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The Heat Is On
A world of climate promises
not yet delivered

Emissions Gap Report 2021

Emissions Gap Report 2021: The Heat Is On

Acknowledgements
The United Nations Environment Programme (UNEP) would
like to thank the members of the steering committee, thelead and contributing authors, reviewers and the secretariat
for their contribution to the preparation of this assessment
report. Authors and reviewers have contributed to the reportin their individual capacities. Their affiliations are only
mentioned for identification purposes.

for Global Environmental Strategies, Japan), Heleen van
Soest (PBL Netherlands Environmental Assessment Agency,
the Netherlands), Jorge Villareal (Iniciativa Climatica, Mexico),
Sachi Vohra (The Energy and Resources Institute [TERI], India),
Lisa Wijayani (Institute for Essential Services Reform [IESR],
Indonesia), William Wills (Eos Estratégia & Sustentabilidade,Brazil), Ryan Wilson (Climate Analytics, Germany)

Steering committee

Chapter 3

Juliane Berger (German Environment Agency), John
Christensen (CONCITO [Denmark’s climate think tank]),
Navroz K. Dubash (Centre for Policy Research, India),James Foster (UK Department for Business, Energy andIndustrial Strategy), Samuel Karslake (UK Department for
Business, Energy and Industrial Strategy), Mike Keoghan(UK Department for Business, Energy and Industrial
Strategy), Gerd Leipold (Climate Transparency), Jian Liu(UNEP), Simon Maxwell (independent), Surabi Menon(ClimateWorks Foundation), Bert Metz (European Climate
Foundation), Katia Simeonova (independent), Oksana
Tarasova (World Meteorological Organization) and Xuehong
Wang (United Nations Framework Convention on Climate
Change [UNFCCC])

Lead authors: Joeri Rogelj (Imperial College London, UK;
International Institute for Applied Systems Analysis [IIASA],
Austria), Stephen M. Smith (Oxford University, UK), Sha Yu(Pacific Northwest National Laboratory [PNNL], USA)

Authors
Chapter 1
Authors: Anne Olhoff (UNEP DTU Partnership, Denmark),
John Christensen (CONCITO [Denmark’s climate think tank])

Chapter 2
Lead authors: Takeshi Kuramochi (NewClimate Institute,
Germany), Michel den Elzen (PBL Netherlands Environmental
Assessment Agency, the Netherlands), Taryn Fransen(World Resources Institute, USA), Glen Peters (Center forInternational Climate Research [CICERO], Norway)
Contributing authors: Andrzej Ancygier (Climate Analytics,
Germany), Ayşe Ceren Sarı (SHURA, Turkey), Anna Chapman(Climate Analytics, Australia), Monica Crippa (Joint ResearchCentre [JRC], Italy), Mengpin Ge (World Resources Institute,USA), Johannes Gütschow (Potsdam Institute for Climate
Impact Research, Germany), Mariana Gutierrez (Iniciativa
Climatica, Mexico), Diego Guizzardi (JRC, Italy), Gahee Han(Solutions For Our Climate, Republic of Korea), Niklas Höhne(NewClimate Institute, Germany), Louise Jeffery (NewClimate
Institute, Germany), Kimon Keramidas (JRC, Spain), Caroline
Lee (Canadian Institute for Climate Choices, Canada),
Enrique Maurtua Konstantinidis (Fundación Ambiente y
Recursos Naturales [FARN], Argentina), Victor Maxwell(Climate Analytics, Australia), Malte Meinshausen (Universityof Melbourne, Australia), Marilena Muntean (JRC, Italy),
Leonardo Nascimento (NewClimate Institute, Germany),
Jos Olivier (PBL Netherlands Environmental Assessment
Agency, the Netherlands), Mark Roelfsema (PBL Netherlands
Environmental Assessment Agency, the Netherlands), Efisio
Solazzo (JRC, Italy), Hajime Takizawa (Institute for Global
Environmental Strategies, Japan), Kentaro Tamura (InstituteContributing authors: Jiyong Eom (Korea Advanced
Institute of Science and Technology [KAIST], Republic ofKorea), Taryn Fransen (World Resources Institute, USA),
Claire Fyson (Climate Analytics, Germany), Thomas Hale(Oxford University, UK), Frederic Hans (NewClimate Institute,
Germany), John Lang (Energy & Climate Intelligence Unit,
UK), Silke Mooldijk (NewClimate Institute, Germany), Katie
Ross (World Resources Institute, USA)

Chapter 4
Lead authors: Michel den Elzen (PBL Netherlands
Environmental Assessment Agency, the Netherlands),
Joana Portugal-Pereira (Graduate School of Engineering[COPPE], Universidade Federal do Rio de Janeiro, Brazil),
Joeri Rogelj (Grantham Institute, Imperial College London,
UK; International Institute for Applied Systems Analysis[IIASA], Austria)
Contributing authors: Ioannis Dafnomilis (PBL Netherlands
Environmental Assessment Agency, the Netherlands),
Johannes Gütschow (Potsdam Institute for Climate Impact
Research, Germany), Kimon Keramidas (Joint ResearchCentre [JRC], Spain), Robin Lamboll (Imperial College London,
UK), Jared Lewis (University of Melbourne, Australia), Malte
Meinshausen (University of Melbourne, Australia), Zebedee
Nicholls (University of Melbourne, Australia)

Chapter 5
Lead authors: Brian O’Callaghan (University of Oxford, UK;
Harvard University, USA), Jean-Paul Adam (United Nations
Economic Commission for Africa [UNECA], Ethiopia)
Contributing authors: Bartholomew Armah (UNECA,
Ethiopia), Jean Paul Boketsu Bofili (UNECA, Ethiopia),
Hopestone Kayiska Chavula (UNECA, Ethiopia), Frederic
Hans (NewClimate Institute, Germany), Andrew Prag
(Organisation for Economic Co-operation and Development[OECD], France), David Tritsch (University of Oxford, UK)

Chapter 6
Lead authors: Drew Shindell (Duke University, USA), Marielle
Saunois (Université de Versailles Saint-Quentin [UVSQ],
Laboratoire des Sciences du Climat et de l'Environnement[LSCE], France)

VEmissions Gap Report 2021: The Heat Is On

Contributing authors: Dominik Brunner (Swiss Federal
Laboratories for Materials Science and Technology [EMPA],
Switzerland), Lena Höglund-Isaksson (International Institutefor Applied Systems Analysis [IIASA], Austria), Kevin Karl
(Food and Agriculture Organization of the United Nations[FAO], Italy), Euan Nisbet (Royal Holloway, University of
London, UK), Stefan Schwietzke (Environmental Defense
Fund [EDF], USA), Francesco Tubiello (FAO, Italy)

Chapter 7
Lead authors: Sha Yu (Pacific Northwest National Laboratory[PNNL], USA), Maosheng Duan (Tsinghua University, China),
Jae Edmonds (PNNL, USA)
Contributing authors: Katherine Calvin (PNNL, USA),
Stefano De Clara (International Carbon Action Partnership[ICAP], Germany), Dirk Forrister (International Emissions
Trading Association [IETA], Switzerland), Stephanie La Hoz
Theuer (adelphi, Germany), Luca Lo Re (International Energy
Agency [IEA], France), Ruben Lubowski (Environmental
Defense Fund [EDF], USA), Axel Michaelowa (Perspectives
and University of Zurich, Switzerland), Clayton Munnings(University of California, Berkeley, USA), Karen Holm Olsen(UNEP DTU Partnership, Denmark), Mandy Rambharos(Eskom, South Africa), Chandra Shekhar Sinha (World Bank,USA), Detlef van Vuuren (PBL Netherlands Environmental
Assessment Agency, the Netherlands)

Reviewers
Jesica Andrews (UNEP Finance Initiative), Juliane Berger(German Environment Agency), Thomas Bernheim(European Commission Directorate-General for Climate
Action), Nathan Borgford-Parnell (Scientific Advisory Paneland Climate and Clean Air Coalition [CCAC]), Derik Broekhoff(Stockholm Environment Institute), Louise Burrows (UKDepartment for Business, Energy and Industrial Strategy),
Manfredi Caltagirone (UNEP), Cyril Cassisa (BHP), Oliver
Chaplin (UK Department for Business, Energy and Industrial
Strategy), John Christensen (CONCITO [Denmark’s climate
think tank]), Laura Cozzi (International Energy Agency[IEA]), Navroz K. Dubash (Centre for Policy Research, India),
Virender K. Duggal (Asian Development Bank), James
Dyke (University of Exeter), Veronika Elgart (Federal Officefor the Environment of the Swiss Confederation), Kate
Ervine (Saint Mary’s University), Kai Remco Fisher (UNEP
Finance Initiative), Shinichiro Fujimori (Kyoto University),
James Foster (UK Department for Business, Energy
and Industrial Strategy), Oliver Geden (German Institutefor International and Security Affairs), Muhammad Arif
Goheer (Global Change Impact Studies Centre), Martin
Hession (European Commission Directorate -General
for Climate Action), Andrea Hinwood (UNEP), Andrew
Howard (Koru Climate), Jason Jabbour (UNEP), Yasuko
Kameyama (National Institute for Environmental Studies,Japan), Maarten Kappelle (UNEP), Karsten Karschunke(German Environment Agency), Samuel Karslake(UK Department for Business, Energy and Industrial
Strategy), Mike Keoghan (UK Department for Business,

VI

Energy and Industrial Strategy), Katre Kets (European
Commission Directorate-General for Climate Action),
Gerardus Klaassen (European Commission DirectorateGeneral for Climate Action), Gerd Leipold (Climate
Transparency), Thomas Liesch (Allianz), Jian Liu (UNEP),
Michael Luker (UK Department for Business, Energy andIndustrial Strategy), James Mabbutt (UK Department
for Business, Energy and Industrial Strategy), Kathleen
McAfee (San Francisco State University), Simon Maxwell(independent), Surabi Menon (ClimateWorks Foundation),
Ber t Metz (European Climate Foundation), Brendan
Moore (University of East Anglia), Susan Mutebi-Richards(UNEP), Nick Nuttall (We Don’t Have Time), Miles Perry(European Commission Directorate-General for Climate
Action), Frederik Pischke (German Environment Agency),
Rula Qalyoubi (UNEP), Mark Radka (UNEP), Akkihebbal
Ramaiah Ravishankara (Colorado State University), Yann
Robiou du Pont (Climate & Energy College), Katie Ross
(World Resources Institute), Christian Schoder (World
Bank), Himanshu Sharma (UNEP), Katia Simeonova(independent), Thomas Spencer (IE A), Jamal Srouji(World Resources Institute), Oksana Tarasova (World
Meteorological Organization), Jacopo Tattini (IEA), Melvin
van Velthoven (European Commission Directorate-General
for Climate Action), Xuehong Wang (United Nations
Framework Convention on Climate Change [UNFCCC]),
Carsten Warnecke (New Climate Institute), Bob Watson(East Anglia University), Daniel Wetzel (IE A), Zhao
Xiusheng (Tsinghua University), Jinhua Zhang (UNEP),
Yuqiang Zhang (Duke University), Edoardo Zandri (UNEP),
Caroline Zimm (International Institute for Applied Systems
Analysis [IIASA])

Chief scientific editors
Anne Olhoff (UNEP DTU Partnership), John Christensen(CONCITO [Denmark’s climate think tank])

Editorial support
Julia Rocha Romero (UNEP DTU Partnership)

Secretariat, production and coordination
Anne Olhoff (UNEP DTU Partnership), Julia Rocha Romero(UNEP DTU Partnership), Kaisa Uusimaa (UNEP), Maarten
Kappelle (UNEP), Edoardo Zandri (UNEP)Media and launch support
Daniel Cooney (UNEP), David Cole (UNEP), Katie Elles(UNEP), Florian Fussstetter (UNEP), Maria Vittoria Galassi(UNEP), Nancy Groves (UNEP), Rune Kier (UNEP), Viola Kup(UNEP), Nicolien Schoneveld-de Lange (UNEP), Michael
Logan (UNEP), Beverley McDonald (UNEP), Pooja Munshi(UNEP), Keishamaza Rukikaire (UNEP), Laila Saada (UNEP),
Reagan Sirengo (UNEP), Neha Sud (UNEP) and several
other members of the UNEP Communication Division,
Mette Annelie Rasmussen (UNEP DTU Partnership),Lasse Hemmingsen (UNEP DTU Partnership), Monna
Hammershøy Blegvad (UNEP DTU Partnership)

Emissions Gap Report 2021: The Heat Is On

Design and layout
Joseph & Sebastian (cover), Strategic Agenda (figuresand layout)

Translations of the executive summary andlanguage editing
Strategic Agenda

Thanks also to:
Magda Biesiada (UNEP), Angeline Djampou (UNEP), Johan
Falk (Exponential Roadmap Initiative), Owen Gaffney(Stockholm Resilience Centre), Frank Geels (Universityof Manchester), Dany Ghafari (UNEP), Niklas Hagelberg(UNEP), Suzana Kahn Ribeiro (Universidae Federal do Rio
de Janeiro), Yawo Konko (UNEP), Kelly Levin (Bezos EarthFund), Paz Lopez-Rey (UNEP), Omar Masera (Universidad
Nacional Autónoma de México), Sofía Méndez Mora
(UNEP), Jane Muriithi (UNEP), Ekaterina Poleshchuk(UNEP), Joyashree Roy (Asian Institute of Technology),
Sybrig Smit (NewClimate Institute), Nandita Surendran(UNEP), Ying Wang (UNEP)
UNEP would like to thank the ClimateWorks Foundation,
the Danish Ministry of Foreign Affairs, the Dutch Ministryof Economic Affairs and Climate Policy, the German
Federal Ministry for the Environment, Nature Conservation
and Nuclear Safety (BMU) and its International Climate
Initiative (IKI), the Nordic Working Group for Climate
and Air (NKL) of the Nordic Council of Ministers and theSwedish International Development Cooperation Authority(SIDA) for supporting the work of the Emissions Gap
Report 2021.

VII

Emissions Gap Report 2021: The Heat Is On

VIII

Emissions Gap Report 2021: The Heat Is On

Contents
Acknowledgements
Glossary		Foreword		
Executive summary

V
XI
XV
XVI

Chapter 1
1.1		
1.2		

Introduction
Context of the Emissions Gap Report 2021
Focus, approach and structure of the report11
1

Chapter 2
2.1		
2.2		
2.3		

Trends in global emissions, new pledges for 2030 and G20 status and outlook
Introduction
Current global emissions: status and trends
Trends and implications of the new or updated NDCs and other announced mitigation
pledges for 2030
Assessment of G20 members’ progress towards NDCs and mitigation pledges
for 2030

3
3
4

12

Chapter 3
3.1		
3.2		
3.3		
3.4		
3.5		

Net-zero emissions targets
Introduction
The science of net-zero emissions targets
Net-zero at the national level
Tracking national net-zero targets globally
A closer look at net-zero targets in the G20

18
18
18
22
24
25

Chapter 4
4.1		
4.2		
4.3		
4.4		

The emissions gap
Introduction
Scenarios considered for the 2030 gap assessment
The emissions gap
Temperature implications of the emissions gap

29
29
29
32
36

Chapter 5
5.1		
5.2		
5.3		

Are COVID-19 fiscal recovery measures bridging or extending the emissions gap?
Introduction
How could COVID-19-related public spending bridge the emissions gap?
What are the characteristics of fiscal rescue and recovery spending to date andhow may they impact the emissions gap?
Do lower-income nations face greater barriers for low-carbon recovery spending?
If so, what can be done?

38
38
39

43

Chapter 6
6.1		
6.2		
6.3		
6.4		
6.5		
6.6		

The role of anthropogenic methane emissions in bridging the emissions gap
Introduction
Optimizing methane emission reductions
Short- and long-term mitigation potentials
Link between methane mitigation and paths to net-zero CO 2
Methane mitigation in the first NDCs
Measurement-based verification of uncertain emission reporting

47
47
48
49
52
52
54

Chapter 7
7.1		
7.2		

The role of market mechanisms in bridging the emissions gap
Introduction: The role of carbon markets and current status
The potential role of international carbon markets under the Paris Agreement:
near-term versus net-zero implications
Using market mechanisms under article 6
The way forward

56
56

2.4		

5.4		

7.3		
7.4		

References		

6

41

58
61
62
63

IX

Emissions Gap Report 2021: The Heat Is On

XEmissions Gap Report 2021: The Heat Is On

Glossary

This glossary is compiled according to the Lead Authorsof the Report drawing on glossaries and other resources
available on the websites of the following organizations,networks and projects: Intergovernmental Panel on Climate
Change, United Nations Environment Programme, United
Nations Framework Convention on Climate Change andWorld Resources Institute.
Anthropogenic methane: Methane emissions derived fromhuman activities. Anthropogenic emission sources include
coal mining, agricultural practices, wastewater treatment,
certain industrial processes and oil and gas systems,
among others.
Baseline/reference: The state against which change ismeasured. In the context of climate change transformation
pathways, the term ‘baseline scenarios’ refers to scenariosthat are based on 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 canserve to highlight the level of emissions that would occur
without further policy effort. Typically, baseline scenarios
are compared 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 ‘BAU’ has fallen out
of favour because the idea of ‘business as usual’ in centurylong socioeconomic projections is hard to fathom.
Carbon border adjustment mechanisms: Mechanismsthat act to equalize the price of carbon between domestic
products and imports to eliminate financial incentives inorder to relocate production outside of regions with strong
climate controls.
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 (CO 2)
emission trajectory that satisfies assumptions about limits

on cumulative emissions estimated to avoid a certain level ofglobal mean surface temperature rise.
Carbon dioxide equivalent (CO 2e): A way to place emissionsof various radiative forcing agents on a common footing
by accounting for their effect on climate. It describes, for agiven mixture and amount of greenhouse gases, the amountof CO 2 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 CO 2 e
assuming a 100-year global warming potential.
Carbon markets: A term for a carbon trading systemthrough which countries may buy or sell units of greenhousegas emissions in an effort to meet their national limits
on emissions, either under the Kyoto Protocol or otheragreements, such as that among member states of theEuropean Union. The term comes from the fact that CO 2 is the
predominant greenhouse gas, and other gases are measured
in units called carbon dioxide equivalent.
Carbon neutrality: This is achieved when an actor’s net
contribution to global CO 2 emissions is zero. Any CO 2
emissions attributable to an actor’s activities are fullycompensated by CO 2 reductions or removals exclusively
claimed by the actor, irrespective of the time period or the
relative magnitude of emissions and removals involved.
Carbon offset: See Offset.
Carbon price: The price for avoided or released CO 2 or CO 2eemissions. This may refer to the rate of a carbon tax or the
price of emission permits. In many models that are used toassess the economic costs of mitigation, carbon prices areused as a proxy to represent the level of effort in mitigation
policies.
Clean development mechanism (CDM): A mechanism under
the Kyoto Protocol, the purpose of which, in accordance witharticle 12 of the Protocol, is to assist non-Annex I parties
in achieving sustainable development and in contributing
to the ultimate objective of the United Nations Framework
Convention on Climate Change, and to assist Annex I parties
in achieving compliance with their quantified emissions

XI

Emissions Gap Report 2021: The Heat Is On

limitation and reduction commitments under article 3 of theProtocol.

Greenhouse gas removal: Withdrawal of a greenhouse gas
and/or a precursor from the atmosphere by a sink.

Conditional nationally determined contribution (NDC): An
NDC proposed by some countries that are contingent on a
range of possible conditions, such as the ability of national
legislatures to enact the necessary laws, ambitious action
from other countries, realization of finance and technicalsupport, or other factors.

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 full chainof climate change, from production of greenhouse gases toatmospheric responses. This necessarily includes relevant
links and feedbacks between socioeconomic and biophysicalprocesses.

Conference of the Parties (COP): The supreme body of
the United Nations Framework Convention on Climate
Change. It currently meets once a year to review theConvention’s progress.
Double counting: Double counting involves two countries
taking credit for the same emissions reductions, thereby
giving the impression that the world has reduced emissions
more than it actually has. For example, emissions reduction
credits from one country might be sold to another country, but
the reductions may still be counted towards the achievementof the NDC of the country where the credits originated.
Emission pathway: The trajectory of annual greenhouse gas
emissions over time.
Emissions trading: One of the three Kyoto mechanisms, bywhich an Annex I party may transfer Kyoto Protocol units to,or acquire units from, another Annex I party. An Annex I party
must meet specific eligibility requirements to participate inemissions trading.

Katowice Climate Package: The Katowice Climate Package,also known as ‘the Katowice outcome ’, is a complex
package containing operational guidance on information
provision, communication and rules for the functioning of
the climate transparency framework, the global stocktakingof overall progress and the evaluation of progress, and theprovision of prior information on financial assistance. The
package sets out the essential procedures and mechanismsthat operationalized the Paris Agreement. The guidelinesof the package aim to build greater trust and strengtheninternational cooperation.

EU Emissions Trading System (ETS): The EU ETS is a trading
system for carbon emissions and the first internationalemissions trading system in the world. The EU ETS covers thefollowing sectors and gases: electricity and heat generation,energy-intensive industry sectors (including oil refineries, steel
works and production of iron, aluminium, metals, cement,
lime, glass, ceramics, pulp, paper, cardboard, acids and bulk
organic chemicals, commercial aviation within the European
Economic Area), nitrous oxide from production of nitric, adipic
and glyoxylic acids and glyoxal, and perfluorocarbons fromproduction of aluminium.

Kyoto Protocol: An international agreement, standing on
its own, and requiring separate ratification by governments,
but linked to the United Nations Framework Convention on
Climate Change. The Kyoto Protocol, among other things,
sets binding targets for the reduction of greenhouse gas
emissions by industrialized countries.

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.

Leakage: A phenomenon whereby the reduction in emissions(relative to a baseline) in a jurisdiction/sector associated with
the implementation of mitigation policy is offset to somedegree by an increase outside the jurisdiction/sector throughinduced changes in consumption, production, prices, land
use and/or trade across the jurisdictions/sectors. Leakage
can occur at a number of levels: project, state, province,
nation or world region.

Greenhouse gases: The atmospheric gases responsible
for causing global warming and climatic change. The major
greenhouse gases are carbon dioxide (CO 2), methane (CH 4)
and nitrous oxide (N 2 O). Less prevalent, but very powerful,
GHGs are hydrofluorocarbons (HFCs), perfluorocarbons(PFCs) and sulfur hexafluoride (SF6).

XII

Intended nationally determined contribution (INDC): INDCs
are submissions from countries describing the national
actions that they intend to take to reach the Paris Agreement’s
long-term temperature goal of limiting warming to well below
2°C. Once a country has ratified the Paris Agreement, its INDC
is automatically converted to its NDC, unless it chooses tofurther update it.

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.

Emissions Gap Report 2021: The Heat Is On

Least-cost pathway: Such scenarios identify the least
expensive combination of mitigation options to fulfil aspecific climate target. A least-cost scenario is based on
the premise that, if an overarching climate objective is set,society wants to achieve this at the lowest possible costs overtime. It also assumes that global actions start at the baseyear of model simulations (usually close to the current year)
and are implemented following a cost-optimal (cost-efficient)sharing of the mitigation burden between current and future
generations depending on the social discount rate.

Source: Any process, activity or mechanism that releases agreenhouse gas, an aerosol or a precursor of a greenhousegas or aerosol into the atmosphere.

Likely chance: A likelihood greater than 66 per cent chance.
Used in this assessment to convey the probabilities ofmeeting temperature limits.
Mitigation: In the context of climate change, mitigation
relates to a human intervention to reduce the sources, orenhance the sinks of greenhouse gases. Examples include
using fossil fuels more efficiently for industrial processes
or electricity generation, switching to solar energy or wind
power, improving the insulation of buildings and expanding
forests and other ‘sinks’ to remove greater amounts of CO 2from the atmosphere.
Nationally determined contribution (NDC): Submissions
by countries that have ratified the Paris Agreement which
presents their national efforts to reach the Paris Agreement’s
long-term temperature goal of limiting warming to well below
2°C. New or updated NDCs were expected to be submitted
in 2020 and should be submitted every five years thereafter.
NDCs thus represent a country’s current ambition/target for
reducing emissions nationally.
Offset (in climate policy): A unit of CO 2 e emissions thatis reduced, avoided or sequestered to compensate foremissions occurring elsewhere.
Recovery-type measure: Fiscal, monetary or regulatoryintervention by a government to reinvigorate economic
activity in response to a crisis.
Rescue-type measure: Immediate fiscal, monetary or
regulatory intervention by a government to protect citizens’
lives and socioeconomic well-being and/or to provide
emergency support to businesses and the economy inresponse to a crisis.
Scenario: A description of how the future may unfold basedon ‘if-then’ propositions. Scenarios typically include an initialsocioeconomic situation and a description of the key driving
forces and future changes in emissions, temperature or otherclimate change-related variables.
Shared Socioeconomic Pathways (SSP): Scenarios ofprojected socioeconomic global changes up to 2100. They
are used to derive greenhouse gas emissions scenarios
associated with different climate policies scenarios.

XIII

Emissions Gap Report 2021: The Heat Is On

Foreword

Climate change is no longer a future problem. It is a 'now'
problem. As we saw this year, devastating impacts are
spreading across the globe and growing ever stronger. The
Intergovernmental Panel on Climate Change told us a few
months ago that we have a 50 per cent chance of exceeding
a 1.5°C temperature threshold within the next few decades.

Then they must zero in on net zero, ensuring these longterm commitments are linked to the NDCs, and that actionis brought forward. It is time to get the policies in place toback the raised ambitions and, again, start implementing
them. This cannot happen in five years. Or in three years.
This needs to start happening now.

Climate action so far has been characterized by weakpromises, not yet delivered. As the Emissions Gap
Report 2021 shows, the updated nationally determined
contributions (NDCs) under the Paris Agreement fall into
the same trap. These pledges only take 7.5 per cent off
predicted 2030 emissions, compared to the previous roundof commitments. This is far from adequate. Reductions of
30 per cent are needed to stay on the least-cost pathway for
2°C and 55 per cent for 1.5°C.

We can still do it. As this year’s Emissions Gap Reportshows, there is huge potential for large cuts in methane
emissions from the oil and gas, waste and agriculture
sectors. Carbon markets could help to accelerate action
by decreasing mitigation costs. COVID-19 recovery funding
can still be greened. And as previous UNEP Emissions Gap
Reports show, there is potential in nature-based solutions,renewables, energy efficiency and so much more.

If nations only implement unconditional NDCs as theystand, we are likely to hit global warming of about 2.7°C by
the end of the century. Current net-zero pledges could cut
another 0.5°C off global warming – but these pledges arestill ambiguous, delayed in many cases and not folded into
NDCs. At the same time, this year’s Emissions Gap Reportshows that the opportunity to use pandemic recovery
spending to reduce emissions has been largely missed.

We should not despair. We have already shown that climate
action can make a difference. In 11 years, from 2010 to2021, we have put in place policies that will lower annual
emissions by 11 GtCO 2 e in 2030 compared to what would
have happened without these policies. But we need to makethe difference, not a difference. We cannot keep doing thesame things and expect a better result.
The world has to wake up to the imminent peril we face asa species. We need to go firm. We need to go fast. And weneed to start doing it now.

To get on track to limit global warming to 1.5°C, the world
needs to take an additional 28 gigatons of carbon dioxide
equivalent (GtCO 2 e) off annual emissions by 2030, over andabove what is promised in updated unconditional NDCs. For
the 2°C Paris Agreement target, the additional need is lower:a drop in annual emissions of 13 GtCO 2 e by 2030. To beclear: we have eight years to make the plans, put in place
the policies, implement them and ultimately deliver the cuts.
The clock is ticking loudly.

Inger Andersen

Nations must put in place the policies to meet their new
commitments and start implementing them immediately.

Executive Director
United Nations Environment Programme

XVEmissions Gap Report 2021: The Heat Is On

Executive summary

Introduction
This twelfth edition of the United Nations Environment
Programme (UNEP) Emissions Gap Report comes during
a year of constant reminders that climate change is notin the distant future. Extreme weather events around theworld – including flooding, droughts, wildfires, hurricanes
and heatwaves – have continuously hit the news headlines.
Thousands of people have been killed or displaced andeconomic losses are measured in the trillions. Bearing
witness to the increasingly clear signs of climate change,
the Intergovernmental Panel on Climate Change (IPCC)
published the first report in its Sixth Assessment cycle
addressing the “Physical Science Basis” in August 2021.
Dubbed a “code red for humanity” by the United Nations
Secretary-General, the IPCC report documents in far greater
detail and with higher certainty than previous assessments
how climate change and extreme events can be attributed
to the build-up of anthropogenic greenhouse gas (GHG)
emissions in the atmosphere. There is a fifty-fifty chancethat global warming will exceed 1.5°C in the next two
decades, and unless there are immediate, rapid and largescale reductions in GHG emissions, limiting warming to 1.5°C
or even 2°C by the end of the century will be beyond reach.
Building on the new evidence from the IPCC, the twentysixth United Nations Climate Change Conference of theParties (COP26) is charged with the growing urgency ofaccelerating global ambition and action on both mitigation
and adaptation. This year, the spotlight is on the new andupdated nationally determined contributions (NDCs) thatcountries were requested to submit in advance of COP26.
As the September 2021 version of the NDC Synthesis Reportpublished by the United Nations Framework Convention on
Climate Change (UNFCCC) illustrates, the new and updated
NDCs are insufficient to achieve the temperature goal of theParis Agreement.
This Emissions Gap Report confirms the findings of the
UNFCCC report. It expands the assessment to consider
announced mitigation pledges for 2030 in addition to the
new and updated NDCs. The report shows that new or

XVI

updated NDCs and announced pledges for 2030 have only
limited impact on global emissions and the emissions gap
in 2030, reducing projected 2030 emissions by only 7.5 per
cent, compared with previous unconditional NDCs, whereas
30 per cent is needed to limit warming to 2°C and 55 per centis needed for 1.5°C. If continued throughout this century,
they would result in warming of 2.7°C. The achievement of
the net-zero pledges that an increasing number of countries
are committing to would improve the situation, limiting
warming to about 2.2°C by the end of the century. However,the 2030 commitments do not yet set G20 members(accounting for close to 80 per cent of GHG emissions) on aclear path towards net zero.
Moreover, G20 members as a group do not have policies inplace to achieve even the NDCs, much less net zero. Turning
to some of the opportunities for bridging the emissions gap
and getting on track to net zero, the report assesses theextent to which COVID-19 fiscal recovery measures areused to accelerate a green transition. It examines the scopefor reducing emissions from methane, the second-mostimportant GHG in terms of current anthropogenic climate
forcing, to bridge the gap and get on track to net zero. Finally,
the report looks into a key negotiation issue for COP26:
reaching agreement on how to move forward with article 6of the Paris Agreement dealing with cooperative approaches
and market mechanisms. A large number of countries
have included the use of market mechanisms in their NDC
implementation plans and are waiting for the modalities tobe agreed. At the same time, the use of markets and offsets
in meeting net-zero emission goals is often unclear.
As in previous years, the 2021 Emissions Gap Report has
been guided by an experienced steering committee andprepared by an international team of leading scientists,
assessing all available information, including that publishedin the context of the IPCC reports, as well as in otherrecent scientific literature. The assessment process has
been transparent and participatory. The assessment
methodology and preliminary findings were made available
to the governments of the countries specifically mentioned
in the report to give them an opportunity to comment on
the findings.

Emissions Gap Report 2021: The Heat Is On

1.

Following an unprecedented drop of 5.4 percent in 2020, global carbon dioxide emissions
are bouncing back to pre-COVID levels, andconcentrations of GHGs in the atmosphere
continue to rise.

CO 2 emissions could grow by 4.8 per cent in 2021
(excluding cement), and global emissions in 2021
are expected to be only slightly lower than therecord level of 2019.
▶

▶

The COVID-19 pandemic led to an unprecedented
5.4 per cent drop in global fossil carbon dioxide(CO 2) emissions in 2020 (figure ES.1). Data are not
yet available for all GHG emissions in 2020, but thedrop in total global GHG emissions is anticipatedto be smaller than the drop in fossil CO 2 emissions.

▶

A strong rebound in emissions is expected in
2021. Preliminary estimates suggest fossil energy

Despite the large decline in CO 2 emissions in 2020,
the concentration of CO 2 in the atmosphere grewby around 2.3 parts per million, in line with recent
trends. It is unlikely that the reductions in emissions
in 2020 will be detectible in the atmospheric growthrate, as the natural variability of around one partper million is far greater than the effect of a 5.4 percent reduction in CO 2 emissions in a single year.
Solving the climate problem requires rapid andsustained reductions in emissions.

Figure ES.1. Global greenhouse gas emissions from all sources, 1970–2020

Global greenhouse gas emissions (GtCO2e)

60

50

40

30

20

10

20

F-gases

20

N2O

15

20
10

CH4

20

20
05

19
95

LULUCF CO2

2000

Fossil CO2

19
90

19
85

19
80

19
75

19
70

0

2020 data only available for fossil and LULUCF CO2

2.
▶

New mitigation pledges for 2030 show some
progress, but their aggregate effect on global
emissions is insufficient.
As at 30 September 2021, 120 countries (121 parties,
including the European Union and its 27 member
states) representing just over half of global GHG
emissions, have communicated new or updated
NDCs. This year's assessment considers the newor updated NDCs communicated to the UNFCCC as
well as announcements of new mitigation pledges
for 2030 by China, Japan and the Republic of Korea
not submitted as NDCs by 30 September.

▶

Just under half (49 per cent) of the new or updated
NDCs submitted (from countries accounting for
32 per cent of global emissions) result in lower
2030 emissions than the previous NDC. Around18 per cent of the NDCs (from countries accountingfor 13 per cent of global emissions) will not reduce
2030 emissions relative to the previous NDC. The
remaining 33 per cent of NDCs (from countries
accounting for 7 per cent of global emissions)contain insufficient detail to assess their impact
on emissions relative to the previous NDC (figureES.2). Typically, this is due to a lack of informationin the previous NDC, rather than the current one;the current NDCs are more transparent.

XVII

Emissions Gap Report 2021: The Heat Is On

Figure ES.2. Effect of new or updated nationally determined contributions on 2030 greenhouse gas emissions relative toprevious nationally determined contributions

New or updated NDC with lower
2030 emissions than prior NDC

New or updated NDC with equal or
higher 2030 emissions than prior NDC

No new or updated NDC submitted

New or updated NDC not comparable
to prior NDC▶

Of the countries that have submitted new or
updated NDCs, more (89 per cent) have GHG
targets than before (75 per cent). However, thesetargets are only marginally more comprehensive interms of sector and gas coverage. The share of new
or updated NDCs that are completely unconditional
has increased from 24 per cent to 26 per cent, while
the share of NDCs that are completely conditional
has dropped from 31 per cent to 18 per cent.

▶

The aggregate impact of the new or updated
NDCs formally submitted is limited: new or updated
unconditional NDCs are estimated to lead to a total
reduction in 2030 global GHG emissions of about
2.9 gigatons of CO 2 equivalent (GtCO 2 e), comparedwith the previous NDCs (figure ES.3). This estimate
includes reductions of around 0.3 GtCO 2 e resulting
from other factors, including lower projectionsof international aviation and shipping emissions,and adjustments of countries that are projected tooverachieve their NDC targets. If the announced
pledges of China, Japan and the Republic ofKorea are also included, this aggregate reduction
increases to just over 4 GtCO 2 e. The impact ofconditional targets is of similar magnitude.

▶

XVIII

Taking a closer look at the G20 members,
the combined impact of submitted NDCs andannounced GHG reduction targets for 2030 is anannual reduction of about 3 GtCO 2 e compared withthe previous NDCs. Six G20 members have formallysubmitted updated NDCs with enhanced GHG
mitigation pledges: Argentina, Canada, the EU27
(counting the EU27 and its three individual G20
member states France, Germany and Italy as one),
South Africa, the United Kingdom and the UnitedStates of America – all of which entail reduced
emissions in 2030 of about 2.1 GtCO 2 e comparedwith previous NDCs. Two G20 members (Brazil
and Mexico) have submitted targets that lead toan increase in emissions of 0.3 GtCO 2 e, bringing
the net reduction in global GHG emissions of new
or updated NDCs submitted by G20 members to
1.8 GtCO 2 e annually by 2030. In addition, China,
Japan and the Republic of Korea have announced
enhanced pledges that result in annual reductionsof about 1.2 GtCO 2 e, but have not yet formallycommunicated them to the UNFCCC.
▶

The largest reductions come from the UnitedStates of America, the EU27, the United Kingdom,
Argentina and Canada (submitted) and China andJapan (announced). Two G20 members (Australia
and Indonesia) have submitted NDC targets, which
are assessed not to lead to additional reduction
relative to the previous NDCs. One G20 member(the Russian Federation) has submitted an NDC
that improves upon its previous NDC, but still does
not go beyond its current policies and another three
G20 members (India, Saudi Arabia and Turkey)
have not yet submitted a new or updated NDC.

Emissions Gap Report 2021: The Heat Is On

Figure ES.3. Impact of 2030 pledges (nationally determined contributions and other announced pledges) on 2030 global
emissions compared with previous nationally determined contribution submissions
500

0
-500

MtCO2e-1,000-1,500-2,000-2,500-3,000-3,500-4,000

Increased emissions

3.
▶

In comparison, the aggregate impact of the
new or updated NDC submissions for the
non-G20 members is an annual reduction of
0.8 GtCO 2 e by 2030.

As a group, G20 members are not on trackto achieve either their original or new 2030
pledges. Ten G20 members are on track toachieve their previous NDCs, while seven are
off track.
When considering the impact of new pledges, it
should be noted that collectively the G20 members
are not yet on track to achieve their previous NDCs.
If current policy projections are used for thosecountries where policy projections are lower thanwhat NDCs would deliver, the G20 members as a

Total

Republic of Korea

Japan

China

Other factors

Non-G20

USA

TurkeyReduced emissions

Impact of announced pledges▶

South Africa

Saudi Arabia

Russian Federation

MexicoIndonesia

India

UK

EU27

CanadaBrazilAustralia

Argentina-4,500Total impact

group are projected to fall short of achieving theirunconditional NDCs by 1.1 GtCO 2 e annually.
▶

Only 10 G20 members (Argentina, China, EU27,
India, Japan, the Russian Federation, Saudi Arabia,
South Africa, Turkey and the United Kingdom)
are likely to achieve their original unconditional
NDC targets under current policies. Among them,three members (India, the Russian Federation andTurkey) are projected to reduce their emissions
to levels at least 15 per cent lower than theirprevious unconditional NDC emissions target
levels under current policies, indicating that thesecountries have significant room for raising their
NDC ambition. As at 30 September 2021, India andTurkey have not yet submitted a new or updated
NDC, while the Russian Federation has submitted a
new NDC that reduces emissions, but still results inhigher emissions than implied by current policies.

XIXEmissions Gap Report 2021: The Heat Is On

Australia, Brazil, Canada, Mexico, the Republic ofKorea and the United States of America are allassessed to require stronger policies to achieve
prior NDCs, while there is insufficient information
to assess the progress of Indonesia.
▶

▶

4.
▶

XX

G20 members have adopted a range of policies
in recent years. While there are many positive
developments, there are also negative examples,such as fossil fuel extraction projects and coalfired power plant construction plans moving
forward as well as rollback of environmental
regulations during the COVID-19 pandemic. Basedon the central estimates of independent studies,a large number of G20 members (Argentina,
Brazil, China, India, Indonesia, Mexico, the RussianFederation and Saudi Arabia) are expected to emit
more in 2030 under implemented policies than they
did in 2010.
Collectively, the G20 members are projected tofall short of their new or updated unconditional
NDCs and other announced mitigation pledges
for 2030. This is to be expected and it would
indicate a lack of enhanced ambition if the new2030 pledges were projected to be achieved withcurrently implemented policies. It is worth notingthat Canada and the United States of America
have submitted strengthened NDC targets, while
independent studies suggest that they are noton track to meet their previous NDC targets
with currently implemented policies. These twocountries therefore need to make significant
additional efforts to meet their new NDC targets.

A promising development is theannouncement of long-term net-zeroemissions pledges by 52 parties, covering
more than half of global emissions. However,these pledges show large ambiguities.
Net-zero emissions is a state where the sum of allanthropogenic emissions and removals is zero.
Net-zero emissions targets are being defined in avariety of ways – the most important aspect from a
global geophysical perspective being whether they
cover all GHGs or CO 2 only. Global net-zero CO 2
emissions stabilize global warming, whereas netzero GHG emissions result in a peak then a decline
in global warming. To align with a 1.5°C limit, global
CO 2 emissions must reach net zero around 2050,
with global GHG emissions reaching net zero
15–20 years later. A delay of 15–20 years in either
net-zero CO 2 or net-zero GHGs implies limiting
warming to 2°C rather than 1.5°C.

▶

Globally, 51 countries and one party (the EU27
in addition to the net-zero pledges made by its
individual member states) have pledged a net-zeroemissions target that is stated in national legislation,
in a policy document or in a public announcementby the government or a high-level government
official. These pledges cover more than half ofcurrent global domestic GHG emissions, over halfof gross domestic product (GDP) and one third of
the global population. Thirteen targets covering 12
per cent of global emissions are enshrined in law.

▶

By number, the majority of these targets (40) are for2050, coincident with the mid-century timescale
for global CO 2 emissions indicated by the IPCC
as necessary for limiting warming to 1.5°C. Eighttargets are aimed at earlier years (2030–2045) and
four at later years. In terms of emissions, however,
the targets are split almost entirely and equally
between 2050 (due to the European Union andUnited States of America pledges) and 2060 (dueto China’s pledge).

▶

Existing targets show variations in scope and large
ambiguities with respect to the inclusion of sectors
and GHGs. The majority are furthermore unclear
or undecided on the inclusion of emissions frominternational aviation and shipping and the use ofinternational offsets.

5.

Few of the G20 members' NDC targets put
emissions on a clear path towards net-zeropledges. There is an urgent need to backthese pledges up with near-term targets andactions that give confidence that net-zeroemissions can ultimately be achieved and theremaining carbon budget kept.

▶

Twelve G20 members covering just over half ofglobal domestic GHG emissions have currently
pledged a net-zero target, of which six are inlaw, two are in policy documents and four are
government announcements. All are for the year
2050, with the exception of China’s 2060 target andGermany’s target for 2045. The remaining eight
G20 members have so far not set net-zero targets,
but three of them have communicated long-term
low GHG emission development strategies to the
UNFCCC (Indonesia, Mexico and South Africa).

▶

G20 pledges also show ambiguity. Most targets areunclear or undecided on the inclusion of offsets andof international aviation and shipping emissions.
Lack of clarity is also notable on coverage ofsectors and gases, but pledges that are clear show

Emissions Gap Report 2021: The Heat Is On

Figure ES.4. Near-term targets are critical to set global emissions on a clear path towards achieving long-term net-zerotargets and stringent climate goals

Global total greenhouse gas emissions[GtCO2e/yr]

Linear: the NDC setsemissions approximately on alinear path towards achieving
the net-zero target.

60
Additional cumulative emissions leading tohigher warming, higher mitigation challenges, andgreater difficulty in achieving the net-zero target40= near-term targets setting emissions...
on a delayed pathon a linear path, or

20

on an accelerated path... towards achieving thelong-term net-zero target

0
2010

2020

2030

2040

2050

a tendency for comprehensive coverage. However,most show a lack of transparency regarding
the approach taken to fairness, the plans forachievement (including on use of removals), andprogress reporting and review. Only Canada, theEuropean Union, France, Germany and the Republicof Korea have published their plans at the time ofcompleting this report, and only these countries
plus the United Kingdom have accountableprocesses for reviewing their targets.
▶

Delayed: the NDC reduces
emissions more slowly than implied
by a linear path towards the net-zerotarget. Cumulative emissions andresulting global warming are higher
compared to a linear path.

Accelerated: the NDC reduces
emissions further than implied by alinear path towards the net-zerotarget. Cumulative emissions
are further reduced compared to alinear path.

The pathway to net zero counts: the path followedfrom today until net-zero CO 2 emissions arereached determines the total amount of emitted
CO 2 and thereby the total carbon budget used(see bullet below). Whether a linear, an accelerated,or a delayed path is followed will affect the climate
outcome (figure ES.4).

2060

2070

2080

2090

2100

▶

Global warming is close to linearly proportional
to the total net amount of CO 2 that has ever been
emitted in the atmosphere as a result of humanactivities. Therefore, limiting global warming toa specified level requires that the total amountof CO 2 emissions ever emitted be kept within afinite carbon budget. New IPCC estimates put
the remaining carbon budget to limit warming to
1.5°C relative to pre-industrial levels, with 66 percent chance, at 400 GtCO 2 . For 2°C, the estimate is
1,150 GtCO 2 . Current annual global CO 2 emissions
are above 40 GtCO 2 /year, meaning that urgent anddeep emissions reductions over the next decade
are required to stay within the remaining budgets.

▶

As an indication of the consistency between
nearer-term actions and net-zero targets, figureES.5 plots the emissions paths for a subgroup of
G20 members implied by their current NDCs and

XXIEmissions Gap Report 2021: The Heat Is On

Figure ES.5. Overview of net-zero pathways implied by climate pledges by selected G20 members

BrazilArgentina

Canada

200
0

2020

2040

MtCO2e/yr

MtCO2e/yr

MtCO2e/yr

400
1,000
0

2060

2020

5,000
2040

2,000
0

2060

500
0

2020

2040

2020

2040

2060

2060

2020

2040

2060

500
0

2020

2040

2060

United States

500
0

2040

1,000

United Kingdom

MtCO2e/yr

MtCO2e/yr

Republic of Korea

2020

MtCO2e/yr

2020

0

Japan

MtCO2e/yr

10,000
0

2060

EU27

MtCO2e/yr

MtCO2e/yr

China

2040

500

2060

5,000
0

2020

2040

2060

Note: Only G20 members with net zero targets are included. Member states of the European Union have no separate assessment of theirpath to net zero, because their NDC is not assessed separately as part of this report.

XXII

Emissions Gap Report 2021: The Heat Is On

their net-zero target. Of the nine G20 members forwhich an emissions path can be estimated basedon their net-zero target and their NDC, none have
NDC targets that put them on an accelerated path
towards their net-zero emissions targets. Five of
these nine members, accounting for about one
fifth of global domestic GHG emissions, have NDC
targets that put the country’s domestic emissions
onto a linear path towards achieving their net-zerotargets. In the other four cases, the NDCs lead toemissions in 2030 that are about 25 per cent to95 per cent higher than a linear path towards their
net-zero targets would imply. Recognizing thatcountries face very different circumstances, thesecountries urgently need strengthened and more
ambitious near-term climate plans for their netzero targets to remain achievable.
▶

6.

There is an urgent need for (i) more G20 members– and indeed all countries – to pledge netzero emissions, (ii) all countries to increase therobustness of their net-zero pledges, and (iii) all netzero targets to be backed up by near-term actions
that give confidence that the net-zero targets canultimately be achieved.

The emissions gap remains large: compared
to previous unconditional NDCs, the newpledges for 2030 reduce projected 2030
emissions by only 7.5 per cent, whereas 30
per cent is needed for 2°C and 55 per cent isneeded for 1.5°C.

▶

As in previous reports, the emissions gap for2030 is defined as the difference between total
global GHG emissions from least-cost scenariosthat keep global warming to 2°C, 1.8°C or 1.5°C
with varying levels of likelihood and the estimatedtotal global GHG emissions resulting from the full
implementation of the NDCs.

▶

This year, the NDC scenario has been expanded toinclude all the most recent NDCs (new or updated
NDCs if submitted, and previous NDCs otherwise)
as well as all officially announced climate change
mitigation pledges for 2030 with a cut-off date of
30 August 2021. The three least-cost scenarios
consistent with the Paris Agreement have been
updated and their temperature outcomes re assessed based on the Contribution of Working
Group I to the Sixth Assessment Report of theIntergovernmental Panel on Climate Change.
As a result, global emissions in 2030 consistent
with keeping global warming below 2.0°C witha 66 per cent chance are now estimated at
39 GtCO 2 e, which is about 2 GtCO 2 e lower thanin earlier reports. Similarly, the estimate for 1.8°C
is about 2 GtCO 2 e lower than the 1.8°C estimate
of previous reports. There are no changes to the
1.5°C estimate (table ES.1). This implies that while
the aggregate effect on global emissions in 2030of new or updated NDCs and announced pledges
is estimated at 4 GtCO 2 e (see point two of thissummary), the gap with respect to 2°C is only
reduced by 2 GtCO 2 e compared with last year.
▶

The updated current policies scenario is estimatedto reduce global GHG emissions in 2030 to about
55 GtCO 2 e (range: 52–58 GtCO 2 e) in 2030, whichis 4 GtCO 2 e lower than the median estimate of
the 2020 Emissions Gap Report and 9 GtCO 2 elower than the 2010-policies scenario (table ES.1).
Around half of the decrease between the 2020 and
2021 Reports reflects climate policy progress inthe countries, while the other half is because of
the general slowdown of economies due to the
COVID-19 pandemic.

▶

Collectively, countries are falling short of meeting
their new or updated NDCs and announced pledges
with current policies. This implementation gap
in 2030 is 3 GtCO 2 e for unconditional NDCs and
5 GtCO 2 e for conditional NDCs.

▶

Compared to last year, the emissions gap is only
slightly narrowed by the new or updated NDCs
and announced mitigation pledges. By 2030,
annual emissions need to be 13 GtCO 2 e (range:
10–16 GtCO 2 e) lower than current unconditional
NDCs imply for the 2°C goal, and 28 GtCO 2 e (range:
25–30 GtCO 2 e) lower for the 1.5°C goal. Bothestimates are for a 66 per cent chance of staying
below the stated temperature limit. If conditional
NDCs are also considered, these gaps are reduced
by around 2 GtCO 2 e and 3 GtCO 2 e respectively(figure ES.6, table ES.1).

XXIII

Emissions Gap Report 2021: The Heat Is On

Table ES.1. Total global greenhouse gas emissions in 2030 under different scenarios, temperature implications, and theresulting emissions gap

GlobalScenario (rounded Number of total
to the nearest
scenarios emissions
gigaton)in setin 2030[GtCO2e]

Estimated temperature outcomes

50%
chance66%
chanceClosestcorresponding
IPCC SR1.5
scenario class90%
chanceEmissions gap in 2030
[GtCO2e]

Below
2.0°C

Below
1.8°C

Below
1.5°C

Year 2010 policies

6

64 (60–68)

Current policies

955 (52–58)

15
22(12–18) (19–25)

30(28–33)

Unconditional
NDCs (updated
NDCs andannouncements)

8

52 (49–55)

13
19(10–16) (16–22)

28(25–30)Conditional
NDCs (updated
NDCs andannouncements)

8

50 (46–52)

11(7–13)

25(22–28)Below 2.0°C(66% chance)

Below 1.8°C(66% chance)

Below 1.5°C(66% chance in2100 with no or
limited overshoot)

7.

▶

XXIV

71

23

26

39 (33–49)

33 (27–41)

25 (17–33)

Peak:

Peak:

Peak:

1.7–1.8°C

1.8–2.0°C

2.2–2.4°C

In 2100:

In 2100:

In 2100:

1.3–1.7°C

1.5–1.9°C

1.9–2.4°C

Peak:

Peak:

Peak:

1.6–1.7°C

1.7–1.8°C

2.0–2.2°C

In 2100:

In 2100:

In 2100:

1.2–1.6°C

1.4–1.8°C

1.8–2.2°C

Peak:

Peak:

Peak:

1.5–1.6°C

1.6–1.7°C

1.9–2.1°C

In 2100:

In 2100:

In 2100:

1.0–1.3°C

1.2–1.5°C

1.5–1.9°C

Global warming at the end of the century is
estimated at 2.7°C if all unconditional 2030
pledges are fully implemented and 2.6°C if allconditional pledges are also implemented.
If the net-zero emissions pledges are
additionally fully implemented, this estimate
is lowered to around 2.2°C.
To estimate the global warming implications
at the end of this century, estimated emissions
for the year 2030 are projected out to 2100, andtheir climate outcomes assessed using a climate
model. This approach assumes a continuationof climate action beyond 2030, without further
strengthening. Extrapolations until the end of the17(13–19)Higher-2°C
pathways

Lower-2°C
pathways

1.5°C withno or limited
overshootcentury are inherently uncertain and subject toscenario assumptions, such as the level at whichclimate action continues or technology costs.
This uncertainty is currently of the order of ±0.5°C
around the best-estimate 2.7°C projection, but
is reduced to ±0.3°C when taking into account
countries’ net-zero targets. Furthermore, it should
be noted that this year’s estimates are basedon improved methods and the latest climate
assessment of Working Group I in the IPCC Sixth
Assessment Report (AR6). These methodological
updates alone lower temperature projections forunconditional NDCs by about 0.2°C compared tolast year's estimates.

Emissions Gap Report 2021: The Heat Is On

Figure ES.6. Global greenhouse gas emissions under different scenarios and the emissions gap in 2030 (median estimate
and tenth to ninetieth percentile range)

70.0

2010 policies scenario
60.0

Current policies scenario
Unconditional NDC and pledge scenario

40.0

30.0

Conditional
NDC and11
pledgescenario GtCO2e

2°C range
Turquoise area shows
pathways limiting global
temperature increase to
below 2°C with about
66% chance.

1.8°C range

13

GtCO2e25

Median GtCO2e
estimateof levelconsistent
with 2°C:
39 GtCO2e(range 33–49)

Remaining gap
to stay within
2°C limit

1.5°C range
Green area shows pathways
limiting global temperature
increase to below 1.5°C with a 66%
chance by 2100 and minimum 33%
chance over the course of the century.

20.0
2015

2020

GtCO2eMedianestimateof levelconsistent
with 1.5°C:
25 GtCO2e(range 17–33)

Estimated global
warming over
21st century

60.0

Current policies
scenario: 2.8°C(66% chance)
Unconditional NDC
and pledge
scenario: 2.7°C(66% chance)

50.0
40.0
30.0

2°C range

Unconditional
NDC and pledge
scenario with
net-zero targets:
2.2°C (66%chance)1.8°C range

20.0
10.0
0.0
2015

28

2025

70.0

GtCO2e

GtCO2e50.0

1.5°C range

2020

2025

2030

2035

2040

2045

2050

XXV

Emissions Gap Report 2021: The Heat Is On▶

Acknowledging these caveats, a continuation of
the new or updated unconditional NDCs and pledge
announcements is estimated to limit warming to
2.7°C (range: 2.2–3.2°C) by the end of the century
with a 66 per cent chance. If conditional pledges
are also fully implemented, these estimates arelowered to 2.6°C (range: 2.1–3.1°C). By contrast,
a continuation of current policies, which are
insufficient to meet the 2030 pledges, is estimatedto limit warming to 2.8°C (range 2.3–3.3°C).

▶

The full implementation of the net-zero pledges, inaddition to new or updated unconditional NDCs andannounced pledges, further lower these temperature
estimates markedly to 2.2°C (range 2.0–2.5°C) with
66 per cent chance. Even under this scenario, there
is still more than 15 per cent chance that global
warming will exceed 2.5°C by the end of the century,and just short of 5 per cent chance that it will exceed
3°C. Finally, these estimated improvements fromnet-zero targets should be caveated by the fact that
only a few current NDCs set countries’ emissions
on a linear path towards reaching longer-term netzero targets.

Figure 5.4
Figure ES.7. Global recovery spending as at May 2021 across sectors by region (US$ billion). Low-carbon initiatives (top)and high-carbon initiatives (bottom)
AfricaAsia

EuropeLatin America & the Caribbean

Clean energy

Northern America

Oceania(4.1%)

Clean R&D

(1.6%)

Clean transport

Lowcarbon
measures(3.3%)

Energy efficiency
Naturalinfrastructure
Armed forces(2.2%)(3.8%)(0.8%)

Traditional transport(9.2%)

Traditional energy(1.6%)
0

50

100

150

200

Highcarbon
measures

US$250 bn

Note: R&D stands for research and development.

8.
▶

XXVI

The opportunity to use COVID-19 fiscal
rescue and recovery spending to stimulate
the economy while fostering a low-carbon
transformation has been missed in mostcountries so far. Poor and vulnerable
countries are being left behind.
The COVID -19 pandemic has precipitated anenormous increase in public expenditure, inthe form of: (i) short-term rescue spending, tokeep businesses and people alive; (ii) longerterm recovery investment, to reinvigorate theeconomy; and (iii) reinforcement spending, toembed new economic trajectories into long-term
development plans. Low-carbon rescue spending
has incentivized decarbonization through green

conditionalities attached to short-term businesssupport. Low-carbon recovery investment has
set out to accelerate the low-carbon transition
directly by supporting green projects and indirectly
by incorporating green incentives into traditional
investment. Green reinforcement initiatives deliver
long-term support to the projects and sectors
targeted by green recovery investment.
▶

Approximately US$16.7 trillion was spent to May
2021 on COVID-19-related rescue and recovery
packages (excluding unallocated European
Union funds). However, most resources havebeen for immediate rescue spending, mostly on
unemployment and worker support programmes,
p a n d e m i c m a n a g e m e n t , a n d h e al t h - c a re

Emissions Gap Report 2021: The Heat Is On

Figure ES.8. COVID-19-related spending per capita across development categories (US$)

Advanced economies
US$11,826
per person

Emerging market and developing economies
US$578per person

services. US$2.25 trillion is considered recovery
spending. Of this, only around 17–19 per cent
(US$390–4 40 billion) is likely to reduce GHG
emissions.
▶

▶

▶

Low- carbon fiscal spending has covered awide range of sectors. Over 500 green rescue
and recovery measures have been introduced
globally. Policies have covered most emerging
and established green industries (figure ES.7).
The range of spending has been notably wider
in advanced economies, with emerging market
and developing economies focusing their green
recovery funds on clean energy generation andnatural capital investments.
International disparities are large in terms of both
total spending and low-carbon spending. Almost
90 per cent of recovery spending is accounted forby seven countries: the Republic of Korea, Spain,
Germany, the United Kingdom, China, France andJapan. The Global Recovery Observatory finds
that, up to May 2021, France, Germany, Canada,
Finland, Norway and Denmark can be classified as‘leaders’ on green recovery, with green spending
as a share of recovery spending ranging from 39
per cent to 75 per cent. The United Kingdom, Spainand Sweden also rank highly, according to Vivid
Economics’ Greenness of Stimulus Index.
Vulnerable nations are being lef t behind.
COVID-19 spending has been far lower in lowincome economies (~US$60 per person) thanadvanced economies (~US$11,800 per person)

Low-income economies
US$57
per person(figure ES.8). Less diversified economies, risingdebt as a percentage of GDP, and corresponding
limited fiscal space have constrained the ability ofemerging economies and low-income countries tomobilize resources.
▶

9.

Without a substantial increase in foreign aid,
the difference in spending between advanced
economies and emerging markets and developing
economies will exacerbate gaps in development
and restrict progress against climate change.
Additionally, without significantly increased
climate finance, emerging markets and developing
economies are likely to become the world’s top GHG
emitters, all while disproportionately suffering theburden of climate change, which has historically
been caused primarily by high-income nations.

Reduction of methane emissions from thefossil fuel, waste and agriculture sectors
can contribute significantly to closing theemissions gap and reduce warming in the
short term.

▶

Methane is the second-most-important GHG in
terms of current anthropogenic climate forcing,and global anthropogenic methane emissions
continue to increase.

▶

With a lifetime of about 12 years, and a global
warming potential (GWP) of approximately 82
over a 20 -year period and 29 over a 100 -year
period, reducing methane emissions represents

XXVII

Emissions Gap Report 2021: The Heat Is On

an important opportunity to slow down the rate ofwarming in the short term, reduce peak warming
during this century and help bridge the emissions
gap between current trajectories and thoseconsistent with the 2°C or 1.5°C temperature goals.
▶

▶

▶

▶

XXVIII

Strong abatement potential exists at net-negativeand low costs (<US$600/tCH 4 ; <~US$20/tCO 2 e
using GWP100), especially in the fossil fuel sector,
even without accounting for the avoided costs ofenvironmental damages. Abatement potential via
technical measures is also large in the waste sector
and to a lesser extent in agriculture, where it will
be difficult to greatly mitigate emissions withoutchanging diets at the global or regional levels.
Available net-negative or low- cost technicalmi tigation measures alone c ould re duc eanthropogenic methane emissions byapproximately 20 per cent by 2030, whereas all
targeted measures could reduce emissions by
about one third. Additional measures, such as
switching from natural gas to renewables, dietarychanges and food waste reduction could add
15 per cent to the 2030 mitigation potential. Thisis consistent with methane reductions in most 2°C
and 1.5°C pathways, which are approximately 34
per cent and 44 per cent, respectively, at the global
level in 2030 compared to 2015.
Current NDCs cover only about one third of themethane reduction required to be consistent with
a 2°C temperature goal, and only about 23 percent of what is needed for the 1.5°C goal. There
are, however, excellent opportunities to include
additional methane reduction measures in NDCs,
as several countries are already demonstrating,for example through actions such as upstreamleak detection and repair in oil and gas systems,
elimination of gas flaring, energy recovery fromlandfill gas, and reducing food waste and loss.
Action is often hampered by the fact that reported
methane emissions are highly uncertain given thelarge number and complexity of emission sources
and the uncertainty over emission factors. Recent
developments in measurement capabilities enable
total emissions rates to be monitored, including
at the facility scale for larger emission sources.
Although these measurements will provide a muchbetter basis for decisive actions, they need to be
used systematically and to become a key elementin preparing national policies.

10.

Carbon markets can deliver real emissions
abatement and drive ambition, but only
when rules are clearly defined, designed toensure that transactions reflect actual
reductions in emissions, and supported byarrangements to track progress and provide
transparency.

▶

Article 6 of the Paris Agreement and international
markets are not a direct source of ambition but
can function as a lever for implementing andunlocking greater ambition. Markets can provide
an oppor tunity for countries, companies andother actors to achieve their emission reduction
goals at lower costs and thereby create roomto enhance their ambition in both the near- andlong term. Particularly, participants with hard-toabate emissions would be enabled to meet their
mitigation goals at lower costs.

▶

From a market-integrity perspective, the optimalsituation would be for NDCs to come withcomprehensive GHG coverage, clearly quantifiable
mitigation goals, and robust accounting, but
NDCs are currently very heterogeneous. This
creates challenges for developing a robustinternational market. The agreed rules need toensure environmental integrity and encourageenhanced ambition. A global market system would
best facilitate progress towards meeting the Paris
goals, if countries are not allowed to capture thebenefits of lower cost without raising ambition, or
if countries that are selling off cheap mitigation
options subsequently ensure deliver y on the
costlier ones.

▶

The use of market mechanisms could haveimportant implications for both mitigation andsustainable development pathways. In addition
to potentially lowering the cost of additional
ambition everywhere, markets could lead to a shift
in capital investment towards selling regions, andin this way affect metrics such as local air quality,
employment and sustainability, and shift costs.
Nevertheless, there is a risk that this could lead to
reduced incentives for technological innovation inbuying regions.

▶

Global modelling studies estimate that if all
NDCs were transformed into tradable emissions
abatement and all countries had economy-widetargets, around 4–5 GtCO 2 e could be traded peryear by 2030. If the savings from more cost-Emissions Gap Report 2021: The Heat Is On

effective global implementation of NDCs wereredeployed towards increased ambition, theemissions reductions planned in current NDCs
could be roughly doubled over the next decadeat no added cost to parties, compared to parties
acting alone to implement their commitments.
▶

These studies indicate the significant theoreticalpotential of carbon markets. For this potential
to be realized, these theoretical findings need to
be translated into real-world policy changes. The
challenge for COP26 negotiations is to decide on
the necessary guidance for article 6 that can launcha global market that is able to gradually expand
and improve as pledges evolve and experiences
are gained.

▶

The number of countries that in their new or
updated NDCs have indicated the planned or
possible use of voluntary cooperative approaches
has almost doubled compared to the previous
NDCs, indicating significantly increased interest.

▶

For markets to play a role in the process towards
net-zero emissions, NDCs should cover all sectors
and gases and have economy-wide quantitative
goals. With narrowing cost differences over time,the volume of trading would likely diminish, while
the transactional value would increase. The market
would increasingly focus on CO 2 removal from theatmosphere.

XXIX

Emissions Gap Report 2021: The Heat Is On

1Introduction

Authors:
Anne Olhoff (UNEP DTU Partnership), John Christensen (CONCITO [Denmark’s climate think tank])

1.1

Context of the Emissions Gap
Report 2021

This twelfth edition of the United Nations Environment
Programme (UNEP) Emissions Gap Report comes during
a year of constant reminders that climate change is notin the distant future. Extreme weather events around theworld – including flooding, droughts, wildfires, hurricanes
and heatwaves – have continuously hit the news headlines.
Thousands of people have been killed or displaced andeconomic losses are measured in the trillions. Bearing
witness to the increasingly clear signs of climate change,
the Intergovernmental Panel on Climate Change (IPCC)
published the first report in its Sixth Assessment cycle
addressing the “Physical Science Basis” in August 2021.
Dubbed a “code red for humanity” by the United Nations
Secretary-General, the IPCC report documents in far greater
detail and with higher certainty than previous assessments
how climate change and extreme events can be attributed
to the build-up of anthropogenic greenhouse gas (GHG)
emissions in the atmosphere. There is a fifty-fifty chancethat global warming will exceed 1.5°C in the next two
decades, and unless there are immediate, rapid and largescale reductions in GHG emissions, limiting warming to 1.5°C
or even 2°C by the end of the century will be beyond reach.
Building on the new evidence from the IPCC, the twentysixth United Nations Climate Change Conference of theParties (COP26) is charged with the growing urgency ofaccelerating global ambition and action on both mitigation
and adaptation. This coincides with an important milestone
in the five-year ambition-raising cycle of the Paris Agreement,
whereby countries were requested to submit new or updated
nationally determined contributions (NDCs) that represent a
progression compared with previous NDCs before COP26.
There is therefore a special focus both in the international
discussions and in this year's Emissions Gap Report on theambition level in the new and updated NDCs.
As the September 2021 version of the NDC Synthesis Reportpublished by the United Nations Framework Convention on
Climate Change (UNFCCC) illustrates, the new and updated
NDCs are insufficient to achieve the temperature goal of theParis Agreement (United Nations Framework Convention

on Climate Change 2021). This Emissions Gap Reportconfirms the findings of the UNFCCC report. It expands theanalysis to consider new or updated NDCs and mitigation
pledges that have been announced for 2030 and assesses
the impacts of these on global emissions, the emissions
gap and projected global warming at the end of the century.
Furthermore, it provides an in-depth assessment of the netzero pledges that an increasing number of countries arecommitting to, including whether 2030 plans set countries
on a clear path towards their longer-term net-zero pledges.

1.2

Focus, approach and structure of
the report

Each year, the Emissions Gap Report provides an updated
assessment of the gap between i) estimated future global
GHG emissions if countries implement their climate
mitigation pledges and ii) the global emission levels fromleast-cost pathways that are aligned with achieving the Paris
Agreement goal of limiting global warming to well below 2°C
and pursuing 1.5°C. This difference between where we will
likely be and where we need to be is now well known as the‘emissions gap’. This year, the new or updated NDCs as well
as officially announced mitigation pledges for 2030, witha cut-off date of 30 September 2021, are included in theassessment.
One of the United Kingdom’s key goals for its COP26
presidency is to secure global net zero by mid-century andkeep 1.5°C within reach (United Nations and United Kingdom
undated). To date, 49 countries (50 parties, including theEuropean Union) have firmly pledged net-zero emission
goals by around mid-century, and a large number of nonstate actors have joined the High-Level Climate Champions
in the Race To Zero campaign that aims to elevate ambition
and mobilize credible climate action among cities, regions,businesses and investors. Given the increasing importanceof and attention to net-zero emission pledges, the report
includes a special chapter on net zero which assesses thetrends in and robustness of these goals, including whether
2030 commitments set countries on a clear path towards
their longer-term net-zero pledges.

1

Emissions Gap Report 2021: The Heat Is On

The report also includes three chapters on opportunities tobridge the emissions gap that are pertinent to the current
global situation and the COP negotiations. First, an updated
assessment is provided on the extent to which COVID-19
fiscal recovery measures are used to accelerate a green
transition. Second, the scope for reducing emissions frommethane, the second largest GHG, to bridge the gap and geton track towards net zero is examined. Finally, the report
looks into a key negotiation issue for COP26: reaching
agreement on how to move forward with article 6 of the Paris
Agreement dealing with cooperative approaches and market
mechanisms. A large number of countries have included theuse of market mechanisms in their NDC implementationplans and are waiting for the modalities to be agreed.
As in previous years, this 2021 Emissions Gap Reporthas been prepared by an international team consisting of
78 leading scientists from 44 expert institutions across
24 countries, assessing all available information, includingthat published in the context of the IPCC reports, as wellas in other recent scientific studies. The transparent andparticipatory assessment process has been overseen
by an experienced steering committee. All chaptershave undergone external review and the assessment
methodology and preliminary findings were made available
to the governments of the countries specifically mentioned

2

in the report in order to provide them with the opportunity tocomment on the findings.
The report is organized into seven chapters, including thisintroduction. Chapter 2 assesses the trends in global GHG
emissions and how they are affected by COVID-19, andprovides a global and G20-member-specific overview ofnew, updated and announced NDCs. Chapter 3 provides
an assessment of net-zero emission pledges. Chapter 4
updates the assessment of the likely emissions gap in2030, based on new or updated NDCs as well as officiallyannounced mitigation pledges for 2030. The chapter thenlooks at the implications of the emissions gap on thefeasibility of achieving the long-term temperature goal of theParis Agreement. Chapter 5 assesses the extent to which
COVID-19 fiscal rescue and recovery measures to date can
support low-carbon or high-carbon development. It also
looks at the disparities between high-income and developing
countries. Chapter 6 assesses the role of methane in the
NDCs and in bridging the emissions gap, and considers
options for cost-effective reductions of the otherwise
growing emissions of methane. Finally, chapter 7 looks at
the potential role of market mechanisms in implementing
NDCs and enhancing future ambitions, and discusses what
is required to make the use of markets environmentallyeffective, transparent and credible.

Emissions Gap Report 2021: The Heat Is On

2

Trends in global emissions, new pledges for 2030 andG20 status and outlook

Lead authors:
Takeshi Kuramochi (NewClimate Institute, Germany), Michel den Elzen (PBL Netherlands Environmental Assessment
Agency, the Netherlands), Taryn Fransen (World Resources Institute, USA), Glen Peters (Centre for International Climate
Research [CICERO], Norway)

Contributing authors:Andrzej Ancygier (Climate Analytics, Germany), Ayşe Ceren Sarı (SHURA, Turkey), Anna Chapman (Climate Analytics,
Australia), Monica Crippa (Joint Research Centre [JRC], Italy), Mengpin Ge (World Resources Institute, USA),
Johannes Gütschow (Potsdam Institute for Climate Impact Research, Germany), Mariana Gutierrez (Iniciativa Climatica,
Mexico), Diego Guizzardi (JRC, Italy), Gahee Han (Solutions For Our Climate, Republic of Korea), Louise Jeffery (NewClimate
Institute, Germany), Kimon Keramidas (JRC, Spain), Caroline Lee (Canadian Institute for Climate Choices, Canada),
Enrique Maurtua Konstantinidis (Fundación Ambiente y Recursos Naturales [FARN], Argentina), Victor Maxwell(Climate Analytics, Australia), Malte Meinshausen (University of Melbourne, Australia), Marilena Muntean (JRC, Italy),
Leonardo Nascimento (NewClimate Institute, Germany), Jos Olivier (PBL Netherlands Environmental Assessment Agency,
the Netherlands), Mark Roelfsema (PBL Netherlands Environmental Assessment Agency, the Netherlands), Efisio Solazzo(JRC, Italy), Hajime Takizawa (Institute for Global Environmental Strategies, Japan), Kentaro Tamura (Institute for Global
Environmental Strategies, Japan), Heleen van Soest (PBL Netherlands Environmental Assessment Agency, the Netherlands),
Jorge Villareal (Iniciativa Climatica, Mexico), Sachi Vohra (The Energy and Resources Institute [TERI], India), Lisa Wijayani(Institute for Essential Services Reform [IESR], Indonesia), William Wills (Eos Estratégia & Sustentabilidade, Brazil),
Ryan Wilson (Climate Analytics, Germany)

2.1

Introduction

This chapter reviews the current status of global greenhousegas (GHG) emissions as well as the outlook for 2030
emissions under new or updated nationally determined
contributions (NDCs) and announced mitigation pledges. It
also reviews progress towards implementing 2030 pledges,
with a special focus on G20 members.1
Section 2.2 provides an overview of current trends intotal global GHG emissions and global carbon dioxide(CO 2) emissions from fossil fuel use and industry-related
sources, considering the impact of COVID-19 on 2020 and
2021 emissions. Section 2.3 presents new or updated
NDCs communicated under the Paris Agreement, as wellas additional pledges for 2030 that are yet to be formallysubmitted as NDCs. It discusses the characteristics ofthese pledges (in aggregate) and assesses their impact

on global and G20 2030 emissions. Section 2.4 presents
G20 members’ pledges, assessing whether and how they
have been updated, along with progress towards theirimplementation. The assessment covers all individual G20
members and regions, except European Union member
states. 2 The cut-off date for the assessments of new or
updated NDCs was set as 30 September 2021.
For this Emissions Gap Report, progress towards achieving
the Cancun Pledges has not been assessed, due to thelarge uncertainty around 2020 emissions as a result of the
COVID-19 pandemic. A more comprehensive assessment on
the achievement of the Cancun Pledges is expected in the
Emissions Gap Report 2022.
All GHG emission figures in this report are expressedusing the 100-year global warming potentials (GWPs) fromthe Intergovernmental Panel on Climate Change (IPCC)

1

The members of the G20 are: Argentina, Australia, Brazil, Canada, China, France, Germany, India, Indonesia, Italy, Japan, Mexico, the Republic of Korea,
the Russian Federation, Saudi Arabia, South Africa, Turkey, the United Kingdom, the United States of America and the European Union.

2

The United Kingdom has left the European Union but was in a transition period until the end of 2020, during which the European Union’s NDC still
applied to the country.

3

Emissions Gap Report 2021: The Heat Is On

Fourth Assessment Report, 3 unless otherwise noted.
In terms of historical emissions data, section 2.2 uses
globally consistent and independent data sets rather thanofficially reported United Nations Framework Convention
on Climate Change (UNFCCC) inventory reports, whereas
sections 2.3 and 2.4 use UNFCCC inventory reports whencomparing historical emissions to individual G20 members’
NDC targets.
The methodology and preliminary findings of this chapter
were made available to the governments of the countries
specifically mentioned to provide them with the opportunity
to comment on the findings.

2.2 Current global emissions: status andtrendsDifferent GHGs play different roles in the changes in total
GHG emissions (figure 2.1). Fossil CO 2 emissions dominate
total GHG emissions including LUC (66 per cent since2010), as well as the growth in GHG emissions. Fossil
CO 2 emissions reached a record 37.9 GtCO 2 in 2019, but
dropped to 36.0 GtCO 2 in 2020. CO 2 emissions from LUC
have constituted 10 per cent of cumulative GHG emissions
since 2010, and can change significantly from year toyear due to climate conditions (Friedlingstein et al. 2020;
Canadell et al. 2021). Estimates in this chapter only consider
the direct effects of LUC and represent the average ofthree bookkeeping models (Friedlingstein et al. 2020).
Furthermore, the estimates assume that 2020 emissions
are similar to the 2010–2019 average, based on preliminary
estimates of fire data. No preliminary estimates are available
for the growth of non-CO 2 emissions in 2020.

At present, there are no estimates available of total global
GHG emissions for 2020. However, the COVID-19 pandemic
led to an unprecedented 5.4 per cent drop in CO 2 emissions
in 2020 (figure 2.1), with a smaller drop in total GHG
emissions expected for the year. From 2010 to 2019, GHG
emissions grew by 1.3 per cent per year on average, bothwith and without land-use change (LUC). GHG emissions
reached a record high of 51.5 gigatons of CO 2 equivalent(GtCO 2 e) in 2019 without LUC emissions and 58.1 GtCO 2 ewhen including LUC 4 (figure 2.1). These 2019 estimatesof global GHG emissions have been downward adjusted
compared with the Emissions Gap Report 2020, as more
complete data have become available.

4

3This change was made to be more in line with the decisions of the twenty-fourth United Nations Climate Change Conference of the Parties (COP24)
held in Katowice, where parties agreed to use GWPs from the IPCC Fifth Assessment Report for reporting reasons. However, a full switch to using
Fifth Assessment Report GWPs in this report is not yet possible as the literature is still not up to date on this decision.

4

The GHG emissions data in this report are based on the Emissions Database for Global Atmospheric Research (EDGAR; Crippa et al. 2021), PBL
Netherlands Environmental Assessment Agency (Olivier and Peters 2021) and LUC from the Global Carbon Project (Friedlingstein et al. 2020). EDGAR
data are available until 2020 for CO 2 , but only until 2018 for non-CO 2 emissions. Non-CO 2 emissions were extrapolated to 2019 based on the Emissions
Gap Report 2020. GWPs were used from the IPCC Fourth Assessment Report. All estimates for 2019 and 2020 should be considered preliminary.

Emissions Gap Report 2021: The Heat Is On

Figure 2.1. Global greenhouse gas emissions from all sources, 1970–2020

Global greenhouse gas emissions (GtCO2e)

60

50

40

30

20

10

20

F-gases

20

N2O

15

20
10

CH4

20

20
05

19
95

LULUCF CO2

2000

Fossil CO2

19
90

19
85

19
80

19
75

19
70

0

2020 data only available for fossil and LULUCF CO2
Notes: LULUCF – land use, land-use change and forestry. EDGAR data were used until 2018 for methane, nitrous oxide and fluorinatedgases, but were extrapolated to 2019 using growth rates from the previous version of EDGAR (published in the Emissions Gap Report 2019).
Sources: EDGAR – Crippa et al. (2021); Olivier and Peters (2021); LUC – Friedlingstein et al. (2020)

As mentioned previously, the COVID-19 pandemic led to an
unprecedented decline in fossil CO 2 emissions in 2020, bothin relative and absolute terms. Global fossil CO 2 emissions
fell 5.4 per cent according to this report’s data set, withother estimates suggesting declines of 5.8 per cent (Global
Carbon Project, updated based on Friedlingstein et al. 2020),
5.8 per cent (excluding cement) (International Energy Agency[IEA] 2021) and 6.3 per cent (BP 2021, excluding cement).
The change in fossil CO 2 emissions varied across countries.
Despite the pandemic, Chinese fossil CO 2 emissions grew
1.3 per cent in 2020, though most other major emitters saw adecline in emissions, including the United States of America(10 per cent), the EU27 (10 per cent), India (6.2 per cent), withinternational transportation (shipping and aviation) droppingby 20 per cent.

A strong rebound in emissions is expected in 2021
(figure 2.2). In April 2021, the International Energy Agency(IEA) estimated a 4.8 per cent increase in emissions in 2021,
after the 5.8 per cent decline in 2020 (IEA 2021). Carbon
Monitor (Liu et al. 2020) estimates near real-time estimatesof daily CO 2 emissions, and based on data from January
to July 2021, global fossil CO 2 emissions are only slightly
lower (1 per cent) than the same period in 2019. Of the major
emitters, only Brazil, China and the Russian Federation show
an increase in emissions from January to July 2021 relative
to 2019. Based on the IEA and Carbon Monitor data, fossil
CO 2 emissions are expected to have a near full recovery in
2021, with emission levels only slightly lower than the record
high in 2019.

5

Emissions Gap Report 2021: The Heat Is On

Figure 2.2. Change in emissions in 2020 and 2021, both relative to 2019 levels due to COVID-19 lockdowns

BrazilChina
EU27FranceGermany
India
Italy
Japan
Rest of world
Russian Federation
Spain
UK
USA

2020/2019

10
%

5%

0%

-5
%

-1
0%

-1
5%

-2
0%

-2
5%

World

2021/2019

Source: Liu et al. (2020)

Despite the large decline in CO 2 emissions in 2020, theconcentration of CO 2 in the atmosphere grew by around
2.3 parts per million, in line with recent trends. It is unlikelythat the reductions in emissions in 2020 will be detectible
in the atmospheric growth rate for three reasons. First,
although emission levels declined, they were still high andaround the same levels as those seen in the early 2010s,
meaning the amount of CO 2 remaining in the atmosphere is
expected to be only marginally less than if emissions grew.
Second, CO 2 is a cumulative pollutant with a long lifetime, sosustained emission reductions are needed to see a change
in the atmospheric signal. Finally, the natural variability ofaround one part per million is far greater than the effectof a 5.4 per cent reduction in emissions. Similar factors
mean that methane and nitrous oxide concentrations also
continued to grow in line with trends, with the increase inthese concentrations in 2020 the highest ever recorded.
The lack of change in atmospheric concentrations despitea record drop in emissions highlights that solving theclimate problem requires rapid and sustained reductions
in emissions.

56

2.3 Trends and implications of the
new or updated NDCs and otherannounced mitigation pledges for2030
2.3.1 Global summary of trends in the new or
updated NDCs
The decision text that accompanied the Paris Agreement(1/CP.21) requested that parties whose intended nationallydetermined contributions (INDCs) contained a time frame
up to 2025 communicate a new NDC, and that parties whose
INDC contained a time frame up to 2030 communicate
or update that contribution by 2020. As at 30 September
2021, 5 121 parties (including the European Union and its 27
member states, which submit a single NDC), representing
around 52 per cent of 2018 global domestic GHG emissions(Climate Watch 2021), had submitted 94 new or updated
NDCs. The NDCs communicated thus far reflect emerging
trends related to the ambition, form, coverage andAll figures presented in section 2.3 reflect new or updated NDCs submitted until 30 September 2021.

Emissions Gap Report 2021: The Heat Is On

conditionality of GHG mitigation pledges, as well as the
expected use of market mechanisms in their achievement.
Effect on 2030 emissions: Of the 94 new or updated NDCs,
just under half (46 NDCs from countries representing
32 per cent of global GHG emissions) would result in lower
2030 emissions relative to the previous NDCs (figure 2.3).
Eighteen per cent (17 NDCs from countries representing

13 per cent of global GHG emissions) had communicated a
new or updated NDC that would not reduce 2030 emissions
relative to the previous NDCs. Thirty-four per cent (32 NDCs
from countries representing 7 per cent of global emissions)
could not be compared with the previous NDCs in terms of2030 emissions, typically due to insufficient information in
the previous NDCs, as transparency has improved in thecurrent NDCs.

Figure 2.3. Effect of new or updated nationally determined contributions on 2030 greenhouse gas emissions relative toprevious nationally determined contributions

New or updated NDC with lower
2030 emissions than prior NDC
No new or updated NDC submitted

New or updated NDC with equal or
higher 2030 emissions than prior NDC
New or updated NDC not comparable
to prior NDC

Source: Climate Watch (2021)

Pledge form: Of the new or updated NDCs, more (89 percent) have GHG targets than before (75 per cent).6 Thesecomprise several types of GHG targets, including base-yeartargets (commitments to reduce or control the increase inemissions by a specified amount relative to a base year)
and baseline scenario targets (commitments to reduce
emissions by a specified amount relative to a projected
emissions baseline scenario), among other formulations.
Base-year targets typically (though not always) result inemissions decreasing over time relative to historical levels,
whereas baseline scenario targets are typically (though notalways) formulated to allow absolute emissions to continue
to grow. The form of GHG targets in new or updated NDCs
evolved relative to the previous round, with a slightly larger
share of NDCs now setting base-year targets (from 19 per

6cent to 28 per cent of NDCs). Most countries adopting a
GHG target for the first time in their new or updated NDC
adopted a baseline scenario target.
Sector and gas coverage: GHG targets can be formulated
to cover a country’s entire economy or only a subset ofit. Targets with full coverage include the energy, industrial
process and product use, waste and land sectors, as well
as CO 2 , methane, nitrous oxide, hydrofluorocarbons (HFCs),
perfluorochemicals (PFCs), sulfur hexafluoride and nitrogen
trifluoride. The GHG targets in the current round of NDCs
are only marginally more comprehensive in terms of sector
and gas coverage than in the previous round. Of the new or
updated NDCs, 19 per cent had full sector and gas coverage,up from 14 per cent in those countries’ first NDCs. While

These figures include only those countries that have submitted new or updated NDCs.

7

Emissions Gap Report 2021: The Heat Is On

seven countries improved their NDCs from partial coverage
to full or nearly full coverage, three countries downgradedtheir NDCs from nearly full coverage to partial coverage.
Conditionality: Some parties have submitted NDCs thatare entirely or partially conditional on factors such as
international support (e.g. finance or technology transfer),
while others have submitted NDCs that are not conditional.
This round of NDCs includes more unconditional
elements than the last round, with 26 per cent completely
unconditional, up from 24 per cent in countries’ firstcontributions. This was largely due to countries making any
mixed conditional and unconditional elements completely
unconditional in their new or updated NDCs. Likewise, theshare of completely conditional NDCs fell from 31 per centto 18 per cent.
Finally, parties are increasingly recognizing gender
integration as a means to enhance the ambition andeffectiveness of their climate action in their new or updated
NDCs (United Nations Framework Convention on Climate
Change [UNFCCC] 2021).

2.3.2 Impacts on GHG emissions by 2030 at the
global and G20 levels, considering new or updated
NDCs and announced mitigation pledges
This section quantifies the impacts of the new or updated
NDCs and announced mitigation pledges on global 2030
emissions, relative to the previous NDCs. The analysis isbased on the difference in projected GHG emissions by
2030 under the full implementation of the new or updated
NDC submissions and announced pledges compared withthe previous NDCs. The data are from five model groups andtwo open-source tools.7, 8Aggregate impact on global GHG emissions in 2030
The analysis shows that the aggregate impact of the
new or updated unconditional NDCs is estimated tolead to a reduction in 2030 global GHG emissions ofabout 2.9 GtCO 2 e, compared with the previous NDCs
(figure 2.4). This estimate includes reductions of around
0.3 GtCO 2 e resulting from other factors, including
lower projections of international aviation and shipping
emissions, and adjustments of countries that are projected
to overachieve their NDC targets. If the announced pledgesof China, Japan and the Republic of Korea are included,
this reduction increases to 4.1 GtCO 2 e. For the conditionaltargets, these reductions are 2.8 GtCO 2 e and 4.0 GtCO 2 e,
respectively.

8

7

Climate Action Tracker (2021a; 2021b); Joint Research Centre with the Prospective Outlook on Long-term Energy Systems (POLES) model (Joint
Research Centre 2021); PBL Netherlands Environmental Assessment Agency with the Integrated Model to Assess the Global Environment (IMAGE)
model (den Elzen et al. 2021, in preparation; Nascimento et al. 2021). The two open-source tools that provide NDC emissions projections for many
countries are: Climate Resource (Meinshausen et al. 2021) and the World Resources Institute’s Climate Watch (2021). All GHG emissions projectionsof the Climate Action Tracker and Climate Resource exclude LULUCF.

8

The following data sources have been used to assess announced pledges that have not yet been formally submitted: Climate Action Tracker, PBL
and the Joint Research Centre. Climate Action Tracker accounts for the impact of the announcements of China and Japan, Joint Research Centre for
China and Japan, and PBL for the impact of China, Japan and the Republic of Korea.

Emissions Gap Report 2021: The Heat Is On

Figure 2.4. Impact of 2030 pledges (nationally determined contributions and other announced pledges as at 30 September2021) on 2030 global emissions compared with previous nationally determined contribution submissions
500

0
-500

MtCO2e

-1000
-1500
-2000
-2500
-3000
-3500
-4000

Increased emissions

Total

Japan

Republic of Korea

China

Other factors

USA

Non-G20

TurkeyReduced emissions

Impact of announced pledges

G20 members
Taking a closer look at the G20 members, the combined
impact of submitted NDCs and announced GHG reduction
targets for 2030 is an annual reduction of about 3 GtCO 2 ecompared with the previous NDCs. Six G20 members
have formally submitted updated NDCs with enhanced
GHG mitigation pledges: Argentina, Canada, the EU27
(counting the EU27 and its three individual G20 member
states France, Germany and Italy as one), South Africa, theUnited Kingdom and the United States of America – all ofwhich entail reduced emissions in 2030 of about 2.1 GtCO 2 ecompared with previous NDCs. Two G20 members (Brazil
and Mexico) have submitted targets that lead to an increasein emissions of 0.3 GtCO 2 e, bringing the net reduction in
global GHG emissions of new or updated NDCs submitted
by G20 members to 1.8 GtCO 2 e annually by 2030. In addition,
China, Japan and the Republic of Korea have announced
enhanced pledges that result in annual reductions of about
1.2 GtCO 2 e, but have not yet formally communicated themto the UNFCCC. The largest reductions come from theUnited States of America, the EU27, the United Kingdom,
Argentina and Canada (submitted), and China and Japan(announced). Two G20 members (Australia and Indonesia)
have submitted NDC targets, which are assessed not to leadto an additional reduction relative to the previous NDCs.
One G20 member (the Russian Federation) has submitted
an NDC that improves upon its previous NDC, but still does

South Africa

Saudi Arabia

MexicoRussian Federation

India

Indonesia

UK

EU27

CanadaBrazilAustralia

Argentina-4500

Total impact

not go beyond its current policies and another three G20
members (India, Saudi Arabia and Turkey) have not yet
submitted a new or updated NDC (table 2.1).
Non-G20 members
In comparison, the aggregate impact of the new or updated
NDC submissions for the non-G20 members is an annual
reduction of about 0.8 GtCO 2 e by 2030.
Other factors
Finally, additional reductions of around 0.3 GtCO 2 e comefrom the decreased international aviation and shipping
emissions projections, and from countries that are projected
to overachieve their NDC targets. As explained previously,
for some countries, NDC emission levels are expected to
be above the estimated current policies scenario, with the
projections of the current policies scenario assumed for the
global emissions estimate. Due to the impact on COVID-19
on GHG emissions projections under the current policies
scenario, the emissions projections of many countries havelowered. This means that a larger number of countries are
expected to overachieve their NDC targets, in particular India,
the Russian Federation and Turkey, which lowers global GHG
emissions. In addition, the methodology of the underlying
models may have also been updated, which could lead tochanges in global emissions estimates between scenarios.

9Emissions Gap Report 2021: The Heat Is On

Table 2.1. Summary of greenhouse gas mitigation pledges in previous and new or updated nationally determined
contributions by G20 members
G20 member

Original NDC

New or updated 2030
pledgeChange in 2030
emissions relative tooriginal NDC Basedon modelling studies(median and range)

G20 members that have submitted new or updated NDCs

9

10Argentina

Cap 2030 net emissions at 483
megatons of CO 2 equivalent (MtCO 2 e)
(unconditional) and 369 MtCO 2 e(conditional)

Cap 2030 net emissions
at 359 MtCO 2 e(unconditional)-0.12 GtCO 2 e(range: -0.11 – -0.13)

Australia

Reduce GHG emissions by 26–28 per centfrom 2005 levels by 2030*

Reduce GHG emissions by
26–28 per cent from 2005
levels by 2030*

No change

BrazilReduce GHG emissions by 37 percent from 2005 levels by 2025 and(indicatively) 43 per cent from 2005 levels
by 2030

Reduce GHG emissions
by 43 per cent from 2005
levels by 2030 9

0.3 GtCO 2 e(range: 0.15–0.4)

CanadaReduce GHG emissions by 30 per centfrom 2005 levels by 2030

Emissions 40–45 per centbelow 2005 levels by 2030

-0.09 GtCO 2 e(range: -0.08 – -0.1)

EU27

Reduce GHG emissions by at least 40 per
cent from 1990 levels by 2030 (appliedoriginally to EU28 collectively)

Reduce net GHG emissions
by at least 55 per centfrom 1990 levels by 2030

-0.6 GtCO 2 e(range: -0.5 – -0.7)

Indonesia

Reduce GHG emissions by 29 percent (unconditional) and 41 per cent(conditional) relative to business as usual(BAU) by 2030

Reduce GHG emissions by
29 per cent (unconditional)
and 41 per cent(conditional) relative to
BAU by 2030

No change

MexicoReduce GHG emissions by 22 percent (unconditional) and 36 per cent(conditional) from BAU by 2030

Reduce GHG emissions by
22 per cent (unconditional)
and 36 per cent(conditional) from BAU by
2030

Marginal increase
due to change in BAU
scenario

RussianFederation

Limit 2030 emissions to 70–75 per cent of1990 level

Limit 2030 emissions to 70
per cent of 1990 levels

Reduced, but thetarget still results inhigher emissions thanthe current policy
projection

South Africa

Limit 2025–2030 emissions to 398– 614
MtCO 2 eLimit 2030 emissions to
350–420 MtCO 2 e

ReducedThe updated NDC leads to an absolute increase in emissions. Both NDCs present the same reduction target of 43 per cent by 2030 below 2005
emission levels. Brazil’s NDC emissions (and therefore the absolute emissions in the NDC scenario) vary a great deal due to revisions of the 2005
base year. The country’s second and third inventory reports and Fourth National Communication (its latest) give different values. The first NDC refers
to the second inventory report, while the updated NDC cites the 2005 base year emissions of the third inventory report (Fifth Assessment Review
metrics), but also specifies that “information on emissions in 2005 and reference values may be updated and recalculated due to methodologicalimprovements applicable to the inventories” (Brazil 2020).

Emissions Gap Report 2021: The Heat Is On

United Kingdom

Contribution to EU28-wide emissions
target: reduction target of at least 40 per
cent

Reduce GHG emissions byat least 68 per cent from1990 levels by 2030

-0.17 GtCO 2 e(range: -0.1 – -0.2)

United States ofAmerica

Reduce GHG emissions by 26–28 per centfrom 2005 levels by 2025 10

Reduce GHG emissions by
50–52 per cent from 2005
levels by 2030

-0.85 GtCO 2 e(range: -0.8 – -0.9) 11

G20 members that have announced mitigation pledges for 2030
China

Peak CO 2 emissions around 2030
Reduce CO 2 /gross domestic product(GDP) by 60–65 per cent from 2005 levels
by 2030
Increase the share of non-fossil fuels inprimary energy consumption to around 20
per cent by 2030
Increase forest stock volume by around
4.5 billion m3 by 2030

Peak CO 2 emissions before
2030-0.8 GtCO 2 e(range: -0.5 – -1.2)

Reduce CO 2 /GDP by 65 percent from 2005 levels by
2030
Increase the share of
non-fossil fuels in primaryenergy consumption toaround 25 per cent by
2030
Increase forest stock
volume by around 6 billion
cubic metres in 2030
Increase the installedcapacity of wind and solar
power to 1,200 GW by
2030

Japan

Reduce GHG emissions by 26 per centfrom 2013 levels by 2030

Reduce GHG emissions
by 46 per cent from fiscal
year 2013 levels by fiscal
year 2030, with efforts to
reduce by 50 per cent-0.27 GtCO 2 e(range: -0.17 – -0.32)

Republic of
Korea

Reduce GHG emissions by 37 per centfrom BAU by 2030

Reduce GHG emissions
by 35 per cent from 2018
levels by 2030**

Reduced**G20 members that have not yet submitted new or updated NDCs or announced pledges
India

Reduce emissions/GDP by 33–35 per centfrom 2005 levels by 2030

N/A

N/A

Increase the share of non-fossil fuels inprimary electricity production to 40 per
cent (conditional)
Saudi Arabia

Annually abate up to 130 MtCO 2 e by 2030

N/A

N/A

TurkeyReduce GHG emissions by up to 21 percent from BAU by 2030

N/A

N/A

Notes: *Australia’s original NDC was ‘to be developed into an emissions budget’ over the 2021–2030 period. The updated NDC of December
2020 provided an indicative emissions budget of 4,832–4,764 MtCO 2 e.
**On 31 August 2021, the National Assembly passed the Framework Act on Carbon Neutrality, which outlines the new 2030 target (Republicof Korea, Ministry of Environment 2021). There is no study available yet that compares the ambition of the new 2030 target with theprevious NDC.
Sources: Climate Watch (2021)

10 For comparison with the updated NDC, modelling studies interpolate the previous 2025 and 2050 targets (80 per cent from 2005 levels).
11 Climate Action Tracker (2021a) also reports the calculated impact relative to the current policies scenario. As the withdrawal of the United States ofAmerica from the Paris Agreement took effect on 4 November 2020, the country no longer had an official NDC in 2020. The calculated impact of the
updated NDC relative to the current policies scenario would therefore be a reduction of about 2.0 GtCO 2e.

11

Emissions Gap Report 2021: The Heat Is On

2.4 Assessment of G20 members’
progress towards NDCs andmitigation pledges for 2030
This section assesses the progress of G20 members
towards their previous NDC targets and indicates progress
towards new, updated or announced 2030 targets basedon emissions projections. GHG emissions projections
were compiled and reviewed to assess the emission levels
expected for G20 members under existing policies, i.e. thecurrent policies scenario,12 and whether members are likely
to meet their respective emission reduction targets for 2030.
Projections of the current policies scenario assume thatno additional mitigation policies and measures are taken
beyond those adopted and/or implemented as of a certain
cut-off date (den Elzen et al. 2019). This report’s assessment
is based on ‘point-in-time’ emissions projections in the NDC
target year.

2.4.1 Methods and limitations
Current policies scenario projections were comparedagainst the original unconditional NDCs at the time of
publication of the Emissions Gap Report 2020 (November2020), as presented in table 2.1. This assessment follows
the methodology of den Elzen et al. (2019) to enable arobust comparison of projections published by independent
research institutions. European Union member states areassessed as the EU27 (and not individually), with the United
Kingdom now assessed separately. Official assessments
published by national governments were compared withindependent assessments. All data sources are presented
in appendix A (available online). Policy cut-off dates ranged
from 2017 to 2021 across studies. The progress assessment
was based on emissions figures including land use, land-use
change and forestry (LULUCF; see appendix A on how theemissions projections excluding LULUCF were adjusted).
Recently published emissions projections for the current
policies scenario and NDC scenario were collected fromindependent studies and considered. As at October 2021, only
a few of the institutions regularly publishing national-level
CO 2 and GHG emissions projections for the current policies
scenario had released updates that considered the potential
impact of COVID-19. Annually published global studies, suchas Climate Action Tracker (2021b), Joint Research Centreof the European Commission (Joint Research Centre 2021)
and PBL Netherlands Environmental Assessment Agency(Nascimento et al. 2021; PBL Netherlands Environmental
Assessment Agency 2021), as well as national studies, suchas the Rhodium Group study for the United States of America(Pitt et al. 2021), all include the impact of COVID-19 andrecent policies. For these studies, the progress assessment

used NDC target emission estimates from their previous
updates (used in the Emissions Gap Report 2020).
Other recent studies included several new national model
scenarios from Fragkos et al. (2021) and the COMMIT13
scenario database (International Institute for Applied
Systems Analysis [IIASA] 2021; van Soest et al. 2021) for
Australia, China (two national studies), the EU27 and theUnited States of America. These studies updated some 2020
national model scenario projections from the European
Horizon 2020 Linking Climate and Development Policies –Leveraging International Networks and Knowledge Sharing(CD-LINKS) project (Roelfsema et al. 2020). However, it
should be noted that these scenarios did not include theimpact of COVID-19. After examining the projections fromthe studies collected, a number of pre-2020 studies were
excluded whose 2020 emission estimates were more than
10 per cent higher than the highest estimates of the threestudies published in 2021 that considered the impact of
COVID-19 and recent policies (Climate Action Tracker 2021b;
Joint Research Centre 2021; Nascimento et al. 2021).
Up-to-date official emissions projections publishedsince November 2020 were collected from various
sources, including countries’ recently published national
communications and biennial update reports, and othernational government reports (see appendix A). Suchinformation included annually updated projections madeby the Australian and Canadian governments (Australia,
Department of Industry, Science, Energy and Resources
2020; Canada, Environment and Climate Change
Canada 2021).
The most important limitation for the 2021 assessment
is the impact of the COVID-19 pandemic on the current
policies scenario projections. As at September 2021, several
recent projections had either been published or preparedprior to the pandemic, and therefore did not account for its
potentially significant impact on emission trends in 2020
and 2021, and in the period until 2030. Other important
limitations are similar to those of previous Emissions Gap
Reports (see appendix A).

2.4.2 G20 progress towards previous NDC targets
and indications of progress towards new,updated or announced targets for 2030
Collectively, the G20 members are projected to fall shortof their new or updated unconditional NDCs and otherannounced mitigation pledges for 2030. Similarly, G20
members are projected to collectively fall short of theirprevious unconditional NDCs (as at November 2020) by
1.1 GtCO 2 e per year, if the unconditional NDCs of the three
G20 members that are projected to significantly overachieve

12 Current policy scenario projections assume that no additional mitigation action is taken beyond current policies, even if it results in NDC targets
not being achieved or being overachieved (United Nations Environment Programme [UNEP] 2015; den Elzen et al. 2019). Current policies scenario
projections reflect all adopted and implemented policies, which for the purpose of this report are defined as legislative decisions, executive orders
or their equivalent. This implies that officially announced plans or strategies alone would not qualify, while individual executive orders to implement
such plans or strategies would qualify.
13 COMMIT – Climate policy assessment and mitigation modeling to integrate national and global transition pathways.

12

Emissions Gap Report 2021: The Heat Is On

their targets (India, the Russian Federation and Turkey; seetable 2.2) are substituted with current policies scenario
projections. However, the G20 members are collectively
expected to slightly overachieve their previous unconditional
NDCs by about 0.3 GtCO 2 e per year by 2030, based on
scenario projections by independent studies.
Table 2.2 shows the progress of G20 members towards theirprevious NDC targets as of November 2020, organized by thestatus and assessment of their new or updated NDC targets
and other announced 2030 targets submitted or announced
thereafter. Ten of 1714 G20 members are likely to achieve
their unconditional NDC targets based on previous or first
NDC submissions under current policies (i.e. Argentina,
China, the EU27, India, Japan, the Russian Federation, Saudi

Arabia, South Africa, Turkey and the United Kingdom – as aformer European Union member state; see table 2.2). Three
G20 members (India, the Russian Federation and Turkey)
are projected to be at least 15 per cent lower than theirprevious unconditional emission target levels and therefore
have significant room to increase the ambition of their NDCs
(figure 2.5). Central estimates of emissions projections for2030 under current policies were lower than those of the
Emissions Gap Report 2020 for all previously mentioned
G20 members, with the exception of Argentina, whose
estimate remained largely unchanged. For example, for the
EU27 and South Africa, current projections are roughly 10
per cent and 20 per cent lower than the projections of lastyear’s assessment, respectively, due to enhanced policies
and the impact of COVID-19.

14 An assessment of individual European Union member states was not conducted.

13

Emissions Gap Report 2021: The Heat Is On

Table 2.2. Assessment of progress towards achieving the previous unconditional nationally determined contribution targets
for G20 members under current policies based on independent studies mainly published after the COVID-19 outbreak
Projected progress towards the previous NDC target[x studies meet the target/out of y studies]

Status of
NDC orannounced
targetAchieve previous target(indicated by +, if
overachieved by more than
15 per cent)Miss previous target

Submitted
stronger target

Argentina [3/3], EU27 [inEmissions Gap Report2020 for EU27+UK; 1/3,
one within reach],1,2 RussianFederation+ [4/5],1 South
Africa [3/3], UK (formerly
part of the EU)

USA [0/5], Canada [1/3]

Announced
stronger target

China [4/6], Japan [3/3]

Republic of Korea [0/3] 3

No new target
submitted

India+ [4/6], Saudi Arabia[2/2], Turkey + [3/3]

Submitted
equivalent or
weaker target

Australia [1/4], Brazil [1/4, one
within reach], Mexico [0/3]

Uncertain

Indonesia [0/3, two
within reach]

Notes: See appendix A for the list of studies reviewed. The number of independent studies that project a country to meet its previous or
first NDC target were compared with the total number of studies and are indicated in square brackets. ‘Within reach’ indicates that only
the lower bound estimate of the current policies scenario is within the NDC target range.
1.
Current policies scenario projections were also examined from official publications. The number of official publications that projected
countries would achieve their point-in-time NDC target were: Australia: 0 of 1, Canada: 0 of 1, EU27: 0 of 1, Russian Federation: 0 of
1 and the United Kingdom: 0 of 1.
2.

The EU Reference Scenario was used for the EU27, which assumes full implementation of the national energy and climate plansby European Union member states and sees European Union emissions reduce by around 43 per cent below 1990 levels by 2030
(European Commission 2021). Including net removals from LULUCF increases the reduction to 45 per cent. This baseline scenario
indicates that additional effort would be required to meet the European Union’s current 2030 energy-efficiency target, though its
current 2030 renewable energy target would be met. Additional measures for member states are being prepared to fully implement
national energy and climate plans submitted in 2020 (European Commission 2020).

3.

The Republic of Korea’s Emissions Trading Scheme (K-ETS) is an instrument used to fully achieve the country’s NDC target and covers
about 70 per cent of its GHG emissions. Among the three independent studies, only one (PBL Netherlands Environmental Assessment
Agency) explicitly quantified the impact of the K-ETS up to 2025 based on the Master Plans for K-ETS Phase III (2021–2025) andPhase IV (2026–2030) and the Phase III National Allowances Allocation Plan. This partially explains why the studies project that theRepublic of Korea will miss its NDC target under current policies.

For China, four out of six independent studies projectedthat the country would achieve its original NDC target.
However, since five of the six studies reviewed only
provided a single NDC target value for 2030 – despite
China’s NDC containing multiple targets, which are partly
dependent on GDP growth rates – it was not possible toanalyse in detail which targets would likely be met or
overachieved. The long-term impacts of COVID-19 on GHG
emissions were also highly uncertain, especially given thefact that China’s fossil CO 2 emissions rebounded strongly
in the second half of 2020 and in 2021 (section 2.2).

14This stronger-than-expected rebound was not consideredin China’s latest emissions projections that estimated theimpact of COVID-19 (Climate Action Tracker (2021b), Joint
Research Centre (2021) and PBL Netherlands Environmental
Assessment Agency (2021)).
Six G20 members’ GHG emissions were projected to fallshort and therefore require further action of varying degree tomeet their previous (or original) unconditional NDC targets.
These G20 members are Australia, Brazil, Canada, Mexico,
the Republic of Korea and the United States of America.

Emissions Gap Report 2021: The Heat Is On▶

▶

For Australia, official projections showed that it will
fall short of achieving its point-in-time target of 26–
28 per cent by 2030 with implemented measures.
Australia is also projected to miss its emissions
budget targets for 2021–2030 without relying on past
overachievement (Australia, Department of Industry,
Science, Energy and Resources 2020). However, theofficial projections also indicated that Australia would
achieve its point-in-time NDC target if its Technology
Investment Roadmap is fully implemented (‘High
technology’ scenario) (Australia, Department ofIndustry, Science, Energy and Resources 2020).
For Canada, official projections indicated that if its
strengthened climate plan, A Healthy Environment
and a Healthy Economy, introduced in December
2020, is fully implemented, its GHG emissions would
be reduced by 31 per cent below 2005 levels, thus
overachieving its previous NDC target of 30 per centbelow 2005 levels (Canada, Environment and Climate
Change Canada 2021).

▶

For Mexico, all three independent studies reviewed
in this assessment showed a (minor) increase in
2030 emissions projections compared with previous
assessments included in the Emissions Gap Report
2020, finding that the country would narrowly miss its
original NDC target.

▶

The United States of America has returned to theParis Agreement and reversed many policies of the
Trump Administration that would have led to increased
emissions. The central estimate for the country’s
2030 emissions in this year’s assessment decreased
by about 0.5 GtCO 2 e/year (about 10 per cent). The
main reasons for this result include the exclusion of
two projections developed with a 2017 cut-off date
for policies (Chai et al. 2017; Roelfsema et al. 2020),
which were replaced with one updated national model
projection of the COMMIT scenario database, and theinclusion of projections that quantified the potential
impact of the COVID-19 pandemic on emissions
in 2020 and beyond, and to a lesser extent on thequantified impact of the reversal of the previous
Administration’s policies.

It is worth noting that Canada and the United States ofAmerica have strengthened their NDC targets, though
independent studies suggest that they are not on track tomeet their earlier NDC targets with implemented policies.
Although positive trends have been observed as described
previously, these two countries need to make significant
additional efforts to meet their new NDC targets.
Independent studies either do not agree or are inconclusive
on whether Indonesia is on track to meet its unconditional
NDCs. This is mainly due to the uncertainty of LULUCF
emissions projections as a result of peat fires. The central
estimate for 2030 emissions in this year’s assessment are
higher than that of the 2020 assessment, partially due to themajor revision of LULUCF emissions data and projections.
The aggregate emissions for G20 members in 2030 undercurrent policies are projected to be about 2 GtCO 2 e lower
than that of the 2020 assessment. Consideration of 2020
emission reductions and the long-term impact of COVID-19
on the global economy has contributed significantly to thelower emissions projections. Another key factor behindthese estimated lower emissions is the impact of policies
adopted by G20 members in recent years, which will affecttheir progress towards achieving their NDC targets.15 A listof key policy measures that may have significant direct
impacts on future GHG emissions adopted in 2020 and 2021
are presented in appendix A. Many of these policies wereadopted after the publication of the scenario studies reviewed
in this section. Although there have been many positive
developments, there have also been several negative ones,
such as the implementation of fossil fuel extraction projects
and coal-fired power plant construction plans, as well as therollback of environmental regulations during the pandemic.
Based on the central estimates of independent studies,
several G20 members, namely Argentina, Brazil, China, India,
Indonesia, Mexico, the Russian Federation and Saudi Arabia,
are expected to emit more emissions in 2030 than they did
in 2010 under implemented policies. Figure 2.5 provides amore detailed overview of G20 members’ projected GHG
emissions under various scenarios, which are also comparedwith historical emissions.

15 There are several other factors for the lower emissions projections, including revisions in GHG inventory data and changes in emissions scenario
methodologies, along with other underlying assumptions.

15

Emissions Gap Report 2021: The Heat Is On

Figure 2.5. Greenhouse gas emissions (all gases and sectors, including land use, land-use change and forestry) of the G20
and its individual members by 2030 under the current policies scenario, previous nationally determined contributions andnew, updated or announced pledges compared with historical emissions
Figure 2.5a.

18
Emissions (GtCO2e/yr)

16
14
12
10
8
6
4
2
0

China

EU27

India

USA

Figure 2.5b.

3 GtCO2eEmissions (GtCO2e/yr)

3.0

3 GtCO2e

2.5
2.0
1.5
1.0
0.5

UK

y
rk
e
Tu

o

bl
Ko ic o
re f
a
Fe Ru
de ss
ra ia
tio n
n
Sa
ud
iA
ra
bi
a
So
ut
h
Af
r ic
a

Re

pu

M

ex
ic

n
Ja
pa

es
ia
on

In
d

na
da
Ca

az
il
Br

lia
st
ra
Au

Ar
ge

nt

in
a

0.0

Historical data from national inventory report for 2010
Unconditional NDC (previous)

Current policies 2030 (independent studies)

Unconditional NDC (new or updated)

Announced pledge

Notes: For current policies scenario projections, estimates based on independent studies are presented. For NDCs, official values (adjusted
to Fourth Assessment Report GWPs) are presented where available. For reporting reasons, the emissions projections for China, the EU27,
India and the United States of America are shown in figure 2.5a, and the other countries shown in figure 2.5b, using two different verticalaxes. See appendix A for details. For the United States of America’s previous NDC, the average of 2030 estimates from two studies areshown (Joint Research Centre 2021; Climate Action Tracker 2021b). For China and South Africa, the estimated emissions under the
new 2030 announced targets are based on Climate Action Tracker and PBL Netherlands Environmental Assessment Agency studies(Nascimento et al. 2021; Climate Action Tracker 2021b). Estimates for China, Japan and the Republic of Korea use announced targets.

To supplement the findings presented above, figure 2.6
presents per capita GHG emissions under the current policies
scenario, NDC targets and other announced 2030 pledges
as at 30 September 2021, as well as the 2010 historicalestimates for the 17 G20 members (counting the EU27 andits three individual G20 member states as one). In 2030, theaverage per capita emissions of G20 members under latest

16

NDCs and other announced 2030 pledges are projected tobe slightly lower (7 tCO 2 e) than under the current policies
scenario (7.4 tCO 2 e) and the previous NDCs (7.2 tCO 2 e).
However, compared with 2010 levels, average emissions
are not expected to be lower and as the figure illustrates
they are still far off the median estimates consistent with
2°C and 1.5°C scenarios by 2050, which are 1.9 tCO 2 e (tenthEmissions Gap Report 2021: The Heat Is On

and ninetieth percentile range: 1.2–2.3 tCO 2 e) and 0.6 tCO 2 e(0.3–1.1 tCO 2 e), respectively.16 Per capita emissions varysignificantly across G20 members, with India’s emissions
about half the G20 average for example, and Saudi Arabia’s
three times greater. The EU27 and the United Kingdom
perform well in both absolute and per capita emission
levels by 2030 and their reduction rates compared with2010 levels. Australia and South Africa are also projected

to reduce their per capita emissions by more than one third
between 2010 and 2030 under current policies. Mexico
also performs well in terms of its projected development of
per capita emissions under both current policies and NDC
scenarios. Per capita emissions under current unconditional
NDC targets are projected to increase between 2010 and
2030 for seven G20 members.

Figure 2.6. Per capita greenhouse gas emissions of the G20 and its individual members by 2030 under nationally determined
contributions and other announced 2030 pledges as at 30 September 2021, current policies scenario projections fromindependent studies mainly published after the COVID-19 outbreak, and 2010 historical levels

Per capita emissions (tCO2e/capita)

30
25
20
15
10
5
1.6 tCO2e/capita

0

2010

Current policies

Unconditional NDC

India

UK

EU27

South Africa

MexicoJapan

BrazilIndonesia

Argentina

USA

China

Republic of Korea

CanadaTurkeyRussian Federation

Australia

Saudi Arabia

G20

0.9 tCO2e/capita

Announced pledge

Levels of per capita emissions consistent with 2°C and 1.5°C scenarios by 2050

Notes: i) Figures include LULUCF. ii) Central estimates are a median value when five or more studies were available, otherwise they are
average values. iii) Data on historical and projected (medium fertility variant) population per country are taken from the 2019 Revision ofWorld Population Prospects (United Nations Department of Economics and Social Affairs [UN DESA], Population Division 2019). iv) The
figures presented here may not exactly match official data due to the differences in data sources. v) G20 members are sorted in decreasingorder of NDC emissions projections. vi) To estimate G20 total emissions for the NDC and announced 2030 pledges scenario, emissions
projections under the current policies scenario were used for India, the Russian Federation and Turkey.

16 Estimated based on emission estimates from the IPCC Special Report on global warming of 1.5°C and United Nations population projections. The
medium fertility variant was used (UN DESA, Population Division 2019).

17

Emissions Gap Report 2021: The Heat Is On

3

Net-zero emissions targets

Lead authors:
Joeri Rogelj (Imperial College London, UK; International Institute for Applied Systems Analysis, Austria), Stephen M. Smith(Oxford University, UK), Sha Yu (Pacific Northwest National Laboratory, USA)

Contributing authors:
Jiyong Eom (Korea Advanced Institute of Science and Technology [KAIST], Republic of Korea), Taryn Fransen (World
Resources Institute, USA), Claire Fyson (Climate Analytics, Germany), Thomas Hale (Oxford University, UK), Frederic Hans
(NewClimate Institute, Germany), John Lang (Energy & Climate Intelligence Unit, UK), Silke Mooldijk (NewClimate Institute,
Germany), Katie Ross (World Resources Institute, USA)

3.1

Introduction

Achieving global net zero in line with the Paris Agreement
requires rapid and deep reductions in global greenhousegas (GHG) emissions, and the scaling-up of removals.
Emissions reductions are essential to keep the challengeof halting global warming as manageable as possible.
Removals are used to balance out emissions from activities
for which we have not reduced emissions to zero – hence
the concept of ‘net zero’ – as well as to deliver net-negative
global emissions that can gradually reverse the warming
already caused.
One promising development is the announcement of longterm net-zero emissions pledges by an increasing number ofcountries that currently account for more than half of global
emissions. However, these pledges have large ambiguities
and few of the latest nationally determined contributions(NDCs) put countries on a clear path towards their net-zeropledges. There is an urgent need to back net-zero pledges
up with near-term targets and actions that give confidence
that net-zero emissions can ultimately be achieved.
This chapter looks at how net-zero emissions targets haveemerged from the scientific understanding of the climate
system and the goals of the Paris Agreement (section 3.2).
It sets out the considerations when translating net zero froma global scientific concept to national policy targets (section3.3), and assesses current targets in terms of their ambition,scope, transparency and consistency with near-term plans
and actions (sections 3.4 and 3.5).

3.2 The science of net-zero emissions
targets
Net-zero emissions is a state where the sum of allanthropogenic emissions and removals is zero.

18

Net-zero emissions targets are being defined in a variety
of ways – the most important aspect from a global
geophysical perspective being whether they cover all GHGs
or carbon dioxide (CO 2) only (Rogelj et al. 2015). Net-zero
GHG emissions are achieved when total aggregate GHG
emissions over a given period are equal to an equivalentamount of aggregate GHG removal (Intergovernmental
Panel on Climate Change [IPCC] 2021b). Net-zero CO 2
emissions are defined similarly but for CO 2 only.
Other terms such as ‘carbon neutrality’ and ‘climate
neutrality’ are often used interchangeably for net-zero CO 2
and net-zero GHG emissions, respectively. However, as their
meaning can differ depending on context and language,
further specification is needed to avoid ambiguity (seeglossary for various definitions of net-zero terms).

3.2.1 Net-zero CO2 emissions stabilize global
warming, whereas net-zero GHG emissions
result in a peak and decline in global warming
As a concept, net-zero emissions were introduced well over a
decade ago as a way of thinking about minimizing society’s
impact on the climate and the environment (United Nations
Environment Programme [UNEP] 2008; Worth 2005). The
concept gained traction after several scientific studies in
the 2000s established a near-linear relationship between
global warming and the total amount of net anthropogenic
CO 2 emissions ever emitted.
Reaching net-zero CO 2 emissions results in CO 2
concentrations gradually declining over time towards along-term equilibrium as part of the excess CO 2 in theatmosphere is redistributed by the uptake in the biosphere onland and in the ocean. As a result, CO 2 -induced temperaturestabilizes (Allen et al. 2009; Collins et al. 2013; Joos et al.
2013; Knutti and Rogelj 2015; Lee et al. 2021; MacDougall et
al. 2020; Matthews et al. 2009; Matthews and Caldeira 2008;
Meinshausen et al. 2009; Solomon et al. 2010; Zickfeld etal. 2009).

Emissions Gap Report 2021: The Heat Is On

These insights were consolidated in the Fifth Assessment
Report of the Intergovernmental Panel on Climate Change(IPCC) where they were used to establish the geophysicalrequirements for halting global warming and to estimate
carbon budgets consistent with preventing warming fromexceeding specified levels (Collins et al. 2013; IPCC 2014,2013; Stocker et al. 2013) (see box 3.1). The most recent
IPCC assessment report (the Sixth Assessment Report,
AR6) confirms that warming is expected to stabilize once
global CO 2 emissions reach net-zero levels (IPCC 2021a; Leeet al. 2021).
For non-CO 2 emissions, the global temperature impact ofachieving net-zero emissions depends on how long the GHG
persists in the atmosphere (Pierrehumbert 2014; Solomon etal. 2010). Methane, currently the second-largest contributor
to warming, has a much shorter lifetime than CO 2 . Therefore,
if methane emissions reduce to zero, concentrations fall
faster, and their contribution to global temperature will
decline. Achieving net-zero GHG emissions expressed withthe default GWP-100 metric through a combination of low

residual non-CO 2 emissions and CO 2 removal results in apeak then a decline in global warming (figure 3.1) (Forster
et al. 2021; Fuglestvedt et al. 2018; IPCC 2021b; Rogelj et
al. 2021). The magnitude of this decline depends on theminimum level to which non-CO 2 GHGs can be reduced,
but could potentially be around 0.02–0.05°C/decade(Fuglestvedt et al. 2018).
At present, none of the available mitigation scenarios fully
eliminate all CO 2 or other GHG emissions (Clarke et al. 2014;
Gernaat et al. 2015; Rogelj et al. 2018; Smith et al. 2014).
To reach net-zero emissions, residual emissions are thusbalanced by removals from the atmosphere: hence theinclusion of ‘net’ in net-zero targets. The most scalable formsof GHG removal are CO 2 removal measures (Fuss et al. 2018;
Nemet et al. 2018). This means that net-zero CO 2 emissions
are achieved before net-zero GHG emissions. Reachingnet-zero GHG emissions targets therefore involves at least
two, and in most cases three, interlinked strategies: deep
reductions in CO 2 emissions, the upscaling of CO 2 removal,
and deep reductions in other GHG emissions (figure 3.1).

Box 3.1. Carbon budgets
Global warming is close to linearly proportional to thetotal net amount of CO 2 that has ever been emitted into
the atmosphere as a result of human activities. Therefore,
limiting global warming to a specified level requires thatthe total amount of CO 2 emissions ever emitted be kept
within a finite carbon budget. Recently, AR6 published
new estimates of the remaining carbon budget for limiting
warming to 1.5°C or 2°C relative to pre-industrial levels(Canadell et al. 2021; IPCC 2021b). According to these,
human activities resulted in about 2,390 GtCO 2 between
1850 and 2019, contributing around three quarters of the
1.07°C of human-induced warming from 1850-1900 to
2010-2019.
To limit warming to 1.5°C with a 66 per cent or 50 per centchance, the remaining carbon budget is estimated at 400
and 500 GtCO 2 , respectively. For 2°C, these estimatesare 1,150 and 1,350 GtCO 2 , respectively. Current annual
global CO 2 emissions are above 40 GtCO 2 /year, meaningthat urgent and deep emissions reductions over the next
decade are required to stay within the remaining budgets.
AR6 clarifies that methodological improvements cause
the estimates in the latest report to be markedly larger
than in AR5 (Stocker et al. 2013), but very similar to thosereported in the IPCC Special Report on global warming of

1

1.5°C (Rogelj et al. 2018) (see box 5.2 in Canadell et al.
(2021) for more information).
Carbon budgets are not the only determinant of global
warming. The warming that accompanies non- CO 2
emissions also plays a role. AR6 carbon budgets assume
that non-CO 2 emissions are reduced following the median
reductions from deep mitigation scenarios (Canadell et
al. 2021; Rogelj et al. 2018). For methane, this implies atleast a 30 per cent reduction in 2030 compared with 2010,
and about a 50 per cent reduction in 2050. Remaining
carbon budgets may vary by an estimated 220 GtCO 2 ormore, depending on how deeply future non-carbon-dioxide
emissions are reduced (Canadell et al. 2021). Chapter 6
assesses the role of methane in meeting these emissions
reductions and bridging the emissions gap.
Total GHG emissions are aggregated in units of CO 2
equivalence. Although several different metrics fordefining this equivalence exist (Myhre et al. 2013), under
the Paris Agreement GHG emissions must be aggregatedusing the global warming potential over a 100-year timehorizon (GWP-100) metric 1 (United Nations Framework
Convention on Climate Change [UNFCCC] 2018).

Parties to the Paris Agreement are mandated to report aggregated greenhouse gas emissions by using the GWP-100 metric, while additional
information that uses other aggregations can also be provided. Note that in addition, emissions of the various GHGs also have to be reported
individually.

19

Emissions Gap Report 2021: The Heat Is On

Figure 3.1. Illustration of how net-zero carbon dioxide or net-zero greenhouse gas emissions are reached at a global level(top) and the typical global warming implications of reaching these respective targets (bottom)
Figure 3.1a. Global greenhouse gas (GHG) emissions and times of achieving net zero for an illustrative pathway that keeps
warming well below 2°C
Gross CO2 emissions
Gross CO2 removal

Global CO2-equivalent
Global CO2-equivalentemissionsemissions(GtCO2e (GtCO2e
/yr)
/yr)

60

Non-CO2 emissions (CH4, N2O and flourinated gases in GWP-100)

CO2emissions
Non-CO2 emissionsNet-zero(CH4, N2O
andflourinated gases in GWP-100)
achieved when residual CO2
emissions are balanced by an
Net total GHG emissions
equal amountof CO2 removal
Net-zero
CO2 emissions
achieved when residual
CO2GHG emissions
Net-zeroemissions are balanced
by anachieved
when residual CO2
Net total GHG emissions
equal amount of CO2
andremoval
other GHG emissions are

Gross CO2 emissions
Gross CO2 removal

60
40

balanced GHG
by anemissions
equivalent
Net-zeroamount ofwhen
CO2 removal
achieved
residual CO2
and other GHG emissions arebalanced by an equivalent
GHG emissions
amountNet-negativeof CO2 removal

40
20
20
0

Net CO2 emissions
Net CO2 emissions

Net-negative GHG emissions

0
–20
2010

2020

2030

2040

2050

2060

2070

2080

2090

2100

–20
2010

2020

2030

2040

2050

2060

2070

2080

2090

2100

Global average
Global temperature
average temperature
increase increase(°C relative(°Cto
relative
1850–1900)
to 1850–1900)

2.5Global warming implications
Figure 3.1b.
2.5
2.0

Net-zero CO2 emissions
Global warming
roughly stabilizes
Net-zero CO2 emissions
Global warming
roughly stabilizes

2.0
1.5

Net-zero GHG emissions
Global warming
peaks then declines
Net-zero GHG emissions
Global warming
peaks then declines

1.5
1.0

0.5
0
2010

2020

2030

2040

2050

2060

2070

Continued decline
accelerated further if
net-negative GHG
emissionsare achieved
Continued decline
accelerated further if
net-negative GHG
emissions2090
are achieved
2080
2100

0
2010

2020

2030

2040

2050

2060

2070

2080

1.0
0.5

2090

2100

Note: GWP-100 stands for global warming potential over a 100-year time-horizon, and is the metric that is mandated to be used under
the United Nations Framework Convention on Climate Change (UNFCCC) to report aggregated anthropogenic emissions and removalsof GHGs. Reaching net-zero CO 2 emissions results in global warming stabilizing, provided that non-CO 2 forcing is also stabilized (Allen etal. 2018; IPCC 2018), while reaching net-zero GHG emissions defined with GWP-100 results in global warming peaking and subsequently
gradually declining (Fuglestvedt et al. 2018). Figure adapted from Rogelj et al. (2021). Pathway taken from Huppmann et al. (2018a, 2018b)
and climate outcome assessed using the Model for the Assessment of Greenhouse Gas Induced Climate Change (MAGICC) (Meinshausen
et al. 2011). Note that this figure shows one illustrative scenario in which the net-zero timings of CO 2 and total GHG emissions are notnecessarily equal to the median estimates of the IPCC Special Report on global warming of 1.5°C (IPCC 2018).

20

Emissions Gap Report 2021: The Heat Is On

3.2.2 The Paris Agreement and the timing of netzero emissions
In the lead-up to the Paris Agreement, these geophysicalconcepts of carbon budgets and net-zero emissions were
proposed as key elements for a legal architecture (Haites,
Yamin and Höhne 2013), and studies proposed net-zerodates for global CO 2 and total GHG emissions in line withspecific temperature limits (Rogelj et al. 2015). The Paris
Agreement marked the incorporation of the net-zeroconcept into international policy, aiming to “achieve abalance between anthropogenic emissions by sources andremovals by sinks of greenhouse gases in the second halfof this century, on the basis of equity, and in the context ofsustainable development and efforts to eradicate poverty”(UNFCCC 2015). Subsequently, the IPCC Special Report on

global warming of 1.5°C highlighted that to limit warming to
1.5°C above pre-industrial levels with no or limited overshoot,global CO 2 emissions should reach net zero around midcentury (IPCC 2018). The latter spurred a wave of net-zerotarget declarations.
Table 3.1 provides global net-zero timings from model
pathways aligned with 1.5°C and 2°C limits. For 1.5°C, CO 2
emissions must reach net zero around 2050, with GHG
emissions reaching net zero 15–20 years later. A delay of
15–20 years in either net-zero CO 2 or net-zero GHGs implies
limiting warming to 2°C rather than 1.5°C.

Table 3.1. Global timing of net-zero carbon dioxide and net-zero greenhouse gas emissions. Median and interquartile range

Pathway category

No. ofscenarios

Timing of reaching net zero
Timing of reaching net zero
Global CO2 emissions

Global GHG emissions

SR1.5: 1.5°C with no or limited
overshoot (50–66% chance in2100 with maximum of 0.1°C
overshoot until then)

422050 (2046, 2055)

2067 (2061, 2084)

SR1.5: Lower-2°C (66% chance)

542070 (2063, 2079)

Post-2100 (2090, post-2100)

1.5°C pathways (66% chancein 2100, and minimum
33% chance over the course of
the century, chapter 4)

262054 (2049, 2059)

2071 (2058, post-2100)

1.8°C pathways (66% chance,
chapter 4)232067 (2057, 2083)

2086 (2068, post-2100)

2°C pathways (66% chance,
chapter 4)712069 (2059, 2089)

2090 (2077, post-2100)

Note: SR1.5 stands for IPCC Special Report on global warming of 1.5°C. IPCC estimates as reported in table 2.4 of SR1.5 (Rogelj et al. 2018).
Values show the median and interquartile range across scenarios available in the SR1.5 scenario database (Huppmann et al. 2018a). In thepathway categories as used in chapter 4 of this report, pathways with emissions reductions before 2020 are excluded. The temperature
outcomes of these pathways have also been reassessed based on the physical climate assessment of the IPCC AR6 – see cross-chapter
box 7.1 in Forster et al. (2021).

3.2.3 The pathway to net-zero counts
Carbon budgets come with climate implications for netzero targets: the path followed from today until net-zero
CO 2 emissions are reached determines the total amount ofemitted CO 2 and thereby the total carbon budget. Whether
we follow a linear, an accelerated, or a delayed path impacts
the climate outcome (figure 3.2). Following a delayed pathcompared to an accelerated path to net-zero GHG emissions

by 2065 could lead to about 0.1°C more warming. At worst,
a delay could result in a complete failure to achieve thenet-zero target, resulting in higher warming. Near-termemissions reductions that sketch a linear or accelerated
path towards a longer-term net-zero target therefore provide
higher confidence that the net-zero target can ultimately beachieved.

21

Emissions Gap Report 2021: The Heat Is On

Figure 3.2. Near-term targets are critical to set global emissions on a clear path towards achieving long-term net-zerotargets and stringent climate goals

Global total greenhouse gas emissions[GtCO2e/yr]

Linear: the NDC setsemissions approximately on alinear path towards achieving
the net-zero target.

60
Additional cumulative emissions leading tohigher warming, higher mitigation challenges, andgreater difficulty in achieving the net-zero target40= near-term targets setting emissions...
on a delayed pathon a linear path, or

20

on an accelerated path... towards achieving thelong-term net-zero target

0
2010

2020

2030

2040

2050

Global net-zero emissions targets in isolation set only a weaklimit on the maximum level of global warming (Rogelj et al.
2015), as the maximum level of warming is largely definedby the cumulative amount of CO 2 emissions emitted until
net zero (IPCC 2018).

3.3 Net-zero at the national level
Setting net-zero emissions targets at the national level
involves several steps in addition to the aforementioned
global considerations. These steps represent both technicalchoices and normative decisions related to equity andfairness. Although this chapter focuses on countries, there
are similar steps to translate global net-zero targets tosectors, companies, investment portfolios and other entities(see box 3.2).
First, at a technical level, the scope of emissions coveredby a net-zero target needs defining (Levin et al. 2020; Rogelj
et al. 2021). This includes defining the GHGs and activity
sectors that are covered. For countries, the UNFCCC's

22

Delayed: the NDC reduces
emissions more slowly than implied
by a linear path towards the net-zerotarget. Cumulative emissions andresulting global warming are higher
compared to a linear path.

Accelerated: the NDC reduces
emissions further than implied by alinear path towards the net-zerotarget. Cumulative emissions
are further reduced compared to alinear path.

2060

2070

2080

2090

2100

requirement that parties report emissions and removals ofa basket of GHGs on a territorial basis informs the scopeof national targets. Countries could however exclude somegases or activities, include others such as international
aviation and shipping, or take a different approach such as
consumption-based accounting (Davis and Caldeira 2010;
Munksgaard and Pedersen 2001; Wyckoff and Roop 1994).
A further choice in scope is the inclusion and use of carbon
offsets, which are credits generated by projects carryingout emissions reduction or removal outside a country’s (orother entity's) boundary. These credits are transferred to beaccounted for within the boundary, often – but not always –by financial purchase through a market. Markets can allow
entities to meet targets in a more economically efficient way(Grubb et al. 2011).
However, experience shows that international carbon
markets can have pitfalls. Large numbers of creditgenerating projects in the Clean Development Mechanism– the market operated under the Kyoto Protocol – were
found not to fully represent additional carbon benefits

Emissions Gap Report 2021: The Heat Is On(Cames et al. 2016). The Paris Agreement anticipates a newinternational regime for carbon markets under article 6, theoperation of which is still under negotiation. This will require
clearly defined rules and robust accounting mechanisms
to track progress, deliver real emissions reductions anddrive ambition. Chapter 7 further discusses challenges andopportunities in using markets in achieving Paris Agreementtargets in both the near-term and net-zero context.
Second, normative choices are required when translating
global net-zero targets to the country level, involving
questions of equity and fairness. A deadline for global netzero emissions does not require all countries to achieve net
zero at the same time (Robiou du Pont et al. 2016; Rogelj et
al. 2021). Factors such as responsibility, capacity and levelof development imply that some nations should achieve (andgo beyond) net-zero emissions more quickly than others(Dubash et al. 2021; Rogelj et al. 2021). Furthermore, thecosts of and potential for achieving emissions reductions
and removals are geographically unevenly distributed.
Reaching global net-zero emissions is therefore likely to
involve a combination of positive and negative emissions
contributions across countries and sectors, keeping in
mind that the global potential for negative CO 2 emissions
is limited because of technical, social and sustainability
reasons (IPCC 2019, 2018). This variation between countries
is illustrated by the different times at which regions (Rogelj2018) or major emitting countries (van Soest et al. 2021)
reach net-zero CO 2 or GHG emissions as part of a global
least-cost transition, irrespective of additional equity or
fairness considerations.

2

Aside from questions of equity and scope, debates haveemerged over whether net-zero targets promote or hinder
actions consistent with the Paris Agreement. Net-zero isseen as more actor-centred and effective than a temperature
limit (Geden 2016). It also represents greater ambition thanthe current long-term pledges of most countries. 2
Nevertheless, the concept of net-zero has faced criticism
on the grounds that it may slow mitigation, either throughover-reliance on carbon removal (McLaren et al. 2019) oron carbon credits (Stabinsky, Bhatnagar and Shaw 2021),
or because an emphasis on long-term targets can distractfrom a lack of near-term actions. Other critics highlightthat a narrow focus on net-zero targets can lose sight ofdifferences in national climate politics, or the credibilityof pledges, as well as equity (Dubash et al. 2021; Rogelj et
al. 2021). Net-zero targets are not to be viewed in isolation
as the sole policy mechanism for effecting change; theyshould be accompanied by near-term actions as well as
detailed and transparent plans for delivery (Rogelj et al.
2021; Smith 2021). The Paris Agreement encourages thesethrough the submission of NDCs and long-term strategies
to the UNFCCC.
In response to these issues and criticisms, several recent
studies have focused on identifying a set of criteria against
which the robustness of net-zero pledges can be assessed(Black et al. 2021; Climate Action Tracker 2021; Levin etal. 2020; Rogelj et al. 2021). They share several common
features, summarized in table 3.2.

See https://unfccc.int/process/the-paris-agreement/long-term-strategies.

23

Emissions Gap Report 2021: The Heat Is On

Table 3.2. Overview of criteria used to assess national net-zero pledges

Goal

Studies
Climate Action
Tracker (2021)

Energy &ClimateIntelligence
Unit – Oxford(Black et al.
2021)

Target year
When will net zero be achieved?

xx

Legal status
Is the target binding in domestic law, or what other form ofcommitment is it?

xx

Global climate goal
What global temperature level is the target designed tocontribute to?
x

Pathway after net zeroIs the intent to maintain net zero, or to reach net negative?

Transparency

Scope

Gas coverage
Does the target include all GHGs under the Paris Agreement,
or a subset?

x

World
Resources
Institute (Levinet al. 2020)xx

xInterim targets/action
What is the path to net zero?

Reference to fairness
Has the target been justified as a fair and adequate
contribution to the global goal? If so, how?

Rogelj et al.
(2021)

x

x

x
x

x

x

x

x

x

x

x

Sector coverage
Does the target include all domestic activities, or a subset?

xx

Coverage of international aviation and shipping
Does the target include a share of international aviation and/or shipping?

xx

Use of international offsets
Does the target allow such offsets to be counted towards thetarget?

x

x

x

x

Published planHas the government set out a plan of actions to achieve thetarget?

x

x

x

x

Review process
Is there a regular, binding process for reviewing and revising
the target?

x

Reporting of progress
Is there regular reporting of progress against the target?

x

x
x

x

Separate reductions and removals
Does the target include separate subtargets for emissions andremovals?

xxxTransparency on removals
Are assumptions about use of removal methods, both in theland and industry sectors, transparent?

x

x

x

Metric for aggregating emissions
If the target is for multiple GHGs, does it use the GWP-100
metric under the Paris Agreement? If not, why not?

x

Note: “x” indicates which criteria are included in each of the four published studies.

3.4 Tracking national net-zero targets
globally
The number of national net-zero targets has grown rapidly
over the last four years. By the broadest definition, as manyas 136 countries covering more than half of global GHG
emissions either have some form of commitment to such24

a target or are considering it (Climate Action Tracker 2021;
Energy & Climate Intelligence Unit [ECIU] 2021; UNEP 2020;
World Resources Institute 2020). This includes countries
whose governments are merely discussing net-zero targets,and signatories to the Climate Ambition Alliance which cites
working towards net-zero CO 2 emissions by 2050 among its
aims (Climate Ambition Alliance 2019).

Emissions Gap Report 2021: The Heat Is On

Here we define a net-zero target as a statement innational legislation, in a policy document (i.e. an NDC or
long-term strategy communicated to the UNFCCC, or asimilar document published by a national government),
or a public announcement by the government or a highlevel government official (e.g. Head of State). We include
references to net-zero emissions, net-zero carbon, carbon
neutral(ity), GHG neutral(ity), climate neutral(ity) and adecarbonized economy or society. Our analysis reflects
developments up to 13 September 2021.

Using this classification, 52 parties (51 countries plus theEuropean Union) have pledged a net-zero target. These
cover around 57 per cent of current global domestic GHG
emissions, 60 per cent of gross domestic product (GDP)and 34 per cent of the global population (Climate Watch
2021; World Resources Institute 2021). Thirteen targets areenshrined in law, covering 12 per cent of global emissions(table 3.3).

Table 3.3. Overview of current national net-zero pledges across all United Nations Framework Convention on Climate
Change (UNFCCC) parties, by year and by legal status
Parties

EmissionsGDP

Population

In law

13

12%

10%

3%

In policy document

24

15%

24%

7%

Government
announcement

15

30%

26%

24%

Sources: Total coverage of current net-zero pledges by percentage of global domestic emissions in 2018 (World Resources Institute 2021),
GDP (World Bank 2019, in purchasing power parity (PPP) constant international $ terms) and population (UN World Population Prospects
2019)

By number, the majority of these targets (40) are for 2050,
coincident with the mid-century timescale for global CO 2
emissions indicated by the IPCC as necessary for limiting
warming to 1.5°C. Eight targets are aimed at earlier years(2030–2045) and four at later years. In terms of emissions,however, the targets are split almost entirely and equally
between 2050 (due to the pledges by the European Union andUnited States of America) and 2060 (due to China’s pledge).
It is important to note that approaches to counting carbon
sources and sinks can differ between global studies andnational reporting. Some care is therefore needed whenassigning net-zero status to countries, or interpreting claims
by countries that ‘carbon neutrality’ has been achieved. In
particular, national GHG inventories label all carbon uptake
on managed land (including naturally occurring uptake) as
anthropogenic, resulting in greater removal numbers thanin the scientific modelling studies that form the basis forthe global emissions pathways assessed in chapter 4 of thisreport (Grassi et al. 2021, 2018). However, one available study
indicates that differences between the two approaches at
the global level lead to a negligible difference in terms oftiming of net-zero emissions (Grassi et al. 2021). Further indepth studies are required to confirm this.
Existing net-zero targets show variations in scope, as well aslarge ambiguities (World Resources Institute 2020). Thirtysix are clear in including all sectors of domestic activity,
while the remaining 16 are unclear or undecided. Regarding

inclusion of GHGs, 17 targets are unclear or undecided,
however those that are clear all include at least some nonCO 2 gases as well as CO 2 . The majority (41) are unclear orundecided on inclusion of emissions from international
aviation and shipping. However, three explicitly include
them. Similarly, on use of offsets, five include them explicitly,
eight rule them out and 39 are unclear or undecided.
As already explained, achieving net-zero emissions is key
to halting or even gradually reversing global warming. Withan increasing share of global emissions covered by netzero targets, their impact on temperature projections is
also increasingly important. Chapter 4 – which provides an
overview of global warming implications of current policies,
NDCs and net-zero targets – estimates that if fully achieved,
net-zero targets could reduce global warming projections
by about 0.5°C relative to projections that only take into
account unconditional NDCs.

3.5 A closer look at net-zero targets in
the G20
Twelve of the G20 members, covering 54 per cent of global
domestic GHG emissions, currently have pledged a net-zerotarget, of which six are in law, two are in policy documents
and four are government announcements. All are for theyear 2050, with the exception of China’s 2060 target andGermany’s target for 2045.

25

Emissions Gap Report 2021: The Heat Is On

Figure 3.3 provides an assessment of these targets against
most of the criteria provided in table 3.3. Where information
relevant to the criteria is available from countries, figure 3.3
highlights its existence rather than assessing its sufficiency.
For instance, a plan may be published and it may refer tothe fairness of its contribution to global efforts, however
additional assessment is required to establish whether theplan is detailed enough and the fairness appropriate.
Similar to the global assessment of national net-zerotargets, a notable feature of current net-zero targets of G20
members is their ambiguity. Regarding scope, most targets
are unclear or undecided on inclusion of offsets and ofinternational aviation and shipping emissions. Lack of clarity
is also notable on coverage of sectors and gases, but thosethat are clear show a tendency for comprehensive coverage.
Most show a lack of transparency regarding the approachtaken to fairness, the plans for achievement (including on
use of removals), and on reporting and reviewing progress.
Only Canada, the European Union, France, Germany and theRepublic of Korea have published their plans so far, and only
these countries plus the United Kingdom have accountableprocesses for reviewing their targets.
As an indication of the consistency between nearer-term
actions and net-zero targets, figure 3.3 also plots theemissions paths for G20 members implied by their mostrecent NDCs or announced mitigation pledge for 2030 andtheir net-zero target. As highlighted in section 3.2 and figure
3.2, near-term targets need to be aligned on a clear path
towards achieving net-zero targets and limiting cumulativeemissions. Indeed, the Emissions Gap Report 2020 (UNEP2020) argued that the litmus test of net-zero pledges is theextent to which they are reflected in near-term policy action
and in significantly more ambitious NDCs for the period to2030. Near-term emissions reductions that follow a linear
or accelerated path towards a net-zero target provide higher
confidence that the net-zero target can be achieved.

26

To summarize, eight G20 members have so far not set netzero targets, whereas 12 (covering 54 per cent of global
domestic GHG emissions) have. Of the nine G20 members
for which we can estimate an emissions path based on
their net-zero target and their NDC, none have NDC targets
that put them on an accelerated path towards their net-zeroemissions targets. Five of these nine members (covering
21 per cent of global domestic GHG emissions) have NDC
targets that put the country’s domestic emissions onto alinear path towards achieving their net-zero targets. For
four G20 members (covering 28 per cent of global domestic
GHG emissions), the NDCs lead to emissions in 2030 thatare about 25 per cent to 95 per cent higher than a linear path
towards their net-zero targets would imply. These countries
urgently need strengthened and more ambitious near-termclimate plans for their net-zero targets to remain achievable.
There is an urgent need for (i) more G20 members – andindeed all countries – to pledge net-zero emissions, (ii)all countries to increase the robustness of their net-zeropledges, and (iii) all net-zero targets to be backed up by nearterm actions that give confidence that the net-zero targets
can ultimately be achieved.

Emissions Gap Report 2021: The Heat Is On

Figure 3.3. Analysis of current net-zero targets of G20 members
Path tonet zeroAll
sectors

Int. aviation& shipping

Excludesoffsets

Government
announcement

?

?

?

?

2050

Government
announcement

?

?

?

2050

In law?

?

2060

Government
announcement

?

?

2050

In law

France2050

In law

Annually

Germany2045

In law

Annually

Italy

2050

Government
announcement

2050

In law

2050

In policy
document

2050

In law

2050

In policy
document

Argentina

Year

Targetstatus2050

Refers tofairness

Published
plan

All
gases

Country

Review
process

Reportingprogress

Separatetargets

Removalstransparency

2050

Brazil2050

Canada
2050

China
2060

European
Union

?

Not
annually

?

2050

Japan

?

?

?

?

?

?

Not
annually?

?

Notannually

2050

Republicof Korea

2050

UK

?

?

Not
annually

Annually

2050

USA

?

?

2050

Key:

2020

2040

2060

Schematic illustration of whether
NDCs are putting national GHG
emissions on a delayed, linear
or accelerated path towards
achieving the national net-zerotarget (see box 3.1)

Yes

No

Unclear or undecided

Not annually (reporting progress
but less frequently than annually)

Note: Only G20 members with net zero targets are included. Member states of the European Union have no separate
assessment of their path to net zero, because their NDC is not assessed separately as part of this report. Table 3.2 provides
definitions of what is covered under the various headers.

27

Emissions Gap Report 2021: The Heat Is On

Box 3.2. Non-state action on net zero
Businesses, cities, regions, investors, civil society groups,
and other non-state and subnational actors (NSAs) play
an increasingly important role in raising ambition andaccelerating implementation. The Paris Agreement
institutionalized the engagement of NSAs in achieving
long-term climate goals and created an ongoing process
to catalyse climate commitments made by NSAs, including
net-zero targets (Chan, Ellinger and Widerberg 2018; Hale
2016; Hsu et al. 2018).
Efforts by NSAs towards global net-zero emissions arestrengthening and broadening, which helps mobilize
stakeholders to achieve net zero (Data-Driven EnviroLab
and NewClimate Institute 2020; Hsu et al. 2020). The
United Nations Race To Zero campaign rallies NSAs
globally to take rigorous actions to reduce emissions by
50 per cent by 2030 and achieve net-zero carbon emissions
by 2050 at the latest, vetting members via an independent
expert group. More than 3,000 businesses, 730 cities,
170 investors, 30 regions and 600 universities have joined
Race To Zero, together covering around 25 per cent of
global CO 2 emissions and 50 per cent of GDP (Black et
al. 2021; NewClimate Institute and Data-Driven EnviroLab
2020; Smit and Kuramochi 2020; UNFCCC 2021).
Actions taken by NSAs can also contribute to achieving
net-zero targets set by governments, while at the sametime creating more favourable conditions for governments
to increase their ambition going forward. A recent studyof major non-state actor initiatives found they had thepotential to reduce 2030 emissions by 5–15 GtCO 2 e (Blacket al. 2021; Hale et al. 2021; Hsu et al. 2019; NewClimate
Institute and Data-Driven EnviroLab 2020; NewClimate
Institute et al. 2021).

28

At the national level, NSAs are supporting implementationand enhancement of climate goals. For instance, America
Is All In, a coalition of over 1,800 institutions representing
65 per cent of the United States of America’s population
and 70 per cent of its GDP, is an initiative to enhance nonstate actions to cut the United States of America’s GHG
emissions by 50 per cent below 2005 levels by 2030 and put
the country on a trajectory consistent with limiting global
temperature rise to 1.5°C (Hultman et al. 2021). Meanwhile,the European Commission launched the European Climate
Pact to mobilize NSAs and communities to participate inclimate actions. The Japan Climate Initiative, made up ofbusinesses and municipalities, has played a key role insupporting the government’s new NDC.
However, the increase in NSA net-zero pledges needs tobe treated with caution, because as they have proliferated,
they have varied in robustness. The scope and coverageof net-zero targets; the existence of implementationplans, transparency and reporting to track progress; thealignment between near-term actions and long-term netzero targets; and the robustness of carbon offsets are
critical to credible net-zero targets (Black et al. 2021; Haleet al. 2021; Hsu et al. 2019; NewClimate Institute and DataDriven EnviroLab 2020; NewClimate Institute et al. 2021).
NSAs have started to take actions to address these issues.
For example, the Taskforce on Scaling Voluntary Carbon
Markets, a private-sector-led initiative, aims to develop athreshold standard to ensure high integrity offset credits
and create robust and transparent markets.

Emissions Gap Report 2021: The Heat Is On

4

The emissions gap

Lead authors:
Michel den Elzen (PBL Netherlands Environmental Assessment Agency, the Netherlands), Joana Portugal-Pereira (Graduate
School of Engineering (COPPE), Universidade Federal do Rio de Janeiro, Brazil), Joeri Rogelj (Grantham Institute, Imperial
College London, UK; International Institute for Applied Systems Analysis [IIASA], Austria)

Contributing authors:
Ioannis Dafnomilis (PBL Netherlands Environmental Assessment Agency, the Netherlands), Johannes Gütschow (Potsdam
Institute for Climate Impact Research, Germany), Kimon Keramidas (Joint Research Centre [JRC], Spain), Robin Lamboll(Imperial College London, UK), Jared Lewis (University of Melbourne, Australia), Malte Meinshausen (University of Melbourne,
Australia), Zebedee Nicholls (University of Melbourne, Australia)

4.1

Introduction

The emissions gap is estimated as the difference between
projected global greenhouse gas (GHG) emissions
assuming full implementation of the mitigation pledges
that countries have made for 2030, and emissions under
least-cost pathways consistent with the Paris Agreement’s
long-term goal of limiting global average temperature
increase to “well-below 2°C” and pursing efforts to limit it
to 1.5°C, compared with pre-industrial levels. This year, theupdate of the emissions gap is particularly interesting as itis the first time countries have submitted new or updated
nationally determined contributions (NDCs) as part of theParis Agreement’s five-year ambition-raising cycle. Thus,
the update of the emissions gap provides an indicationof the extent to which the NDC process under the Paris
Agreement is working and the progress made.

4.2 Scenarios considered for the 2030
gap assessment
This section updates the eight scenarios considered for the2030 emissions gap assessment. These scenarios comprisereference scenarios (4.2.1), NDC scenarios (4.2.2), and leastcost mitigation scenarios starting in 2020 consistent withspecific temperature targets (4.2.3). Table 4.1 lists anddescribes all scenarios included in the assessment

To estimate the emissions gap, updated scenarios that
underlie its quantification are assessed (section 4.2). This
year, the mitigation pledge scenarios include the latest
available NDCs as well as announced mitigation pledges
for 2030 with a cut-off date of 30 August 2021. Further,scenarios consider the repercussions of the COVID-19
pandemic and possible economic recovery paths. The
emissions gap assessment for 2030 is presented in
section 4.3, while the implications of failing to bridge theemissions gap for global temperature rise are discussed
in section 4.4. In this context, the key questions assessedin this chapter are: What is our current best estimate of
the emissions gap for 2030 taking into account the new or
updated NDCs, announced pledges and the impact of the
COVID-19 pandemic and associated recovery measures?
What are the global warming implications over the courseof the century?

29

Emissions Gap Report 2021: The Heat Is On

Table 4.1. Summary of assessed scenarios
Scenario
Reference

NDCs andannounced
mitigation pledges

Mitigation
scenarios
consistent
with the Paris
Agreement

130

Cut-off year

Description

Year 2010 policies

2010

This scenario includes only climate polices
implemented up to 2010 (no additional measuresfrom 2010 onward).

Current policies

2020/21

Current policies updated to reflect climate
mitigation policies adopted and implemented
as of 2020/21. Scenario also adjusted to reflect
short- and midterm socioeconomic impacts
from COVID-19.1

Unconditional NDCs
and announced
mitigation pledges

2021

This scenario reflects new or updated NDCs
as well as officially announced mitigation
pledges for 2030 that have been indicated to
be implemented without any explicit external
support. (Cut-off date: 30 August 2021)

Conditional NDC
and announced
mitigation pledges

2021

In addition to the unconditional pledges, this
scenario considers new or updated NDCs as
well as officially announced mitigation pledges
for 2030 to be implemented conditional uponreceiving international support (finance,technology transfer and/or capacity-building).
(Cut-off date: 30 August 2021)

Below 2°C

Starting from 2020

Long-term least-cost pathway consistent withholding global warming below 2°C throughout
the twenty-first century with at least 66 per centchance.

Below 1.8°C

Starting from 2020

Long-term least-cost pathway consistent withholding global warming below 1.8°C throughout
the twenty-first century with at least 66 per centchance.

Below 1.5°C

Starting from 2020

Long-term least-cost pathway consistent
with holding global warming below 1.5°C
throughout the twenty-first century with limited
or no overshooting. Global warming in 2100
is projected to be below 1.5°C with at least 66
per cent chance, while throughout the twentyfirst century it is kept below 1.5°C with at least
33 per cent chance.

The updated current policy scenario adjusts original modelling studies to account for different policy cut-off dates, which range from 2017 to 2020,and varying consideration of the impact of the COVID-19 pandemic on socioeconomic drivers.

Emissions Gap Report 2021: The Heat Is On

4.2.1 Reference scenarios and updates
Two reference scenarios are considered: the ‘year 2010
policies’ scenario and the ‘updated current policies’
scenario. Only the latter has changed compared tolast year.
The year 2010 policies scenario assumes that no
additional climate mitigation policies are implemented
after 2010. As in previous gap reports, global GHG
emissions in this scenario are based on the baseline
projections of Shared Socioeconomic Pathway scenarios
from six modelling studies assuming middle-of-the-roadsocioeconomic assumptions (SSP2) (Fricko et al. 2017)that also underpin the current policies scenario projections
as of 2019 (McCollum et al. 2018; Roelfsema et al. 2020). 2
The updated current policies scenario projects global
GHG emissions assuming all currently adopted andimplemented policies (defined as legislative decisions,executive orders, or equivalent) are realized and that no
additional measures are undertaken. It also considers
the impact of COVID-19. The data for this scenario arebased on updates by four modelling studies 3 that include
the impacts of COVID-19 and have a cut-off date ofNovember 2020 and four international modelling groups. 4
The international modelling groups have 31 December
2016 as their cut-off date for current policies (Roelfsema
et al. 2020) and do not include COVID-19 effects. They
are included to ensure consistency of the data set andmethodology across the Emissions Gap Reports. Theirresults were adjusted to reflect updates of policies until
November 2020 by comparing them to the results of thefour modelling studies that provide estimates for both cutoff dates (den Elzen, Höhne and Jiang 2017).
Following this approach, the median estimate of the impactof recent policies is a reduction in global GHG emissions of
1.5 gigatons of carbon dioxide equivalent (GtCO 2 e) (range:
3.0–0.4). To capture the impact of COVID-19, the fourinternational modelling groups' estimates were adjusted
based on three of the four modelling studies (Climate
Action Tracker, International Energy Agency [IEA] and PBL)
that provide global GHG emissions projections based on
consistent current policies scenarios, including as well as
excluding the impact of the COVID-19 pandemic. Following
this approach, the impact of COVID-19 is an estimatedreduction in global GHG emissions of about 2.5 GtCO 2 e(range: 3.2–1.4) by 2030. Considering both of these
impacts, the median estimate of global GHG emissions in

2030 for the updated current policies scenario becomes
55 GtCO 2 e (range of 52–58 GtCO 2 e; see table 4.2) in 2030,
which is 4 GtCO 2 e lower than the median estimate of the2020 UNEP Emissions Gap Report.
It remains critically important to understand the potential
structural changes of the COVID-19 pandemic and thepost-COVID rescue and recovery packages on emission
levels out to 2030 (see chapter 5). This is particularly
important given the use of 2030 as a target year in many
countries’ NDC submissions and as a benchmark to gauge
global climate action. Research is ongoing in this area, but
not yet published in the peer-reviewed literature.
While understanding of energy-related GHG emissions
trends during the COVID-19 pandemic is improving (Forster
et al. 2020; Le Quéré et al. 2021, 2020; Liu et al. 2020),
there is more uncertainty around trends in agriculture,
forestr y and other land - use (AFOLU) - based GHG
emissions. However, these emissions seem to continue toincrease. In 2020, agricultural activities had limited losses
due to the COVID-19 pandemic and some commodities
even increased their production (Food and Agriculture
Organization of the United Nations [FAO] 2021a, 2021b;
World Bank 2021). Further global deforestation rates
increased significantly, resulting in a loss of tree cover by
25.2 Mha, 12 per cent more than in 2019 (Hansen et al.
2013; World Resources Institute [WRI] 2021).
Although near-term impacts on land-use dynamics
are yet to be better known, as in the 2000s and 2010s,
production of agricultural commodities (mainly beef, soy,and palm oil), illegal logging, mining extraction and wild
fires were major drivers of deforestation (Curtis et al.
2018; FAO 2021c). The rising trend of prices for most foodand metal commodities (FAO 2021a, 2021b; World Bank2021), along with governmental stimulus into agribusinessactivities, extractive industries, and development of roadinfrastructure in protected land regions drove deforestationand forest degradation, mainly in the tropics (Brancalion
et al. 2020; Ferrante and Fearnside 2020). During the
COVID-19 crisis and due to limited financing resources,
some governments have also relaxed environmental
laws and decreased their national budgets of regulatory
mechanisms, which has reduced the enforcement ofenvironmental protection laws (Amador-Jiménez et al.
2020; Vale et al. 2021). Furthermore, national lockdowns
and disruption of non-forest economic activities have
limited the income of forest-dependent communities,2

From the CD-LINKS Scenario Database, version 1.0.

3

Climate Action Tracker (2021); Joint Research Centre's POLES model (Joint Research Centre, forthcoming); PBL Netherlands Environmental
Assessment Agency's IMAGE model (Dafnomilis et al. 2021; den Elzen et al. in review; Nascimento et al. 2021) (see also: www.pbl.nl/ndc); and thestated policies scenario of the International Energy Agency [IEA]’s World Energy Outlook 2020 (IEA 2020). The more-optimistic stated policies scenarioof the IEA World Energy Outlook 2020 that was used as a current policies scenario is not yet included. Furthermore, the energy-related CO 2 emissionsof IEA were supplemented with the median estimates of the non-CO 2 GHG emissions and CO 2 land-use-related emissions of the current policies
scenarios from the COMMIT database.

4

International Institute for Applied Systems Analysis (IIASA) with the MESSAGE–GLOBIOM model (Fricko et al. 2017); National Institute for Environmental
Studies (NIES) with the AIM model (Fujimori et al. 2017); Potsdam Institute for Climate Impact Research (PIK) with the REMIND–MAgPIE model(Luderer et al. 2015) and COPPE, Universidade Federal do Rio de Janeiro (COPPE/UFRJ) with the COFFEE model (Rochedo et al. 2018).

31

Emissions Gap Report 2021: The Heat Is On

thereby increasing pressure on forest products (Golar etal. 2020; Rahman et al. 2021).
Another issue related to land-use emissions is that about
half of the global scenarios analyses and national GHG
inventories use different definitions for anthropogenic
removals in the land-use sector, resulting in different
amounts of net land-use carbon dioxide (CO 2) emissions
being reported, with a historic difference of up to 4
GtCO 2 e/year between national GHG inventories andglobal emission pathway studies (Grassi et al. 2018).
The solutions that have been published to account andcorrect for this discrepancy are integrated in these studies
by applying a constant adjustment term over the 2010–
2030 period. 5

4.2.2 NDC and announced pledge scenarios andupdates
The NDC and announced pledge scenarios include all themost recent NDCs (new or updated NDCs and previous
NDCs for countries where no updates are available) as
well as announced climate change mitigation pledges
for 2030 that could be linked to updated NDCs and that
focus on indicators or targets also included in their NDCs.
The estimated impact of revised reduction targets in the
new or updated unconditional NDC submissions andannouncements lowers the emissions projection of theunconditional NDC scenario by about 4 GtCO 2 e (about
15 per cent) compared with the previous NDCs. For theconditional NDC scenario including announced pledges, asimilar impact is found. This results in a median estimateof global GHG emissions of 52 GtCO 2 e and 50 GtCO 2 e,if the unconditional and conditional NDCs are fully
implemented. This is about 4 GtCO 2 e lower than last year’s
projections (based on previous NDCs, see figure 4.1).
The NDC and announced pledge scenario estimate isbased on four model studies (Climate Action Tracker,
PBL, JRC and Climate Resource) (Meinshausen et al.
2021), 6 all of which include the NDC updates (as at end of
August 2021), while only the first three studies consider
the impact of the announcements. 7, 8 In addition, it isbased on projections of four model groups (IIASA, theNational Institute for Environmental Studies [NIES], thePotsdam Institute for Climate Impact Research [PIK] andResources for the Future and Euro Mediterranean Centeron Climate Change [RFF–CMCC]) that have been adjusted
to reflect the impact of the new or updated NDCs andannounced pledges.

32

4.2.3 Mitigation scenarios consistent with the Paris
Agreement and updates
Emission projections of the latest NDCs and announced
pledges scenarios, and updated current policies scenarios
are compared to least-cost mitigation scenarios that meet
specific temperature targets relative to pre-industrial levels.
Here, we categorize emissions pathways from the literature
based on their projected peak warming outcomes over thecourse of this century (Huppmann et al. 2018b, 2018a; Rogelj
et al. 2018. See also chapter 3). We define three scenariosthat differ in their estimated maximum warming over thecourse of this century (see table 4.1).
This year, the scenarios have been updated by re-assessing
their temperature outcomes based on the Intergovernmental
Panel on Climate Change (IPCC) Assessment Report 6
Working Group I assessment. The temperature outcomeof the scenarios is assessed with the reduced-complexity
carbon-cycle and climate model MAGICC (Meinshausen
et al. 2011) in a set up that captures the uncertainties inradiative forcing as well as climate and carbon-cycle
response (Nicholls et al. 2021) as assessed in cross-chapter
box 7.1 of the IPCC Sixth Assessment Report (Forster et
al. 2021).
As a result of the updates, global emissions in 2030
consistent with keeping global warming below 2.0°C witha 66 per cent chance are estimated at 39 GtCO 2 e, which isabout 2 GtCO 2 e lower than in earlier reports. Similarly, theestimate for 1.8°C is about 2 GtCO 2 e lower than the 1.8°C
estimate of previous reports. There are no changes to the
1.5°C estimate (table 4.2). As pathways often assume netnegative CO 2 emissions in the second half of the century,
the estimated global warming in the year 2100 is typicallylower than the maximum warming over the course of thetwenty-first century.

4.3 The emissions gap
The emissions gap for 2030 is defined as the difference
between global total GHG emissions from least-cost
scenarios that keep global warming to 2°C, 1.8°C or 1.5°C
with varying levels of likelihood and the estimated global
GHG emissions resulting from a full implementation of NDCs
and announced reduction pledges. This section updates thegap based on the scenarios described in section 4.2.

5This approach is consistent with the detailed adjustments calculated by Grassi et al. (2021), which are virtually constant until 2030 for emissions
scenarios in line with updated current policies or NDCs scenarios. Previous reports already applied a similar adjustment method, when comparing
model studies (such as the integrated assessment model studies) or in the emissions gap calculations. Although the literature now provides a moreelaborate evidence base in support of this adjustment, this approach does not result in shifts in estimates of the global emissions gap.

6

Climate Action Tracker: https://climateactiontracker.org/global/cat-emissions-gaps/; PBL: www.pbl.nl/ndc; JRC: https://ec.europa.eu/jrc/en/geco.

7

The Climate Action Tracker accounts for the impact of the announcement of Japan and China, JRC for China and Japan, and PBL includes the impactof China, Japan and the Republic of Korea, and also includes the impact of the latest NDC of South Africa.

8

As these studies do not fully account for all announced pledges, the estimate is slightly lower than the estimate in chapter 2, but it has been roundedto avoid apparent inconsistencies.

Emissions Gap Report 2021: The Heat Is On

Table 4.2 provides a full overview of 2030 emission levels
for the eight scenarios considered, as well as the resulting

emissions gap between the scenario and the 2°C, 1.8°C or
1.5°C pathways.

Table 4.2. Global total greenhouse gas emissions in 2030 under different scenarios, temperature implications, and theresulting emissions gap

Scenario (rounded
to the nearest
gigaton)GlobalNumber of total
scenarios emissions
in setin 2030[GtCO2e]

Estimated temperature outcomes

50%
chance†Closestcorresponding
IPCC SR1.5
scenario classEmissions Gap in 2030
[GtCO2e]

Below
2.0°C

66% chance 90% chance

Below
1.8°C

Below
1.5°C

Year 2010 policiesi6

64 (60–68)

Current policiesii

955 (52–58)

15
22(12–18) (19–25)

30(28–33)8

52 (49–55)

13
19(10–16) (16–22)

28(25–30)850 (46–52)

11(7–13)

25(22–28)Unconditional
NDCs (updated
NDCs andannouncements)
Conditional
NDCsiii (updated
NDCs andannouncements)

Below 2.0°C(66% chance)**

Below 1.8°C(66% chance)**

Below 1.5°C(66% chance in2100 with no or
limited overshoot)

71

23

26

39 (33–49)

33 (27–41)

25 (17–33)

Peak:

Peak:

Peak:

1.7–1.8°C

1.8–2.0°C

2.2–2.4°C

In 2100:

In 2100:

In 2100:

1.3–1.7°C

1.5–1.9°C

1.9–2.4°C

Peak:

Peak:

Peak:

1.6–1.7°C

1.7–1.8°C

2.0–2.2°C

In 2100:

In 2100:

In 2100:

1.2–1.6°C

1.4–1.8°C

1.8–2.2°C

Peak:

Peak:

Peak:

1.5–1.6°C

1.6–1.7°C

1.9–2.1°C

In 2100:

In 2100:

In 2100:

1.0–1.3°C

1.2–1.5°C

1.5–1.9°C

17(13–19)Higher-2°C
pathways

Lower-2°C
pathways

1.5°C withno or limited
overshooti All scenarios represent pre-COVID-19 estimates. Values represent the median and tenth to ninetieth percentile range across scenarios; ii
All scenarios are adjusted to reflect the impact of COVID-19 and recent policies (cut-off date 2020). Values represent the median and tenth
to ninetieth percentile range across scenarios; iii Values represent the median and tenth to ninetieth percentile range across scenarios.
† Temperature outcomes are estimated for global surface air temperature (GSAT) with the reduced-complexity carbon-cycle and climate
model MAGICC (Meinshausen et al. 2011) in a set up that captures the uncertainties in radiative forcing as well as climate and carbon-cycle
response (Nicholls et al. 2021).
** Values represent the median and tenth to ninetieth percentile range across scenarios. Probabilities (‘chances’) refer to peak warmingat any time during the twenty-first century for the below-1.8°C and below-2.0°C scenarios. When deploying net-negative CO 2 emissions
in the second half of the century, global warming can be further reduced from these peak warming characteristics. For the below-1.5°C
scenario, it applies to the year 2100, while the “no or limited overshoot” characteristic is captured by ensuring projections do not exceed
1.5°C with at least 33 per cent chance over the course of the twenty-first century.
Note: The gap numbers and ranges are calculated based on the original numbers (without rounding), and these may differ from the rounded
numbers (third column) in the table. Numbers are rounded to full GtCO 2 e. GHG emissions have been aggregated with 100-year global
warming potential (GWP) values of the IPCC AR4 (to be consistent with table 2.4 of IPCC Special Report on Global Warming of 1.5°C). IPCC
SR1.5 refers to the IPCC Special Report on global warming of 1.5°C.

33

Emissions Gap Report 2021: The Heat Is On

Figure 4.1. Overview of changes in greenhouse gas emissions projections for 2030 for different scenarios= Emissions Gap Report2020= Change between
Emissions Gap Report2020 and Emissions Gap
Report 2021

70

Global GHG emissions(GtCO2e/yr) values for 2030

60

-4

-4

-4

50

-2
-2

40
30
20
10

th 1.5
w °C
ay
s
pa

th 1.8
w °C
ay
s
pa

w 2°C
ay
s
th
pa

iti
an ona
d lN
pl D
ed C
ge s
s
Co
nd
iti
an ona
d lN
pl D
ed C
ge s
s

Un

co

nd

C
po urrelic ntiesYeapo r 20
lic 10ies0Note: Numbers in bubbles are rounded to nearest GtCO 2 e.

The current policies scenario is estimated to reduce global
GHG emissions in 2030 to about 55 GtCO 2 e (52–58), which
is 9 GtCO 2 e lower than in the year 2010 policies scenario. It isalso 4 GtCO 2 e lower than the median estimate of the current
policies scenario of the 2020 UNEP Emissions Gap Report.
The implementation gap, which is the difference between
emissions expected under the current policies scenario andthose needed to achieve the NDCs and announced reduction
pledges, is estimated to be 3 GtCO 2 e and 5 GtCO 2 e for theunconditional and conditional NDCs and pledge scenarios
respectively.
Figure 4.2 illustrates the emissions gap in 2030, highlightingthat while the new and updated NDCs together withannounced mitigation pledges narrow the gap slightly
compared to previous NDCs, they are highly insufficient
to bridge the gap. They take only 7.5 per cent off projected
2030 emissions, compared to earlier unconditional NDCs,
whereas 30 per cent is needed for 2°C and 55 per cent is34

needed for 1.5°C. Figure 4.2 shows that full implementationof unconditional NDCs and announced reduction pledges is
estimated to result in a gap to a 1.5°C pathway of 28 GtCO 2 e(range: 25–30). This is about 4 GtCO 2 e lower than the gap
assessed in the 2020 report (United Nations Environment
Programme [UNEP] 2020), due to the updated NDCs andannounced reduction pledges. If the conditional NDCs andannounced reduction pledges are also fully implemented,
the emissions gap is further reduced by about 3 GtCO 2 e.
The emissions gap between unconditional NDCs andannounced reduction pledges and below 2°C pathways is
about 13 GtCO 2 e (range: 10–16 GtCO 2 e), which is about
2 GtCO 2 e lower than last year. While NDC and announced
mitigation pledges reduce global emissions by about
4 GtCO 2 e compared with previous NDCs, the updated 2°Cscenario estimate for 2030 is about 2 GtCO 2 e lower thanin previous Emissions Gap Reports (section 4.2.3), whichmeans that the gap is only reduced by about 2 GtCO 2 e.

Emissions Gap Report 2021: The Heat Is On

Figure 4.2. Global greenhouse gas emissions under different scenarios and the emissions gap in 2030 (median estimate
and tenth to ninetieth percentile range)

70.0

2010 policies scenario
60.0

Current policies scenario
Unconditional NDC and pledge scenario

40.0

30.0

Conditional
NDC and11
pledgescenario GtCO2e

2°C range
Turquoise area shows
pathways limiting global
temperature increase to
below 2°C with about
66% chance.

1.8°C range

13

GtCO2e25
MedianGtCO2eRemaining gap
to stay within
2°C limit

estimateof levelconsistent
with 2°C:
39 GtCO2e(range 33–49)

1.5°C range
Green area shows pathways
limiting global temperature
increase to below 1.5°C with a 66%
chance by 2100 and minimum 33%
chance over the course of the century.

20.0
2015

2020

GtCO2eMedianestimateof levelconsistent
with 1.5°C:
25 GtCO2e(range 17–33)

Estimated global
warming over
21st century

60.0

Current policies
scenario: 2.8°C(66% chance)
Unconditional NDC
and pledge
scenario: 2.7°C(66% chance)

50.0
40.0
30.0

2°C range

Unconditional
NDC and pledge
scenario with
net-zero targets:
2.2°C (66%chance)1.8°C range

20.0
10.0
0.0
2015

28

2025

70.0

GtCO2e

GtCO2e50.0

1.5°C range

2020

2025

2030

2035

2040

2045

2050

35

Emissions Gap Report 2021: The Heat Is On

4.4 Temperature implications of theemissions gap
Neither current policies nor the latest NDCs and announced
pledges are consistent with limiting warming to the goal of
the Paris Agreement. To understand how far off the markcurrent policies and NDCs are, estimated emissions forthe year 2030 for each of these scenarios are projected
out to 2100, and their climate outcomes assessed witha climate model (see box 4.1). This approach assumes
a continuation of climate action beyond 2030 without
additional strengthening. Extrapolations until the end of
the century are inherently uncertain and subject to scenario
assumptions such as the level at which climate action
continues or technology costs.
This year, the method to extend emissions to 2100 and theclimate model set up used was updated based on improved
methods and the latest climate assessment of IPCC AR6
Working Group I. These updates alone result in temperature
projections that are about 0.2°C lower than in previous
Emissions Gap Reports, which should be factored in whencomparing the results below with previous estimates. A
continuation of the effort implied by the latest unconditional
NDCs and announced pledges is at present estimated toresult in warming of about 2.7°C (range: 2.2–3.2°C) with a
66 per cent chance.9 This implies a 50 per cent chance that936

warming is kept to 2.5°C (range: 2.0–2.9°C) by the end of
the century and a 90 per cent chance that it is kept to 3.3°C(range: 2.7–3.9°C). A continuation of conditional NDCs andannounced pledges lowers these estimates by about 0.1°C
to 2.6°C (2.1–3.1°C), 2.4°C (1.9–2.8°C) and 3.2°C (2.6–3.8°C),
respectively. By contrast, a continuation of current policies,
which are insufficient to meet the 2030 pledges, increase theestimates by about 0.1°C to 2.8°C (range 2.3–3.3°C), 2.6°C(range 2.1–3.0°C) and 3.4°C (range 2.8–3.9°C), respectively.
Net-zero pledges, which have been announced by many
countries (chapter 3), further lower these temperature
estimates markedly by about 0.5°C, if fully implemented.
Sixty-six per cent, 50 per cent and 90 per cent percentile
global warming projections of pathways assuming
unconditional NDCs and net-zero targets would thenbecome 2.2°C (2.0–2.5°C), 2.0°C (1.8–2.3°C), and 2.7°C(2.3–3.1°C), respectively. Even with the implementation ofcurrent NDCs and all net-zero targets, there is still morethan a 15 per cent chance that global warming will exceed
2.5°C by the end of the century, and a just short of 5 percent chance that it will exceed 3°C (figure 4.3). Finally, theseestimated improvements from net-zero targets should also
be caveated by the fact that in many cases, current NDCs
do not yet set countries’ emissions on a direct path towards
reaching longer-term net-zero targets (see chapter 3).

This range reflects the uncertainty due to extrapolation of GHG emissions after the year 2030 and is given for the central estimate of 2030 emissions
implied by current policies, NDCs and/or other pledges. Taking the higher or lower end of the range surrounding the 2030 emissions estimateswould lead to an additional increase or decrease in the temperature projections by about 0.1°C, respectively. Geophysical uncertainties in the climate
response are reflected by the estimates for different warming percentiles (50 per cent, 66 per cent and 90 per cent).

Emissions Gap Report 2021: The Heat Is On

Figure 4.3. Range of global warming outcomes projected if unconditional nationally determined contributions andannounced pledges continue (left) and if additionally net-zero targets announced by countries are achieved (right)>4.0°C

3.0–4.0°C<1.5°C
3.0–4.0°C

1.5–2.0°C

2.5–3.0°C

1.5–2.0°C
2.0–2.5°C

2.0–2.5°C

d iti on al N D C s a nd

<1.5°Cpled

1.5–2.0°C

ti o

n

co n

di

pl

co

Un

ed

Un

ge

s

2.5–3.0°Csge

2.0–2.5°C

2.5–3.0°C

na

lN

DCs

with net-zero ta

3.0–4.0°C

ts
rg e

an

d

>4.0°C

Note: See box 4.1 for background.

Box 4.1. Estimating global warming implications of NDCs
A variety of methods exist to extend near-term emissions
until the end of the century (Gütschow et al. 2018). We
first estimate the global carbon price implied by the NDC
emissions reductions in 2030 from a no-policies baseline.
Here, we use the marker quantification of the second
Shared Socioeconomic Pathway, called SSP2, whichassumes a continuation of historical socioeconomic
dynamics (Fricko et al. 2017; Riahi et al. 2017), to estimate
the relationship between emission reductions and implied
carbon prices in 2030. Subsequently, the carbon priceimplied by the global NDC reductions (e.g. globally about
US$20 2010 in 2030 for unconditional NDCs) is extended out
until the end of the century by applying the same annual
growth rate as for projected global gross domestic product(GDP) under SSP2.
Based on the relationship between implied carbon
prices and global GHG emissions levels over the courseof the century, an emissions trajectory is estimated anddivided into its constituting gases (Lamboll et al. 2020).

Subsequently, the global warming outcome of eachpathway is assessed with the reduced-complexity carboncycle and climate model MAGICC (Meinshausen et al.
2011) in a set up that captures the uncertainties in radiative
forcing as well as climate and carbon-cycle response(Nicholls et al. 2021) as assessed in cross-chapter box 7.1of the IPCC AR6 (Forster et al. 2021). Countries’ net-zerotargets, described and assessed in chapter 3, further bring
down emissions projections over the course of this century(Höhne et al. 2021). The impact of this strengthening ofclimate action after 2030 is also estimated.
This approach is an update compared to previous reports,
both in terms of the method used to extend emissions
to 2100 and the climate model set up used. If the NDC
estimates of this report are assessed using last year’s
methods, the temperature projections for unconditional
NDCs would be about 0.2°C higher than this year’s
estimates.

37

Emissions Gap Report 2021: The Heat Is On

5

Are COVID-19 fiscal recovery measures bridging or
extending the emissions gap?

Lead authors:
Brian O’Callaghan (University of Oxford, UK; Harvard University, USA), Jean-Paul Adam (United Nations Economic
Commission for Africa [UNECA], Ethiopia)

Contributing authors:
Bartholomew Armah (UNECA, Ethiopia), Jean Paul Boketsu Bofili (UNECA, Ethiopia), Hopestone Kayiska Chavula (UNECA,
Ethiopia), Frederic Hans (NewClimate Institute, Germany), Andrew Prag (Organisation for Economic Co-operation andDevelopment [OECD], France), David Tritsch (University of Oxford, UK)

5.1

Introduction

In response to COVID-19, government fiscal investment inclimate change mitigation and adaptation can bolster longterm prosperity by creating jobs and accelerating economic
growth while also meeting environmental, gender and social
objectives. Academic evidence and political narratives
support this approach (Barbier 2020; O’Callaghan andMurdock 2021). Countries that fail to capitalize on thisopportunity for low-carbon and climate-resilient economictransformation risk their economic prosperity, environmental
sustainability and long-term social cohesion.
Despite this, most governments have so far failed toprioritize a transformative low-carbon recovery, with therelatively insignificant low-carbon investment announced
to date likely to maintain current unsustainable situations.1
As at May 2021, only 2.5–12.1 per cent of US$16.7 trillion in
total COVID-19 spending (excluding unallocated European
Union spending) has been low-carbon or had mitigation
co-benefits, while of a total US$2.25 trillion in announced
COVID-19 ‘recovery’ spending, 2 only 17–19 per cent hasgone towards low-carbon spending, representing an
insufficient commitment to align fiscal policies with theParis Agreement (Andrijevic et al. 2020; O'Callaghan etal. 2021; Organisation for Economic Co-operation andDevelopment [OECD] 2021; Vivid Economics 2021). A small
number of wealthy economies account for the overwhelming
majority of low-carbon spending, 3 with emerging market

38and developing economies in danger of being left behind.
Although low-carbon recovery funds have supported arange of initiatives, they have so far been skewed towards
clean energy and natural capital investments.
This chapter explores three questions:1.

How could COVID-19-related public spending bridge theemissions gap?
Section 5.2 summarizes key principles for low-carbon
public spending in response to the pandemic. The section
considers: (i) short-term rescue spending, to keep businesses
and people alive; (ii) longer-term recovery investment,
to reinvigorate the economy; and (iii) reinforcement
processes, to embed new economic trajectories fromrecovery investment into long-term development plans.
Targeted low-carbon rescue spending incentivizes thedecarbonization of hard-to-abate sectors 4 by including lowcarbon conditionalities or commitments in liquidity andother short-term business support and/or by sustaining
the industries likely to foster low-carbon economic growth(Barbier 2020). Low-carbon recovery investment accelerates
the low-carbon transition both directly and indirectly
by incorporating low-carbon incentives into traditional
investment. Low-carbon reinforcement initiatives build
long-term support for the projects and sectors targetedby low-carbon recovery investment, aligning long-term
development pathways with a low-carbon and climateresilient transformation of the economy. At every stage,
low-carbon spending and regulatory reforms should be1

Low-carbon investment is defined in this chapter as spending that is likely to reduce net greenhouse gas (GHG) emissions.

2

Fiscal ‘recovery’ initiatives are defined in this chapter as taxation or expenditure measures that aim to reinvigorate economic growth. Recovery
initiatives are distinct from ‘rescue’ initiatives, which act over the short term and aim to keep businesses and people alive in the face of immediate
crisis.

3

China, France, Germany, the Republic of Korea, Spain and the United Kingdom together account for 77.4 per cent of total low-carbon spending(O’Callaghan, Bird and Murdock 2021a).

4

Hard-to-abate sectors are those in which low-carbon means of production are significantly more expensive or lacking in scalability than traditional
means of production. Many of these sectors will require significant technological innovation to enable economically competitive GHG abatement
without productivity loss.

Emissions Gap Report 2021: The Heat Is On

considered in tandem, as successful implementation of thelatter can amplify the impact of the former.
2.

What are the characteristics of fiscal rescue andrecovery spending to date and how may they impact
the emissions gap?
Section 5.3 shows that low-carbon recovery measures havereceived only 17–19 per cent of fiscal investment and policy
focus to date. Status quo policymaking risks a lock-in andpossible expansion of high levels of greenhouse gas (GHG)
emissions towards and beyond 2030. While examples of
low-carbon investment are numerous and wide-ranging,
they largely come from a small set of advanced economies.
Long-term human capital development, including skills
development, remains underprioritized. Without asubstantial pivot towards higher low-carbon investment,
countries risk lower economic and social returns, as well
as a significant rebound in GHG emissions (United Nations
Environment Programme [UNEP] 2020).
3.

Do lower-income nations face greater barriers for lowcarbon recovery spending? If so, what can be done?
Section 5.4 indicates that although emerging market anddeveloping economies have suffered disproportionately
under the pandemic and are more exposed to climate risk,

their recovery spending has been low, inhibited by restricted
access to affordable finance. A global green recovery will
require concessional finance, including direct grants, tovulnerable countries that are significantly above current
proposals.5

5.2 How could COVID-19-related public
spending bridge the emissions gap?
This section discusses trends in fiscal response towards
recovery investment before asking why a low-carbon
recovery should be pursued and what it should incorporate.
In the early stages of the pandemic, fiscal packages
focused overwhelmingly on ‘rescue’ through the immediate
protection of lives, livelihoods and business continuity. As
death rates have gradually been controlled in many advanced
economies, packages have slowly shifted to incorporate
funds for reinvigorating the economy through ‘recovery
spending’ (figure 5.1). However, recovery efforts continue
to be inhibited by persistent COVID-19 outbreaks in many
countries, particularly emerging market and developing
economies (International Monetary Fund [IMF] 2020).

Figure 5.1. Announced rescue, recovery and unclear spending for advanced economies and emerging market and developing
economies

18

Announced spending (US$ tn)

16
14
12
10
8
6
4
2

Ja

n
2
Fe 0
b
2
M 0
ar
2
Ap 0
r2
M 0
ay
2
Ju 0
n
2
Ju 0
l2
0
Au
g
2
Se 0
p
2
Oc 0
t2
0
N
ov
2
De 0
c
2
Ja 0
n
2
Fe 1
b
2
M 1
ar
2
Ap 1
r2
M 1
ay
21

0

Advanced economies
Emerging market and developing economies

Unspecified

Unspecified

RecoveryRecoveryRescueRescueSource: O’Callaghan et al. (2021)

5

Concessional finance refers to loans and other financial instruments that are extended on terms substantially more generous than market financial
instruments.

39

Emissions Gap Report 2021: The Heat Is On

Opportunities for rescue spending: Low-carbon rescue
spending can ease industrial decarbonization, particularly
in hard-to-abate sectors, through including green incentives
in business liquidity support and other short-term support
mechanisms (e.g. reduced taxation) and/or by directing
support to industries likely to foster green growth(International Renewable Energy Agency [IRENA] 2020). 6
These programmes should empower businesses to makecost-efficient choices to transition to carbon neutrality
without compromising jobs and livelihoods.
Opportunities for recovery spending: Growing evidence
suggests that low-carbon investment can deliver stronger
economic returns than conventional stimulus, whilestrengthening climate mitigation, adaptation, air pollution
reduction, natural capital protection, 7 health outcomes,
inequality reduction, human mobility and broad social
progress and prosperity. 8 Carbon-intensive recovery
packages that grow fossil fuel industries without conditions
for a sustainable transition endanger economic returns asfossil fuel assets become devalued with reduced demand
for their outputs (Mercure et al. 2018; Ansari and Holz 2020;
van der Ploeg and Rezai 2020). An expert survey in Hepburn
et al. (2020) identified traditional transport and energy
infrastructure investment as the most harmful recovery
policies for long-term GHG emissions, although this analysis
did not consider armed forces infrastructure spending,which is also harmful compared with others (O’Callaghan,
Murdock and Yau 2021).
Some of the most attractive recovery measures for
reducing emissions – those which balance the potential
to spur economic growth in a contractionary environment
and the potential to mitigate emissions – include electricvehicle incentives and public transport modernization,clean energy infrastructure investments, energy efficiency
upgrades, natural capital investments and clean researchand development programmes (Barbier 2020; GarrettPeltier 2017; United Kingdom, Climate Change Committee

2020; Hepburn et al. 2020). Continental unions and regional
economic commissions of the United Nations havehighlighted similar priorities (see appendix B.1). Although theaccessibility of these options depends on the developmentof technological infrastructure and the availability of naturaland human resources, input-output modelling indicatesthat low-carbon investment could generate significantly
more jobs and greater economic value than traditional‘dirty’ and ‘neutral’ alternatives.9 This is true for bothadvanced economies and emerging market and developing
economies.
Opportunities for reinforcement spending: The role of
low-carbon reinforcement measures following recovery
remains largely undiscussed in academic and professional
literature. However, as COVID-19 spending becomesintegrated intro regulatory budgetary processes, it becomesincreasingly less distinguishable from normal ‘peacetime’
spending. Going forward, sustainability-proofing the entire
budgetary process and increasing policy coherence acrosssectors and levels will be crucial to maximize the impactof a low-carbon recovery. This could be achieved throughimplementing green budget tagging processes (Eltokhy etal. forthcoming) or applying more advanced green publicfinancial management frameworks.
Non-governmental and academic advisers collectively
propose at least seven key principles for designing a lowcarbon fiscal response to the pandemic, as summarized infigure 5.2. Consensus opinion suggests that policy design
should be consultative, evidence-based and gender-sensitive,
while ensuring prompt implementation that is considerate ofpandemic realities. Importantly, fiscal action represents only
one of several mechanisms available to advance climate
action and stimulate economic growth following COVID-19.
Regulatory and market interventions, among others, canplay a key role.10 Fiscal measures are also likely to prove
most effective when combined with appropriate regulatory
and market interventions (OECD 2020b).

6

Publicly-financed liquidity support and other short-term business support help businesses meet their immediate costs and continue operations,
without the threat of expeditious liquidation. Low-carbon conditionalities may require businesses to take environmental commitments as a conditionof receiving public funds (or having a lower temporary tax or expense load). Since these measures incentivize innovation, they may increase theeconomic impact of taxpayer spending while also delivering environmental and social benefits (O’Callaghan and Hepburn 2020).

7

Natural capital refers to ecosystems, biodiverse habitats, clean water and air, productive soils and a stable and resilient climate.

8

Hepburn et al. (2020), OECD (2020a), Georgieva (2021), O’Callaghan and Murdock (2021) and United Nations Economic Commission for Africa [UNECA](2021), among others, expand on existing evidence to support economic, environmental and social narratives for low-carbon public investment.

9

See International Energy Agency [IEA] (2020); Malliet et al. (2020); Pollitt et al. (2020); Vivid Economics modelling in O’Callaghan, Bird and Murdock(2021a); Vivid Economics modelling in O’Callaghan, Bird and Murdock (2021b); Kiss-Dobronyi et al. (2021); Schreiner and Madlener (2021). Ongoing
initiatives to improve comparative modelling methods also present a similar finding (Batini et al. 2021).

10 For instance, in renewable energy generation, streamlined approval processes, contracts for difference models, and feed-in tariffs drasticallyaccelerated uptake in pre-pandemic times (Haas et al. 2011; Schumacher 2019; Welisch and Poudineh 2020).

40

Emissions Gap Report 2021: The Heat Is On

Figure 5.2. Principles for a green recovery

Upholdingcommitments

Building resilience

Need to uphold 2030
SDGs and the Paris
Agreement

Mitigating climate risk
by emphasizing
nature-based
solutionsFiscal spending as anindicator of progressagainst NDCs

Investment in
effective disastermanagement

Centring
participation
Protecting the mostvulnerable andsynthesizing thediverse priorities ofdifferent socioeconomic groups,
genders, ethnicities
and age groups

Supporting theprivate sector

Creating alliances

Accelerating thetransition

Small andmedium-sizedenterprises andinformal enterprises
are vulnerable,account for most of
global employment
and can rapidly takeup green innovations

Building trade andinnovation networks
can support recovery

Stimulating markets
where the transition
is well under way (e.g.
renewable energy)

Shared governanceapproaches cancreate fiscal spacefor recovery indeveloping countries

Limiting fossil fuelsubsidies and making
dirty energy bailouts
conditional on green
transformations

Prioritizing
transparency
Transparent andinclusive policy
consultation isessential
Spending should notundermine
environmental
protections or
generate
unsustainable deficits

Sources: Synthesized from Butterworth (2020); C40 (2020); Corkal et al. (2020); Green Growth Knowledge Platform (2020); Partners for
Inclusive Green Economies (2020); United Kingdom, Climate Change Committee (2020); Ocean Conservancy (2021); The Lancet COVID-19
Commission Task Force on Green Recovery (2021)

To support accountability and transparency, low-carbon
recovery investment of all kinds should include appropriate
management structures for monitoring, reporting andverifying the effective implementation and use of recovery
funds (Agrawala et al. 2020), as well as designated funds andstandards for ex-post impact assessment. Such measures
may also improve understanding of the relative strengths of
low-carbon fiscal investment over alternatives.11 Oversighttools, such as the ‘do no significant harm’ principle
included in the European Union’s Recovery and Resilience
Facility regulation, can counter measures that endanger
environmental objectives (European Commission 2021).

5.3 What are the characteristics of fiscal
rescue and recovery spending todate and how may they impact theemissions gap?
This section provides a high-level assessment of thecharacteristics of global COVID-19 rescue and recovery
spending so far with respect to mitigation.

Across countries and data sources, several primary themes
have emerged:
1)

Only 2.5 per cent of US$16.7 trillion in total
COVID-19 fiscal spending (excluding unallocatedEuropean Union spending) has been low-carbon,
with only 17–19 per cent of a total US$2.25 trillion
in announced COVID-19 recovery spending likely
to reduce GHG emissions (O’Callaghan et al. 2021).
Seven countries account for almost 90 per cent of
this spending: China, France, Germany, Japan, theRepublic of Korea, Spain and the United Kingdom(figure 5.3). The percentage of recovery spending thatis low carbon has slowly increased since Emissions
Gap Report 2020 (UNEP 2020), perhaps driven inpart by a better understanding of the potential for
low-carbon investments to deliver strong economic,
environmental and social returns. High-carbon,
neutral and unclear spending (87.9–97.5 per centof total spending) either worsens or maintains
the unsustainable status quo of the current global
emissions trajectory (O’Callaghan et al. 2021; OECD
2021; Vivid Economics 2021).

11 Proposed economic indicators include short- and long-term multiplier effects and labour impacts, environmental indicators, such as GHG emissions
and air and water quality, and social indicators, such as cost-of-living, inequality, public health and gender equity impacts (Jotzo, Longden and Anjum
2020; World Bank 2020).

41

Emissions Gap Report 2021: The Heat Is On

Figure 5.3. Non-exhaustive overview of total fiscal rescue and recovery measures of G20 members with high-carbon,
neutral and low-carbon impacts as a share of 2020 gross domestic product12
10%
Argentina
Australia

BrazilCanada

China

GRO
GRO

% of GDP0%

Total (US$ bn, GRO)

0%

% of GDP

10%

Highly negative
US$354.98 bn

OECD
GRO
OECD
GRO
OECD
GRO

Negative
US$327.16 bn

OECD
GRO

France

OECD
E3G
GRO

Germany

Relatively neutral
US$13,706.29 bn

OECD
E3G

India

Indonesia

GRO
OECD
GRO
OECD
GRO

Italy

OECD
E3G

Japan
Republic of Korea

Mexico

GRO
OECD
GRO
GRO
OECD

RussianFederation

GRO

Saudi Arabia

GRO

South Africa
TurkeyUK

USA

Positive
US$15.3 bn

Highly positive
US$61.71 bn

GRO
OECD
GRO

Unclear
US$2,112.94 bn

GRO
OECD
GRO
OECD

Notes: GRO – Global Recovery Observatory of the University of Oxford, UNEP, Green Fiscal Policy Network and United Nations Development
Programme (UNDP); OECD – OECD Green Recovery Database; E3G – Green Recovery Tracker of Third Generation Environmentalism (E3G)
and Wuppertal Institute.

12 Data for the overall spending bar are from the Global Recovery Observatory, as it is the only current tracker that accounts for ‘neutral’measures. The International Monetary Fund (IMF) and Climate Action Tracker (CAT) have discontinued their trackers since the release of
the 2020 Emissions Gap Report. The Greenness of Stimulus Index from Vivid Economics has changed its methodology, such that it no longer
directly assesses policy-level climate impacts. Instead, the Greenness of Stimulus Index assigns a ‘greenness value’ (positive or negative)
to each sector of every tracked country, with the final index for each country being an average of sectoral impact. As this methodology is notcomparable with other trackers, Vivid Economics advised excluding the Greenness of Stimulus Index information from the figure. The IEA’s
Sustainable Recovery Tracker and the Energy Policy Tracker only cover energy spending and are therefore excluded from this analysis.
Many discrepancies between the included trackers relate to key differences in methodology: for instance, the Green Recovery Tracker (E3G undated)
does not include certain types of rescue spending, while the Global Recovery Observatory (O’Callaghan et al. 2021) accounts for all fiscal measures.
Trackers also vary in their definitions of ‘low-carbon’: one measure may receive a low-carbon tag by one tracker and a neutral tag by another, resulting
in substantial differences in spending recorded in either category. A comparison of trackers and their methodologies can be found in appendix B4.

42

Emissions Gap Report 2021: The Heat Is On

2)

Low-carbon fiscal investment has covered a wide
range of policy types. Over 500 low-carbon rescue
and recovery measures have been introduced
worldwide, covering most emerging and establishedlow-carbon industries (figure 5.4). The range of
spending has been notably wider in advanced
economies, with emerging market and developing
economies focusing their low-carbon recovery
funds on clean energy generation and natural
capital investments. Spending on worker retraining
initiatives remains low across countries, indicating
an insufficient focus on long-term human capitaldevelopment. A minor portion of investment in what
have traditionally been considered ‘neutral sectors’
include accompanying low-carbon incentives
Figure5.4(appendix
B.2 lists a few examples of this type ofinvestment).

3)

International disparities are significant in both
total spending and low-carbon spending. Somecountries are already well into their economic
recovery while others have been unable to act at all,constrained by low access to capital and continuing
COVID-19 mobility restrictions. Of those who havespent significantly, some have integrated green
priorities to a considerable degree, with others
having failed to consider environmental concerns in
any way. The Global Recovery Observatory has foundthat Canada, Denmark, Finland, France, Germany and
Norway can be considered as ‘leaders’ in low-carbon
recovery, with their low-carbon spending as a shareof recovery spending ranging between 39 and 75 percent. Spain, Sweden and the United Kingdom alsorank highly according to Vivid Economics’ Greennessof Stimulus Index.13

Figure 5.4. Global recovery spending as of May 2021 across sectors by region (US$ billions)
AfricaAsia

EuropeLatin America & the Caribbean

Clean energy

Northern America

Oceania(4.1%)

Clean R&D

(1.6%)

Clean transport

Lowcarbon
measures(3.3%)

Energy efficiency
Naturalinfrastructure
Armed forces(2.2%)(3.8%)(0.8%)

Traditional transport(9.2%)

Traditional energy(1.6%)
0

50

100

150

200

Highcarbon
measures

US$250 bn

Note: Low-carbon initiatives (top) and high-carbon initiatives (bottom).
Source: O’Callaghan et al. (2021)

As chapter 2 shows, global emissions dropped in 2020, but
are expected to bounce back in 2021. Studies on the impactof announced fiscal investment on global emissions suggestthat decisions made so far will maintain the unsustainable
trajectory of pre-pandemic economies (Forster et al. 2020;
Malliet et al. 2020; Meles et al. 2020; Pollitt et al. 2020; IEA
2021; Shan et al. 2021). In line with the 2020 Emissions Gap
Report, the studies suggest that a more carbon-intensive
recovery would increase emissions substantially in themedium to long term, while a low-carbon recovery would
significantly reduce emissions (see also appendix B.3).

5.4 Do lower-income nations face
greater barriers for low-carbon
recovery spending? If so, what canbe done?
This section describes the disproportionately negative
impacts of COVID-19 on vulnerable nations. It thendiscusses the need for significantly increased international
aid to simultaneously support economic recovery, long-term
economic development and climate priorities.

13 Leaders’ are classified as having spent above 1 per cent of gross domestic product (GDP) on fiscal recovery and above 30 per cent of this on lowcarbon measures (O’Callaghan and Murdock 2020). The Greenness of Stimulus Index score is calculated by combining the flow of stimulus into five
key sectors with an indicator of each sector’s environmental impact (Vivid Economics 2021).

43

Emissions Gap Report 2021: The Heat Is On

5.4.1 Vulnerable nations are being left behind
The COVID-19 crisis has had an especially negative impact onvulnerable nations: global extreme poverty rose in 2020 for
the first time in over 20 years, with an estimated 120 million
additional people estimated to be living in poverty due to thepandemic (World Bank 2021a). Foreign direct investment fellby 8 per cent in developing countries in 2020 compared with2019, driven by a 15.6 per cent decline in Africa and a 45.4
per cent decline in Latin America and the Caribbean (United
Nations Conference on Trade and Development [UNCTAD]
2021).14 Despite these trends, COVID-19 spending has been
far lower in low-income economies (~US$60 per person)
than advanced economies (~US$11,800 per person; seefigure 5.5).

Figure 5.5. COVID-19-related spending per capita across development categories (US$)

Advanced economies
US$11,826
per person

Emerging market and developing economies
US$578per person

Low-income economies
US$57
per person

Source: O’Callaghan et al. (2021)

Unequal access to finance is a key driver of disparities in
COVID-19 spending between high- and low-income nations(O’Callaghan and Murdock 2021).15
In 2020, development partners committed US$89.5 billion
to support African nations in response to COVID-19, of
which US$59.5 billion has been disbursed (figure 5.6). This
represents just 0.4 per cent of total global COVID-19 spending.
Without a substantial increase in foreign aid, the differencein spending between advanced economies and emerging
market and developing economies will exacerbate gaps indevelopment, while also restricting progress against climatechange. Emerging market and developing economies arealso likely to become the world’s top GHG emitters if climate
finance does not significantly increase (World Resources
Institute undated), all while disproportionately suffering
the burden of climate change, which has historically beencaused by high-income economies (see IMF 2021a).

14 Foreign direct investment refers to cross-border investment where an investor establishes lasting financial interest in and influence over an enterprise
domiciled in another economy.
15 Although many advanced countries have announced dramatic increases in expenditure at near- or below-zero financing costs (Blanchard 2019), thesame is not true of most emerging market and developing economies. Severe pandemic-induced economic contractions in most emerging market
and developing economies have caused a dramatic rise in debt-to-GDP ratios (IMF 2021b), temporarily increased credit default insurance premiums
as measured by credit default swap spreads (Council on Foreign Relations [CFR] 2021) and reduced current account balances (World Bank 2021b),
leaving emerging market and developing economies in the Latin America and the Caribbean, and Europe, the Middle East and Africa regions withhistorically low credit risk ratings (S&P 2021a; S&P 2021b). Across both advanced economies and emerging market and developing economies, climatechange is likely to expose some forms of debt to even more risk, particularly debt to finance climate-exposed investments such as agriculture (Dibley,
Wetzer and Hepburn 2021; European Central Bank 2021).

44

Emissions Gap Report 2021: The Heat Is On

Figure 5.6. Funding commitments and disbursements to Africa by development partners in 2020–2021 (US$ billions)

Multilateral financial
institutions (MFIs)
U$29.4 bn

Multilateral developmentbanks (MDBs)
US$60.1 bn
Commitments

Gavi, the Vaccine
Alliance
US$0.1 bn
Global Partnership for Education
US$0.3 bn

Actuals

MDBs
US$18.8 bn

MFIs
US$24.9 bn

European Union
US$6.4 bn

World Bank
Debt Service
Suspension
Initiative
US$9.0 bn

Key:
World Bank

African Development Bank

Islamic Development Bank

Arab Bank for Economic Development

International Monetary Fund

African Export-Import Bank

Arab Monetary FundWB Debt Service Suspension Initiative

European Union

Gavi Vaccine Alliance

Global Partnership for Education
Source: Non-public UNECA analysis (2021)

5.4.2 How to support vulnerable nations
As in advanced economies, low-carbon investment inemerging market and developing economies has thepotential to shorten the duration of COVID-19 impacts,
address climate concerns and set strong long-term
development pathways. Natural resource endowments inmany low-income nations make investments in renewableenergy generation facilities and natural capital solutions
particularly attractive (Kim 2020). By prioritizing local supply
chains, long-term partnerships between emerging market
and developing economies and high-income economies
can enable sustainable growth and build future-proof
infrastructure.
Wealthier economies could support vulnerable nations inseveral ways:●

Debt forgivenessBased on IMF and World Bank debt sustainability analysis,debt treatments, including debt write-offs, must be

considered for vulnerable countries. Debt relief programmes,
including debt-for-climate swaps, could help support lowcarbon recovery and a transition to low-carbon growth.16
A haircut of 10 per cent in debt repayments could result insavings of US$100 billion for reinvestment in low-carbon
recoveries (Jensen 2021). Debt restructuring, including
private debt, through new bond issuances aligned with
the Sustainable Development Goals (SDGs) and the Paris
Agreement could help avert a ‘lost decade’ and provide fiscal
resources for investment in a low-carbon recovery (Volz etal. 2021).
●

Direct grants and concessional financeNew low-carbon and climate-resilient recovery investments
can improve inclusion while advancing progress on the
SDGs. Advanced economies can accelerate this by providing
resources commensurate with the scale of the required
transformation, i.e. significantly more than the commitments
agreed at the sixteenth United Nations Climate Change
Conference of the Parties (COP16) of US$100 billion per year

16 Debt for climate-resilience swaps exchange the cancellation of a developing country’s public debt for increased investment in climate-related projects
in that same country. These instruments offer a vehicle for generating low-carbon recovery investment in sectors that facilitate the transition to lowcarbon growth.

45

Emissions Gap Report 2021: The Heat Is On(United Nations 2010). Disjointed interventions may widen
further divergence.
●

Concessional finance for green and blue bonds

The proceeds of green and blue bond issuances respectively
finance environmentally-friendly projects and ocean
conservation projects, often unlocking new finance toadvance climate goals (Banga 2018; World Bank 2008).
Green and blue debt markets are growing in emerging
market and developing economies, yet several challenges
remain, including only a small pricing benefit of green andblue bonds over regular bonds (Doran and Tanner 2019;
Otek Ntsama et al. 2021).17 Foreign monetary authorities
and governments could commit to purchasing green andblue bonds at lower interest rates in emerging market anddeveloping economies (Liaw 2020). Robust, standardized
and stringent certification and monitoring systems could
provide greater credibility for such issuances.
●

Guaranteeing private sector debt

The impact of public investment in climate resilience andmitigation can be significantly improved by ‘crowding-in’
additional private sector resources. Blended finance andpartial guarantees have a key role in supporting this for
emerging market and developing economies, particularly
following the pandemic-induced crash in international
project finance and other forms of foreign direct investment(UNCTAD 2021).
●●

Considerations for carbon border adjustment
mechanisms18

Carbon border adjustment mechanisms, such as those
proposed by the European Union, could provide highly
effective trade-based regulations to drive down emissions
and reward sustainable supply chains. However, althoughsuch mechanisms are primarily intended as protective
environmental measures, their unequal trade implications
and potentially high burden on vulnerable nations must be
acknowledged. If carbon border adjustment mechanisms
are implemented, standards and controls must be
developed that both support global environmental needs
and development priorities of vulnerable nations. Thesemechanisms (and their standards and controls) must
be implemented with significant financial and technicalresources to support capacity-building in vulnerable nations(see Gore 2021).
To ensure a successful sustainable and inclusive transition,
emerging market and developing countries requiresignificant technology transfer and capacity-building in
addition to financial support, needs that should be reflected
in updated nationally determined contributions (NDCs).
Support for low-carbon recovery in emerging market anddeveloping economies often relies directly on the nation’s
demonstrated interest to pursue public policy reforms thatare consistent with the Paris Agreement goals, such as, forexample, consideration of and action on carbon pricing,fossil fuel subsidies reform, green budgeting systems andregulations for financial sector greening.19

Redistributing multilateral finance tovulnerable nations

The proposed IMF issuance of US$650 billion in new
special drawing rights could strongly support a low-carbon
recovery if funds are directed to future-oriented low-carbon
and climate-resilient investments. On-lending a substantial
amount of such funds to the world’s most vulnerable
countries could significantly enhance the issuance. Without
such an action, only 3.2 per cent of the issuance will bedirected to low-income countries (The Economist 2021).
While the current IMF call for US$100 billion to be on-lent is
positive, it remains insufficient given the extreme disparity infiscal space between advanced and vulnerable economies.
Appendix B5 compares alternative approaches that could
be implemented.

17 For example, Egypt’s October 2020 issuance of a US$750 million green bond was broadly price aligned to its normal standard bond issuances (London
Stock Exchange 2020).
18 Carbon border adjustment mechanisms act to “equalise the price of carbon between domestic products and imports” to eliminate financial incentives
to relocate production outside of regions with strong climate controls (European Commission undated).
19 Emerging tools, such as the sustainable development and climate action green recovery screening tool (SCREEN, of the NewClimate Institute) can
assist in identifying high-potential opportunities.

46

Emissions Gap Report 2021: The Heat Is On

6

The role of anthropogenic methane emissions inbridging the emissions gap

Lead authors:
Drew Shindell (Duke University, USA), Marielle Saunois (Université de Versailles Saint-Quentin [UVSQ], Laboratoire desSciences du Climat et de l'Environnement [LSCE], France)

Contributing authors:
Dominik Brunner (Swiss Federal Laboratories for Materials Science and Technology [EMPA], Switzerland), Lena HöglundIsaksson (International Institute for Applied Systems Analysis [IIASA], Austria), Kevin Karl (Food and Agriculture Organizationof the United Nations [FAO], Italy), Euan Nisbet (Royal Holloway, University of London, UK), Stefan Schwietzke (Environmental
Defense Fund [EDF], USA), Francesco Tubiello (FAO, Italy)

6.1

Introduction

Methane emissions are the second largest contributor to
global warming to date after carbon dioxide (CO 2), accounting
for about one third of the warming impact of all well-mixed
greenhouse gas (GHG) emissions and 45 per cent of the
net warming impact of all anthropogenic activities in 2019
(Intergovernmental Panel on Climate Change [IPCC] 2021).
Along with black carbon, tropospheric ozone and somehydrofluorocarbons (HFCs), methane is a short-lived climate
pollutant (SLCP), a class that has much greater warming
impacts per ton than CO 2 , but a much shorter atmosphericresidence time. Methane accounts for more than half of thewarming of all SLCPs.
Atmospheric observations show that emission growth rates
have accelerated over the past 15 years, with methane
atmospheric concentrations reaching 1,879 parts per billion
in 2020 on annual average, which was 6 per cent higher thanin 2000 (Dlugokencky undated) and 260 per cent higher
than during pre-industrial times (World MeteorologicalOrganization [WMO] 2020). Anthropogenic emissions
account for roughly 60 per cent of total methane fluxes tothe atmosphere, amounting to around 365±30 megatonsof methane (MtCH 4)/year. Approximately 35 per cent comefrom fossil fuels (two thirds from oil and gas and one thirdfrom coal), 40 per cent from agriculture (three quartersfrom enteric fermentation and manure management and
one quarter from rice) and 20 per cent from waste (mostly
landfills and solid waste), with the remaining ~5 per centemitted through biofuel and biomass burning (Saunois etal. 2020).
The remaining roughly 40 per cent of total methane emissions
are generated by several natural sources: inland freshwaters(including wetlands, lakes, reservoirs and rivers), geologicalreleases, wild animals, termites and permafrost. Sectoral
partitioning of methane emissions varies greatly among
countries/regions and large uncertainties remain in bothanthropogenic and natural emissions (figure 6.1). Over thelast two decades, the main cause of increasing atmosphericmethane is likely increasing anthropogenic emissions, withhotspot contributions from agriculture and waste in Southand South-East Asia, South America and Africa, and fromfossil fuels in China, the Russian Federation and the UnitedStates of America (Jackson et al. 2020). Emissions fromnatural sources may also be increasing, as wetlands warm,
tropical rainfall increases and permafrost thaws.
The size of methane sinks (mainly oxidation in theatmosphere), and how this varies over time, remain difficult
to predict and study. Unlike CO 2 , little attention has been given
to capturing methane from the air, and further assessmentof the feasibility of methane removal is therefore required(Jackson et al. 2019).
Although methane emission reductions are a necessary partof long-term mitigation strategies alongside CO 2 reductions(Rogelj et al. 2018), mitigating methane emissions would
especially contribute to reducing climate change-related
damages in the near term, while reducing the level of
eventual temperature stabilization and decreasing peakwarming during this century.
As a result, there has been increased focus in recent years
on the immediate need and opportunity to reduce methane
emissions. The United Nations Environment Programme(UNEP) and Climate and Clean Air Coalition (CCAC)
released a Global Methane Assessment in May 2021, whichanalysed the benefits of reducing methane emissions, the47

Emissions Gap Report 2021: The Heat Is On

policies and costs of mitigation actions and the reductions
needed to meet Paris Agreement goals (United Nations
Environment Programme [UNEP] and Climate and Clean
Air Coalition [CCAC] 2021). Several groups have recently
analysed abatement potentials for methane, while others
have both examined mitigation and described the impactsof such mitigation on the ability to meet climate targets(Nisbet et al. 2020; Ocko et al. 2021; UNEP and CCAC 2021).
The main findings of these studies are assessed below, withsome elements highlighted and implications for nationallydetermined contributions (NDCs) explored.

Figure 6.1. Average methane emissions for 2008–2017 in MtCH 4 /year for 18 continental regions

40

40

40

40

40

40

40

30

30

30

30

30

30

30

20

20

20

20

20

20

20

10

10

10

10

10

10

10

0

0

0

0

0

0

CanadaUSA

EuropeRussian Federation

0

China

Central Asia

Korea and Japan

40

40

30

30

20

20

10

10

0

0

Central America

40

40

30

30

20

20

10

10

0

0

Northern SouthAmerica

TD WETLBU WETLTD FOSBU FOSTD AGRIWBU AGRIW

40

40

40

40

40

40

40

30

30

30

30

30

30

30

20

20

20

20

20

20

20

10

10

10

10

10

10

10

0

0

0

0

0

0

South-WesternSouth America

BrazilSouthern Africa

Equatorial
AfricaNorthern Africa

South-East Asia

Oceania0

Middle East

South Asia

Note: Emissions are shown for three main emission categories: wetlands (WETL), fossil fuel-related (FOS) and agriculture and waste(AGRIW). Coloured bars represent the minimum and maximum range of available estimates from top-down (TD) and bottom-up (BU)
approaches. Black dots show the average for each approach (based on Saunois et al. 2020 data sets). The colours in the map indicate
regions only.

6.2 Optimizing methane emission
reductions
The level of methane emissions (and other short-lived
substances) at the time of reaching net zero for long-lived
GHGs will play an important role in determining the levelat which temperatures stabilize. Methane stabilization at alevel greater than the pre-industrial level will mean a longterm commitment to warming relative to the pre-industrial
level, whereas changes in methane emissions will contribute
further to future temperature changes. As a GHG that does
not accumulate semi-permanently in the atmosphere,
achieving net-zero methane emissions is not required for148

climate stabilization, nor is it expected, in marked contrast
to the sum of CO 2 and nitrous oxide (N 2 O), for which net-zeroemissions are required for stabilization (Rogelj et al. 2018;see also chapter 3).
Methane abatement would affect warming rates in the nearterm, resulting in benefits for ecosystems and the ability ofhumans to adapt. As a precursor of tropospheric ozone,1
which can be toxic to both humans and plants, methane
emissions affect public health and crop yields via air
pollution. Defining the optimal path for methane emission
reductions is therefore arguably more suited to a multiplebenefits analysis than other GHGs, rather than an analysis

The troposphere is the lowest level of the atmosphere, which includes surface air.

Emissions Gap Report 2021: The Heat Is On

only defined by a climate metric (though other GHGs may
also have co-benefits that affect air pollution and health).
Captured methane has a clear use and market value as
natural gas. As a result, many methane reduction measures
have low or even negative costs, with many models
examining least-cost pathways to meet low warming targets
reducing methane sharply in the current decade (Harmsen
et al. 2019a; UNEP and CCAC 2021), though such reductions
are not yet occurring.
Depending on progress in mitigating emissions of long-lived
GHGs, rapid reductions of methane are also likely to play arole in limiting peak warming (chapter 3). That role depends
heavily on how quickly emissions of CO 2 are reduced, howmuch CO 2 removal is deployed, and on the emissions
trajectories of other short-lived climate forcers.

6.3 Short- and long-term mitigation
potentials
The UNEP and CCAC Global Methane Assessment assessed
the methane mitigation potential and cost estimates
produced by several teams. This assessment included
sector-specific assumptions about technology turnovertimes, estimates for improvements in technology overtime and the achievable pace of regulations. Costs include
estimates for the future value of recovered gas as well as
the discounting of future returns with rates of 4–10 per cent.
Implementation of readily available methane-targetedabatement measures alongside broader structural andbehavioural measures could reduce methane emissions byapproximately 180 Mt/year by 2030, which is equal to nearly
50 per cent of current methane emissions. Implementationof readily available methane-targeted measures alone (i.e.
excluding structural and behavioural measures) could
reduce 2030 methane emissions by around 30 per cent.
The fossil fuel sector shows the largest all-cost (i.e. notrestricting the analysis to low or negative net emission
control costs) absolute 2030 abatement potential inanalyses by three teams (Harmsen et al. 2019b; UnitedStates Environmental Protection Agency [U.S. EPA] 2019;
Höglund-Isaksson et al. 2020). Methane emissions fromthis sector could be reduced by approximately 75 Mt/year(~2.2 gigatons of CO 2 equivalent (GtCO 2 e)/year using global
warming potential over 100 years – GWP100) in the shortterm (2030) using methane-specific emission abatement
measures relative to ~130 Mt/year in projected 2030
business-as-usual (BAU) emissions. Within the sector, oiland gas has a substantially larger reduction potential thancoal in two of the analyses and roughly equal potential in thethird analysis. Based on the Global Methane Assessment,
all-cost oil and gas emission mitigation potential is 25–58
Mt/year by 2030 and 35–95 Mt/year by 2050 (relative toprojected BAU 2050 emissions of ~155 Mt/year). Averaged
over all measures, abatement costs are quite similar
for the coal subsector, but vary substantially for the oiland gas subsector. Restricting the analysis to low cost(< US$600/tCH 4 ; < ~US$20/tCO 2 e using GWP100) measures
only, ~17–32 Mt/year can be abated by 2030 in the oil andgas subsector, compared with ~8–24 Mt/year in the coalsubsector. The largest and most cost-effective abatement
potentials within the fossil fuel sector for 2030 are to preventall venting of associated gas during oil and gas extraction(including from inefficient flaring), to install leak detection
and repair programmes for natural gas infrastructure and toutilize ventilation air methane oxidation technology in coalmines (table 6.1).
Reducing methane emissions from waste and agriculture
will be more challenging but is crucial to achieving low
warming targets. For waste, the three analyses assessedin the Global Methane Assessment have very similar 2030
all-cost abatement potentials relative to projected 2030 BAU
emissions (~28–32 Mt/year; ~30–35 per cent; ~0.9 GtCO 2 e/year using GWP100), but with widely varying cost estimates(+US$3 to -US$200/tCO 2 e using GWP100). The largest andmost cost-effective abatement in the waste sector comesfrom municipal solid waste, typically either by divertingorganic waste from the waste stream or capturing andutilizing landfill gas. More simply, covering landfills with soil
is a very effective and low-cost measure, and reduces fires,
odours and air pollution. This could be an attractive option
for many tropical and subtropical megacities, which typicallyhave extremely large and ill-managed landfills. Crop waste
fires are widespread in the tropics, leading to significant air
pollution and methane emissions from partial combustion.
Such crop waste could instead be burned under controlled
conditions to generate electricity or returned to the soil toprovide nutrients.
All-cost abatement estimates for rice cultivation have
similar abatement potentials (~7–10 Mt/year) but vary
markedly in costs (roughly US$3–100/tCO 2 e using GWP100),
whereas low-cost abatement potentials and costs are quite
similar across analyses. Abatement within rice cultivationis possible through changes in agricultural production
techniques, such as alternate wetting and drying of paddy
fields, though the benefits can be undermined by increased
N 2 O emissions (table 6.1). In contrast, all-cost abatement
potential estimates for the livestock sector have similar
costs (~US$13–30/tCO 2 e using GWP100) but significantly
varied abatement potentials (4 to > 40 Mt/year). These
differences are largely attributable to assumptions about thefeasibility of some countries being able to switch to higheryielding livestock breeds. The average abatement potential
is therefore smallest in the agriculture sector at ~20–25
per cent. Several less well-established abatement options
are also under study for the livestock sector, including feed
substitutes and methane inhibitors (UNEP and CCAC 2020;
Ocko et al. 2021). At the same time, substantial mitigationof livestock-related methane could be achieved throughwidespread changes in human dietary choices, possibly
reaching 30 Mt/year (~0.9 GtCO 2 e/year using GWP100) by
2050, with additional CO 2 and N 2 O reductions (Willett et al.
2019; UNEP and CCAC 2021).

49

Emissions Gap Report 2021: The Heat Is On

For 2050, abatement potentials tend to increase moderately
compared with 2030, with the exception of waste and oil
and gas in one analysis that shows very large abatement
increases. The average abatement potential for waste
across the three estimates roughly doubles between 2030
and 2050. Similarly, the average all-cost abatement potential
in oil and gas increases to ~80 per cent of the 2050 value,with roughly half of these emission controls available
at low net cost. Targeted abatement estimates (without
behavioural changes) increase only modestly in agriculture,
which is expected to become the main anthropogenic
source of emissions in low warming scenarios (e.g. Rogelj
et al. 2018). Abatement costs also change, with some of themost noticeable shifts being that oil and gas abatement will
become more expensive on average. Changes in livestock
abatement costs vary significantly among analyses.
There are additional opportunities to reduce methane beyond
methane-targeted abatement measures. These include

50

fuel switching from natural gas to renewables in electricity
generation and in buildings, and behavioural changes suchas reduced consumption of cattle-based foods and reduced
food waste and loss. Integrated assessment models show
large ranges in potential methane mitigation due to theseprocesses. On average, these models indicate that suchactions could reduce methane emissions by another 15 percent beyond the targeted measures, for a total 2030 reduction
under 1.5°C scenarios of 45 per cent relative to BAU (UNEP
and CCAC 2021). Both the Global Methane Assessment andOcko et al. (2021) emphasize that fast methane action, as
opposed to slower or delayed action, can contribute greatly
to reducing midterm (2050) temperatures, i.e. peak warming
if long-lived GHG emissions are also controlled. Fast action
to reduce methane to a trajectory consistent with 1.5°C
scenarios was found to be able to reduce both 2050 and
2100 global mean temperatures, by 0.2–0.4°C and 0.4–
0.8°C, respectively, compared with a broad set of potential
baseline scenarios (UNEP and CCAC 2021).

Emissions Gap Report 2021: The Heat Is On

Table 6.1. Global annual abatement potential in 2030 and 2050 (MtCH 4 and MtCO 2 e)SectorTechnical abatement measure

2030
MtCH4

2030
MtCO2e

2050
MtCH4

2050
MtCO2eLivestock

Manure anaerobic digestion with biogas
recovery on large farms >100
livestock units

1.2

35

2.6

77

Breeding for improved productivity,
longevity and reproduction

1.2

36

12.2

354

Feed management and feed additives

1.8

54

9.5

274

Rice cultivation

Improved water management, use ofalternative hybrids and soil amendments

6.1

177

3.9

112

Burning of agricultural
waste residuals

Ban and enforcement of bans

1.8

52

3.1

89

Coal mining

Pre-mining degasification

4.4

128

17.7

513

Ventilation air methane oxidation

6.0

173

16.8

488

Flooding of abandoned coal mines

1.7

50

8.0

231

Increased recovery of associatedpetroleum gas

14.8

429

12.6

366

Leak detection and repair programmes

4.7

136

17.5

507

Gas production

Leak detection and repair programmes

9.4

274

14.4

416

Gas transmission
pipelines

Leak detection and repair programmes

2.7

79

10.6

308

Gas distribution
networks

Replacement of grey cast iron pipes andleak detection and repair

6.7

195

18.0

522

Food industry waste

Anaerobic digestion with biogas recovery

3.2

93

21.3

617

Paper, textile and woodindustry waste

Recycling and incineration with energy
recovery

1.8

53

5.1

147

Municipal solid waste

Source separation and anaerobic digestion
with biogas recovery

6.1

177

11.8

341

Source separation and recycling

5.9

170

14.1

410

Source separation and incineration withenergy recovery

3.7

109

13.3

385

Wastewater – industry

Two-stage anaerobic and aerobic
treatment with biogas recovery

6.7

195

23.1

671

Wastewater – municipal

Upgrade of primary to secondary/tertiary
with biogas recovery

1.2

35

5.8

169

91

2,650

241

7,000

Oil production

All sectors
Source: Höglund-Isaksson et al. (2020)

51

Emissions Gap Report 2021: The Heat Is On

6.4 Link between methane mitigationand paths to net-zero CO2
There are important links between methane emissions
and the path to net-zero CO 2 . Scenarios with strong
climate change mitigation policies include decarbonizing
the economy, which would reduce methane leakage fromfossil fuel systems due to reduced demand. However,decarbonization will lead to more abandoned oil and gas
wells and coal mines, which would need targeted actions
to reduce methane emissions that are distinct from direct
decarbonization policies (e.g. Kholod et al. 2020). By 2050,
methane abatement associated with decarbonization
alone is only about 30 per cent of the methane abatement
seen under a broad multi-pollutant, multi-policy 2°C
scenario, emphasizing the large role played by methanespecific policies.
On a more fundamental physical level, the less methaneis reduced, the smaller the available carbon budget willbe that is consistent with a given target (e.g. Rogelj et al.
2018). Quantitatively, every ~100 Mt of methane emissions
reduced and kept reduced increases the cumulative twentyfirst century carbon budget by around 450 GtCO 2 .
There are also many linkages between methane reduction
actions and opportunities for decarbonization. For example,
within land use, the abatement of livestock-related methane
typically involves reduced demand for cattle, which thenfrees up pasture and feed lands for potential production of
biofuels or afforestation. Methane-formed surface ozone is
known to reduce the growth rate of many plants, affecting
both crops (and therefore land use, as a greater area would
be required to produce the same yield) and decreasing
CO 2 uptake by forests (e.g. Sitch et al. 2007). Finally, usingorganic material from landfills as plastic substitutes could
reduce the need for petroleum-based plastics, which could
play a role in the transition away from fossil fuels (though
likely a modest role), while reducing landfill-related methane
emissions. As shown, several methane mitigation pathways
also have the potential to contribute to CO 2 mitigation.

informed by policy-specific input from national experts,
the project developed a range of plausible implementation
pathways to achieve the NDCs (Roelfsema et al. 2020). The
project also examined a least-cost 2°C scenario (accounting
for mitigation costs only, and excluding environmental
costs), with reductions starting in 2020 and a 66 per centchance of staying below 2°C.
According to those estimates, some countries have madepledges that would lead to substantial decreases in theirmethane emissions by 2030 (table 6.2). Extrapolating
countries’ NDCs reveals that most are projected to achieve
substantially greater reductions by 2050 than 2030. Japanis the exception, showing a smaller reduction in 2050. A
group of major emitting countries, including the UnitedStates of America, European Union nations, Japan andCanada, have NDCs that will likely result in reductions of~80–88 per cent of those seen in 2°C least-cost pathways
by 2030 compared with 2015, and ~69–77 per cent by
2050. However, most of the world is not yet as close to
2°C pathways, so at the global scale, NDCs are expected
to deliver only about a third of 2030 methane reductions
expected under 2°C scenarios. Among the major emitting
countries analysed, China, the Russian Federation, India andAustralia show the greatest emission gaps for methane, with
their NDC reductions relative to their 2°C reductions lessthan the global mean for both 2030 and 2050. Methane
reductions in 1.5°C least-cost pathways are 44 per cent at
the global level by 2030 compared with 2015, rather than
34 per cent for 2°C. The NDCs are therefore projected todeliver only about one quarter of 2030 reductions in 1.5°C
pathways. The International Institute for Applied Systems
Analysis (IIASA) has also carried out analyses of the impact
of NDCs on methane for the European Union, which show
decreases of 21 per cent by 2030 and 34 per cent by 2050
(relative to 2015), results that are very similar to those shownin table 6.2.

6.5 Methane mitigation in the first NDCs
Many countries present their mitigation pledges for GHG
emission reductions in various ways in their NDCs. 2 Someemissions targets are not quantitative, while most thatare quantitative tend to be provided as aggregated GHGs,
which makes it difficult to discern projections for individual
gases (at present, individual gases are only reported innational communication submissions by Annex I countries
for trajectories based on current policies). The emissions
implications of many major emitters’ first NDC commitments
have been analysed as part of a large international research
project. Using a suite of global and national models and252

The assessment in this chapter only considers the first round of NDCs. New or updated NDCs are not considered.

Emissions Gap Report 2021: The Heat Is On

Table 6.2. Projected changes in methane emissions relative to 2015 under nationally determined contributions and undera 2°C scenario
2050

2050

2050

Country%
decreasein NDC%
decreasein 2°CNDC/2°C
fraction

89

USA

44

57

77

34

88

EU

37

50

74

44

51

87

Japan

39

55

71

Japan

46

54

86

Canada

50

72

69

EU

22

28

80

Indonesia

40

65

61

Indonesia

23

40

59

Brazil21

38

56

Turkey22

38

58

Republic of
Korea

31

64

49

Brazil11

23

48

Turkey26

59

44

Global11

34

34

Global23

55

41

Rest of world

10

34

30

Rest of world

22

57

39

Australia

2

9

18

China

18

59

30

RussianFederation

5

35

16

RussianFederation

19

63

30

China

6

40

15

India

8

46

17

India

1

26

3

Australia

5

43

12

2030

2030

2030

Country%
decreasein NDC%
decreasein 2°CNDC/2°C
fraction

Republic of
Korea

26

29

USA

30

CanadaNote: Projections for both the NDCs and the 2°C scenario are based on Roelfsema et al. (2020) and PBL Netherlands Environmental
Assessment Agency (undated). Although ranges across the models were not specified for methane alone, the tenth to ninetieth percentile
range of the emissions gap between the NDCs and 2°C scenario for all GHGs was ~36 per cent at the global level and 30–55 per cent at
the national level, indicating that a similar uncertainty range is appropriate for methane estimates. The assumptions and underlying data
are described in Roelfsema et al. (2020).

Although there are signs that transformation is taking placein some parts of the world, more ambitious efforts are clearlyneeded if the world is to aim for 2°C or 1.5°C pathways.
In countries or regions with large projected decreases inmethane emissions, specific policies have been put into
place to achieve such reductions. Examples include the2016 North American Leaders’ Summit agreement to reduce
oil and gas methane emissions by 40–45 per cent by 2025
(relative to 2012) in Canada, Mexico and the United Statesof America, the European Union’s 2020 strategy to reduce
methane emissions (COM/2020/663 final) and the goalsof Nigeria and Côte d'Ivoire to reduce oil and gas methane
emissions by 60–75 per cent by 2030 as part of the UNEP
and CCAC Global Methane Alliance. In September 2021, theUnited States of America and the European Union announced
a Global Methane Pledge to reduce anthropogenic methane

emissions by at least 30 per cent globally relative to 2020
levels by 2030. On 11 October 2021, they reported that morethan 30 additional countries had committed to joining the
Pledge, with coverage now including nine of the top 20
methane emitters globally, and urged others to sign on
before the official launch at the twenty-sixth United Nations
Climate Change Conference of the Parties (COP26). Thereis a clear need for increased ambition almost everywhere,with possible actions that policymakers could consider
including increased efforts to build on growing momentum
to monitor and address environmental impacts within theprivate investment community. More transparent data on
sector-specific ‘best practice’ methane emissions would
help support a market for both monitoring and mitigation
services by facilitating the identification of the bestperforming companies.

53

Emissions Gap Report 2021: The Heat Is On

NDCs typically include more information about the energy
sector than the agriculture or waste sectors. Every country
emits GHGs from municipal waste, which is largely
generated by the human population (Eggelston et al.
2006). In NDCs representing 174 countries, 137 included
general waste sector mitigation commitments, with 67
citing specific mitigation actions (Powell et al. 2018). The
most common mitigation action was improved landfilling,followed by converting waste into energy (e.g. incinerationand conversion of landfill gas into energy). Improvements
in waste management systems could provide public healthco-benefits, such as reducing hazards associated with
wastewater mismanagement, improving air quality anddiminishing land and water contamination (Mittal et al. 2017;
Cohen et al. 2021).
Agricultural methane emissions primarily derive fromanimal stocks and rice cultivation, as well as deliberatebiomass burning, factors that vary widely from country tocountry (Food and Agriculture Organization of the United
Nations [FAO] 2021). In their first NDCs, 32 countries
referred to ‘climate-smart agriculture’, with aims to optimize
agricultural systems to increase productivity and incomes,enhance resilience and reduce GHG emissions (Strohmaier
et al. 2016). However, countries rarely included quantitative
targets for reducing agricultural methane emissions (Hönle
et al. 2019). In fact, of the top 46 countries that contribute to
90 per cent of global agricultural emissions, only a quarter
included broadly-stated measures targeting emissions
from ruminant livestock. This may be due to relatively highabatement costs and the impact such measures may haveon economically important sectors such as beef and dairy.
Mitigation measures such as sustainable intensificationof rice cultivation were more likely to be included, in part
because they present clear co-benefits for modernization or
productivity (Hönle et al. 2019). The magnitude of agricultural
methane emissions suggests that agriculture should receive
more attention than it currently does in methane mitigation
strategies, and that strategies that include changes in
consumption through a food systems approach will need
to be considered (Tubiello et al. 2021). Setting quantitative
goals for cropland and livestock management, which could
come in the form of targets for best practices, would help
countries raise their ambition in this sector.

6.6 Measurement-based verification of
uncertain emission reporting
In many cases, methane mitigation efforts are hamperedby uncertainties relating to actual emission numbers,
making it important to urgently improve approaches formeasuring and reporting emissions. Improved monitoringat the facility level could serve to motivate action to reduce
emissions and to verify the effectiveness of such action.
This would open up opportunities for regulators to use
flexible policy instruments that directly target measurable

54

emission reductions compared with more prescriptive
best available technology standards. Effectively prioritizing
methane sources, reducing methane emissions andtracking mitigation progress necessitates a broad suite ofmeasurement-based technologies that draw on the uniqueadvantages of each.
Traditional bottom-up approaches, based on sourcespecific emission factors combined with statistical activity
data (for example, livestock numbers, amount of oil and gas
extracted), have inherent uncertainties that can be large at
the national/sectoral scale (figure 6.1), especially for nonAnnex 1 countries with limited institutional capacity anddata availability (Solazzo et al. 2021). Even in countries
such as Germany and the United Kingdom, which havewell-established emission reporting systems, methane
inventories have been revised by up to 60 per cent between
subsequent submissions (Bergamaschi et al. 2010).
New top-down approaches have been developed that use
atmospheric observations (at the surface, airborne or fromsatellites), which when combined with atmospheric transportmodels, can be applied to determine emissions for a specificfacility, sector, region or other aggregation. These top-down
approaches have proven effective in correcting emission
factors and in revising sectoral methane emissions in
multiple geographies (e.g. Alvarez et al. 2018; Zavala-Araiza
et al. 2021), and in this way have provided opportunities for
identifying specific sources and mitigation opportunities(Lyon et al. 2016; Johnson et al. 2017).
Top-down approaches can also support the transparency
of reporting processes, with the updated IPCC reporting
guidelines recommending the application of suchapproaches as additional quality control (Bartram et al.
2019). However, at present, only Switzerland and the United
Kingdom include top-down methane estimates in an annex
to their national inventory reports (Manning et al. 2011;
Henne et al. 2016).
New observational capabilities are revealing emission
hotspots and facility- or city-scale emissions throughmeasurements from cars, drones and aircraft, and satellite
remote sensing, especially in remote world regions, which inat least a few cases has led to industry action to eliminate
major emission point sources (Nisbet et al. 2020). However,at a larger scale, top-down methods depend highly on thedensity of observations and are challenged by the difficultyin disentangling different sources and separating naturalemissions from anthropogenic emissions, which is crucial
for many countries with large natural emissions. Comparedwith high-frequency in situ surface measurements, satellite
observations have a broader coverage but less sensitivity tomethane sources, and are limited by cloud coverage. Further
deployment of mobile measurements and fixed stations
should therefore be supported to better monitor methane
concentrations, especially over tropical and boreal regions.

Emissions Gap Report 2021: The Heat Is On

In the near future, wider use of top-down approaches will
be facilitated by a new International Methane Emissions
Observatory (IMEO) hosted by UNEP. The International
Energy Agency (IEA) Methane Tracker (2020) alreadyincludes data on leaked methane of super emitters, which
is detected by the TROPOspheric Monitoring Instrument(TROPOMI), with a new generation of satellites, such as
GHGSat (Varon et al. 2020), being specifically designed tomap and quantify point sources.

55

Emissions Gap Report 2021: The Heat Is On

7

The role of market mechanisms in bridging theemissions gap

Lead authors:
Sha Yu (Pacific Northwest National Laboratory [PNNL], USA), Maosheng Duan (Tsinghua University, China), Jae Edmonds(PNNL, USA)

Contributing authors:
Katherine Calvin (PNNL, USA), Stefano De Clara (International Carbon Action Partnership [ICAP], Germany), Dirk Forrister(International Emissions Trading Association [IETA], Switzerland), Stephanie La Hoz Theuer (adelphi, Germany), Luca Lo Re(International Energy Agency [IEA], France), Ruben Lubowski (Environmental Defense Fund [EDF], USA), Axel Michaelowa(Perspectives and University of Zurich, Switzerland), Clayton Munnings (University of California, Berkeley, USA), Karen Holm
Olsen (UNEP DTU Partnership, Denmark), Mandy Rambharos (Eskom, South Africa), Chandra Shekhar Sinha (World Bank,USA), Detlef van Vuuren (PBL Netherlands Environmental Assessment Agency, the Netherlands)

7.1

Introduction: The role of carbon
markets and current status

In the Paris Agreement, cooperation among countries is
considered a way to both implement nationally determined
contributions (NDCs) and promote greater ambition, while
also fostering sustainable development and encouraging
broad participation from the private and public sectors.
Market mechanisms are therefore seen as an importantcomponent in collective action to achieve the long-termgoals of the Paris Agreement. In principle, the role ofmarkets within the context of the agreement is to enable allparties engaged in mitigation actions to implement these ina cost-effective manner, while simultaneously providing an
opportunity to enhance their ambition.
Under article 6, the Paris Agreement provides for aninternational framework for market mechanisms to enable
greater ambition in both mitigation and adaptation actions(Bodansky et al. 2016). It also allows countries to voluntarily
cooperate to achieve their NDCs, “promote sustainable
development and ensure environmental integrity andtransparency” (article 6.2), so long as parties avoid double
counting mitigation outcomes. The fact that 87 per centof new and updated NDCs specify countries’ intentions
to possibly use voluntary cooperation under article 6(United Nations Framework Convention on Climate Change[UNFCCC] 2021) confirms a significantly increased interestin this approach, compared with previous NDCs.

56

Although article 6 established these principles, the rulesthat facilitate their implementation in practice are still thesubject of negotiations, including guidance for cooperative
approaches (article 6.2), which covers all forms ofinternational mitigation markets, the rules for a mechanism(article 6.4), and a framework and work programme topromote non-market cooperation (articles 6.8 and 6.9).
These rules, modalities and procedures are an anticipated
key outcome of the of twenty-sixth United Nations Climate
Change Conference of the Parties (COP26).
There is already considerable experience in designing andimplementing market mechanisms to control pollutants,
including different forms of carbon markets (Schmalensee
and Stavins 2017; Michaelowa et al. 2019a; World Bank
2021a). The current state of carbon markets is very diverse.
Such markets include both voluntary and compliancedriven programmes, which are used both domestically andinternationally to reduce emissions, and involve different
types of allowances and credits and both public and private
sector entities as buyers and sellers (box 1, figure 7.1).

Emissions Gap Report 2021: The Heat Is On

Box 7.1. Current state of carbon markets
Compliance carbon markets are marketplaces in which
participants act in response to an obligation establishedby a regulatory body. The most prominent examples
of such markets are national or regional emissions
trading systems. In national emissions trading systems,
governments set a cap on the aggregate level ofgreenhouse gas (GHG) emissions that regulated entities
can emit over a period of time. These entities are required
to submit an emission permit (or allowance) for each tonof carbon dioxide equivalent (tCO 2 e) they emit. Emissions
trading systems can be restricted to domestic borders or
may have international elements through links with otheremissions trading systems (e.g. the European Union, theEuropean Union-Swiss link and the California-Quebec link)
and/or the acceptance of international offsets (e.g. theRepublic of Korea’s Emissions Trading Scheme – K-ETS).
In voluntary carbon markets, participants are under noformal obligation to achieve a specific target. Instead,companies, private entities and national governments
seek to voluntarily offset their emissions, for example, aspart of a social responsibility strategy. Voluntary buyers
can procure domestic or international carbon credits

from various different crediting programmes, as well as
allowances from compliance markets (Doda et al. 2021).
Compliance carbon markets have historically generated
more mitigation action and stronger incentives for
decarbonization than voluntary carbon markets, though
they may face more political opposition and entail higher
regulatory burdens. Voluntary carbon markets can be an
important tool to mobilize the private sector and expand
the reach of carbon markets beyond sectors and regions
subject to explicit climate regulation.
In terms of structure, domestic carbon markets havethe advantage of normally allowing better oversightand control through full regulatory control by a relevant
authority, with little risk of spillover effects from othersystems or jurisdictions, and all mitigation benefits
accrued domestically. Adding international elements tomarkets will increase their complexity, but also presents asignificant advantage of potentially reducing compliancecosts by making use of cheaper mitigation opportunities
in other jurisdictions.

Figure 7.1a Market typology

Figure 7.1a. Market typology

Domestic
carbon markets

VoluntaryCompliance

Domestic

International
InternationallylinkedETSs

Aviation
offsetting(CORSIA)
Government
compliance withinternational country
targets (UNFCCC)

Domestic carbon
markets withintl offsets

Corporate andpersonal carbon
footprint offsetting

Government
voluntaryoffsetting

Governments

Private entities

Source: Adapted from La Hoz Theuer (2021)

57

Emissions Gap Report 2021: The Heat Is On

Figure 7.1b Cross-border unit transfers

Figure 7.1b. Cross-border unit transfers

Sellers

Asset

Asset oversightframework

Allowances

Emissionstradingsystems

Private entities
Carboncredits

Creditingprograms:

BuyersCompliancebuyers (countries,
companies,
airlines)• UN-operated• Governmentoperated• Independent
Voluntary buyers(companies,
individuals,
governments)

Governments

Overachievementof NDCs

Governments

Paris
Agreement
articles 6 and13

Private entities

Public/Private

Source: Adapted from La Hoz Theuer (2021)

Experiences from these various markets and approaches
provide important learnings for the design of new cooperative
approaches. This chapter initially provides an assessmentof the potential role of market mechanisms under the Paris
Agreement in both the near term and in achieving long-termclimate goals (section 7.2), then examines technical issues
that have implications for the effective implementation ofarticle 6 (section 7.3), and finally discusses actions that canbe taken to unlock market potentials and enhance ambition(section 7.4).

7.2

The potential role of international
carbon markets under the Paris
Agreement: near-term versus netzero implications

7.2.1 Near-term implications
NDCs define the mitigation contribution of each party
to meeting the goals of the Paris Agreement. Countries
have prepared their NDCs using different target types andmetrics ranging from reductions in all greenhouse gas(GHG) emissions relative to a fixed emissions level (e.g. a
50 per cent reduction in all GHGs in 2030 relative to 2005), to
specific actions such as planting a specific number of trees
by a specific date, to conditional contributions that apply
only if an additional condition is met (Hood and Soo 2017).
The heterogenous nature of the current NDCs in this way
creates challenges for both negotiating and establishing58

effective real-world markets, as well as the risks of double
counting, emission leakages and unattainable targets.
There is growing interest from countries in using markets
and voluntary cooperation to implement their NDCs. Asof 30 July 2021, the share of parties that indicated an
intention or possibility of using voluntary cooperation
has nearly doubled, from 44 to 87 per cent in the new or
updated NDCs, compared with previous NDCs. Moreover,the share of parties that have set qualitative limits onvoluntary cooperation, such as using certain standards andguidelines to ensure additionality and avoid double counting,has increased from 19 to 39 per cent (UNFCCC 2021).
The existing quantitative literature that estimates the
maximum potential gains from cooperation generally
assumes that the heterogeneous NDCs could be translated
into a common comprehensive, transferable emissions
mitigation metric. This is evidently not something thatis going to happen quickly, if at all, and the results must
therefore be interpreted as estimates of potential gains fromcooperation compared with independent implementationof the same targets. These studies do not include ancillarydomestic benefits that may have motivated countries’
choice of NDC target methods.
A relatively limited number of studies have so far provided
quantification of the gains from cooperative implementation
of NDC pledges (e.g. Fujimori et al. 2016; Hof et al. 2017;
Edmonds et al. 2019; Böhringer et al. 2021; Edmonds et al.

Emissions Gap Report 2021: The Heat Is On

2021). With the aim of achieving the current NDC ambition
through global cooperation, most models estimate a
global carbon price of US$9–38/tCO 2 between 2025 and2030.1 In contrast, the studies find that due to the varying
stringency in NDCs, the shadow price of carbon for acountry to independently and cost-effectively achieve its
unconditional NDC pledge by 2030 ranges from US$0/tCO 2
to over US$250/tCO 2 across models and studies (with eachstudy analysing then-current NDC pledges), highlighting thepotential gains through international emissions trading. As
a result, the estimated mitigation costs by 2030 in an ideal
situation could be reduced by 40–60 per cent through thefull use of market mechanisms (Aldy et al. 2016; Fujimori etal. 2016; Hof et al. 2017; Edmonds et al. 2019; Edmonds etal. 2021). Although there are uncertainties associated witheconomic modelling, results in all studies suggest significant
potential cost reductions and economic gains from using
market mechanisms. These results provide a strong
incentive for countries to negotiate a credible agreement
on article 6 and to move towards more compatible NDCs
over time.
The modelling studies estimate that around 4–5 GtCO 2 e
could be traded per year by 2030 with a market volume of
US$60–100 billion per year if NDCs are transformed into
tradable emission mitigation actions (Fujimori et al. 2016;
Edmonds et al. 2019; Edmonds et al. 2021). Net market
transactions constitute balance-of-trade changes andtherefore changes to participants’ gross domestic product(GDP) and/or exchange rate position. For selling regions,this would represent a potentially significant new net export(Piris-Cabezas et al. 2019; Edmonds et al. 2021; Kachi etal. 2020). The extent to which this will actually occur isvery uncertain, with many parties emphasizing domestic
implementation and mentioning flexible mechanisms as anadditionality in their NDCs.
Carbon markets shift both emission mitigation actions andemission mitigation investments from buyers to sellers.
Provided that sellers are primarily developing countries,
carbon markets have the potential to transfer emission
mitigation-related capital towards developing economies,
help prevent lock-ins to carbon-intensive infrastructure andcontribute to capacity-building to further reduce emissions.
Redistributing capital investments potentially carries
implications for other sustainability metrics, such as local
air quality, forest conservation, rural livelihoods, food prices,
water quality and energy access, as well as for the regional
distribution of incentives for technology development andinnovation.
While increasing emission mitigation innovations inselling regions, carbon markets could reduce incentives inbuying regions. In buying regions with greater capacity to1develop capital-intensive emission mitigation technologies,
the overall pace of technological change that favours
emissions mitigation could be reduced if ambitions are
not increased at the same time. However, under different
policy designs, near-term flexibility facilitated by low-cost
mitigation options, such as reducing tropical devastation,
can free resources to boost investments into research anddevelopment and yield improved technologies in the longer
term (Szolgayová, Golub and Fuss 2014; Koch et al. 2017).
Studies of potential emissions mitigation with international
markets indicate that land-use emission mitigation
opportunities are undertaken earlier than under independent
NDC implementation (Edmonds et al. 2021). By valuingland-use change emissions, international carbon markets
can also provide incentives to prevent deforestation andincrease afforestation and reforestation (Lubowski andRose 2013; Fujimori et al. 2016; Edmonds et al. 2019; PirisCabezas et al. 2019; Edmonds et al. 2021; Fuss, Lubowski
and Gulub 2021).
The need for an interlinked implementation of climate
goals and the Sustainable Development Goals (SDGs)
is being increasingly recognized at the political level toenhance synergies and maximize co-benefits. However,tools and approaches to assess and report on sustainable
development impacts of article 6 cooperative approaches
are lacking and remain an unresolved topic in negotiations(Olsen, Arens and Mersmann 2018; Kachi and Mooldijk
2020). Similarly, there are unresolved issues about how
the use of cooperative approaches can be designed tocontribute to financing adaptation in vulnerable countries
with limited potential for direct participation.

7.2.2 Net-zero implications
For climate change to stabilize, global anthropogenic
net emissions must decline to zero (chapter 3). As of
13 September 2021, 50 parties to the United Nations
Framework Convention on Climate Change (UNFCCC) haveannounced net-zero targets, of which five parties have
explicitly indicated their intent to use international trading
to achieve their net-zero pledges. In addition, a growing
number of non-State and subnational actors have madenet-zero pledges with trading considered.
When global net carbon emissions start to approach zero,carbon market conditions will be very different to how they
are currently. Reducing global carbon emissions to net
zero involves reducing carbon emissions to near zero in all
sectors in all regions, with emissions that remain positive
being offset by so-called negative emissions or carbon
dioxide (CO 2) removal (see chapter 3). This suggests thatthe overall scope for transactions in physical (i.e. tons of
CO 2 – tCO 2) will shift towards negative emissions over time.

The Asia-Pacific Integrated Model/Computable General Equilibrium (AIM/CGE) 2.0 ADVANCED analysis from the Intergovernmental Panel on
Climate Change (IPCC) Special Report on global warming of 1.5°C database estimates a substantially higher value of carbon price (US$73/tCO 2) by
2030.

59

Emissions Gap Report 2021: The Heat Is On

The marginal cost of removing the final tons of CO 2 fromsome hard-to-abate sectors and regions could become high,
implying that transactions that occur could be very valuable.
As discussed in chapter 3, net-zero pledges across countries
and organizations have different timings, sectoral coverage,gas coverage and legal statuses. In addition to the challenges
discussed in section 5.3, ambiguity of net-zero targets
creates additional barriers to using market mechanisms
to achieve net-zero targets. Further complexity arises fromuncertainty in how to treat the various forms of CO 2 removal(National Academies of Sciences, Engineering, and Medicine2019) in carbon markets. Some carbon markets (Australia,
Colombia, New Zealand and the Republic of Korea, andCalifornia, Alberta and China’s regional systems) alreadyrecognize the role of nature-based removal credits and thelong-term importance of bringing emission sources andsinks into a common market framework aimed at achieving
net-zero emissions (La Hoz Theuer et al. 2021).
To reach global net-zero emissions, countries with emissions
greater than zero may need to be balanced by countries withnegative emissions. Almost all global net-zero scenarios
assessed in the Intergovernmental Panel on Climate Change(IPCC) Special Report on global warming of 1.5°C and Fifth

Assessment Report databases have similar marginal costs
across world regions, which implicitly assume international
cooperation to achieve global net-zero scenarios. Van Soest
et al. (2021) examined cost-optimal emission phase-out
years, without fairness considerations, for both 1.5°C and
2°C targets across six integrated assessment models. Theirfindings revealed significant variations in the timing in whichcountries reached net-zero emissions, which indicates that
there is potential for using market mechanisms to achievea global net-zero goal.
The magnitude, value and patterns of emissions trading
to reach a global net-zero target are dynamic and dependon several factors, such as the use of CO 2 removal
technologies and the timing of reaching net zero in eachregion (Yu et al. 2021). Market size, for example, reaches
US$300–400 billion in 2030 and around US$1 trillion in
2050 in scenarios with different net-zero timings. Studies
have found that land resources also play an important role
(Intergovernmental Panel on Climate Change [IPCC] 2018;
Yu et al. 2021). Removal credits by technology-based CO 2
removal approaches could play an increasingly importantrole to achieve net-zero emissions but will be limited by the
global removal capacity of these technologies (Allen et al.
2020; La Hoz Theuer et al. 2021).

Box 7.2. Enhancing ambition through carbon markets
The main goal of article 6 of the Paris Agreement is toenable parties to increase their ambition towards achieving
the agreement’s long-term goals. Many researchers
have documented that the initial nationally determined
contributions (NDCs) are insufficient to be aligned withtrajectories to reach the long-term Paris Agreement
goals (Fawcett et al. 2015; United Nations Environment
Programme [UNEP] 2020). However, recent studies by
Piris-Cabezas et al. (2019) and Edmonds et al. (2021)
have shown that if the savings from more cost-effective
global implementation of NDCs were redeployed towards
increased ambition, global emission reductions could
be roughly doubled over the next decade at no added
cost to parties compared with parties acting alone to
implement their commitments (figure 7.2). A major partof the potential ambition increases derives from natural
climate solutions, notably forests. Piris-Cabezas et al.
(2019) estimate that this doubling of climate ambition
provides about two thirds of the reductions necessary to
get on a 2°C pathway through 2035, closing about half ofthe current gap without any added cost compared withparties acting independently. Although these calculations
are evidently speculative, they highlight both the potential
power of carbon markets and how far NDCs need to beenhanced to capture that potential.

60

Carbon markets do not create ambition for parties. Rather,
they create conditions that make enhanced ambitions more
attractive through the implicit incentive that emissions
mitigation is cost-effective, thereby lowering political andstakeholder resistance to tightening targets and facilitating
emission reductions and strengthened targets over time.
Experience from the world’s current major emissions
trading systems supports this approach (Parker 2019).
Emissions within trading systems have always fallen fasterand at a lower cost than initially expected (Haites 2018).
Periods of low prices have been followed by a period ofpolicy reassessment and more ambitious targets, as seen
under the European Union Emissions Trading System (EUETS), the Regional Greenhouse Gas Initiative (RGGI) andCalifornia’s cap-and-trade programme.
Various explicit mechanisms have been proposed toincrease ambition. These include, for example, taxing or‘cancelling’ a portion of emission mitigation trades. Undera fixed emissions budget, such schemes could increase
overall emissions abatement in the near term. However,according to Piris-Cabezas et al. (2019), such an approach
applied on a per transaction basis functions as a typeof tariff on mitigation exports and hinders the ability ofmarkets to deliver cost-effective mitigation. In the longterm, this prevents markets from lowering costs andthereby from facilitating increases in ambition.

Emissions Gap Report 2021: The Heat Is On

Figure 7.2. Increased ambition potentially available from economic efficiency savings available from the ideal implementationof article 6
1.5

Current policies

Conditional NDCs

2015 = 1

Enhanced ambition from article 6

1

20
30

20
25

20
20

20
15

0.5

Source: Adapted from Edmonds et al. (2021)

7.3

Using market mechanisms underarticle 6

Although there is potential for international carbon markets
to reduce costs to achieve NDC goals and increase ambition,such potential will remain unknown until important details
are determined under article 6. These include establishingrobust rules to ensure environmental integrity, including the
avoidance of double counting, capacity-building and the
management of potential carbon leakages.

7.3.1 Getting the accounting right
To avoid double counting the same emission reductions/removals, the Paris Agreement requires parties participatingin article 6.2 cooperative approaches to apply ‘corresponding
adjustments’, i.e. adjusting the balance of their emissions
or removals covered by their NDCs to reflect internationallytransferred mitigation outcomes.
To ensure environmental integrity under article 6.4, parties arenegotiating the application of corresponding adjustments,
though their implementation is being complicated by thediverse scope and formulation of the parties’ NDC pledges(Greiner et al. 2019; Asian Development Bank 2020). Parties
have different views on how to define the scope of NDCs, forexample, whether to define them in terms of sectors, gases
and/or policies and measures. There is also disagreement
over whether corresponding adjustments should be
required for internationally transferred mitigation outcomesgenerated outside the scope of selling countries’ NDCs.

Many NDCs only include single-year targets, such as 2025
or 2030, which raises the question of how to treat noncompliance years when accounting for internationallytransferred mitigation outcomes. Several accounting
methods have been put forward to address this challenge(Greiner et al. 2019; Lo Re and Vaidyula 2019; AsianDevelopment Bank 2020).

7.3.2 Trade when the basic policy environment
lacks a fixed emissions limit
Target setting in the NDCs is still very heterogeneous.
Some NDC emission mitigation targets (Graichen, Camesand Schneider 2016; Vaidyula and Hood 2018; Schneider et
al. 2019) are expressed in non-GHG terms, such as energy
efficiency and forestry, while others are framed as intensity
targets and/or targets relative to projected business-asusual (BAU) emissions. Uncertainties in BAU emission
projections may weaken the actual ambition of mitigation
targets (Hood, Briner and Rocha 2014; Graichen, Cames andSchneider 2016; Hood and Soo 2017; Vaidyula and Hood
2018; and Rocha and Ellis 2020). The scope of NDCs also
differ in terms of sectors and GHGs: some cover all sectors
and all GHGs, some have more limited coverage and others
are unclear and only include indicators, such as policies
and measures.
The lack of a fixed emissions limit in many NDCs makes
accounting complex. Some researchers have recommended
the use of economy-wide absolute emission targets for all
NDCs to facilitate robust accounting and reduce complexity

61Emissions Gap Report 2021: The Heat Is On(Graichen, Cames and Schneider 2016; Schneider et al.
2019). Although this is not likely to happen anytime soon,
parties could be requested to provide clearer and moretransparent NDC targets as a potential short-term step.
For this purpose, the Katowice Climate Package includes
detailed provisions on how countries should describe or
clarify the scope of their NCDs. However, some provisions of
this package are only mandatory for second and subsequent
NDCs or require countries to provide relevant information by2024 (Schneider et al. 2020).
The treatment of mitigation outcomes generated outside
the scope of NDCs is an important issue in negotiations. The
main advantages of allowing emission reductions outside
the scope of NDCs include the full utilization of mitigation
potential, reduced mitigation costs, improved data quality of
uncovered sectors and the facilitation of their inclusion into
future NDCs (Spalding-Fecher 2017; Schneider et al. 2020).
Disadvantages include disincentives to enhancing the scopeof NDCs, a lack of fairness, scrutiny and quality assurance,and double-counting risks (Spalding-Fecher 2017; Howard
2018; Warnecke et al. 2018; Hood 2019; Michaelowa et al.
2019b; Schneider and La Hoz Theuer 2019; Schneider et
al. 2020).
Many options have been raised to address the above citedconcerns, such as applying corresponding adjustments
regardless of NDC scope, bringing relevant sectors and
GHGs into the scope of next NDCs, imposing internationaloversight on the quality of NDCs and restrictions on thenumber of and deadline for achieving internationallytransferred mitigation outcomes, quantifying NDC targets
in terms of GHG emissions and specifying the scope of
NDCs (Marcu et al. 2017; Mizuno 2017; Spalding-Fecher
2017; Howard 2018; Greiner et al. 2019; Warnecke et al.
2018; Schneider and La Hoz Theuer 2019; Schneider et
al. 2020). Care needs to be taken in framing such offset
programmes so that macroscale outcomes deliver theintended aggregate emissions mitigation. Calvin et al. (2015)
showed that well-intentioned offset programmes have thepotential to inadvertently lower overall ambition.
Although some of the proposed options are ideal in theory,
they may lack political feasibility. Many parties have been
concerned by potential limitations on article 6 participationand threats to the bottom-up nature of NDCs.

62

7.4

The way forward

One possible outcome of COP26 is that initial article 6 rules
will be agreed upon, with the intention that they be improved
gradually over time and strengthened through other market
arrangements. This has been the case for other parts of
the Paris Agreement. The Clean Development Mechanism(CDM) could be a useful reference in this regard, as despite
receiving many criticisms, it has played a crucial role infacilitating or enhancing many countries’ mitigation efforts.
In many developing countries, the capacities developed
through participation in the CDM (e.g. to measure and verify
emissions) have helped them prepare their initial NDCs. In
some countries, such as China and the Republic of Korea,
participation in the CDM provided valuable lessons andcapacities for establishing domestic carbon markets.
Success of the Paris Agreement market arrangements will
require the establishment of solid managerial, technicaland institutional capacity. Parties participating in article
6.2 will need to jointly agree on a cooperative framework
for emission reductions, decide how to establish domestic
modalities and procedures to complete the authorization,
quantification, monitoring, verification and reporting ofinternationally transferred mitigation outcomes and makecorresponding adjustments after the transfer of theseoutcomes (World Bank 2021b). Participation in the article
6.4 mechanism will be more demanding for host parties
than the CDM, as it will involve documenting transparent
reductions, as well as showing additionality to their NDCs
and supporting sustainable development.

Emissions Gap Report 2021: The Heat Is On

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