
PWC Indonesia and ICMA. (2016). ‘Supplying and Financing Coal-fired Power Plants in 35 GW Programme.’ http://www.apbi-icma.
org/wp-content/uploads/2016/03/03-03-2016-APBI-PwC-Report-on-Supplying-and-Financing-the-35-GW-program-FINALFINAL-rev-8-32016.pdf
Ragwitz, M., Schade, W., Breitschopf, B., Walz,R., Helfrich, N., Rathmann, M., Resch, G., Panzer, C., Faber, T. and Haas, R. (2009).
‘EmployRES. The Impact of Renewable Energy Policy on Economic Growth and Employment in the European Union. Final
Report, Contract No.’ TREN.
Rausch, S., Metcalf, G. E. and Reilly, J.M. 2011. ‘Distributional Impacts of Carbon Pricing: A General Equilibrium Approach with
Micro-Data for Households.’ Energy Economics, Supplemental Issue: Fourth Atlantic Workshop in Energy and Environmental
Economics, 33, Supplement 1 (December): S20–33.
Reddy, B. S. (2016). ‘India’s Energy System Transition—Survival of the Greenest.’ Renewable Energy 92: pp. 293–302.
Ren, P., Liu, C. and Zhang, L. (2017). ‘China’s Involvement in Coal-Fired Power Projects along the Belt and Road.’ Global Environmental Institute. http://www.geichina.org/_upload/file/report/China’s_Involvement_in_Coal-fired_Power_Projects_OBOR_EN.pdf
Renn, O., and Marshall, J.P. (2016). ‘Coal, Nuclear and Renewable Energy Policies in Germany: From the 1950s to the ‘Energiewende.’’ Energy Policy 99 (December): pp. 224–232.
Rentschler, J. (2015). Incidence and Impact: A Disaggregated Poverty Analysis of Fossil Fuel Subsidy Reform. OIES working Paper:
SP 36. Oxford: Oxford Institute for Energy Studies.
Rentschler, J and Bazilian, M. (2016). ‘Reforming Fossil Fuel Subsidies: Drivers, Barriers and the State of Progress.’ Climate Policy,
17 (7): pp. 891–914.
Riahi, K., Kriegler, E., Johnson, N., Bertram, C., den Elzen, M., Eom, J., Schaeffer, M. (2015). ‘Locked into Copenhagen Pledges –Implications of Short-Term Emission Targets for the Cost and Feasibility of Long-Term Climate Goals.’ Technological Forecasting
and Social Change 90, Part A (January): pp. 8–23.
Rifkin, J. 2011. The Third Industrial Revolution: How Lateral Power Is Transforming Energy, the Economy, and the World. St. Martin’s Press. http://www.ebooks.com/731631/the-third-industrial-revolution/rifkin-jeremy/
Robles, M., Rubio, M. G., and Stampini, M.S. (2015). ‘Have Cash Transfers Succeeded in Reaching the Poor in Latin America and the
Caribbean?’ Inter-American Development Bank (IDB). http://publications.iadb.org/handle/11319/7223

80

The Emissions Gap Report 2017 – References

Rogelj, J., Luderer, G., Pietzcker, R. C., Kriegler, E., Schaeffer, M., Krey, V., and Riahi, K. (2015). ‘Energy System Transformations for
Limiting End-of-Century Warming to below 1.5°C.’ Nature Climate Change 5 (6): pp. 519–527. doi:10.1038/nclimate2572.
Rogelj, J., McCollum, D. L., O’Neill, B.C. and Riahi, K. (2013). ‘2020 Emissions Levels Required to Limit Warming to below 2? C.’ Nature Climate Change 3 (4): pp. 405–412.
Rozenberg, J., Vogt-Schilb, A. and Hallegatte, S. (2017). ‘Instrument Choice and Stranded Assets in the Transition to Clean Capital.’Inter-American Development Bank (IDB).
Sachs, J., Guerin, E., Mas, C., Schmidt-Traub, G., Tubiana, L., Waisman, H., Colombier, M. (2014). ‘Pathways to Deep Decarbonization: 2014 Report.’ INIS-FR--15-0191. France: SDSN/IDDRI.
Sdralevich, C.A., Sab, R., Zouhar, Y. and Albertin, G. (2014). Subsidy Reform in the Middle East and North Africa: Recent Progress andChallenges Ahead. International Monetary Fund.
Shearer, C., Ghio, N., Myllyvirta, L., Yu, A. and Nace, T. (2017). ‘Boom and Bust 2017 - Tracking the Global Coal Plant Pipeline.’ Coalswarm / Sierra Club / Greenpeace.
Singh, R. K. (2016). ‘India Seeks to Shut 12% of Power Capacity in Anti-Pollution Move.’ Live Mint, May 8.http://www.livemint.com/
Industry/QkD9eo3lrSVj1sxV3ubB9K/India-seeks-to-shut-12-of-power-capacity-in-antipollution.html
Sovacool, B. (2017). ‘Reviewing, Reforming, and Rethinking Global Energy Subsidies: Towards a Political Economy Research Agenda.’
Ecological Economics 135 (February): 150–163. doi:http://dx.doi.org/10.1016/j.ecolecon.2016.12.009.
Sovacool, B. K., Heffron R. J., McCauley, D. and Goldthau. A. (2016). ‘Energy Decisions Reframed as Justice and Ethical Concerns.’
Nature Energy 1: 16024.
Steckel, J. C., Edenhofer, O and Jakob, M. (2015). ‘Drivers for the Renaissance of Coal.’ Proceedings of the National Academy of Sciences 112 (29): E3775–81. doi:10.1073/pnas.1422722112.
Steckel, J. C., Jakob, M., Flachsland, C., Kornek, U., Lessmann, K., and Edenhofer, O. (2017). ‘From Climate Finance toward Sustainable Development Finance.’ Wiley Interdisciplinary Reviews: Climate Change 8 (1).
Sterner, T., ed. (2012). Fuel Taxes and the Poor: The Distributional Effects of Gasoline Taxation and Their Implications for Climate
Policy. New York: RFF Press.
Stiglitz, J. and Stern, N. (2017). Report of the High-Level Commission on Carbon Prices. Washington: World Bank Group: Carbon
Pricing Leadership Coalition.
Suwala, W. 2010. ‘Lessons Learned from the Restructuring of Poland’s Coal-Mining Industry.’ Global Subsidies Initiative (GSI), International Institute for Sustainable Development (IISD).
Swartz, J. (2016). ‘China’s National Emissions Trading System: Implications for Carbon Markets and Trade.’ Issue Paper No. 6. International Centre for Trade and Sustainable Development (ICTSD).
Symons, E., Proops, J. and Gay, P. (1994). ‘Carbon Taxes, Consumer Demand and Carbon Dioxide Emissions: A Simulation Analysis
for the UK.’ Fiscal Studies 15 (2): pp. 19–43.
Szpor, A. (2017). ‘Coal Transition in Poland.’ IDDRI and Climate Strategies. www.iddri.org/Publications/Rapports-and-briefing-papers/COAL_PL_v04.pdf
Szulecki, K., Fischer, S., Gullberg, A.T. and Sartor, O. (2016). ‘Shaping the ‘Energy Union’: between National Positions and Governance Innovation in EU Energy and Climate Policy.’ Climate Policy 16 (5): pp. 548–567.
Torvanger, A., Narbel, P., Pillay, K. and Clapp, C. (2016). ‘Instruments to Incentivize Private Climate Finance for Developing Countries.’ CICERO Report.
Trebilcock, C. 1981. The Industrialization of the Continental Powers, 1780–1914. Longman London.
Trebilcock, M. J. (2014). Dealing with Losers: The Political Economy of Policy Transitions. Oxford University Press, USA.
United Nations. (2015). ‘Adoption of the Paris Agreement.’ Framework Convention on Climate Change. http://unfccc.int/resource/
docs/2015/cop21/eng/l09r01.pdf
US Senate. (2017). ‘S.1535 – FUTURE Act.’ Washington, DC. https://www.congress.gov/bill/115th-congress/senate-bill/1535/text
Vogt-Schilb, A. and Hallegatte, S. (2017). ‘Climate Policies and Nationally Determined Contributions: Reconciling the Needed Ambition with the Political Economy.’ WIREs Energy Environment 6 (6). doi:10.1002/wene.256.
Wei, M., Patadia, S. and Kammen, D. M. (2010). ‘Putting Renewables and Energy Efficiency to Work: How Many Jobs Can the Clean
Energy Industry Generate in the U.S.?’ Energy Policy 38 (2): pp. 919–931.
West, J. J., Smith, S. J., Silva, R. A., Naik, V., Zhang, Y., Adelman, Z., Fry, M. M., Anenberg, S., Horowitz, L.W. and Lamarque, J. (2013).
‘Co-Benefits of Mitigating Global Greenhouse Gas Emissions for Future Air Quality and Human Health.’ Nature Climate Change 3(10): pp. 885–889. doi:10.1038/nclimate2009.
White House. (2015). ‘The Budget of the U.S. Government Fiscal Year2015.’ Washington, DC.
White House . (2016). “The Budget of the U.S. Government Fiscal Year 2016.” Washington, DC.
Widera, M., Kasztelewicz, Z. and Ptak, M. (2016). ‘Lignite Mining and Electricity Generation in Poland: The Current State and Future
Prospects.’ Energy Policy 92: pp. 151–157.
Williams, J. H., DeBenedictis, A., Ghanadan, R., Mahone, A., Moore, J., Morrow III, W.R., Price, S. and. Torn, M.S. (2012). ‘The Technology Path to Deep Greenhouse Gas Emissions Cuts by 2050: The Pivotal Role of Electricity.’ Science 335 (6064): pp. 53–59.
World Bank. (2015). The State of Social Safety Nets (2015). Washington DC: The World Bank. http://elibrary.worldbank.org/doi/book/10.1596/978-1-4648-0543-1
World Bank, and Ecofys. (2016). ‘Carbon Pricing Watch 2016: An Advance Brief from the State and Trends of Carbon Pricing 2016 Report, to Be Released Late 2016.’ Washington, DC: World Bank Group. http://documents.worldbank.org/curated/
en/2016/05/26379305/carbon-pricing-watch-2016-advance-brief-state-trends-carbon-pricing-2016-report-released-late-2016
Wynn, G. (2016). ‘The Dutch Coal Mistake: How Three Brand-New Power Plants in the Netherlands Are Already at Risk of Becoming Stranded Assets.’ Cleveland: Institute for Energy Economics and Financial Analysis (IEEFA) http://ieefa.org/wp-content/uploads/2016/11/The-Dutch-Coal-Mistake_November-2016.pdf
Zhang, C. (2017). ‘China Takes Another Step to Reduce Coal-Fired Power.’ ChinaDialogue, March 20. https://www.chinadialogue.
net/article/show/single/en/9678-China-takes-another-step-to-reduce-coal-fired-power

The Emissions Gap Report 2017 – References81Zhou, Y., Li, H., Wang, K. and Bi, J. (2016). ‘China’s Energy-Water Nexus: Spillover Effects of Energy and Water Policy.’ Global Environmental Change 40 (September): pp. 92–100.

Chapter 6
Aggarwal, R.K. and Chandel, S.S. (2004) ‘Review of Improved Cookstoves Programme in Western Himalayan State of India’. Biomass
and Bioenergy, 27(2):131–144. Available at: https://www.cabdirect.org/cabdirect/abstract/20043106078 [Accessed 18 October
2017]. doi:10.1016/j.biombioe.2004.01.001
Allen, M.R., Fuglestvedt, J.S., Shine, K.P., Reisinger, A., Pierrehumbert, R.T. and Forster, P.M. (2016) ‘New use of global warming potentials to compare cumulative and short-lived climate pollutants’. Nature Climate Change, 6:773–776. Available at: http://www.
sequoiaforestkeeper.org/pdfs/attachments/Allen_et_al_on_SLCP_GWP_2016.pdf [Accessed 18 October 2017].
Amann, M., Klimont, Z. and Wagner, F. (2013) ‘Regional and Global Emissions of Air Pollutants: Recent Trends and Future Scenarios’. Annual Review of Environment and Resources, 38:31–55. Available at: http://pure.iiasa.ac.at/10315/ [Accessed 18 October
2017]Bond, T.C., Doherty, S.J., Fahey, D.W., Forster, P.M., Berntsen, T., DeAngelo, B.J., Flanner, M.G., Ghan, S., Kärcher, B., Koch, D., Kinne,
S., Kondo, Y., Quinn, P.K., Sarofim, M.C., Schultz, M.G., Schulz, M., Venkataraman, C., Zhang, H., Zhang, S., Bellouin, N., Guttikunda, S.K., Hopke, P.K., Jacobson, M.Z., Kaiser, J.W., Klimont, Z., Lohmann, U., Schwarz, J.P., Shindell, D., Storelvmo, T., Warren, S.G.
and Zender, C.S. (2013) ‘Bounding the role of black carbon in the climate system: A scientific assessment’. Journal of Geophysical Research: Atmospheres, 118(11):5380–5552. Available at: https://experts.illinois.edu/en/publications/bounding-the-role-ofblack-carbon-in-the-climate-system-a-scienti [Accessed 18 October 2017].
Brander, M., Sood, A., Wylie, C., Haughton, A. and Lovell, J. (2011) ‘Technical Paper - Electricity-specific Emission Factors for Grid
Electricity’. Ecometrica. Available at: https://ecometrica.com/assets/Electricity-specific-emission-factors-for-grid-electricity.pdf[Accessed 18 October 2017].
CAI-Asia (2011) Factsheet No. 17- Roadmap for Cleaner Fuels and Vehicles in Asia. Manila: Clean Air Initiative for Asian Cities Center. Available at: http://cleanairasia.org/wp-content/uploads/portal/files/documents/16_Roadmap_to_Cleaner_Fuels_and_Vehicles_in_Asia_0.pdf [Accessed 18 October 2017].
Cardenas, B., Maiz, P., Márquez, R.O., Munguia, J.L., Angeles, F., Baum, E. and Molina, L.T. (2012) Determining Emissions of Black
carbon, greenhouse gases and other pollutants from artisanal brick production in Mexico. Clean Air Task Force and MCE2.
Chambliss, S., Miller, J., Facanho, C., Minjares, R., Blumberg, K., 2013. The impact of stringent fuel and vehicle standards on premature mortality and emisisons. International Council on Clean Transportation (ICCT), Washington D.C., USA.
Cherian, A. (2015) Energy and Global Climate Change: Bridging the Sustainable Development Divide. Chichester: John Wiley & Sons
Ltd.
Christian, T.J., Yokelson, R.J., Cárdenas, B., Molina, L.T., Engling, G. and Hsu, S.-C. (2010) ‘Trace gas and particle emissions fromdomestic and industrial biofuel use and garbage burning in central Mexico’. Atmospheric Chemistry and Physics, 10(2):565–584.
Available at: https://www.atmos-chem-phys.net/10/565/2010/acp-10-565-2010.html [Accessed 18 October 2017].
Coan, J. (2012) Vehicle emissions standards are a regulatory success story. Fuelfix. Available at: http://fuelfix.com/blog/2012/05/18/
vehicle-emissions-standards-a-regulatory-success-story/ [Accessed 18 October 2017].
Conrad, B.M. and Johnson, M.R. (2017) ‘Field Measurements of Black Carbon Yields from Gas Flaring’. Environmental Science andTechnology, 51(3):1893–1900. Available at: http://pubs.acs.org/doi/abs/10.1021/acs.est.6b03690 [Accessed 18 October 2017].
Crippa, M., Janssens-Maenhout, G., Dentener, F., Guizzardi, D., Sindelarova, K., Muntean, M., Van Dingenen, R. and Granier, C.
(2016) ‘Forty years of improvements in European air quality: regional policy-industry interactions with global impacts’. Atmospheric Chemistry and Physics, 16:3825–3841. Available at: https://www.atmos-chem-phys.net/16/3825/2016/ [Accessed 18
October 2017].
DieselNet (2015). Summary of worldwide engine emission standards. Emission Standards.
EC-JRC/PBL (2013) EDGAR version 4.2FT2010—Emission Database for Global Atmospheric Research.
Etminan, M., Myhre, G., Highwood, E. and Shine, K.P. (2016) ‘Radiative forcing of carbon dioxide, methane, and nitrous oxide: A
significant revision of the methane radiative forcing’. Geophysical Research Letters, 43:614–623. Available at: http://centaur.
reading.ac.uk/68557/1/grl_etminan.pdf [Accessed 18 October 2017].
Evans, M., Kholod, N., Malyshev, V., Tretyakova, S., Gusev, E., Yu, S. and Barinov, A. (2015) ‘Black carbon emissions from Russiandiesel sources: case study of Murmansk’. Atmospheric Chemistry and Physics, 15:8349–8359. Available at: https://www.atmoschem-phys.net/15/8349/2015/ [Accessed 18 October 2017].
FAO (2013) Mitigation of greenhouse gas emissions in livestock production –a review of technical options for non-CO2 emissions.
Rome: Food and Agriculture Organization (FAO) of the United Nations. Available at: http://www.fao.org/docrep/018/i3288e/
i3288e.pdf [Accessed 18 October 2017].
GACC (2015). Five Years of Imapct 2010-2015. Our Story. Our Progress. Our Aspiration. Washington: Global Alliance for Clean Cookstoves (GACC). Available at: http://cleancookstoves.org/resources/reports/fiveyears.html [Accessed 18 October 2017].
Gasser, T., Peters, G.P., Fuglestvedt, J.S., Collins, W.J., Shindell, D.T. and Ciais, P. (2017) ‘Accounting for the climate-carbon feedback inemission metrics’. Earth System Dynamics, 8:235–253. Available at: https://www.earth-syst-dynam.net/8/235/2017/esd-201655.pdf [Accessed 18 October 2017].
Geoffroy, O., Saint-Martin, D., Bellon, G., Voldoire, A., Olivié, D.J.L. and Tytéca, S. (2013) ‘Transient Climate Response in a Two-Layer
Energy-Balance Model. Part II: Representation of the Efficacy of Deep-Ocean Heat Uptake and Validation for CMIP5 AOGCMs’.
Journal of Climate, 23:1859–1876. Available at: http://journals.ametsoc.org/doi/ref/10.1175/JCLI-D-12-00196.1 [Accessed 18
October 2017].
GOI (2014) Auto Fuel Vision and Policy 2025. Report of the Expert Committee. Government of India (GOI). Available at: http://www.
petroleum.nic.in/sites/default/files/autopol.pdf [Accessed 18 October 2017].
Griggs, D., M. Stafford Smith, J. Rockström, M. C. Öhman, O. Gaffney, G. Glaser and P. Shyamsundar (2014) ‘An integrated frameworkfor sustainable development goals’. Ecology and Society, 19(4):49. Available at: https://www.ecologyandsociety.org/vol19/iss4/
art49/ [Accessed 18 October 2017].

82

The Emissions Gap Report 2017 – References

Haines, A., et al. (under review) ‘Short-lived climate pollutant mitigation and the sustainable development goals’. Nature Climate
Change.
Hoesly, R.M., Smith, S.J., Feng, L., Klimont, Z., Janssens-Maenhout, G., Pitkanen, T., Seibert, J.J., Vu, L., Andres, R.J., Bolt, R.M., Bond,
T.C., Dawidowski, L., Kholod, N., Kurokawa, J.-I., Li, M., Liu, L., Lu, Z., Moura, M.C.P., O’Rourke, P.R. and Zhang, Q. (2017). ‘Historical (1750–2014) anthropogenic emissions of reactive gases and aerosols from the Community Emission Data System (CEDS)’.
Geoscientific Model Development Discussions, 1–41. Available at: https://www.geosci-model-dev-discuss.net/gmd-2017-43/[Accessed 18 October 2017].
Höglund-Isaksson, L. (2017) ‘Bottom-up simulations of methane and ethane emissions from global oil and gas systems 1980 to2012’. Environmental Research Letters, 12(2). Available at: http://iopscience.iop.org/article/10.1088/1748-9326/aa583e [Accessed 18 October 2017].
Höglund-Isaksson, L. (2012) ‘Global anthropogenic methane emissions 2005–2030: technical mitigation potentials and costs’. Atmospheric Chemistry and Physics, 12(19):9079–9096. Available at: https://www.atmos-chem-phys.net/12/9079/2012/acp-129079-2012.html [Accessed 18 October 2017].
Höglund-Isaksson, L., Purohit, P., Amann, M., Bertok, I., Rafaj, P., Schöpp, W. and Borken-Kleefeld, J. (2017) ‘Cost estimates of theKigali Amendment to phase-down hydrofluorocarbons’. Environmental Science & Policy, 75:138–147.
Hu, A., Xu, Y., Tebaldi, C., Washington, W.M. and Ramanathan, V. (2013) ‘Mitigation of short-lived climate pollutants slows sealevel rise’. Nature Climate Change, 3:730–734. Available at: http://www.nature.com/nclimate/journal/v3/n8/full/nclimate1869.
html?foxtrotcallback=true [Accessed 18 October 2017].
Huang, K., Fu, J.S., Prikhodko, V.Y., Storey, J.M., Romanov, A., Hodson, E.L., Cresko, J., Morozova, I., Ignatieva, Y. and Cabaniss, J.
(2015) ‘Russian anthropogenic black carbon: Emission reconstruction and Arctic black carbon simulation’. Journal of GeophysicalResearch: Atmospheres, 120(11):306–11.
IEA (2016) World Energy Outlook Special Report: Energy and Air Pollution. Paris: International Energy Agency (IEA). Available at:https://www.iea.org/publications/freepublications/publication/WorldEnergyOutlookSpecialReport2016EnergyandAirPollution.
pdf [Accessed 18 October 2017].
IEA (2012) Energy Technology Perspectives 2012 - Pathways to a Clean Energy System. Paris: International Energy Agency (IEA).
Available at: https://www.iea.org/publications/freepublications/publication/ETP2012_free.pdf [Accessed 18 October 2017].
INDC-Mexico (2015). Intended Nationally Determined Contribution, Mexico. Government of Mexico.
Jacobson, A., Lam, N.L., Bond, T.C. and Hultman, N. (2013) Black Carbon and Kerosene Lighting: An Opportunity for Rapid Action
on Climate Change and Clean Energy for Development. Washington, D.C.: The Bookings Institution. Available at: https://www.
brookings.edu/wp-content/uploads/2016/06/04_climate_change_clean_energy_development_hultman.pdf [Accessed 18 October 2017].
Karekezi, S., K. Lata, and S. T. Coelho (2006) ‘Traditional biomass energy: improving its use and moving to modern energy use’. Renewable Energy, 1:231-261.Kholod, N., Evans, M. and Kuklinski, T. (2016) ‘Russia’s black carbon emissions: focus on diesel sources’. Atmospheric Chemistry and Physics, 16(17):11267–11281. Available at: https://www.atmos-chem-phys.net/16/11267/2016/[Accessed 18 October 2017].
Klimont, Z., Kupiainen, K., Heyes, C., Purohit, P., Cofala, J., Rafaj, P., Borken-Kleefeld, J. and Schöpp, W. (2017) ‘Global anthropogenic
emissions of particulate matter including black carbon’. Atmospheric Chemistry and Physics, 17(14):8681–8723. Available at:https://www.atmos-chem-phys.net/17/8681/2017/ [Accessed 18 October 2017].
Kodjak, D. (2015) Policies to reduce fuel consumption, air pollution, and carbon emissions from vehicles in G20 nations. Washington,
D.C.: International Council on Clean Transportation (ICCT). Available at: http://www.theicct.org/publications/policies-reducefuel-consumption-air-pollution-and-carbon-emissions-vehicles-g20 [Accessed 18 October 2017].
Kondo, Y., Oshima, N., Kajino, M., Mikami, R., Moteki, N., Takegawa, N., Verma, R.L., Kajii, Y., Kato, S. and Takami, A. (2011) ‘Emissions of black carbon in East Asia estimated from observations at a remote site in the East China Sea’. Journal of GeophysicalResearch: Atmospheres, 116(D16). Available at: http://onlinelibrary.wiley.com/doi/10.1029/2011JD015637/abstract. [Accessed
18 October 2017].
Kurokawa, J., Ohara, T., Morikawa, T., Hanayama, S., Janssens-Maenhout, G., Fukui, T., Kawashima, K. and Akimoto, H. (2013)‘Emissions of air pollutants and greenhouse gases over Asian regions during 2000–2008: Regional Emission inventory in ASia
(REAS) version 2’. Atmospheric Chemistry and Physics, 13(21):11019–11058. Available at: https://www.atmos-chem-phys.
net/13/11019/2013/acp-13-11019-2013.html [Accessed 18 October 2017].
Lam, N.L., Chen, Y., Weyant, C., Venkataraman, C., Sadavarte, P., Johnson, M.A., Smith, K.R., Brem, B.T., Arineitwe, J., Ellis, J.E. andBond, T.C. (2012) ‘Household Light Makes Global Heat: High Black Carbon Emissions From Kerosene Wick Lamps’. Environmental
Science & Technology, 46(24):13531–13538. Available at: https://www.ncbi.nlm.nih.gov/pubmed/23163320 [Accessed 18 October 2017].
Lamarque, J.-F., Bond, T.C., Eyring, V., Granier, C., Heil, A., Klimont, Z., Lee, D., Liousse, C., Mieville, A., Owen, B., Schultz, M.G., Shindell, D.T., Smith, S.J., Stehfest, E., Van Aardenne, J.A., Cooper, O.R., Kainuma, M., Mahowald, N., McConnell, J.R., Naik, V., Riahi,
K. and Van Vuuren, D.P.V. (2010) ‘Historical (1850-2000) gridded anthropogenic and biomass burning emissions of reactive gases
and aerosols: Methodology and application’. Atmospheric Chemistry and Physics, 10:7017–7039.
Lu, Z., Zhang, Q. and Streets, D.G. (2011) ‘Sulfur dioxide and primary carbonaceous aerosol emissions in China and India, 1996–
2010’. Atmospheric Chemistry and Physics, 11(18):9839–9864. Available at: https://www.atmos-chem-phys.net/11/9839/2011/
acp-11-9839-2011.html [Accessed 18 October 2017].
Maithel, S., Lalchandani, D., Malhotra, G., Bhanware, P., Uma, R., Ragavan, S., Athalye, V., Bindiya, K., Reddy, S., Bond, T.C., Weyant,
C., Baum, E., Kim Thoa, V.T., Thu Phuong, N. and Kim Thanh, T. (2012) Brick Kilns Performance Assessment; A Roadmap for Cleaner
Brick Production in India. Shakti Sustainable Energy Foundation and Climate Works Foundation.
Malley, C.S., Henze, D.K., Kuylenstierna, J.C.I., Vallack, H.W., Davila, Y., Anenberg, S.C., Turner, M.C. and Ashmore, M.R. (2017) ‘Updated global estimates of respiratory mortality in adults ≥30 years of age attributable to long-term ozone exposure’. Environmental Health Perspectives, 125(8). Available at: https://www.ncbi.nlm.nih.gov/pubmed/28858826 [Accessed 18 October 2017].
MoRTH (2016) Government decides to directly shift from BS-IV to BS-VI emission norms. New Delhi: Ministry of Road Transport &Highways (MoRTH), Government of India.

The Emissions Gap Report 2017 – References

83

Myhre, G., Shindell, D., Bréon, F.M., Collins, W., Fuglestvedt, J., Huang, J., Koch, D., Lamarque, J.F., Lee, D., Mendoza, B., Nakajima,T., Robock, A., Stephens, G., Takemura, T. and Zhang, H. (2013) Anthropogenic and Natural Radiative Forcing, in: Climate Change
2013: The Physical Science Basis. New York: Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, United Kingdom. Available at: https://www.ipcc.ch/
pdf/assessment-report/ar5/wg1/WG1AR5_Chapter08_FINAL.pdf [Accessed 18 October 2017].
Pine, K., Edwards, R., Masera, O., Schilmann, A., Marrón-Mares, A. and Riojas-Rodríguez, H., (2011) ‘Adoption and use of improved
biomass stoves in Rural Mexico’. Energy for Sustainable Development, 15(2):176–183. Available at: https://asu.pure.elsevier.
com/en/publications/adoption-and-use-of-improved-biomass-stoves-in-rural-mexico [Accessed 18 October 2017].
Purohit, P. and Höglund-Isaksson, L. (2017) ‘Global emissions of fluorinated greenhouse gases 2005–2050 with abatement potentials and costs’. Atmospheric Chemistry and Physics, 17(4):2795–2816. Available at: https://www.atmos-chem-phys.
net/17/2795/2017/ [Accessed 18 October 2017].
Rao, S., Klimont, Z., Smith, S.J., Van Dingenen, R., Dentener, F., Bouwman, L., Riahi, K., Amann, M., Bodirsky, B.L., van Vuuren, D.P.,
Aleluia Reis, L., Calvin, K., Drouet, L., Fricko, O., Fujimori, S., Gernaat, D., Havlik, P., Harmsen, M., Hasegawa, T., Heyes, C., Hilaire,J., Luderer, G., Masui, T., Stehfest, E., Strefler, J., van der Sluis, S. and Tavoni, M. (2017) ‘Future air pollution in the Shared Socioeconomic Pathways’. Global Environmental Change, 42:346–358.
Riahi, K., van Vuuren, D.P., Kriegler, E., Edmonds, J., O’Neill, B.C., Fujimori, S., Bauer, N., Calvin, K., Dellink, R., Fricko, O., Lutz,
W., Popp, A., Cuaresma, J.C., KC, S., Leimbach, M., Jiang, L., Kram, T., Rao, S., Emmerling, J., Ebi, K., Hasegawa, T., Havlik, P.,
Humpenöder, F., Da Silva, L.A., Smith, S., Stehfest, E., Bosetti, V., Eom, J., Gernaat, D., Masui, T., Rogelj, J., Strefler, J., Drouet,
L., Krey, V., Luderer, G., Harmsen, M., Takahashi, K., Baumstark, L., Doelman, J.C., Kainuma, M., Klimont, Z., Marangoni, G.,
Lotze-Campen, H., Obersteiner, M., Tabeau, A., Tavoni, M., 2017. The Shared Socioeconomic Pathways and their energy, landuse, and greenhouse gas emissions implications: An overview. Global Environmental Change 42, 153–168. doi:10.1016/j.gloenvcha.2016.05.009
Rogelj, J., Schaeffer, M., Meinshausen, M., Shindell, D.T., Hare, W., Klimont, Z., Velders, G.J.M., Amann, M. and Schellnhuber, H.J.
(2014) ‘Disentangling the effects of CO2 and short-lived climate forcer mitigation’. Proceedings of the National Academy of Sciences, 111:16325–16330. Available at: http://pure.iiasa.ac.at/10817/ [Accessed 18 October 2017].
Ruiz-Mercado, I., Masera, O., Zamora, H. and Smith, K.R. (2011) ‘Adoption and sustained use of improved cookstoves’. Energy
Policy, 39:7557–7566. Available at: http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.394.2048&rep=rep1&type=pdf[Accessed 18 October 2017].
Sabel, C.F. and Victor, D.G. (2015) ‘Governing global problems under uncertainty: making bottom-up climate policy work’. Climatic
Change, 136:1-13. Available at: https://ai2-s2-pdfs.s3.amazonaws.com/1e77/b22f9eafa83e6f060517ff890461ceee0a7d.pdf[Accessed 18 October 2017].
Saikawa, E. (2013) ‘Policy Diffusion of Automobile Emission Standards: Is there a Race to the Top?’ World Politics, 65: 1–33. Available at: https://globalchange.mit.edu/publication/15932 [Accessed 18 October 2017].
Schmale, J., Shindell, D., von Schneidemesser, E., Chabay, I. and Lawrence, M.G. (2014) ‘Air pollution: Clean up our skies’. Nature,
515:335–337. Available at: http://publications.iass-potsdam.de/pubman/faces/viewItemFullPage.jsp?itemId=escidoc%3A7189
05%3A4&view=EXPORT [Accessed 18 October 2017].
Shah, N., Wei, M., Letschert, V. and Phadke, A. (2015) Benefits of Leapfrogging to Superefficiency and Low-Global Warming Potential Refrigerants in Room Air Conditioning. Berkeley: Ernest Orlando Lawrence Berkeley National Laboratory.
Shen, G., Wei, S., Wang, Wen, Zhang, Y., Ming, Y., Wang, B., Wang, R., Li, W., Shen, H., Huang, Y., Yang, Y., Wang, Wei, Wang, Xilong,
Wang, Xuejun and Tao, S. (2012) ‘Emission factors, size distributions, and emission inventories of carbonaceous particulate matter from residential wood combustion in rural China’. Environmental Science & Technology, 46:4207–4214.
Shindell, D., Borgford-Parnell, N., Brauer, M., Haines, A., Kuylenstierna, J.C.I., Leonard, S.A., Ramanathan, V., Ravishankara, A.,
Amann, M. and Srivastava, L. (2017a) ‘A climate policy pathway for near- and long-term benefits’. Science, 356:493–494. Available at: https://www.ncbi.nlm.nih.gov/pubmed/28473553 [Accessed 18 October 2017].
Shindell, D., Fuglestvedt, J.S. and Collins, W.J. (2017b) ‘The social cost of methane: Theory and applications’. Faraday Discussions,200:429-451. Available at: http://pubs.rsc.org/en/content/articlelanding/2017/fd/c7fd00009j#!divAbstract [Accessed 18 October 2017].
Shindell, D., Kuylenstierna, J.C.I., Vignati, E., Van Dingenen, R., Amann, M., Klimont, Z., Anenberg, S.C., Muller, N., JanssensMaenhout, G., Raes, F., Schwartz, J., Faluvegi, G., Pozzoli, L., Kupiainen, K., Höglund-Isaksson, L., Emberson, L., Streets, D., Ramanathan, V., Hicks, K., Oanh, N.T.K., Milly, G., Williams, M., Demkine, V. and Fowler, D. (2012) ‘Simultaneously mitigating nearterm climate change and improving human health and food security’. Science, 335:183-189. Available at: https://www.ncbi.nlm.
nih.gov/pubmed/22246768 [Accessed 18 October 2017].
Sinton, J.E., Smith, K.R., Peabody, J.W., Yaping, L., Xiliang, Z., Edwards, R. and Quan, G. (2004) ‘An assessment of programs to promote improved household stoves in China’. Energy for Sustainable Development, 8:33-52.
Smith, S.J. and Mizrahi, A. (2013) ‘Near-term climate mitigation by short-lived forcers’. Proceedings of the National Academy of Sciences, 110(35):14202–14206. Available at: http://www.pnas.org/content/110/35/14202.abstract [Accessed 18 October 2017].
Stehfest, E., Bouwman, L., Vuuren, D.P., Elzen, M.G.J., Eickhout, B. and Kabat, P. (2009) ‘Climate benefits of changing diet’. Climatic Change, 95(1-2):83–102. Available at: https://link.springer.com/article/10.1007/s10584-008-9534-6 [Accessed 18 October
2017].
Stockwell, C. E., Christian, T. J., Goetz, J. D., Jayarathne, T., Bhave, P. V., Praveen, P. S., Adhikari, S., Maharjan, R., DeCarlo, P. F., Stone,
E. A., Saikawa, E., Blake, D. R., Simpson, I. J., Yokelson, R. J., and Panday, A. K.: Nepal Ambient Monitoring and Source TestingExperiment (NAMaSTE): emissions of trace gases and light-absorbing carbon from wood and dung cooking fires, garbage andcrop residue burning, brick kilns, and other sources, Atmos. Chem. Phys., 16, 11043-11081, https://doi.org/10.5194/acp-1611043-2016, 2016.
Stohl, A., Aamaas, B., Amann, M., Baker, L.H., Bellouin, N., Berntsen, T.K., Boucher, O., Cherian, R., Collins, W., Daskalakis, N., Dusinska, M., Eckhardt, S., Fuglestvedt, J.S., Harju, M., Heyes, C., Hodnebrog, Ø., Hao, J., Im, U., Kanakidou, M., Klimont, Z., Kupiainen,
K., Law, K.S., Lund, M.T., Maas, R., MacIntosh, C.R., Myhre, G., Myriokefalitakis, S., Olivié, D., Quaas, J., Quennehen, B., Raut, J.-C.,
Rumbold, S.T., Samset, B.H., Schulz, M., Seland, Ø., Shine, K.P., Skeie, R.B., Wang, S., Yttri, K.E. and Zhu, T. (2015) ‘Evaluating theclimate and air quality impacts of short-lived pollutants’. Atmospheric Chemistry and Physics, 15(18):10529-10566. Available at:https://www.atmos-chem-phys.net/15/10529/2015/acp-15-10529-2015.html [Accessed 18 October 2017].

84

The Emissions Gap Report 2017 – References

Stohl, A., Klimont, Z., Eckhardt, S., Kupiainen, K., Shevchenko, V.P., Kopeikin, V.M. and Novigatsky, A.N. (2013) ‘Black carbon in
the Arctic: the underestimated role of gas flaring and residential combustion emissions’. Atmospheric Chemistry and Physics,
13(17):8833-8855. Available at: https://www.atmos-chem-phys.net/13/8833/2013/acp-13-8833-2013.html [Accessed 18 October 2017].
Thomas, E., Wickramasinghe, K., Mendis, S., Roberts, N. and Foster, C. (2015) ‘Improved stove interventions to reduce household air
pollution in low and middle income countries: a descriptive systematic review’. BMC Public Health, 15:650. Available at: https://www.ncbi.nlm.nih.gov/pubmed/26169364 [Accessed 18 October 2017].
UNEP/WMO (2011) Integrated Assessment of Black Carbon and Tropospheric Ozone. Nairobi: United Nations Environment Programme (UNEP) and World Meterorological Organization (WMO). Available at: https://wedocs.unep.org/rest/bitstreams/12809/
retrieve [Accessed 18 October 2017].
US EPA (2017) History of Reducing Air Pollution from Transportation in the United States (U.S.). Washington, DC: United States Environmental Protection Agency (USEPA). Available at: https://www.epa.gov/air-pollution-transportation/accomplishments-andsuccess-air-pollution-transportation [Accessed 18 October 2017].
US EPA (2013) Global Mitigation of Non-CO2 Greenhouse Gases: 2010-2030. Washington, DC: United States Environmental Protection Agency (USEPA). Available at: https://nepis.epa.gov/Exe/ZyNET.exe/P100GYHT.TXT?ZyActionD=ZyDocument&Client=EPA&
Index=2011+Thru+2015&Docs=&Query=&Time=&EndTime=&SearchMethod=1&TocRestrict=n&Toc=&TocEntry=&QField=&QF
ieldYear=&QFieldMonth=&QFieldDay=&IntQFieldOp=0&ExtQFieldOp=0&XmlQuery=&File=D%3A%5Czyfiles%5CIndex%20Data%5C11thru15%5CTxt%5C00000008%5CP100GYHT.txt&User=ANONYMOUS&Password=anonymous&SortMethod=h%7C-&Maxi
mumDocuments=1&FuzzyDegree=0&ImageQuality=r75g8/r75g8/x150y150g16/i425&Display=hpfr&DefSeekPage=x&SearchBa
ck=ZyActionL&Back=ZyActionS&BackDesc=Results%20page&MaximumPages=1&ZyEntry=1&SeekPage=x&ZyPURL [Accessed 18
October 2017].
US EPA (2012) Global Anthropogenic Non-CO2 Greenhouse Gas Emissions: 1990 – 2030. Washington, DC: United States Environmental Protection Agency (EPA). Available at: https://www.epa.gov/sites/production/files/2016-08/documents/epa_global_
nonco2_projections_dec2012.pdf [Accessed 18 October 2017].
US EPA (2002) Building owners save money, save the Earth: replace your CFC air conditioning chiller. Washington, DC: United States
Environmental Protection Agency (EPA). Available at: https://nepis.epa.gov/Exe/ZyNET.exe/00000LZT.TXT?ZyActionD=ZyDocum
ent&Client=EPA&Index=2000+Thru+2005&Docs=&Query=&Time=&EndTime=&SearchMethod=1&TocRestrict=n&Toc=&TocEnt
ry=&QField=&QFieldYear=&QFieldMonth=&QFieldDay=&IntQFieldOp=0&ExtQFieldOp=0&XmlQuery=&File=D%3A%5Czyfiles%
5CIndex%20Data%5C00thru05%5CTxt%5C00000004%5C00000LZT.txt&User=ANONYMOUS&Password=anonymous&SortMeth
od=h%7C-&MaximumDocuments=1&FuzzyDegree=0&ImageQuality=r75g8/r75g8/x150y150g16/i425&Display=hpfr&DefSeekP
age=x&SearchBack=ZyActionL&Back=ZyActionS&BackDesc=Results%20page&MaximumPages=1&ZyEntry=1&SeekPage=x&ZyP
URL [Accessed 18 October 2017].
Velders, G.J.M., Fahey, D.W., Daniel, J.S., Andersen, S.O. and McFarland, M. (2015) ‘Future atmospheric abundances and climate
forcings from scenarios of global and regional hydrofluorocarbon (HFCs) emissions’. Atmospheric Environment, 123:200-209.
Available at: http://www.sciencedirect.com/science/article/pii/S135223101530488X [Accessed 18 October 2017].
Velders, G.J.M., Solomon, S. and Daniel, J.S. (2014) ‘Growth of climate change commitments from HFC banks and emissions’. Atmospheric Chemistry and Physics, 14(9):4563-4572. Available at: https://www.atmos-chem-phys.net/14/4563/2014/ [Accessed 18
October 2017].
Venkataraman, C., Sagar, A.D., Habib, G. and Smith, K.R. (2010) ‘The Indian National Initiative for Advanced Biomass Cookstoves:
The benefits of clean combustion’. Energy for Sustainable Development, 14:63-72. Available at: http://citeseerx.ist.psu.edu/
viewdoc/download?doi=10.1.1.648.7301&rep=rep1&type=pdf [Accessed 18 October 2017].
Victor, D.G., Zaelke, D., Ramanathan, V., 2015. Soot and short-lived pollutants provide political opportunity. Nature Clim. Change 5,
796–798. doi:10.1038/nclimate2703
Wang, R., Tao, S., Shen, H., Huang, Y., Chen, H., Balkanski, Y., Boucher, O., Ciais, P., Shen, G., Li, W., Zhang, Y., Chen, Y., Lin, N., Su, S.,
Li, B., Liu, J. and Liu, W. (2014) ‘Trend in global black carbon emissions from 1960 to 2007’. Environmental Science & Technology,
48:6780-6787. Available at: https://www.ncbi.nlm.nih.gov/pubmed/24825392 [Accessed 18 October 2017].
Weyant, C., Athalye, V., Ragavan, S., Rajarathnam, U., Lalchandani, D., Maithel, S., Baum, E. and Bond, T.C. (2014) ‘Emissions fromSouth Asian Brick Production’. Environmental Science & Technology, 48:6477-6483. Available at: https://www.ncbi.nlm.nih.gov/
pubmed/24735080 [Accessed 18 October 2017].
Weyant, C.L., Shepson, P.B., Subramanian, R., Cambaliza, M.O.L., Heimburger, A., McCabe, D., Baum, E., Stirm, B.H. and Bond, T.C.
(2016) ‘Black Carbon Emissions from Associated Natural Gas Flaring’. Environmental Science & Technology, 50:2075-2081. Available at: https://www.ncbi.nlm.nih.gov/pubmed/26764563 [Accessed 18 October 2017].
WHO (2016) Burning Opportunity: Clean Household Energy for Health, Sustainable Development, and Wellbeing of Women and Children.
Geneva: World Health Organization (WHO). Available at: http://apps.who.int/iris/bitstream/10665/204717/1/9789241565233_
eng.pdf [Accessed 18 October 18 2017].
Wickramasinghe, A. (2011). ‘Energy access and transition to cleaner cooking fuels and technologies in Sri Lanka: Issues and policy
limitations’. Energy Policy, 39:7567-7574. Available at: http://agris.fao.org/agris-search/search.do?recordID=US201600071626[Accessed 18 October 2017].
Wiedinmyer, C., Yokelson, R.J. and Gullett, B.K. (2014) ‘Global Emissions of Trace Gases, Particulate Matter, and Hazardous Air Pollutants from Open Burning of Domestic Waste’. Environmental Science & Technology, 48:9523-9530. Available at: http://pubs.
acs.org/doi/abs/10.1021/es502250z [Accessed 18 October 2017].
Winiger, P., Andersson, A., Eckhardt, S., Stohl, A., Semiletov, I.P., Dudarev, O.V., Charkin, A., Shakhova, N., Klimont, Z., Heyes, C. andGustafsson, Ö. (2017) ‘Siberian Arctic black carbon sources constrained by model and observation’. Proceeding of the National
Academy of Sciences, 114:E1054–E1061. Available at: https://www.ncbi.nlm.nih.gov/pubmed/28137854 [Accessed 18 October
2017].
Xu, Y. and Ramanathan, V. (2017) ‘Well below 2°C: Mitigation strategies for avoiding dangerous to catastrophic climate changes’.
Proceedings of the National Academy of Sciences, 114: 10315-10323. Available at: http://www.pnas.org/content/114/39/10315.
abstract [Accessed 18 October 2017].

The Emissions Gap Report 2017 – References85

Xu, Y., Zaelke, D., Velders, G.J.M. and Ramanathan, V. (2013) ‘The role of HFCs in mitigating 21st century climate change’. Atmospheric Chemistry and Physics, 13:6083-6089. Available at: https://www.atmos-chem-phys.net/13/6083/2013/ [Accessed 18
October 2017].
Zeiger, B., Gschrey, B. and Schwarz, W. (2014) Alternatives to HCFCs/HFCs in developing countries with a focus on high ambient
temperatures. Frankfurt/Main: Öko-Recherche.

Chapter 7
Aertsens, J., De Nocker, L., & Gobin, A. (2013). Valuing the carbon sequestration potential for European agriculture. Land Use Policy,
31, 584-594.
American Physics Society Panel on Public Affairs (2011) Direct Air Capture of CO2 Using Chemicals, 87 p. https://www.aps.org/
policy/reports/assessments/upload/dac2011.pdf
Anderson K., Peters G, 2016, The trouble with negative emissions, Science, 354/6309, pp 182-183, DOI: 10.1126/science.aah4567
Aresta (2010): Carbon dioxide as chemical feedstock, Wiley, Weinheim.
Aresta (2013): M. Aresta, A. Dibenedetto & A. Angelini: The changing paradigm in CO2 utilization, Journal of CO2 Utilization, 3, 65-73.
Basso, A.S., Miguez, F.E., Laird, D.A., et al. (2013). Assessing potential of biochar for increasing water‐holding capacity of sandy soils.
GCB Bioenergy, 5(2), pp.132-143.
Benanti, G., Saunders, M., Tobin, B., & Osborne, B. (2014). Contrasting impacts of afforestation on nitrous oxide and methane emissions. Agricultural and forest meteorology, 198, 82-93.
Benson, S. M., and Coauthors, 2012: Chapter 13 - Carbon Capture and Storage. Cambridge University Press, Cambridge, UK and
New York, NY, USA and the International Institute for Applied Systems Analysis, Laxenburg, Austria, 993–1068 www.globalenergyassessment.org.
Berthrong, S. T., Jobbagy, E. G., & Jackson, R. B. (2009). A global meta‐analysis of soil exchangeable cations, pH, carbon, and nitrogenwith afforestation. Ecological Applications, 19(8), 2228-2241.
Bozzi, E., Genesio L., Toscano P, Pieri M, Miglietta F, 2015 Mimicking biochar-albedo feedbackin complex Mediterranean landscapes,
Envir. Res. Letters 10/084014
Bright, R. M., K. Zhao, R. B. Jackson, and F. Cherubini, 2015: Quantifying surface albedo and other direct biogeophysical climate
forcings of forestry activities. Glob. Chang. Biol., 21, 3246–3266, doi:10.1111/gcb.12951.
Bruhn et al. (2016): T. Bruhn, H. Naims, B. Olfe-Kräutlein: Separating the debate on CO2 utilisation from carbon capture and storage’,Environmental Science & Policy, 60, 38-43.
Buck, H. J., 2016, Rapid scale-up of negative emissions technologies: social barriers and social implications, Clim. Change, (2016)
139: 155. Doi:10.1007/s10584-016-1770-6
Cayuela, M.L., Jeffery, S, and Van Zwieten L, (2015). The molar H:Corg ratio of biochar is a key factor in mitigating N2O emissions
from soil. Agriculture Ecosystems and Environment 202, 135-138.
Center for Carbon Removal, 2015, Direct Air Capture explained in 10 questions, http://www.centerforcarbonremoval.org/blogposts/2015/9/20/direct-air-capture-explained-in-10-questions
Center for Carbon Removal, 2017, Carbon removal polices: opportunity for federal action, 39p. http://www.centerforcarbonremoval.org/s/Carbon-Removal-Policy-Opportunities-for-Action.pdf
Chamberlain TC, 1899, “An Attempt to Frame a Working Hypothesis of the Cause of Glacial Periods on an Atmospheric Basis”. Journal of Geology. 7: 575, 667, 751
Chiang PC., Pan SY.,2017, CO2 Mineralization and Utilization via Accelerated Carbonation. In: Carbon Dioxide Mineralization andUtilization. Springer, Singapore https://doi.org/10.1007/978-981-10-3268-4_3
Clarke, L., K. Jiang, K. Akimoto, M. Babiker, G. Blanford, K. Fisher-Vanden, J.-C. Hourcade, V. Krey, E. Kriegler, A. Löschel, D. McCollum,
S. Paltsev, S. Rose, P. R. Shukla, M. Tavoni, B. van der Zwaan, and D. P. van Vuuren. 2014. Assessing Transformation Pathways. In
Climate Change 2014: Mitigation of Climate Change. Contribution of Working Group III to the Fifth Assessment Report of theIntergovernmental Panel on Climate Change [Edenhofer, O., R. Pichs-Madruga, Y. Sokona, E. Farahani, S. Kadner, K. Seyboth, A.
Adler, I. Baum, S. Brunner, P. Eickemeier, B. Kriemann, J. Savolainen, S. Schlömer, C. von Stechow, T. Zwickel and J.C. Minx (eds.)].
Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.
CLCF (2011): The Centre for Low Carbon Futures, Carbon Capture and Utilisation in the green economy: Using CO2 to manufacture
fuel, chemicals and materials. http://www.policyinnovations.org/ideas/policy_library/data/01612/_res/id=sa_File1/CCU.pdf
CO2Sciences, 2016, Global Roadmap for Implementing CO2 Utilization, Innovation for Cool Earth Forum, 61p, https://assets.contentful.com/xg0gv1arhdr3/27vQZEvrxaQiQEAsGyoSQu/44ee0b72ceb9231ec53ed180cb759614/CO2U_ICEF_Roadmap_FINAL_2016_12_07.pdf
Coninck, H. De, and S. M. Benson, 2014: Carbon Dioxide Capture and Storage: Issues and Prospects. Annu. Rev. Environ. Resour., 39,
243–70, doi:10.1146/annurev-environ-032112-095222.
Creutzig, F., Ravindranath, N. H., Berndes, G., Bolwig, S., Bright, R., Cherubini, F., … Masera, O. (2015). Bioenergy and climate change
mitigation: an assessment. GCB Bioenergy, 7(5), 916–944. https://doi.org/10.1111/gcbb.12205
de Best-Waldhober, M., D. Daamen, and A. Faaij, 2009: Informed and uninformed public opinions on CO2 capture and storage technologies in the Netherlands. Int. J. Greenh. Gas Control, 3, 322–332, doi:10.1016/j.ijggc.2008.09.001.
De Coninck, H., Benson, S. (2014). Carbon Dioxide Capture and Storage: Issues and Prospects. Annu. Rev. Environ. Resour. 2014.
39:243–70.
Diaz, D., Hamilton, K., Johnson, E., 2011. State of the Forest Carbon Markets 2011: From Canopy to Currency. Ecosystem Marketplace Report. Forest Trends, Washington, DC.
Field, C. B., & Mach, K. J. (2017). Rightsizing carbon dioxide removal. Science, 356(6339), 706-707.
Frank, S., H. Böttcher, P. Havlík, H. Valin, A. Mosnier, M. Obersteiner, E. Schmid, and B. Elbersen, 2013: How effective are the sustainability criteria accompanying the European Union 2020 biofuel targets? GCB Bioenergy, 5, 306–314, doi:10.1111/j.17571707.2012.01188.x. http://doi.wiley.com/10.1111/j.1757-1707.2012.01188.x (Accessed July 6, 2017).

86

The Emissions Gap Report 2017 – References

Fuss, S. 2017. The 1.5C target, political implications, and the role of BECCS. Oxford Research Encyclopedia of Climate ScienceClimate
Science, DOI: 10.1093/acrefore/9780190228620.013.585
Fuss, S., and Coauthors, 2016: Research priorities for negative emissions. Environ. Res. Lett., 11, 115007, doi:10.1088/17489326/11/11/115007.
Fuss, S., J. G. Canadell, G. P. Peters, M. Tavoni, R. M. Andrew, P. Ciais, R. B. Jackson, C. D. Jones, F. Kraxner, N. Nakicenovic, C. Le Quere, M. R. Raupach, A. Sharifi, P. Smith, and Y. Yamagata. 2014. Betting on negative emissions. Nature Clim. Change 4(10): 850-853.
Genesio, L., Miglietta, F., Lugato, E., Baronti, S., Pieri, M., Vaccari, FP. (2012) Surface albedo following biochar application in durum
wheat. Environmental Research Letters (2012): 1-8. IOP Science. http://iopscience.iop.org/1748-9326/7/1/014025.
Global CCS Institute, 2016, The Global Status of CCS, 2016: Summary Report, Australia, https://hub.globalccsinstitute.com/sites/
default/files/publications/201158/global-status-ccs-2016-summary--report.pdf
Griscom, B.W., Adams, J., Ellis, P., Houghton, R.A., Lomax, G., Miteva, D.A., Schlesinger, W.H., Shoch, D., Siikamäki, J., Woodbury, P.,
Zganjar, C., Blackman, A., Campari, J., Conant, R.T., Delgado, C., Elias, P., Hamsik, M., Kiesecker, J., Landis, E., Polasky, S., Potapov,
P., Putz, F.E., Sanderman, J., Silvius, M., Smith, P., Wollenberg, E. & Fargione, J. 2017. Natural pathways to climate mitigation.
Proceedings of the National Academy of Sciences, USA (in press).
Hamilton, K., Chokkalingam, U., Bendana, M., 2010. State of the Forest Carbon Markets 2009: Taking Root and Branching Out. Ecosystem Marketplace Report. Forest Trends, Washington, DC.
Hartmann J., West A.J., Renforth P, Kohler P, DeLaRocha C.L., Wolf-Gladrow D.A., Durr H.H., Scheffran J, 2013, Enhanced chemical
weathering as a geoengineering strategy to reduce atmospheric carbon dioxide, supply nutrients, and mitigate ocean acidification, Reviews in Geophysics 51(2) pp 113-149, DOI: 10.1002/rog.20004
Havlík, P., and Coauthors, 2011: Global land-use implications of first and second generation biofuel targets. Energy Policy, 39,
5690–5702, doi:10.1016/j.enpol.2010.03.030.
Henderson G., Rickaby R., Bouman H., 2008, Decreasing atmospheric CO2 by increasing ocean alklainity, https://www.earth.ox.ac.
uk/~gideonh/reports/Cquestrate_report.pdf
Houghton, R. A., Byers, B., & Nassikas, A. A. (2015). A role for tropical forests in stabilizing atmospheric CO2. Nature Climate Change,
5(12), 1022-1023.
House KZ, House CH, Schrag DP, Aziz MJ (2007) Electrochemical acceleration of chemical weathering as an energetically feasible
approach to mitigating anthropo- genic climate change. Environ Sci Technol 41(24):8464–8470
Hu, S., Niu, Z., Chen, Y., Li, L., Zhang, H. (2017). Global wetlands: potential distribution, wetland loss, and status. Science of the Total
Environment 586: 319-327.
ICEF, 2017, Carbon Dioxide Utilization (CO2U): ICEF Roadmap 1.0,
International Energy Agency, 2017, Energy Technology Perspectives 2017. Catalysing Energy Technology Transformations, Paris(ISBN 978-92-64-27050-3)
IPCC 2014, 2013 Supplement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories: Wetlands, Hiraishi, T., Krug, T.,
Tanabe, K., Srivastava, N., Baasansuren, J., Fukuda, M. and Troxler, T.G. (eds). Published: IPCC, Switzerland.
IPCC, 2005 - Bert Metz, Ogunlade Davidson, Heleen de Coninck, Manuela Loos and Leo Meyer (Eds.). Cambridge University Press,
UK. pp 431. https://www.ipcc.ch/pdf/special-reports/srccs/srccs_wholereport.pdf
IPCC. 2014. Climate Change 2014: Synthesis Report. Contribution of Working Groups I, II and III to the Fifth Assessment Report of
the Intergovernmental Panel on Climate Change. Geneva, Switzerland: IPCC.
Jones, A. D., K. V. Calvin, W. D. Collins, and J. Edmonds, 2015: Accounting for radiative forcing from albedo change in future global
land-use scenarios. Clim. Change, 131, 691–703, doi:10.1007/s10584-015-1411-5.
Joseph, S., Graber, E.R., Chia, C., Munroe, P., Donne, S., Thomas, T., Nielsen, S., Marjo, C., Rutlidge, H., Pan, G.X. and Li, L., 2013.
Shifting paradigms: development of high-efficiency biochar fertilizers based on nano-structures and soluble components. Carbon
Management, 4(3), pp.323-343.)
Keith, D.W. 2017. Toward a Responsible Solar Geoengineering Research Program. Issues in Science and Technology 33(3), 71-77.
Keith, D.W., Ha-Duong M., Stolaroff J.K., 2006, Climate Strategy with CO2 Capture from the Air, Climate Change, v.74 17-45, DOI:
10.1007/s10584-005-9026-x
Kelemen PB, Matter J, 2008, In situ carbonation of peridotite for CO2 storage. PNAS 105(45) pp 17295–17300
Kemper, J., 2015: Biomass and carbon dioxide capture and storage: A review. Int. J. Greenh. Gas Control, 40, 401–430, doi:10.1016/j.
ijggc.2015.06.012.
Kheshgi, H. S. 1995. Sequestering atmospheric carbon dioxide by increasing ocean alkalinity. Energy, 20(9), 915-922.
Kimaro, A.A., Isaac, M.E. & Chamshama, S.A.O. (2011) Carbon pools in tree biomass and soils under rotational woodlot systems
in Eastern Tanzania. In: ”Carbon Sequestration Potential of Agroforestry Systems”, ed. Kumar, B.M. & Nair, P.K.R., Springer, Dordrecht, NL. pp. 129-143.
Kirschbaum, M. U. F., Whitehead, D., Dean, S. M., Beets, P. N., Shepherd, J. D., & Ausseil, A. G. (2011). Implications of albedo changes
following afforestation on the benefits of forests as carbon sinks. Biogeosciences, 8(12), 3687.
Lackner K.S., Ziock H., Grimes P., 1999, Carbon Dioxide Extraction from Air: Is It an Option? In Proceedings of the 24th Annual Technical Conference on Coal Utilization & Fuel Systems, Clearwater, FL.; pp 885– 896
Lackner KS, Wendt CH, Butt DP, Joyce EL, Sharp DH (1995) Carbon dioxide disposal in carbonate minerals, Energy 11(20) pp. 11531170
Lal, R (2011) Sequestering carbon in soils of agro-ecosystems. Food Policy 36, Supplement 1, pp. S33-S39
Lal, R. (2013) Intensive Agriculture and the Soil Carbon Pool. Journal of Crop Improvement, 27(6), pp.735-751
Lassiter III J.B., Misra S., 2016, Carbon Engineering, Harvard Business School case study, 9-814-040.
Lehmann J., Czimczik, C., Laird, D., Sohi, S. (2015) Stability of biochar in soil. In: Biochar for Environmental Management: Science,
Technology and Implementation (eds. Lehmann, J., Joseph, S.), pp. 235-282, Taylor and Francis, London, UK.
Lehmann, J. and Joseph, S. (2009) Biochar for Environmental Management: Science and Technology. Earthscan Books Ltd., London,UK.

The Emissions Gap Report 2017 – References

87Lenton, T. M. (2014) The Global Potential for Carbon Dioxide Removal. In Geoengineering of the Climate System (eds Harrison, R. M.
and Hester, R. E.), Royal Society of Chemistry, 2014, pp. 52-79.
Li, D., Niu, S., and Luo, Y. (2012). Global patterns of the dynamics of soil carbon and nitrogen stocks following afforestation: a meta‐
analysis. New Phytologist, 195(1), 172-181.
Lomax, G., M. Workman, T. Lenton, N. Shah, 2015, Reframing the policy approach to greenhouse gas removal technologies, Energy
Policy, 78 (2015) 125–136, doi:10.1016/j.enpol.2014.10.002
Marshall C., 2017, “In Switzerland, a giant new machine is sucking carbon directly from the air”, E&E News, June 1 (reprinted in
Science: doi:10.1126/science.aan6915)
McDonough W., 2016, Carbon is not the Enemy, Nature 539, pp 349-351
McLaren, D., 2012: A comparative global assessment of potential negative emissions technologies. Spec. Issue Negat. Emiss. Technol., 90, 489–500, doi:10.1016/j.psep.2012.10.005.
Miles L. and Sonwa D.J. et al. 2015 UNEP Emissions Gap Report, Chapter 6: Mitigation potential from forest-related activities andincentives for enhanced ac on in developing countries
Minasny,B. et al. (2017) Soil carbon 4 per mille. Geoderma 292 (2017)59–86
Minx, J.C.; Lamb, W.; Callaghan, M.; Bornmann, L.; Fuss, S. 2017. Fast growing research on negative emissions. Envir. Res. Letters12/035007
Mitsch, William J., et al. (2012). Wetlands, carbon, and climate change. Landscape Ecology 28.4: 583-597.
Monfreda, C., N. Ramankutty, and J. A. Foley, 2008: Farming the planet: 2. Geographic distribution of crop areas, yields, physiological types, and net primary production in the year 2000. Global Biogeochem. Cycles, 22, doi:10.1029/2007GB002947.
Monkman S., MacDonald M., 2015, Case studies for CO2 utilization in concrete, Spec. Publication 303, American Concrete Institute,pp. 33-44
Naims (2016): H. Naims, Economics of carbon dioxide capture and utilization - A supply and demand perspective. Environmental
Science and Pollution Research, 1-16.
NERC, 2017, Greenhouse Gas Removal from the Atmosphere, Program Overview, http://www.nerc.ac.uk/research/funded/programmes/ggr/#xcollapse2
Nielsen, Anne Sofie Elburg; Plantinga, Andrew J.; Alig, Ralph J. 2014. New cost estimates for carbon sequestration through afforestation in the United States. Gen. Tech. Rep. PNW-GTR-888. Portland, OR: U.S. Department of Agriculture, Forest Service, PacificNorthwest Research Station. 35 p.
Page S.E., Hooijer A. 2016 In the line of fire: the peatlands of Southeast Asia. Phil. Trans. R. Soc. B 371: 20150176. http://dx.doi.
org/10.1098/rstb.2015.0176
Parish, F., Sirin, A., Charman, D.J., Joosten, H., Minayeva, T., Silvius, M., Stringer, L. (2008). Assessment on Peatlands, Biodiversity
and Climate Change: Main Report. Global Environment Centre, Kuala Lumpur and Wetlands International, Wageningen.
Peters, G. P., R. M. Andrew, J. G. Canadell, S. Fuss, R. B. Jackson, J. I. I. Korsbakken, C. Le Quéré, and N. Nakicenovic, 2017: Key
indicators to track current progress and future ambition of the Paris Agreement. Nat. Clim. Chang., 7, 118–122, doi:10.1038/
nclimate3202.
Peters, G.P., O. Geden, 2017: Catalysing a political shift from low to negative carbon. Nat. Clim. Chang., 7, 619–621, doi:10.1038/
nclimate3369.
Plevin, R. J., M. O’Hare, A. D. Jones, M. S. Torn, and H. K. Gibbs, 2010: Greenhouse Gas Emissions from Biofuels’ Indirect Land Use
Change Are Uncertain but May Be Much Greater than Previously Estimated. Environ. Sci. Technol., 44, 8015–8021, doi:10.1021/
es101946t. http://pubs.acs.org.globalproxy.cvt.dk/doi/full/10.1021/es101946t.
Popp, A., Krause, M., Dietrich, J. P., Lotze-Campen, H., Leimbach, M., Beringer, T., & Bauer, N. (2012). Additional CO2 emissions fromland use change — Forest conservation as a precondition for sustainable production of second generation bioenergy. Ecological
Economics, 74, 64–70. https://doi.org/10.1016/j.ecolecon.2011.11.004
Powlson, DS, Stirling, CM, Jat, ML, Gerard, BG, Palm, CA, Sanchez, PA, Cassman, KG (2014) Limited potential of no-till agriculture forclimate change mitigation. Nature Climate Change 4, 678–683 (2014) doi:10.1038/nclimate2292
Rau G., Knauss K.G., Lander W.H., Caldeira K., 2004, CO2 mitigation via accelerated limestone weathering, Am. Chem. Soc., Div. Fuel
Chem. 2004, 49 (1), 376
Rau GH, Knauss KG, Langer WH, Caldeira K, 2007, Reducing energy-related CO2 emissions using accelerated weathering of limestone, Energy 32, pp. 1471-1477, DOI: 10.1016/j.energy.2006.10.011
Raymo, M.E., 1991, Geochemical evidence supporting T.C. Chamberlain’s theory of glaciation, Geology 19(4) 344-347 https://doi.
org/10.1130/0091-7613(1991)019<0344:GESTCC>2.3.CO;2
Renforth P, Kruger T, 2013, Coupling mineral carbonation and ocean liming, Energy Fuels 27(8), pp. 4199-4207 DOI: 10.1021/
ef302030w
Renforth P., Henderson G., 2017, Assessing ocean alkalinity for carbon sequestration, Reviews in Geophysics 55,
10.1002/2016RG000533
Rogelj, J., G. Luderer, R. C. Pietzcker, E. Kriegler, M. Schaeffer, V. Krey, and K. Riahi. 2015. Energy system transformations for limiting
end-of-century warming to below 1.5 [deg]C. Nature Clim. Change 5(6): 519-527.
Rogelj, J., M. den Elzen, N. Höhne, T. Fransen, H. Fekete, H. Winkler, R. Schaeffer, F. Sha, K. Riahi, and M. Meinshausen. 2016. Paris
Agreement climate proposals need a boost to keep warming well below 2°C. Nature 534(7609): 631-639.
Royal Society 2009. Geoengineering the climate Science, governance and uncertainty. Royal Society Policy document 10/09 Issued:
September 2009 RS1636. ISBN: 978-0-85403-773-5.
Sanz-Perez E.S., Murdock C.R., Didas S.A., Jones C.W., 2016, Direct Air Capture of CO2 from Ambient Air, Chem. Rev., v. 116 (19), pp
11840-11876

88

The Emissions Gap Report 2017 – References

Schäfer, S.; Lawrence, M.; Stelzer, H.; Born, W.; Low, S.; Aaheim, A.; Adriázola, P.; Betz, G.; Boucher, O.; Carius, A.; Devine-Right, P.;
Gullberg, A. T.; Haszeldine, S.; Haywood, J.; Houghton, K.; Ibarrola, R.; Irvine, P.; Kristjansson, J.-E.; Lenton, T.; Link, J. S. A.; Maas,A.; Meyer, L.; Muri, H.; Oschlies, A.; Proelß, A.; Rayner, T.; Rickels, W.; Ruthner, L.; Scheffran, J.; Schmidt, H.; Schulz, M.; Scott,V.; Shackley, S.; Tänzler, D.; Watson, M.; Vaughan, N., 2015, The European Transdisciplinary Assessment of Climate Engineering(EuTRACE):Removing Greenhouse Gases from the Atmosphere and Reflecting Sunlight away from Earth. http://www.iass-potsdam.de/sites/default/files/files/eutrace_report_digital_second_edition_0.pdf
Scott, V., R. S. Haszeldine, S. F. B. Tett, and A. Oschlies, 2015: Fossil fuels in a trillion tonne world. Nat. Clim. Chang., 5, 419–423.
Searchinger, T. D., and Coauthors, 2009: Fixing a Critical Climate Accounting Error. Science (80-. )., 326, 527–528, doi:10.1126/science.1178797.
Slade, R., A. Bauen, and R. Gross, 2014: Global bioenergy resources. Nat. Clim. Chang., 4, 99–105.
Smith, P. (2012) Soils and climate change. Current Opinion in Environmental Sustainability 4, 539–544.
Smith P., Bustamante, M., Ahammad, H., Clark, H., Dong, H., Elsiddig, E.A., Haberl, H., Harper, R., House, J., Jafari, M., Masera,O., Mbow, C., Ravindranath, N.H., Rice, C.W., Robledo Abad, C. Romanovskaya, A., Sperling, F. & Tubiello, F. (2014) Agriculture,
Forestry and Other Land Use (AFOLU). In: “Climate Change 2014: Mitigation of Climate Change. Contribution of Working GroupIII to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change” pp. 811-922 (ed. Edenhofer, O., R. PichsMadruga, Y. Sokona, E. Farahani, S. Kadner, K. Seyboth, A. Adler, I. Baum, S. Brunner, P. Eickemeier, B. Kriemann, J. Savolainen, S.
Schlömer, C. von Stechow, T. Zwickel & J. Minx). Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.
Smith, P. (2016) Soil carbon sequestration and biochar as negative emission technologies. Global Change Biology 22, 1315–1324.
Smith, P., and Coauthors, 2016: Biophysical and economic limits to negative CO2 emissions. Nat. Clim. Chang., 6, 42–50, doi:10.1038/
nclimate2870.
Smith, P., Gregory, P., van Vuuren, D. et al. (2010) Competition for land. Philosophical Transactions of the Royal Society, B. 365,
2941-2957.
Smith, P., Martino, D., Cai, Z., Gwary, D., Janzen, H., Kumar, P., McCarl, B., Ogle, S., O’Mara, F., Rice, C., Scholes, B., Sirotenko, O.,
Howden, M., McAllister, T., Pan, G., Romanenkov, V., Schneider, U., Towprayoon, S., Wattenbach, M., Smith, J. (2008). Greenhouse gas mitigation in agriculture. Philosophical transactions of the Royal Society, Series B 363(1492), 789–813.
Taylor, L.L., Quirk, J., Thorley, R.M.S. et al., 2016. Nature Climate Change, 6, 402-406.
The Economist, 2017, Electrifying Everything, Economist Magazine, Aug. 12th
Trabucco, A., Zomer, R. J., Bossio, D. A., van Straaten, O., & Verchot, L. V. (2008). Climate change mitigation through afforestation/reforestation: a global analysis of hydrologic impacts with four case studies. Agriculture, ecosystems & environment, 126(1), 81-97.
Upham, P., and T. Roberts, 2011: Public perceptions of CCS: Emergent themes in pan-European focus groups and implications forcommunications. Int. J. Greenh. Gas Control, 5, 1359–1367, doi:10.1016/j.ijggc.2011.06.005.
USNAS 2015a. Climate Intervention: Carbon Dioxide Removal and Reliable Sequestration. US National Academy of Sciences, Washington D.C.
USNAS 2015b. Climate Intervention: Reflecting Sunlight to Cool Earth. US National Academy of Sciences, Washington D.C.
van Vuuren, D. P., S. Deetman, J. van Vliet, M. van den Berg, B. J. van Ruijven, and B. Koelbl. 2013. The role of negative CO2 emissions
for reaching 2°C—insights from integrated assessment modelling. Climatic Change 118(1): 15-27.
von der Assen, N., Jung, J. & Bardow, A. (2013) Life-cycle assessment of carbon dioxide capture and utilization: avoiding the pitfalls.
Energy Environ. Sci., 6, 2721-2734.
Wallquist, L., S. L. O. Seigo, V. H. M. Visschers, and M. Siegrist, 2012: Public acceptance of CCS system elements: A conjoint measurement. Int. J. Greenh. Gas Control, 6, 77–83, doi:10.1016/j.ijggc.2011.11.008.
Weng, Z.H., Van Zwieten, L., Singh, B.P., Tavakkoli, E., Joseph, S., Macdonald, L.M., Rose, T.J., Rose, M.T., Kimber, S.W., Morris, S. andCozzolino, D., (2017). Biochar built soil carbon over a decade by stabilizing rhizodeposits. Nature Climate Change 7, 371-376.
Willauer H., DiMascio F., Hardy D.R., Williams F.W., 2014, Feasibility of CO2 Extraction from Seawater and Simultaneous Hydrogen
Gas Generation Using a Novel and Robust Electrolytic Cation Exchange Module Based on Continuous Electrodeionization Technology, Industrial & Chem. Res. 53, 12192−12200, dx.doi.org/10.1021/ie502128x.
Williams-Guillén, K., Perfecto, I & Vandermeer, J. (2008) Bats Limit Insects in a Neotropical Agroforestry System. Science, 320, 70.
Williamson P., 2016, Scrutinize CO2 removal methods. Nature, 530: 153–155.
Woolf, D., Amonette, JE., Street-Perrott. A., Lehmann, J., Joseph, S. (2010) Sustainable biochar to mitigate global climate change.
Nature Communications 1, Article 56, doi:10.1038/ncomms1053 (2010).
Worrall, F., Evans, M.G., Bonn, A., Reed, M.S., Chapman, D., Holden, J. (2009). Can carbon offsetting pay for upland ecological restoration? The Science of the Total Environment 408(1), 26–36.
Zakkour, P., J. Kemper, T. Dixon, 2014: Incentivising and accounting for negative emission technologies, Energy Procedia, 63 (2014)
6824 – 6833, doi: 10.1016/j.egypro.2014.11.716.
Zedler, Joy B., and Suzanne Kercher. (2005). Wetland resources: status, trends, ecosystem services, and restorability. Annu. Rev.
Environ. Resour. 30: 39-74.
Zhang, A., Cui, LQ., Pan, G., Li, LQ., Hussain, Q., Zhang, XH., Zheng, JW., Crowley, D. (2010) Effect of biochar amendment on yieldand methane and nitrous oxide emissions from a rice paddy from Tai Lake Plain, China. Agriculture, Ecosystems & Environment
139, 469-475.
Zhao, K., & Jackson, R. B. (2014). Biophysical forcings of land‐use changes from potential forestry activities in North America. Ecological Monographs, 84(2), 329-353.
Zomer, R.J., Neufeldt, H., Xu, J.C., Ahrends, A., Bossio, D., Trabucco, A., van Noordwijk, M. & Wang, M.C. (2016) Global Tree Coverand Biomass Carbon on Agricultural Land: The contribution of agroforestry to global and national carbon budgets. Scientific
Reports 2016, 6: 29987. doi: 10.1038/srep29987.

The Emissions Gap Report 2017 – References

89United Nations Avenue, Gigiri
P O Box 30552, 00100 Nairobi, Kenya
Tel +254 20 7621234 | publications@unenvironment.org
www.unenvironment.org

ISBN: 978-92-807-3617-5
Job Number: DEW/2061/NA