Near-term Climate Protection and 

Clean Air Benefits: 

Actions for Controlling Short-Lived 

Climate Forcers

A UNEP Synthesis Report
Published by the United Nations Environment Programme (UNEP), November 2011

Copyright © UNEP 2011

ISBN: 978-92-807-3232-0

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UNEP 2011. Near-term Climate Protection and Clean Air Benefits: Actions for Controlling Short-Lived Climate Forcers, United 

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Near-term Climate Protection and 

Clean Air Benefits:

Actions for Controlling Short-Lived 

Climate Forcers

A UNEP Synthesis Report
The United Nations Environment Programme (UNEP) would like to thank the Steering Committee, the Lead and 

Contributing Authors, the Stockholm Environment Institute (SEI) for coordinating the project and the Secretariat for their 

contribution to the development of this report. The development of the report was managed jointly by the Chief Scientist 

(Professor Joseph Alcamo) and the Division of Environmental Law and Conventions (Director, Mr. Bakary Kante) of UNEP.

The following individuals have provided input to the report. Authors and reviewers contributed to this report in their 

individual capacity and their organizations are only mentioned for identification purposes.

Steering Committee Members: 

Joseph Alcamo – Chair (UNEP), Francisco Barnes (National 

Institute of Ecology, INE, Mexico), Svante Bodin (Swedish 

Ministry of the Environment), Munjurul Hannan Khan 

(Ministry of Environment and Forests, Bangladesh), 

Leluma Matoane (Department of Science and Technology, 

South Africa).

Lead Authors:

Coordination: Johan C.I. Kuylenstierna (Stockholm 

Environment Institute, SEI, University of York, UK), Maria 

Cristina Zucca (UNEP). Main writing team: Markus Amann 

(International Institute for Applied Systems Analysis, IIASA, 

Austria), Beatriz Cardenas (National Institute of Ecology, 

INE, Mexico), Bradnee Chambers (UNEP), Zbigniew Klimont 

(International Institute for Applied Systems Analysis, IIASA, 

Austria), Kevin Hicks (Stockholm Environment Institute, SEI, 

University of York, UK), Richard Mills (International Union 

of Air Pollution Prevention and Environmental Protection 

Associations, IUAPPA, UK, and Global Atmospheric 

Pollution Forum), Luisa Molina (Massachusetts Institute 

of Technology and the Molina Center for Energy and the 

Environment, USA), Frank Murray (Murdoch University, 

Australia), Pam Pearson (International Cryosphere Climate 

Initiative, ICCI, USA), Surya Sethi (Former Principal Adviser, 

Energy, and Core Climate Negotiator, Government of 

India), Drew Shindell (National Aeronautics and Space 

Administration Goddard Institute for Space Studies, NASAGISS, USA), Youba Sokona (African Climate Policy Centre, 

ACPC, Ethiopia), Sara Terry (US Environmental Protection 

Agency), Harry Vallack (Stockholm Environment Institute, 

SEI, University of York, UK), Rita Van Dingenen (European 

Commission Joint Research Centre, Ispra, Italy), Martin 

Williams (King’s College, London, UK), Clarice Wilson 

(UNEP), Eric Zusman (Institute for Global Environmental 

Strategies, IGES, Japan). 

Contributing Authors:

Susan Anenberg (US Environmental Protection Agency), 

Jiming Hao (Tsinghua University, China), Christopher Heyes 

(International Institute for Applied Systems Analysis, 

IIASA, Austria), Lena Höglund-Isaksson (International 

Institute for Applied Systems Analysis, IIASA, Austria), 

N. T. Kim Oanh (Asian Institute of Technology, Thailand), 

Lara Ognibene (UNEP), Sophie Punte (Clean Air Initiative 

for Asian Cities, CAI-Asia, Philippines), Sunday A. Leonard 

(UNEP), Volodymyr Demkine (UNEP), Harald Dovland 

(Carbon Limits, Norway), Wolfgang Schöpp (International 

Institute for Applied Systems Analysis, IIASA, Austria), 

Durwood Zaelke (Institute for Governance & Sustainable 

Development, USA). 

Additional Contributions to the Report:

Emma Marie Cocks (UNEP Intern), Sarah JornsaySilverberg (UNEP Intern), T.S Panwar (WWF-India), Nathan 

Borgford-Parnell (Law Fellow, INECE), Elizabeth Toba 

Pearlman (Law Fellow, George Washington University).

Scientific Reviewers:

John van Aardenne (European Environment Agency, 

Denmark), Hajime Akimoto (Asia Center for Air 

Pollution Research, Japan), Jane Akumu (UNEP), Myles 

Allen (University of Oxford, UK), Paul Almodovar (US 

Environmental Protection Agency), Kristin Aunan (Centre 

ii Near-term Climate Protection and Clean Air Benefits – ACKNOWLEDGEMENTS

Acknowledgements
for International Climate and Environmental Research, 

CICERO, Norway), John Bachmann (Vision Air Consulting, 

USA), Ellen Baum (Clean Air Task Force, USA), Gufran Beig 

(Indian Institute of Tropical Meteorology, Pune, India), 

Tami Bond (University of Illinois, USA), Niel Bowerman 

(University of Oxford, UK), John F. Burkhart (Norwegian 

Institute for Air Research, NILU), Zoe Chafe (Worldwatch 

Institute, USA), Linda Chappell (US Environmental 

Protection Agency), Dennis Clare (Institute for Governance 

and Sustainable Development, USA), Robert Dobias (Asian 

Development Bank, The Philippines), Elisa Dumitrescu 

(UNEP), Dale Evarts (US Environmental Protection 

Agency), Amy Fraenkel (UNEP), Peter Gilruth (UNEP), 

Patience Gwaze (South African Weather Service), JeanneMarie Huddleston (Environment Canada), Francis X. 

Johnson (Stockholm Environment Institute, Sweden), 

Jennifer Kerr (Environment Canada), Arkadiy Levintanus 

(UNEP), Rocio Lichte (UN Framework Convention on 

Climate Change UNFCCC), Peter Louie (Hong Kong 

Environmental Protection Department, Government of 

the Hong Kong Special Administrative Region, China),

Peter Lukey (Department of Environmental Affairs, South 

Africa), Judy Meltzer (Environment Canada), Ray Minjares 

(International Council on Clean Transportation, USA),

Brian Muehling (US Environmental Protection Agency),

Nicholas Muller (Middlebury College, USA), Iyngararasan 

Mylvakanam (UNEP), Cindy Newberg (US Environmental 

Protection Agency), Lars Nordberg (ScandEnvironment 

Advisory Services, Sweden), Romina Picolotti (Ex 

Secretary of Environment and Sustainable Development, 

Argentina), Erika Rosenthal (Earth Justice, USA), Sumeet 

Saksena (The East-West Center, USA), Marcus Sarofim 

(US Environmental Protection Agency), Erika Sasser (US 

Environmental Protection Agency), Sangeeta Sharma 

(Environment Canada), Andreas Schild (International 

Centre for Integrated Mountain Development, ICIMOD, 

Nepal), Kunihiko Shimada (Ministry of the Environment, 

Japan), Joseph Somers (US Environmental Protection 

ACKNOWLEDGEMENTS – Near-term Climate Protection and Clean Air Benefits iii

Agency), Katsunori Suzuki (Institute for Global 

Environmental Strategies, IGES, Kanazawa University, 

Japan), Michael Walsh (International Council on 

Clean Transportation, USA), Yuxuan Wang (Tsinghua 

University, China), Chien Wang (Massachusetts Institute 

of Technology, USA), Catherine Witherspoon (Climate 

Works Foundation, USA), Jongikhaya Witi (Department of 

Environmental Affairs, South Africa).

Editorial Assistance:

Joseph Alcamo (UNEP), Svante Bodin (Swedish Ministry 

of the Environment). Science editor: Bart Ullstein 

(Banson), UK.

Project Management and Coordination:

External: Johan Kuylenstierna, Harry Vallack, Kevin Hicks 

(Stockholm Environment Institute, SEI, University of York, 

UK); Internal: Maria Cristina Zucca (UNEP).

Secretariat Support:

Administrative support from the Office of the Chief 

Scientist (Ms. Harsha Dave) and Support Staff from the 

Division of Environmental Law and Conventions at the 

UNEP Secretariat and from Emma Wright, Kerstin Wedlich 

and Erik Willis from the Stockholm Environment Institute, 

SEI, University of York. 

Production Team:

Design cover and inside pages: Robsondowry Ltd. 2011; 

Layout inside pages: Catherine Kimeu (UNON); 

Layout cover: Gideon Mureithi (UNON); Coordination: 

Pouran Ghaffarpour; Printing: UNON Publishing Services 

Section, Nairobi, ISO 14001:2004 - certified

Funding:

UNEP would like to thank the Swedish Ministry of the 

Environment for funding the development of this report.
iv Near-term Climate Protection and Clean Air Benefits – CONTENTS

Acknowledgements ii

Foreword v

Glossary vi

Acronyms and Abbreviations viii

Main Findings x

Executive Summary xi

Chapter 1: Introduction 1

Chapter 2: Short-lived Climate Forcers and their Impacts on Air Quality and Climate 3

2.1 Methane 3

2.2 Tropospheric ozone 4

2.3 Black carbon 4

Chapter 3: Policies and Measures to Reduce Short-Lived Climate Forcers 6

3.1 Strategic approach 6

3.2 Identifying priority control measures 7

3.3 Baseline year and reference scenario emissions 7

3.4 Identifying key methane measures 9

3.5 Identifying key black carbon measures 9

Chapter 4: Costs and Benefits of Implementing the Measures: A Regional Analysis 12

4.1 Costs of implementing the measures 12

4.2 Quantifying the climate and air quality benefits of regional implementation of measures 16

4.3 Comparing costs and benefits 24

Chapter 5: National-scale Action 25

5.1 Integrating SLCFs into existing policy and regulatory frameworks 25

5.2 Implementing emission reductions: opportunities and barriers 26

5.3 Enabling activities 33

5.4 Other considerations for national actions 33

5.5 Elements of a national action plan 35

Chapter 6: Regional-scale Action 36

6.1 Potential for action through regional entities with established infrastructure and a policy focus 37

6.2 Potential for action through regional entities with permanent structure and a science focus 39

6.3 Potential for action on SLCFs through other initiatives 40

6.4 Economic groupings 41

6.5 Possible options for progress at a regional Level 41

Chapter 7: Global-scale Action 43

7.1 Building upon existing legal instruments 43

7.2 Promoting further efforts by international organisations and cooperative mechanisms 44

7.3 Enabling mechanisms at the global scale to facilitate implementation of national SLCF mitigation 46

Chapter 8: A Way Forward 50

8.1 The need for awareness raising 51

8.2 Setting the agenda 51

8.3 Establishing an effective governance framework 52

References 54

Appendices available on-line at http://www.unep.org/publications/ebooks.SLCF

Contents
Achim Steiner

UN Under-Secretary-General, 

UNEP Executive Director

A range of compelling, and in many cases highly costeffective options for fast action on black carbon, methane 

and tropospheric ozone are outlined in this report: Nearterm Climate Protection and Clean Air Benefits: Actions for 

Controlling Short-Lived Climate Forcers.

Research, convened by the United Nations Environment 

Programme (UNEP) and involving scientists from across the 

globe, has already outlined the sustainable development 

opportunities for acting on these kinds of emissions.

• Fast action has the potential to avoid an estimated 2.4 

million premature deaths from outdoor air pollution 

annually by 2030;

• Fast action could assist in avoiding annual losses from 

four major crops—wheat, rice, maize and soybean-of 

about 32 million tonnes per year.

Meanwhile early and sustained action on short-lived 

climate forcers could also slow the increase in nearterm global warming by around 0.4°C by 2050—thereby 

assisting the international community in meeting a target 

of keeping a temperature rise to 2°C or less during the 

21st century.

In this report, requested by governments, 16 control 

options are discussed that cover the wide range of sources 

of black carbon and methane emissions from cookstoves 

and diesel engines through to leaky gas distribution pipes 

and municipal waste.

The study has grouped the options into low, moderate 

and high cost options as well as a further category where 

the cost-benefit analysis is complex and contingent on for 

example, strong regulatory frameworks.

It underlines the fact that action on some options 

might actually trigger costs savings—for example reducing 

leaks from gas pipelines, replacing traditional brick kilns 

with more efficient ones and separation of biodegradable 

materials from waste going to landfills in order to cut 

methane emissions.

Other options, for example replacing traditional coke 

ovens with modern ones, may carry costs but these are 

well within the range of today’s carbon markets whereas 

others including feed switches in cattle may currently be 

more costly than current carbon prices.

There is increasing interest among governments in the 

developed and developing world to carry out fast action 

on short-lived climate forcers, some for health reasons 

and others for the agricultural benefits alongside the 

climate change opportunities.

This is a landmark report making a bridge between 

new scientific knowledge justifying action on SLCFs and 

practical measures that can be taken by countries to 

reduce the burden of air pollution and climate change 

on their sustainable development. This report identifies 

priority areas and sectors for action in each region with 

the indicative costs and benefits. It also describes the 

many fora where fast action could occur—regional and 

national air quality agreements being a case in point. This 

report also outlines the important role of action at the 

global scale and the enabling actions that could facilitate 

and speed up implementation of SLCF measures.

Climate change will, in the final analysis, never be 

controlled unless the principal long-lived greenhouse gas—

carbon dioxide—is substantially and significantly curbed. 

Nevertheless, short-lived climate forcers represent a 

complementary measure with multiple near-term benefits 

increasingly ripe and ready for cooperative action.

FORWARD – Near-term Climate Protection and Clean Air Benefits v

Foreword
Albedo: a measure of the reflectivity of the earth’s 

surface. It is the fraction of solar energy (shortwave 

radiation) reflected from the Earth back into space. Ice, 

especially with snow on top of it, has a high albedo.

Biofuels: non-fossil fuels (e.g. biogas, biodiesel, 

bioethanol). They are energy carriers that store the energy 

derived from organic materials (biomass), including plant 

materials and animal waste.

Biomass: in the context of energy, the term biomass is 

often used to refer to organic materials, such as wood, 

animal dung and other agricultural wastes that can be 

burned to produce energy or converted into a gas and 

used for fuel.

Black carbon (BC): operationally defined aerosol species 

based on measurement of light absorption and chemical 

reactivity and/or thermal stability. Black carbon is formed 

through the incomplete combustion of fossil fuels, biofuel 

and biomass and is emitted as part of anthropogenic 

and naturally occurring soot. It consists of pure carbon 

(C) in several linked forms. Black carbon warms the 

Earth by absorbing sunlight and re-emitting heat to the 

atmosphere and by reducing albedo (the ability to reflect 

sunlight) when deposited on snow and ice.

Capacity building: in the terms of this document, the 

process of developing the technical skills and institutional 

capability in developing countries and countries with 

economies in transition to enable them to effectively 

address the causes and results of climate change and air 

pollution caused by short-lived climate forcers (SLCFs).

Carbon dioxide equivalent (CO2

e): a quantity that 

describes, for a given mixture and amount of greenhouse 

gas, the amount of carbon dioxide that would have 

the same global warming potential (GWP) or global 

temperature potential (GTP), when measured over a 

specified timescale – generally, 20 or 100 years. The carbon 

dioxide equivalency for a gas is obtained by multiplying 

the mass and the GWP or GTP of the gas. For example, 

the GWP for methane (CH4

) over 100 years is 25, including 

also indirect effects e.g. ozone formation. This means that 

emissions of 1 million tonnes of methane is equivalent to 

emissions of 25 million tonnes of carbon dioxide.

Clean Development Mechanism (CDM): one of the three 

market-based mechanisms under the Kyoto Protocol 

to the UN Framework Convention on Climate Change 

(UNFCCC), whereby developed countries may finance 

greenhouse gas emissions-avoiding projects in developing 

countries, and receive credits for doing so, which they 

may apply towards meeting mandatory limits on their 

own emissions.

Discount rate: The rate (as a percentage) used to convert 

the future expected streams of costs and benefits into a 

present value amount. The social discount rate (SDR) is 

a measure used by social planners to help guide choices 

about the value of diverting funds to social projects. The 

SDR is usually a much lower rate than that used by private 

sector businesses who expect a higher ‘market rate’ 

return on their capital investments. 

Euro-6/VI: European vehicle emission standards (Euro 

standards) define the acceptable limits for exhaust 

emissions of new vehicles sold in EU member states. 

The current standard is Euro-5/V. The future Euro-6/VI 

standards will come into force between 2013 and 2015 

depending on the class of vehicle.

Ground-level ozone: ozone at the bottom of the 

atmosphere and the level at which humans, crops and 

ecosystems are exposed. 

Global Temperature Potential (GTP): To take the limitations 

of the GWP metric regarding SLCFs into account, an 

Glossary

vi Near-term Climate Protection and Clean Air Benefits – GLOSSARY
GLOSSARY – Near-term Climate Protection and Clean Air Benefits vii

alternative metric, the global temperature potential (GTP) 

has been developed (Shine et al., 2005) which provides 

a comparison of a more policy-relevant impact – global 

mean temperature change – rather than the integrated 

forcing depicted by the global warming potential. GTP is 

defined as the temperature change due to 1 kg of emitted 

pollutants relative to that of 1 kg of emitted CO2

 after a 

given time period such as 20 or 100 years. GTP focuses 

on one particular chosen future point in time and gives 

the temperature effect at that time, relative to that of the 

same amount of carbon dioxide. It is expressed in terms 

of equivalent carbon dioxide (CO2

e) emissions. This metric 

provides an estimate that includes climate sensitivity so 

it has greater uncertainty than metrics based purely on 

radiative forcing and cannot be directly measured. 

Global Warming Potential (GWP): The global warming 

potential (GWP) is a metric that has been used extensively 

by the IPCC to compare the impacts of various wellmixed, long-lived greenhouse gases. It is defined as the 

integrated radiative forcing due to 1 kg of emission of a 

pollutant relative to that of 1 kg of CO2 over a particular 

time period such as 20 or 100 years. It is expressed in 

terms of equivalent carbon dioxide (CO2

e) emissions. 

The GWP compares the integrated radiative forcing of a 

particular forcing agent with the forcing from the same 

amount of carbon dioxide over some chosen time period 

resulting from pulse emissions of an equal mass. The GWP 

with the time horizon of 100 years (GWP100) is used in 

the Kyoto Protocol. The use of GWP20 with a time horizon 

of 20 years has been proposed to better capture the 

importance of the more short-lived gases and aerosols. 

The choice depends on the preferred time horizon. There 

are many limitations to the GWP concept, especially with 

regards to its use for short-lived species.

High emitting vehicles: on-road measurements have 

shown that a relatively small fraction of the vehicle fleet 

is responsible for a relatively large share of emissions. 

Here, high emitting vehicles are defined as vehicles 

with emissions above a certain regional, pollutant and 

technology-specific threshold.

Near-term warming: in terms of this document and the

Integrated Assessment of Black Carbon and Tropospheric 

Ozone (UNEP/WMO, 2011), this refers to global warming 

from the present up to about the next 20 to 40 years (i.e., 

global warming during the 2010-2050 period).

Ozone and particulate matter (PM) concentrations:

Ozone concentrations are generally measured in parts per 

billion (ppb). For other gases their concentration in the 

atmosphere is usually measured as μg/m3

, or micrograms 

in each cubic metre of air. In studies of their effect on 

human health, a distinction is commonly made between 

PM10 and PM2.5 – the mass of aerosols with a diameter of 

less than 10 and 2.5 μm (micrometres), respectively. 

Premature deaths: the number of deaths occurring earlier 

due to a risk factor than would occur in the absence of 

that risk factor.

Radiative forcing: a measure of the net change in the 

energy balance of the Earth with space, that is, the change 

in incoming solar radiation minus outgoing terrestrial 

radiation. At the global scale, the annual average radiative 

forcing at the top of the atmosphere, or tropopause, is 

generally a good indicator of the global mean temperature 

change – though for black carbon in particular, forcing 

corresponds less closely to temperature change than for 

other agents.

Short-lived climate forcers (SLCFs): substances such as 

methane, black carbon, tropospheric ozone and many 

hydrofluorocarbons (HFCs) which have a significant 

impact on near-term climate change and a relatively short 

lifespan in the atmosphere compared to carbon dioxide 

and other longer-lived gases.

Surface forcing: refers to the instantaneous perturbation 

of the surface radiative balance by a forcing agent (Forster 

et al., 2007). The radiative forcing at the surface may be 

quite different from that at the top of the atmosphere.

Tropospheric ozone: ozone in that portion of the 

atmosphere from the Earth’s surface to the tropopause 

that is the lowest 10-20 km of the atmosphere.

Reference scenario: the progression of emissions based 

on energy and fuel projections of the International 

Energy Agency (IEA) World Energy Outlook 2009 and 

incorporating all presently agreed policies affecting 

emissions. This scenario is also used in the Integrated 

Assessment of Black Carbon and Tropospheric Ozone

(UNEP/WMO 2011) for comparison with the scenarios 

where black carbon and methane measures have been 

implemented.

Win-win measures: mitigation measures which are likely 

to reduce global warming and at the same time provide 

clean air benefits by reducing air pollution.
ABC Atmospheric Brown Cloud

ACAP Arctic Contaminants Action Programme

ADB Asian Development Bank

AF Adaptation Fund

AMAP Arctic Monitoring and Assessment 

Programme

AMCEN African Ministerial Conference on the 

Environment

AOSIS Alliance of Small Island States 

AR5 IPCC fifth assessment report

ASEAN Association of South East Asian Nations

BAQ-SSA Better Air Quality in sub-Saharan Africa

BC black carbon 

C carbon

CAI-Asia Clean Air Initiative for Asian Cities

CDM Clean Development Mechanism

CEB Chief Executive Board for Coordination

CEC Commission for Environmental 

Cooperation

CER Certified Emissions Reductions

CFCs chlorofluorocarbons

CH4 methane

CLRTAP Convention on Long-Range Transboundary 

Air Pollution

CO carbon monoxide

CO2 carbon dioxide

CO2

e carbon dioxide equivalent

DPF Diesel Particle Filter

EANET Acid Deposition Monitoring Network in 

East Asia

ECA Emission Control Area

ECE UN Economic Commission for Europe

ECHAM European Centre Hamburg Model

EMG Environmental Management Group

EU European Union

FAO Food and Agriculture Organization of the 

United Nations

GACC Global Alliance for Clean Cookstoves

GAP Forum Global Atmospheric Pollution Forum

GAINS Model Greenhouse Gas and Air Pollution Model 

Interactions and Synergies

GCM General Circulation Model

GEF Global Environment Facility

GGFR Global Gas Flaring Reduction

GISS NASA Goddard Institute for Space Studies

GMI Global Methane Initiative

GTP Global Temperature Potential 

GURME Global Atmospheric Watch (GAW) Urban 

Research Meteorology and Environment 

of the WMO 

GWP Global Warming Potential

HCFC hydrochlorofluorocarbons

HFC hydrofluorocarbons

HLPC High Level Committee on Programmes

HTAP Hemispheric Transport of Air Pollution

JRC Joint research Centre of the EU

IDB Inter-American Development Bank

IEA International Energy Agency 

IIASA International Institute for Applied Systems 

Analysis

IMF International Monetary Fund

IMO International Maritime Organization

ICAO International Civil Aviation Organization

IPCC Intergovernmental Panel on Climate 

Change

LDCF Least Developed Countries Fund

LPG liquefied petroleum gas

Malé Malé Declaration on Control and 

Declaration Prevention of Air Pollution and its Likely 

Transboundary Effects for South Asia

MARPOL The International Convention for the 

Prevention of Marine Pollution from Ships, 

1973, as modified by the Protocol of 1978 

relating thereto (MARPOL 73/78)

MEPC Marine Environmental Protection 

Committee

MDG Millennium Development Goals

NAAEC North American Agreement on 

Environmental Cooperation

Acronyms and Abbreviations

viii Near-term Climate Protection and Clean Air Benefits – ACRONYMS AND ABBREVIATIONS
ACRONYMS AND ABBREVIATIONS – Near-term Climate Protection and Clean Air Benefits ix

NAFTA North American Free Trade Agreement

NAMA Nationally Appropriate Mitigation Actions 

under the UNFCCC

NASA National Aeronautics and Space 

Administration

NEC EU National Emissions Ceilings Directive

NMVOCs non-methane volatile organic compounds

NOx nitrogen oxides

O3 ozone

OC organic carbon

OECD Organisation for Economic Cooperation 

and Development

ODA Official Development Assistance

ODS (stratospheric) ozone-depleting 

substances

PCFV Partnership for Clean Fuels and Vehicles

PM particulate matter (PM2.5 has a diameter 

of 2.5μm or less. PM10 has a diameter of 

10μm or less.)

PMFF Prototype Methane Financing Facility

ppb parts per billion 

RIO+20 UN Conference on Sustainable 

Development (2012)

SACEP South Asia Cooperation Environment 

Programme

SADC Southern African Development 

Community

SAARC South Asian Association for Regional 

Cooperation

SBSTA Subsidiary Body for Scientific and 

Technological Advice under the UNFCCC

SCCF Special Climate Change Fund

SLCF Short-Lived Climate Forcers

SO2 sulphur dioxide

SO4

2- sulphates

SREP Scaling-up renewable energy programme

TEMM Tripartite Environmental Ministers’ 

Meeting

TM5-FASST Fast Scenario Screening Tool of TM5

TOA Top of the atmosphere or tropopause

UN United Nations

UNCED United Nations Conference on 

Environment and Development

UNCRD United Nations Centre for Regional 

Development

UNDG United Nations Development Group

UNDP United Nations Development Programme

UNECE United Nations Economic Commission for 

Europe

UNEP United Nations Environment Programme

UNFCCC United Nations Framework Convention on 

Climate Change

USEPA United States Environmental Protection 

Agency

VAM Ventilation-Air Methane

VOCs Volatile Organic Compounds

WHO World Health Organization

WMO World Meteorological Organization
1. Reducing atmospheric concentrations of short-lived 

climate forcers (SLCFs), specifically black carbon, 

tropospheric ozone and methane, offers a real opportunity 

to improve public health, reduce crop-yield losses, and 

slow the rate of near-term climate change, thereby aiding 

sustainable development. Because such reductions are 

likely to only make a modest contribution to longer-term 

climate goals, they must be viewed as a strategy that 

complements but does not replace carbon dioxide emission 

reductions.

2. The health benefits from implementing black carbon 

mitigation measures would be realized immediately and 

almost entirely in the regions that reduce their emissions.

Regions taking action on black carbon would also benefit 

significantly from reduced regional warming, reduced 

disruption of regional weather patterns, as well as a 

substantial reduction in crop-yield losses. 

3. The mix of measures that give rise to substantial national, 

regional and global benefits vary by region. This report 

estimates that the following actions would bring about the 

largest benefits:

• for Africa: reducing black carbon emissions from biomass 

cookstoves and methane emissions from oil and gas 

production and municipal waste;

• for Asia: reducing black carbon emissions from diesel 

vehicles and biomass cookstoves, and reducing methane 

emissions from coal mining, oil and gas production and 

municipal waste; 

• for North America and Europe: reducing methane 

emissions from oil and gas production, from longdistance natural gas transmission pipelines and municipal 

waste, and reducing black carbon emissions from 

residential biomass heating, shipping activities, and open 

agricultural biomass burning near the Arctic region;

• for Latin America and the Caribbean: reducing black 

carbon emissions from biomass cookstoves and diesel 

vehicles, and reducing methane emissions from oil and 

gas production and municipal waste.

4. About 50 per cent of both methane and black carbon 

emission reductions can be achieved through measures 

that result in net cost savings (as a global average) over 

their technical lifetime. The savings occur when initial 

investments are offset by subsequent cost savings from, 

for example, reduced fuel use or utilization of recovered 

methane. A further third of the total methane emission 

reduction could be addressed at relatively moderate costs.

5. The current state of knowledge is sufficiently robust to 

justify action on SLCFs at the national scale. Implementing 

the identified measures can be seen as a ‘no-regrets’ policy 

because there is high confidence that they will significantly 

reduce health and crop-yield air pollution impacts. While 

there is high confidence concerning the climate benefits 

from identified methane measures, it is also likely that black 

carbon measures will lead to climate benefits, especially at 

the regional level. Therefore, these can be seen as ‘win-win’ 

policies providing both air quality and near-term climate cobenefits.

6. National efforts to reduce SLCFs can build upon existing 

institutions, policy and regulatory frameworks related to 

air quality management, and, where applicable, climate 

change. For many developing countries these policies could 

be connected to development goals and mainstreamed into 

development policies. 

7. Countries can take action now to rapidly implement 

control measures addressing the most obvious SLCF 

sources in the knowledge that multiple benefits will be 

realised. Countries could develop national SLCF action plans 

to implement priority measures identified. These action 

plans should consider relevant SLCF sources and appropriate 

measures, the benefits and costs of action, the political 

feasibility of implementation, an inventory of current 

policies and legislation that can be used to implement 

relevant measures, and actions needed to raise awareness. 

8. Regional air pollution agreements, organisations 

and initiatives may be effective mechanisms to build 

awareness, promote the implementation of SLCF 

mitigation measures, share good practices and enhance 

capacity. Emerging regional air pollution initiatives can be 

strengthened by including near-term and regional climate 

change considerations, and can be used to promote national 

implementation of SLCF mitigation measures.

9. Global actions can help enable and encourage national 

and regional initiatives and support the widespread 

implementation of SLCF measures. A coordinated 

approach to combating SLCFs can build on existing 

institutional arrangements, ensure adequate financial 

support, enhance capacity and provide technical 

assistance at the national level. One option for moving 

forward could be an international initiative based upon a 

partnership of willing countries and other partners. This 

could seek, and make available, appropriate financial 

resources and mechanisms, and work with existing global 

structures to support better implementation of SLCF 

measures, mainstreaming them into air quality, climate and 

development policies at all levels.

x Near-term Climate Protection and Clean Air Benefits – MAIN FINDINGS

Main Findings
Introduction 

This report addresses the mitigation of short-lived 

climate forcers (SLCFs) and its key role in air pollution 

reduction, climate protection and sustainable 

development. SLCFs are substances in the atmosphere 

that contribute to global warming and have relatively 

short lifetimes in the atmosphere. The focus is on three 

SLCFs – black carbon, tropospheric ozone and methane 

– because reducing them will provide significant benefits 

through improved air quality and a slowing of near-term 

climate change1

. 

The ‘win-win’ benefits for climate and public health 

have been overlooked in the wider climate change 

and air-quality debate. The challenges of improving air 

quality and mitigating climate change, as well as those 

of human development, are inextricably linked. Policy 

paths that integrate air quality, climate change and key 

development concerns bring mutual payoffs. This report 

builds on the Integrated Assessment of Black Carbon and 

Tropospheric Ozone (UNEP/WMO, 2011)2

 and describes 

the considerable benefits that different regions of the 

world could experience if they were to implement 

specific emission-reduction measures. By including cost 

implications and options to promote action at the national, 

regional and global levels, this report charts a path for the 

widespread implementation of the identified measures. 

Reducing SLCF concentrations now is likely to slow 

the rate of global warming over the next two to 

four decades. Near-term warming is pushing natural 

systems closer to thresholds that may lead to a further 

acceleration of climate change. For example, the melting 

of permafrost in the Arctic is releasing additional 

quantities of methane into the atmosphere, which in turn 

contribute to additional global warming.

Air pollution is impeding sustainable development 

because it threatens human health and crop production, 

especially in developing countries. The World Health 

Organization (WHO) estimates that 3.1 million people 

(WHO, 2009), mostly in developing countries, die 

prematurely each year from indoor and outdoor air 

pollution. Two SLCFs – black carbon and tropospheric 

ozone – are important pollutants causing these health 

impacts. In addition to the direct health impacts, 

ozone pollution reduces the productivity of crops and 

natural vegetation. A third SLCF – methane – is not an 

air pollutant but it contributes to tropospheric ozone 

pollution and its health and environmental impacts. 

Climate change also presents numerous barriers to 

development in the near term. Current warming is 

already having many harmful effects, which will have 

the greatest impact on the world’s most vulnerable 

populations and places. Lakes are building up at the foot 

of melting glaciers and are threatening to burst and cause 

floods downstream; warmer temperatures are leading 

to more frequent heat-waves; the melting of land ice in 

the Arctic is contributing to sea-level rise throughout the 

world; and shifting climatic zones of plant and animal life 

threaten the existence of some species. Slowing down 

near-term warming would reduce the intensity of these 

impacts and give society and nature more time to adapt 

to climate change. 

A package of 16 measures for reducing emissions of 

black carbon and methane has been identified that could 

provide substantial combined benefits for air quality 

1. A subset of hydrofluorocarbons (HFCs) also have short lifetimes and warm the atmosphere, but do not currently have air quality impacts and are not the 

focus of this report.

2. Available from: <http://www.unep.org/dewa/Portals/67/pdf/BlackCarbon_SDM.pdf>

Executive Summary

EXECUTIVE SUMMARY– Near-term Climate Protection and Clean Air Benefits xi
xii Near-term Climate Protection and Clean Air Benefits – EXECUTIVE SUMMARY

and near-term climate protection. These measures 

can accomplish about 38 per cent reduction of global 

methane emissions and around 77 per cent of black 

carbon emissions, if implemented between now and 

2030, relative to a 2030 ‘reference’ emission scenario. 

The ‘reference’ scenario is based on a ‘business-as-usual’ 

energy demand projection and does not include any new 

legislation relevant to SLCF emissions beyond that already 

agreed. These 16 measures form a strong starting point 

for the reduction of SLCF impacts in all regions, although 

additional measures may be more appropriate in specific 

circumstances. The benefits described in the following 

paragraphs assume that the measures will be fully 

implemented worldwide by 2030, starting immediately. 

The air quality benefits of short-lived climate 

forcer mitigation

Confidence is high that black carbon measures would 

provide substantial health benefits. The reduction 

in outdoor particulate air pollution from having fully 

implemented the measures by 2030 would avoid an 

estimated 2.4 million (range 0.7–4.6 million)3

 premature 

deaths annually. It would also greatly reduce impacts 

on health from indoor exposures. The health benefits 

of the measures come from reduced exposure to fine 

particulate matter (PM2.5) resulting from reductions 

in black carbon and other particle emissions. Because 

particulate matter is reduced rapidly after the measures 

have been implemented, the health benefits will also be 

felt immediately. Due to the very high particulate-matter 

burden in Asia, the black carbon measures could prevent 

a greater number of premature deaths in this region than 

elsewhere (Figure ES-1) with the next highest benefit 

likely to be achieved in Africa. Health benefits in these 

two regions are mainly achieved by controlling biomass 

cookstove and transport emissions. 

Confidence is also high that controlling methane 

emissions and ozone precursor emissions by

implementing black carbon measures would reduce ozone 

concentrations and its impacts on crops. Implementing all 

16 measures would avoid annual losses from four major 

crops of about 32 million tonnes (range of 21-57 million 

Figure ES-1: The annual reduction in premature deaths from the implementation of different black carbon measures in each region in 

2030. The percentage given above each bar indicates the proportion of avoided deaths from inhalation of outdoor air pollution particles 

within the region that implements the measures. Vertical grey bars indicate the uncertainty range in the mortality figures based on the 

uncertainty in the concentration-response relationships

3. The ranges for health and crops reflect the uncertainty in the concentration-response relationships alone and not uncertainties in the estimation of 

concentrations. 

Ban of open burning of agricultural 

residue

Additional reduction from Euro-6/VI 

vehicle standards (including DPF) after 

elimination of high-emitters

Elimination of high-emitting vehicles

Replace lump coal with coal briquettes 

in cooking and heating stoves

Replace current residential wood 

burning technologies with pellet stoves 

and boilers (in industrialized countries)

Switch from traditional biomass cookstoves to stoves fueled by LPG or biogas 

or to fan-assisted biomass stoves (in 

developing countries)

Replace traditional coke ovens with 

modern recovery ovens 

Replace traditional brick kilns with 

vertical shaft kilns 

0

500

1000

1500

2000

2500

Total premature mortality avoided in 2030 due to black carbon measures 

(1000s of deaths)

Africa Latin America

and Caribbean

North America

and Europe

North East Asia, 

South East Asia

and Pacific

South, West and 

Central Asia

93% in 

region

87% in 

region

95% in 

region

98% in 

region

99% in 

region
EXECUTIVE SUMMARY – Near-term Climate Protection and Clean Air Benefits xiii

tonnes) each year after 2030 when all the measures have 

been implemented (note that the UNEP/WMO Assessment 

gave a higher central value of 52 million tonnes, reflecting 

differences between global models). Half of these benefits 

result from implementing the methane mitigation 

measures and the other half from black carbon measures. 

The greatest crop benefit from the methane measures 

comes from reducing emissions from coal mines, especially 

in North East Asia, South East Asia and the Pacific; from oil 

and gas production in all regions; and from long-distance 

natural gas transmission pipelines in North America and 

Europe. The crop benefits from action on black carbon 

emissions largely come from the implementation of 

measures in the transport sector, especially the wider 

implementation of Euro-6/VI standards.

The near-term climate benefits of reducing 

short-lived climate forcer concentrations

Reducing the three short-lived climate forcers offers a 

realistic opportunity to significantly reduce the rate of 

global warming over the next two to four decades. If fully 

implemented by 2030, the 16 measures are estimated 

to reduce global warming between 2010 and 2040 by 

about 0.4°C (this study)4

 to 0.5°C (from the Integrated 

Assessment of Black Carbon and Tropospheric Ozone,

UNEP/WMO, 2011). From here on we make reference to 

the 0.4°C global decrease from this study. While maximum 

benefits will be reached by 2050, the bulk of the benefits 

will already be realised by 2040, as indicated by the dotted 

line in Figure ES-2. This is compared to the temperature 

Figure ES-2: Observed deviation of temperature to 2009 and projections under various scenarios from the Integrated Assessment of Black 

Carbon and Tropospheric Ozone (UNEP/WMO, 2011). Implementation of the identified black carbon (BC) and methane (CH4

) measures 

between 2010 and 2030, together with measures to reduce carbon dioxide (CO2

) emissions, would greatly improve the chances of 

keeping the Earth’s temperature increase to less than 2 ̊C relative to pre-industrial levels. The uncertainty of the temperature projections 

in 2070 is shown by the lines on the right hand side5

4. The TM5-FASST model was used to disaggregate the influence of the different measures on temperature. This model estimated total temperature change 

to be closer to 0.4°C than 0.5°C as estimated in the Assessment by the NASA-GISS and ECHAM models (UNEP/WMO, 2011), but this will not affect the 

proportional contribution of the measures to the reduced warming. 

5. The uncertainty for black carbon on global temperature is greater than for methane, whose impact is relatively well known. It is possible that the impact 

of black carbon on warming could be around zero, but current knowledge suggests that it is more likely that removing black carbon would provide a net 

global climate benefit.

Source: UNEP/WMO (2011) using an average of two global composition-climate models (GCMs) that estimate pollutant concentrations, radiative forcing 

and global climate

1900 1950 2000 2050

Temperature ( ̊C) relative to 1890-1910

CH4 + BC measures

CO2 measures Reference

CO2 + CH4 + BC

measures

-0.5

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0
xiv Near-term Climate Protection and Clean Air Benefits – EXECUTIVE SUMMARY

Figure ES-3: The estimated impact of methane (top) and black carbon (bottom) measures on global temperature expressed as their 

percentage share of the global temperature benefit delivered by the sum of all 16 measures in 2050 (left-hand axis) and in terms of 

absolute temperature change (right-hand axis). The absolute temperature benefit sums to 0.4°C (using TM5-FASST). When added 

together, the bars for both methane and black carbon add up to 100 per cent of the temperature reduction. Vertical grey bars indicate 

the uncertainty range in absolute temperature change due to the likely range of the radiative forcing of methane and black carbon (and 

co-emitted substances)

 *Note: For biomass cookstoves, only the effect of substitution with LPG and biogas stoves is shown in the black carbon graph for clarity. With 100 per cent 

substitution by fan-assisted biomass stoves, the reductions would be slightly lower (i.e. the lengths of green bars would be 6 per cent shorter)

Ban of open burning of agricultural 

residue

Additional reduction from Euro-6/VI 

vehicle standards (including DPF) after 

elimination of high-emitters

Elimination of high-emitting vehicles

Replace lump coal with coal briquettes 

in cooking and heating stoves

Replace current residential wood 

burning technologies with pellet stoves 

and boilers (in industrialized countries)

Switch from traditional biomass 

cookstoves to stoves fueled by LPG 

or biogas or to fan-assisted biomass 

stoves (in developing countries)

Replace traditional coke ovens with 

modern recovery ovens 

Replace traditional brick kilns with 

vertical shaft kilns 

Africa

Latin 

America and 

Caribbean

North 

America

and Europe

North East 

Asia, South 

East Asia 

and Pacific

South, West 

and Central 

Asia

-0.11

-0.09

-0.07

-0.05

-0.03

-0.01

0%

5%

10%

15%

20%

25%

30%

Share of the SLCF global temperature reduction benefit achieved by 

black carbon measures in 2050

Change in temperature by 2050 due to black carbon measures (°C)

Africa

Latin America and 

Caribbean

North America

and Europe

North East Asia, 

South East Asia 

and Pacific

South, West 

and Central 

Asia

0.00

-0.01

-0.02

-0.03

-0.04

-0.05

-0.06

-0.07

-0.08

Share of the SLCF global temperature reduction benefit achieved by 

methane measures in 2050

Change in temperature by 2050 due to methane measures (°C)

0%

2%

4%

6%

8%

10%

12%

14%

16%

18%

20%

22%

Intermittent aeration of continuously 

flooded rice paddies

Reduce methane emissions from 

livestock by anaerobic digestion of 

manure

Upgrading primary wastewater 

treatment with gas recovery

Separation and treatment of 

biodegradable municipal waste

Reduced gas leakage from 

long-distance transmission pipelines

Extended methane recovery/utilization 

and reduced fugitive emisions from oil 

and gas production

Pre-mine degasification and recovery 

of methane from coal mine ventilation 

air
EXECUTIVE SUMMARY – Near-term Climate Protection and Clean Air Benefits xv

increase projected in the ‘reference’ scenario (Figure ES2) and represents nearly a halving of the pace of global 

warming between 2010 and 2040. This 0.4°C benefit 

(range 0.1-0.6°C) might be maintained into the future, but 

the contribution of these measures to long-term climate 

protection is difficult to assess as it is hard to predict the 

development of SLCF emissions from different sectors in 

the reference scenario into the more distant future. 

About half of the 0.4°C climate benefit in 2050 comes 

from implementing the black carbon measures, mainly 

in Asia and Africa, and the other half comes from 

implementing the methane measures, mainly in Asia, 

Europe and North America. Figure ES-3 shows the 

contribution of the different measures in the different 

regions to the global warming reduction of 0.4°C in 2050. 

The higher uncertainty of the black carbon measures on 

climate compared with the methane measures is shown. 

The role of short-lived climate forcers in 

achieving longer-term climate goals and 

contributing to closing the ‘emissions gap’

Although reductions of SLCFs would substantially slow the 

rate of climate change over the next few decades, they are 

likely to make only a modest contribution to longer-term 

climate goals and help narrow but not close a greenhouse 

gas ‘emissions gap’ in 20206

. Therefore, reducing SLCFs 

must be viewed as a strategy that complements but does 

not replace carbon dioxide emission reductions. Because 

SLCFs have a relatively short atmospheric lifetime, their 

concentrations decline fairly quickly in the atmosphere if 

their precursor emissions are drawn down. Hence, reducing 

methane and black carbon emissions can be an effective 

way to slow global warming over the next two to four 

decades. However, because SLCFs have a short atmospheric 

lifetime, their removal also has a relatively small effect 

on long-term global warming. As an example, assuming 

that all the SLCF measures were implemented in 2020, 

the influence of the emission reductions achieved in that 

year on global temperature over a 100 year time horizon 

would be about 1.1 Gt CO2

e (range: 0.4-1.7 Gt CO2 e)7. This 

amount would help narrow but not close the 6-11 Gt CO2

e 

emissions gap8

 in 2020, i.e. the gap between expected 

emissions if countries comply with their reduction pledges, 

and emissions consistent with keeping global warming 

below a 2°C increase for a hundred years or more. Hence, 

while reducing SLCFs helps slow global warming and avoid 

exceeding the 2°C target, immediate reductions of CO2

 and 

other long-lived greenhouse gases are needed to meet the 

target over the long run.

Regional variation in benefits from 

implementing the SLCF measures 

In Asia, about 1.9 million premature deaths from 

outdoor air pollution could be prevented each year, 

by 2030, by implementing black carbon measures 

addressing the transport and residential sectors and 

open agricultural biomass burning. Methane measures 

in Asia would provide about the same global climate 

benefit as black carbon measures. Most of the climate 

benefit from methane emission reductions derives from 

coal mine methane recovery, especially in North East Asia, 

and reducing emissions from oil and gas production in 

South, West and Central Asia, as well as through better 

management of municipal waste. For black carbon, 

measures in Asia addressing emissions from traditional 

biomass cookstoves and transport would provide the 

largest climate benefit. 

In North America and Europe, the largest climate 

benefit would be realized by implementing measures 

to reduce methane emissions from coal mining, oil and 

gas production and better management of municipal 

waste. These same measures, together with measures 

in the transport sector, would also bring large crop-yield 

benefits. Further action on black carbon emissions to 

replace current domestic wood-burning technologies with 

pellet stoves/boilers, and banning the outdoor burning 

of agricultural residues in countries where this practice 

continues, would provide climate benefits, especially 

for the Arctic. Shipping activity near the Arctic, which is 

a source of black carbon emissions, is a growing black 

carbon concern. 

In Africa, action on black carbon, especially from biomass 

cookstoves, would potentially provide the largest nearterm climate benefit, although the impact of black carbon 

mitigation on climate is subject to a higher uncertainty than 

6. UNEP, 2011b. 

7. Converting black carbon and methane emission reductions to CO2

 equivalents using their Global Temperature Potentials for a 100 year time horizon.

8. UNEP, 2011b.
xvi Near-term Climate Protection and Clean Air Benefits – EXECUTIVE SUMMARY

methane mitigation. The biomass cookstoves measures 

also provide large benefits to health protection and would 

prevent about 200,000 premature deaths from outdoor 

air pollution each year by 2030. The methane measures 

that bring about the largest benefit for crops and nearterm climate are mainly those in the oil and gas production 

industries, better management of municipal waste and 

reducing the release of methane from coal mines. 

In Latin America and the Caribbean, methane measures 

would provide a larger climate benefit compared to black 

carbon measures, mainly by recovering methane from oil 

and gas production and better management of municipal 

waste. Black carbon measures deliver more modest 

climate and health benefits in this region, but a relatively 

large benefit for crop yields, all from addressing dieselvehicle emissions. 

The package of 16 black carbon and methane reduction 

measures would also have a major positive impact on 

regional climate protection: 

• A reduction in SLCFs would slow the projected warming in 

the Arctic by about 0.7°C in 2040, about two-thirds slower 

than the pace of warming under the reference scenario 

described above. This is very significant in light of the 

rapid rate at which Arctic land- and sea-ice is now melting. 

• Current levels of black carbon and other particles in the 

atmosphere have disrupted regional weather patterns 

including the South Asian monsoon. Because the 

emission reduction measures would noticeably reduce 

the impact of SLCFs on the atmosphere in this region 

(Figure ES-4), it is possible that weather patterns could 

return to a less disturbed state. 

• Reducing black carbon emissions would reduce the 

amount of these dark black carbon particles being 

deposited on snow and ice surfaces in the Himalayas 

and other mountainous areas. The deposition of black 

carbon is suspected of contributing to the accelerated 

melting of glaciers.

Taking action to reduce methane and black carbon 

emissions represents a ‘no-regrets’ policy because there 

is high confidence that the sum of the 16 measures 

would greatly reduce air pollution and its impact, 

thereby lowering barriers to sustainable development. 

Furthermore, there is high confidence that methane 

emission reductions would reduce global warming and 

that black-carbon emission reductions would result in 

regional climate benefits. There is still some uncertainty 

about the magnitude of global-warming benefits of 

black carbon emission measures, but the measures are 

expected to have a net positive global climate benefit. 

The cost implications of the emission 

reduction measures

About half of the emission reductions of both methane 

and black carbon could be achieved by measures that 

would deliver financial cost savings (as a global average) 

over the lifetime of the measures. This estimate of 

Figure ES-4: Change in atmospheric forcing in the year 2030 relative to the reference scenario in the two general circulation models (GISS 

and ECHAM) of the Integrated Assessment of Black Carbon and Tropospheric Ozone (UNEP/WMO, 2011). The greatest benefit for regional 

climate would be expected where there is the greatest change in atmospheric forcing (shown by the darker areas in the two maps). Here 

the benefit is expected to result from reduced disruption of rainfall patterns. The results of two models using the same input data are 

shown and they demonstrate similar results, despite having very different treatment of aerosols in the models

50

0

-50

-20 -10 -4 -3 -2 -1 1

-100 0 100 -100 0 100

50

0

-50

W/m2

GISS ECHAM
EXECUTIVE SUMMARY – Near-term Climate Protection and Clean Air Benefits xvii

cost savings does not account for the economic gains 

associated with reduced health, climate, crop yield and 

ecosystem impacts. These same measures account for 

about half of the temperature benefit that could be 

achieved. However, these measures may be considered 

less profitable by private-sector investors who expect a fast 

return on their investments. As a result, it is unlikely that 

these SLCF measures would be implemented by market 

forces alone under current conditions. Nevertheless, the 

cost saving is an important feature that could encourage 

the development of financing schemes for these measures. 

The remaining temperature reduction could be achieved 

through measures that would be competitive in the global 

carbon market, and also by measures that have already 

been widely implemented by developed countries. 

Options for short-lived climate forcer policy 

development and implementation

It is essential to link SLCF benefits and measures to 

wider policies and processes addressing air quality 

management, sustainable development and climate 

action. Existing processes and institutions at the national, 

regional and global scale could be the starting points 

for raising awareness, implementing measures and 

mainstreaming the issues into these policy arenas.

National-level policy options

The current state of knowledge is sufficiently robust 

to justify immediate action to reduce emissions at the 

national level. Countries can be confident that multiple 

benefits will be achieved if they were to begin the 

implementation of SLCF reduction measures. There 

are good reasons for giving special priority for actions 

at the national level. Firstly, the greatest public health 

benefits of black carbon emission reductions are expected 

to occur close to where the reductions take place. 

Secondly, each country has its own unique combination 

of emission sources, therefore requiring an individualized 

national strategy for reducing emissions. Thirdly, acting 

at the national level allows a country to incorporate the 

reduction of SLCFs into its air quality, climate change and 

development policy and regulatory frameworks, as well 

as into relevant sectoral policies according to its national 

priorities. 

An integrated approach across national agencies 

and policies is required to address SLCFs. Such an 

approach could be established in the context of national 

development planning based on an inter-agency structure 

and integrated with national priorities. 

Developing national action plans for reducing SLCFs 

would be an effective way to consolidate mitigation 

activities on the national scale. Such plans could build on 

existing institutions and policies, including those for air 

quality management, development and climate change 

and could include:

• characterizing sources and opportunities for emission 

reductions;

• assessing the relative costs and benefits of action;

• determining the political feasibility of implementation;

• undertaking an inventory of current policy, legislation 

and institutions that could be used to implement or 

strengthen relevant measures; 

• identifying further policies, where there are gaps, to 

make more rapid progress; and

• taking cost-effective action on SLCF sources.

Key actions that may be suitable for inclusion in a national 

action plan would depend on the specific national SLCF 

sources and national priorities. The actions could include:

• strengthening national regulations for coal, oil and gas 

industries to implement methane mitigation measures;

• strengthening support measures for recovery of 

methane from coal mining operations;

• strengthening support measures for recovery of methane 

from landfill, including separation of waste streams;

• creating and enforcing regulations to ban the open 

burning of agricultural wastes;

• strengthening support measures for alternative uses for 

agricultural wastes;

• introducing support measures to test, select and 

encourage widespread acceptance and use of improved 

cookstoves;

• establishing and strengthening inspection and 

maintenance of vehicles; and

• creating and implementing regulations to establish or 

tighten emission standards for all vehicle categories, 

including non-road vehicles, and stationary sources. 

For many developing countries, national policies for 

reducing SLCFs need to take into account the lack 

of established systems for managing air pollution.

Therefore, policies for controlling SLCFs might be more 

successful if they were incorporated within sustainable 

development frameworks and existing practices. It is also 

likely that financial incentives will be needed. 

Regional-level policy options

Regional coordination has an important role in 

enhancing action taken at the national level. Existing and 

emerging regional air pollution management initiatives 
xviii Near-term Climate Protection and Clean Air Benefits – EXECUTIVE SUMMARY

and inter-governmental agreements could be used as 

an effective way of building awareness, promoting the 

implementation of SLCF measures and enhancing capacity. 

National action could be supported by regional banks 

and other financial institutions and by pooling scientific 

expertise and sharing policy experience across a region. 

Regional initiatives and inter-governmental networks 

for air pollution management are in different stages of 

development, but they have the potential to provide 

a basis for cooperative action as well as enhancing 

and supporting national activity. The many different 

institutions covering air pollution management at a regional 

scale could be clustered into three main categories, each 

requiring a different approach for including SLCF policies: 

i) Legally binding regional agreements such as the 

Convention on Long-Range Transboundary Air 

Pollution (CLRTAP) covering the region of the United 

Nations Economic Commission for Europe (UNECE) 

and the ASEAN Haze Agreement. These institutions 

could be, and in some cases already are, platforms for 

policy action on controlling SLCFs.

ii) Intergovernmental initiatives such as the Malé 

Declaration addressing air pollution in South Asia and 

the Acid Deposition Monitoring Network in East Asia 

(EANET) covering North East and South East Asia, 

which have established structures and a focus on 

monitoring and scientific research. These institutions 

could be platforms for developing the scientific 

information, awareness raising and capacity building 

on SLCFs needed for policy action. 

iii) Agreements or initiatives based on declarations 

of goals with no existing structures for pursuing 

knowledge or policies. These include the Southern 

African Development Community (SADC) Regional 

Policy Framework on Air Pollution (known as the 

Lusaka Agreement) and the Inter-governmental 

Network on Air Pollution in Latin America and the 

Caribbean. These institutions could become forums 

for awareness raising and capacity building with 

regard to SLCFs. If further developed they could 

also become platforms for developing scientific 

information and policy action regarding SLCFs. 

Coordinated regional action is important to effectively 

address certain key impacts, for instance on the Arctic, 

Himalayas and South Asian Monsoon. Short-lived climate 

forcers cross national borders and impact neighbouring 

countries. Securing early progress in collaborative efforts 

to mitigate black carbon in the Arctic is particularly 

important because of increasingly obvious climate impacts 

in this region. This is a priority issue for the Arctic Council, 

which has already acted to move SLCF issues forward for 

that region. The Arctic Council’s approach could provide 

a model for needed action in other regions where the 

effects of climate change and black carbon concentration 

and deposition are particularly important, such as the 

Himalayas and Andes, and the monsoon regions of South 

Asia. Existing regional institutions covering these sensitive 

regions could embrace the issue and work toward regionbased solutions. 

Global-level policy options

There are three main approaches to acting on SLCFs at the 

global level: 

i) Building on existing legal instruments for the 

purpose of abating SLCFs. Some examples include: 

taking further action on methane in the context of 

the UN Framework Convention on Climate Change 

(UN FCCC); exchanging information about SLCF 

measures and policies within the subsidiary bodies 

of the UNFCCC; and working with the International 

Convention for the Prevention of Marine Pollution 

from Ships (MARPOL) to develop SLCF mitigation 

policies. Meanwhile, the Intergovernmental Panel on 

Climate Change, UNEP and other organizations can 

be encouraged to continue to assess the scientific 

knowledge about SLCFs for policymakers.

ii) Promoting further efforts to control SLCFs by 

United Nations agencies and other international 

organizations, and by various partnerships and other 

cooperative mechanisms. These “further efforts” 

could include: 

• convening stakeholders around a shared vision 

and global strategy to mitigate SLCFs;

• developing common standards and guidelines for 

emissions and ambient levels of SLCFs;

• promoting the coherent integration of SLCFs into 

different policy streams such as development, 

public health, climate change and air pollution; 

• encouraging joint action amongst and between 

the private sector, civil society, and governments 

on various activities for SLCF abatement. These 

could include the adoption of best practices 

in industry and improvement of polluting 

technology. 

iii) Putting enabling mechanisms in place at the global 

scale to facilitate national implementation of SLCF 

measures. A few of the many possible global steps for 

enabling action at the national level would be: 

• sponsoring activities such as workshops, 

conferences, and the production of publications 

xviii Near-term Climate Protection and Clean Air Benefits – EXECUTIVE SUMMARY
EXECUTIVE SUMMARY – Near-term Climate Protection and Clean Air Benefits xix

that raise awareness and generate and share 

knowledge about SLCFs;

• providing technical assistance and facilitating 

technology transfer to upgrade and retrofit 

technology to reduce emissions; 

• helping to build capacity for controlling SLCFs, 

including assistance in setting up necessary 

monitoring and observation networks and 

incorporate SLCFs in air quality management 

plans;

• facilitating the financing of SLCF abatement. 

Options include the expansion of existing SLCFspecific funds (or establishing new such funds); 

building on existing climate-related funds and 

funding mechanisms (Global Environmental 

Facility, Clean Development Mechanism, Green 

Climate Fund, and others), and/or integrating 

SLCF abatement into funding for sustainable 

development. 

Action on SLCFs can also be supported at the global 

level through a voluntary partnership of committed 

governments and other interested stakeholders. This 

initiative could be led by a small steering committee 

of country champions working together with a small 

secretariat which could be hosted by UNEP. Such an 

initiative could: 

• identify opportunities for enhanced international 

coordination and outreach;

• identify knowledge gaps, human and financial resource 

requirements; 

• raise public awareness of the problems and 

opportunities and discuss common approaches to taking 

new action, or to promoting and reinforcing action in 

other organizations; and

• promote the development of national or regional 

action plans, tracking progress of programmes and 

commitments and mobilizing funding for SLCF mitigation. 

to many undesirable impacts: lakes are building up at 

the foot of melting glaciers in the Himalayas and other 

glaciated regions and are threatening to burst and cause 

floods downstream; warmer temperatures are leading 

to more frequent heat waves; the melting of land ice in 

the Arctic is contributing to sea-level rise throughout the 

world; and shifting climatic zones threaten the existence 

of some plant and animal species. Slowing the rate of 

warming would slow down the intensification of these 

impacts. Secondly, near-term warming is pushing us closer 

to thresholds that may lead to a further acceleration of 

climate change. For example, the melting of permafrost 

in the Arctic is releasing additional quantities of methane 

into the atmosphere (Christensen et al., 2004), which in 

turn contributes to enhanced global warming. Another 

example is the melting of the summer Arctic sea ice 

which is altering the amount of solar radiation reflected 

over large areas and is likely to lead to climate change 

at regional and, perhaps, wider scales. By reducing the 

rate of warming over the next few decades, some of the 

processes that are accelerating climate change can be 

slowed, and perhaps it will be possible to avoid exceeding 

other thresholds. Finally, slowing down near-term 

warming will give society and nature more time to adapt 

to climate change. The faster the speed of change, the 

less time society has to develop drought-resistant crops, 

re-cultivate wetlands to protect shorelines, or implement 

flood protection schemes to cope with more frequent 

river flooding. The faster the rate of change, the more 

difficult it is for plants and animals to migrate to more 

climatically suitable areas, and the less time society has 

to develop and implement the technologies to control 

CO2

 emissions. Therefore, there is a need to make rapid 

progress to limit the speed of warming in the near term 

and full climate protection can only be achieved by 

addressing both near- and long-term climate change.

Action to reduce concentrations of SLCFs is 

substantiated by key scientific assessments that analyse 

how they influence climate and how they impact human 

well-being around the globe. The analysis in this report 

This report addresses the mitigation of short-lived 

climate forcers (SLCFs) and the role that it can play in air 

pollution control and near-term climate protection and in 

achieving sustainable development goals. The focus is on 

three SLCFs: methane, tropospheric ozone (in the lower 

atmosphere) and black carbon, all of which have relatively 

short atmospheric lifetimes and lead to impacts on human 

health, crops and ecosystems and whose reduction would 

limit the rate of increase in global temperature over the 

next two to four decades. Scientific understanding of the 

role of SLCFs in near-term climate change has improved 

dramatically over recent years. It is now possible to 

examine actions that could mitigate SLCFs and that 

will also bring immediate benefits for health and crop 

production and, more broadly, benefits for development.

Air pollution continues to have significant health, 

ecosystem and crop yield impacts across the globe and 

is estimated globally to cause 1.97 million premature 

deaths from exposure to particulate matter indoors and 

1.15 million deaths from exposure to outdoor particulate 

matter each year (WHO, 2009). Most of these health 

impacts occur in developing countries. These countries, 

in particular, are concerned with the need to protect 

public health and the environment in a way that is 

consistent with their development objectives. The policies 

and measures discussed in this report could reduce 

the economic burden of air pollution and its associated 

negative impact on human health and crop yields, as 

well as limit the potentially negative changes to climate 

affecting their regions, particularly those related to rainfall 

patterns (UNEP/WMO 2011). 

Control of anthropogenic emissions of carbon dioxide 

(CO2

) and other long-lived greenhouse gases, now and 

further into this century, is critical and must continue. 

However, the rate of near-term climate change, and the 

wide range of associated impacts anticipated over the 

next two to four decades, is a growing threat that also 

requires immediate attention. 

Why is it important to slow down warming in the near 

term? First of all, current climate change is already leading 

Chapter 1:

Introduction 

INTRODUCTION– Near-term Climate Protection and Clean Air Benefits 1
2 Near-term Climate Protection and Clean Air Benefits –INTRODUCTION

builds upon the Integrated Assessment of Black Carbon 

and Tropospheric Ozone (UNEP/WMO, 2011), and also 

links to other international assessments and research 

programmes (HTAP, 2010; Arctic Council, 2011; ABC 

project: UNEP and C4, 2002, and Ramanathan et al., 

2008). In addition, the UNEP/WMO (2011) assessment 

demonstrated how widespread implementation, 

worldwide, of a relatively small number of carefully 

identified measures could achieve multiple goals.

As well as achieving significant health and crop yield 

benefits, the implementation of identified black carbon 

and methane measures were shown to significantly slow 

the rate of near-term climate change. Figure 1.1 illustrates 

this impact on global temperatures. It also shows that the 

measures could also increase the chances of remaining 

below the Cancun Agreement of not exceeding a 2°C 

increase in global average temperature above preindustrial levels during the 21st century (see the lower 

line of combined CO2

+CH4+BC measures in Figure 1.1).

This figure also illustrates that the major effects of the 

CO2

 reduction scenario (CO2 measures in Figure 1.1) on 

temperature are realised in the longer term whereas 

the mitigation of SLCFs by black carbon and methane 

measures slow global warming in the near term.

Recognizing the need to make progress on SLCF 

reductions, this report examines options for national 

action, outlining costs and benefits of implementing 

certain measures and emphasizing the potential facilitating 

and catalysing roles of regional inter-governmental 

cooperation and global mechanisms. The main goals of this 

report are to:

• Identify the benefits of reducing SLCFs, including the 

global climate benefits of slowing near-term global 

warming, and the air quality benefits to health and 

agriculture.

• Identify practical policies and measures, available now, 

that can effectively reduce SLCFs, in particular emissions 

of black carbon and the precursors of tropospheric 

ozone, especially methane.

• Highlight the most effective measures within different 

regions to reduce SLCF emissions and concentrations 

and compare the benefits that would offset the 

implementation costs.

• Review and discuss policies and other actions at the 

national, regional and global levels that would lead to 

widespread reductions of SLCFs. 

Figure 1.1: Observed deviation of temperature to 2009 and projections under various scenarios from the Integrated Assessment of Black 

Carbon and Tropospheric Ozone (UNEP/WMO, 2011). Implementation of the identified black carbon (BC) and methane (CH4

) measures 

between 2010 and 2030, together with measures to reduce carbon dioxide (CO2

) emissions, would improve the chances of keeping the 

Earth’s temperature increase to less than 2 ̊C relative to pre-industrial levels. The uncertainties of the temperature projections in 2070 

are shown by the lines on the right hand side9

 Source: UNEP/WMO, 2011

9. The uncertainty for black carbon on global temperature is greater than for methane, whose impact is relatively well known. It is possible that the impact 

of black carbon on warming could be around zero, but current knowledge suggests that it is more likely that removing black carbon would provide a net 

global climate benefit.

2 Near-term Climate Protection and Clean Air Benefits –INTRODUCTION

1900 1950 2000 2050

Temperature ( ̊C) relative to 1890-1910

CH4 + BC measures

CO2 measures Reference

CO2 + CH4 + BC

measures

-0.5

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0
Black carbon and tropospheric ozone cause health and 

climate impacts, while tropospheric ozone also causes 

damage to crop yields and ecosystem structure and 

function. Methane, a potent greenhouse gas, is also one 

of the most important precursors of tropospheric ozone 

and thus contributes to air pollution. 

Black carbon and tropospheric ozone remain in the 

atmosphere for only days or weeks while the atmospheric 

lifetime for methane is about 12 years (Table 2.1). The 

critical point is that these substances have a positive 

radiative forcing and cause warming of the atmosphere 

through a number of different processes. The historical 

contribution of pre-industrial to present-day increases 

in black carbon, tropospheric ozone and methane to 

radiative forcing is about 1.1 W/m2

, 68 per cent of the 

forcing from carbon dioxide over the same time period 

(Forster et al., 2007).

Some hydrofluorocarbons fall into the category of 

SLCFs but do not cause air-quality related impacts and 

therefore, are not considered in this report beyond the 

information in Box 2.1. They are, however, covered in 

another UNEP report (UNEP, 2011a).

2.1 Methane

The increase of methane in the atmosphere has caused 

the largest radiative forcing by any greenhouse gas after 

carbon dioxide. Methane concentrations have grown as a 

result of human activities related to agriculture, including 

rice cultivation and the keeping of ruminant livestock, coal 

mining, oil and gas production and distribution, biomass 

burning and municipal waste landfills. 

Methane has a direct influence on climate, but also has a 

number of indirect effects including its role as an important 

precursor to the formation of tropospheric ozone. For some 

methane sources, emission control measures also reduce 

other co-emitted substances such as the more reactive 

volatile organic compounds that contribute to the local 

formation of ozone, as well as air toxics, such as benzene, 

carbon tetrachloride and chloroform. Thus, some methane 

mitigation measures provide local air-quality benefits. 

Table 2.1: Atmospheric lifetimes of short-lived climate forcers in comparison to the long-lived greenhouse gas CO2

Substance Lifetime Description / Source

Carbon 

dioxide

Decades to centuries 

and 

about 20 per cent 

will persist for many 

millennia

No single lifetime can be defined for carbon dioxide because of the different rates of 

uptake by different removal processes (IPCC: http://www.ipcc.ch/ipccreports/tar/wg1/016.

htm)

Ozone 4 – 18 days http://www.grida.no/climate/ipcc_tar/wg1/pdf/TAR-04.pdf

Methane 12 years http://www.ipcc.ch/publications_and_data/ar4/wg1/en/errataserrata-errata.

html#table214

Black 

carbon

3-8 days The mean residence time in the atmosphere for black carbon varies regionally and with 

the season. The range given here is based on an international evaluation of 16 models 

(Shindell et al. 2008). However, black carbon may also continue to warm the atmosphere 

after being deposited on snow and ice.

Chapter 2:

Short-lived Climate Forcers and their 

Impacts on Air Quality and Climate

SHORT-LIVED CLIMATE FORCERS – Near-term Climate Protection and Clean Air Benefits 3
4 Near-term Climate Protection and Clean Air Benefits – SHORT-LIVED CLIMATE FORCERS

2.2 Tropospheric ozone

Ozone is a reactive gas that exists in two layers of the 

atmosphere: the stratosphere (the upper layer) and the 

troposphere (up to about 10–20 km above the ground). 

In the troposphere, ozone is a significant greenhouse 

gas. The threefold increase in ozone concentrations in 

the northern hemisphere during the past 100 years has 

made it the third most important contributor to the 

human enhancement of the global greenhouse effect, 

after carbon dioxide and methane (Royal Society, 2008). It 

is the main gaseous pollutant affecting the yield of many 

crops and also has impacts on the diversity and growth of 

plant communities. It also affects human health due to its 

action as a powerful oxidising gas causing, for example, 

oxidative stress in lungs once it has been inhaled (Romieu 

et al., 2008). 

Unlike many other air pollutants, ozone is not directly 

emitted. It is a secondary pollutant that is formed in 

the troposphere by sunlight-driven chemical reactions 

involving carbon monoxide (CO), non-methane volatile 

organic compounds (NMVOCs), methane and nitrogen 

oxides (NOX

). These precursors arise from both natural 

sources and a broad range of human activities. The 

breadth of sources of ozone precursors, the role of natural 

and physical processes in ozone distribution, production 

and destruction and its complex chemistry mean that 

controlling ozone requires responses that take these 

complexities into account. The only practical management 

strategy is to control the emissions of precursors from 

human activities and, based on the understanding of 

ozone formation and its impacts, determine which 

precursor reduction is most appropriate in order to 

minimise a particular ozone impact. 

Reductions in both methane and carbon monoxide 

emissions have the potential to substantially reduce 

ozone concentrations and global warming. Methane 

contributes around 50 per cent of the increases in 

background ozone, with smaller contributions from 

non-methane volatile organic compounds and carbon 

monoxide (Royal Society, 2008). The ozone response to 

changes in methane emissions requires several decades to 

be fully realized, given the 12-year average atmospheric 

lifetime of methane. In contrast, reducing other ozone 

precursors, i.e. non-methane volatile organic compounds 

and nitrogen oxides, would only lead to limited globalscale climate benefits, but would play an important role 

in rapidly reducing peak ozone concentrations within 

a given region which will reduce air quality impacts on 

crops, vegetation and human health relatively close to the 

source of emission.

2.3 Black carbon

Black carbon, a major component of soot, exists in the 

atmosphere as particles. It is therefore not a greenhouse 

gas. Instead, black carbon particles absorb sunlight and 

then radiate energy to warm the atmosphere. Black 

carbon results from the incomplete combustion of fossil 

fuels, wood and other biomass. Although complete 

combustion would turn all the carbon contained in the 

fuel into carbon dioxide, in practice, combustion is never 

complete and always releases other gases including 

carbon monoxide, methane, non-methane volatile organic 

compounds, and particulate black carbon and organic 

carbon. Black carbon and other particles are emitted from 

many common sources, such as diesel cars and trucks, 

Hydrofluorocarbons (HFCs) are intentionally made to 

replace stratospheric ozone depleting substances (ODS), 

in such applications as air conditioning, refrigeration, 

solvents, foam blowing and aerosols. Although, they do 

not deplete the ozone layer, they are potent greenhouse 

gases and a substantial fraction of hydrofluorocarbons 

have a lifetime of 29 years or less and can be considered 

short lived (Velders et al., 2009; Forster et al., 2007).

Although the abundance of hydrofluorocarbons in the 

atmosphere is currently small, recent scientific studies 

project substantial growth in their use in the coming 

decades as a result of increased demand for refrigeration 

Box 2.1: Hydrofluorocarbons –climate forcing issues emerging from chemicals designed to 

replace ozone-depleting substances

and air-conditioning, particularly in developing countries. 

If left unchecked, HFC consumption is projected to 

double by 2020, and their emissions could contribute 

substantially to radiative forcing in the atmosphere by the 

middle of the century (UNEP, 2011a; Velders et al., 2009).

Currently, hydrofluorocarbons are included in the 

greenhouse gas emissions to be reduced under the 

Kyoto Protocol, thus there could be greater scope for 

collaboration between the Montreal Protocol, where 

proposals are being discussed to phase out production 

and consumption of HFCs, and the United Nations 

Framework Convention on Climate Change.
SHORT-LIVED CLIMATE FORCERS – Near-term Climate Protection and Clean Air Benefits 5

residential stoves, forest fires, agricultural open burning 

and some industrial facilities. 

There is a close relationship between emissions of 

black carbon, a warming agent, and organic carbon, 

a cooling agent as they are always co-emitted, but in 

different proportions depending on the source. Similarly, 

mitigation measures have varying effects on the black 

carbon/organic carbon mix, and on concentrations of 

other particles and ozone precursors. Therefore, the 

effectiveness of mitigation measures applied to different 

sources must take into account the changes in all 

emissions that influence warming. 

Black carbon causes warming of the atmosphere by 

a number of different processes. These particles absorb 

visible light due to their dark colour. This absorption 

leads to a disturbance of the planetary radiation balance 

and eventually to warming. Another impact of black 

carbon is that when it is deposited on ice and snow it 

reduces the albedo of these surfaces, increasing both 

atmospheric warming and the melting rate caused by 

increased absorption of heat by the darker snow and ice. 

Black carbon particles also influence cloud formation. 

The limited level of knowledge of how some of these 

processes work also leads to a level of uncertainty of the 

overall effect of black carbon on global warming, that is 

higher than that, for example, of methane.

Black carbon aerosols have a large impact on regional 

circulation and rainfall patterns as they cause significant 

asymmetry in heating patterns over a region (Ramanathan 

et al., 2005; Wang, 2004). Whilst not fully quantifiable, the 

impact of black carbon on regional weather patterns and 

regional warming is more certain than its impact on global 

warming. This is because, at the global scale, co-emitted 

species such as organic carbon may offset warming due 

to black carbon. At the regional scale, changes are more 

closely related to atmospheric heating which is dominated 

by black carbon, and co-emitted species have less of an 

impact.

Black carbon and organic carbon make up a substantial 

part of the fine particulate matter in air pollution that is 

the major environmental cause of ill health and premature 

deaths, globally (WHO, 2009). The health-damaging 

particulate matter is characterized as PM2.5, particles with a 

diameter less than 2.5 micrometres – ‘fine’ or ‘small-sized’ 

particles which affect the respiratory and cardiovascular 

systems – and its impacts occur due to both outdoor and 

indoor exposure. The health benefits of reduced emissions 

from measures that focus on black carbon are mainly 

achieved by the overall reduction in this fine particulate 

matter. It should be kept in mind that all reductions of 

black carbon emissions reduce PM2.5 concentrations but all 

reductions of PM2.5 do not necessarily reduce black carbon.
3.1 Strategic approach

The preceding chapter highlighted the SLCFs of interest 

to this report: black carbon, methane and tropospheric 

ozone. The benefits of mitigating emissions have also 

been highlighted in the Integrated Assessment of Black 

Carbon and Tropospheric Ozone (UNEP/WMO, 2011). In 

order to develop effective policies for mitigation of these 

SLCFs, the following guiding principles could be useful: 

• Building on current policies. Strategies to address SLCFs 

can efficiently build on a number of existing policies 

and initiatives. One option is to incorporate SLCFs into 

existing air pollution policies and regulatory frameworks, 

including those at the international level. Another is to 

incorporate them into climate change agreements and 

regulations. In addition, it would be useful to integrate 

SLCF mitigation into development policies. 

• Developing an integrated approach. Society would benefit 

from a more integrated approach to climate change and 

air pollution in policy making, because it would utilise the 

large overlap between the two areas and thereby make 

policy making more efficient and less costly.

• Setting common goals. Setting common goals on national, 

regional, or international levels, can encourage national 

efforts by enabling progress to be measured against 

targets. In the case of air quality, international guidelines 

such as those for particulate matter and ground-level 

ozone from the World Health Organisation (WHO, 2006) 

can be used as targets. In the case of climate change, 

the goal of limiting temperature increase to less than 

2°C above preindustrial temperatures can be used as a 

comparable target. Global goals regarding total emissions 

of black carbon, methane and other tropospheric ozone 

precursors could play an equally useful role. Countries 

could choose to set national targets in relation to 

achieving these global goals. This could also apply to 

near-term climate goals and air quality objectives.

• Rapid implementation of measures. Chapter 1 makes 

it clear that it is important to reduce imminent 

climate impacts, and Chapter 4 explains that this can 

accomplished by reducing SLCFs and slowing down global 

warming over the next two to four decades. Meanwhile, 

Chapter 4 also explains that air pollution impacts on 

health and crops are large and can be addressed by 

reducing SLCFs. From this dual perspective, it is clear that 

there are many benefits to be gained by reducing SLCFs 

as quickly as possible, and to consider options for nearterm implementation of policies and measures focussing 

on the reduction of black carbon and methane emissions. 

• Central role of national action. Special emphasis should 

be given to action at the national level because the 

health and agricultural benefits of implementing the 

measures are normally greatest close to emission 

sources. This is the case for the black carbon and other 

particulate matter emissions from smoky stoves and 

poorly operating brick kilns which endanger the health of 

local people. Moreover, measures can be better targeted 

to specific emission sources and policies by integrating 

them into national priorities for air pollution.

• Enabling activities at regional and global levels. Although 

it makes sense to give priority to national action for 

abating SLCFs, there are also advantages for cooperating 

at the regional and global level. One reason is that 

some SLCFs spread beyond national borders and are 

distributed across regions (e.g. black carbon), across 

hemispheres (such as tropospheric ozone and some of 

its precursors), and even across the globe (for example, 

methane). Often international action is needed to 

bring down levels of SLCFs within a particular country. 

Another reason for cooperating at the regional level is 

that emission sources and abatement measures tend 

to be similar for several countries within a region. 

International cooperation also promotes technology 

transfer and capacity building.

A suitable starting point is to identify measures that 

can clearly achieve the emission-reduction targets in 

a sustainable manner, taking into consideration the 

circumstances of any particular country. Identified 

Chapter 3:

Policies and Measures to Reduce 

Short-Lived Climate Forcers

6 Near-term Climate Protection and Clean Air Benefits – POLICIES AND MEASURES TO REDUCE SHORT-LIVED CLIMATE FORCERS
POLICIES AND MEASURES TO REDUCE SHORT-LIVED CLIMATE FORCERS – Near-term Climate Protection and Clean Air Benefits 7

strategies should be readily implementable, and success 

should be relatively easy to measure and assess. It is 

especially important that the selected measures are cost 

effective, generating positive short-term returns on capital 

expenditure, and have low maintenance costs. 

3.2 Identifying priority control measures

A variety of technical and regulatory SLCF measures 

are available to control emissions. Mitigation measures 

for black carbon, in most instances, will usually result 

in changes in emissions of other co-emitted pollutants. 

Therefore, to understand the full climate and publichealth implications, as well as other air pollution-related 

impacts of each measure, it is important to look at 

the impact of a measure on a suite of pollutants. For 

example, some co-emitted substances, including sulphur 

dioxide (that gives rise to sulphate) and/or organic 

carbon (often co-emitted with black carbon), cool the 

atmosphere and these can potentially offset the climate 

benefits of reducing black carbon. Sulphate and organic 

carbon are particles that scatter light and hence reflect 

a portion of incoming sunlight back into space, thereby 

cooling the Earth. However, over snow-covered reflective 

surfaces, organic carbon actually contributes to warming. 

Understanding the effect of these co-emitted substances 

on warming, climate change and the composition and 

concentrations of air pollutants is important when 

evaluating measures to reduce concentrations of black 

carbon and tropospheric ozone.

To identify ‘win-win’ measures that simultaneously 

achieve air quality and climate change benefits, an 

analysis of available measures that focus on reducing 

emissions of black carbon and methane was performed. 

The analysis was undertaken using information on 

measures compiled within the Greenhouse Gas and 

Air Pollution Interactions and Synergies (GAINS) model 

(Amann et al., 2011; Klimont et al., 2009; Kupiainen 

and Klimont, 2004). The model considered all key 

documented pollution control options, amounting to 

about 2 000 measures, that reduce black carbon and 

methane emissions. All black carbon measures reduce fine 

particulate matter (PM2.5) while ozone precursor emissions 

are reduced by both black carbon and methane measures, 

resulting in reduced air pollution impacts on health, crop 

yields and ecosystems. 

The GAINS model determined which of these measures 

would give net climate benefits. To do this, the measures 

were ranked according to their potential climate impact 

using published values of the global warming potential 

(GWP) for all substances emitted that affect climate and 

that are controlled by the measures. The net effect of the 

emission reduction of ‘warming’ substances compared 

to the emission reduction of ‘cooling’ substances was 

calculated. As a result, measures that reduce warming 

overall were identified. The resulting list therefore 

contains ‘win-win’ measures that reduce both air pollution 

and climate change impacts. Further details on the 

methodology used to derive the selected measures are 

provided in the on-line Appendix.

Of the 2000 measures, the GAINS model identified 

approximately 130 that would achieve a reduction of 

global warming, with the top 16 measures realizing 

nearly 90 per cent of the maximum reduction potential 

in equivalent CO2

 emissions by 2030. These 16 measures 

(Tables 3.1 and 3.2) were therefore selected to form the 

basis of the analysis in the Integrated Assessment of Black 

Carbon and Tropospheric Ozone (UNEP/WMO, 2011) and 

in this report. Whilst they account for a large part of the 

climate benefit from a global perspective, they are not 

the only measures available to policy makers in different 

regions, but this selection does provide a sound starting 

point from which to develop effective policies targeted at 

reducing SLCFs. 

3.3 Baseline year and reference scenario 

emissions

The effectiveness of SLCF mitigation measures was 

analyzed relative to a baseline year - 2005, and also 

relative to a reference scenario - a ‘business-as-usual’ 

scenario. 

The baseline year (2005) emissions were estimated 

with the GAINS model, using available statistical data 

and data from Lamarque et al., (2010) (See UNEP/WMO, 

2011). 

The reference scenario refers to emissions that would 

occur without deployment of further mitigation measures, 

apart from already existing ones. The values of the 

emissions were computed taking into consideration future 

energy and fuel demand as projected by the International 

Energy Agency (IEA) and incorporating the effects of 

all presently agreed policies that could affect the SLCF 

emissions (further details in the on-line Appendix).

 The projected methane and black carbon emissions 

under the reference scenario in 2030 are shown in Figure 

3.1. The figure shows the contributions of different sectors 

to emissions in each region. Details of the emission trends 

for other relevant substances – carbon monoxide, organic 

carbon, nitrogen oxides, non-methane volatile organic 

compounds, PM2.5, sulphur dioxide and methane – are 

also provided in the on-line Appendix of this report.

At the global level three key sources of methane 

contribute about 94 per cent of the total anthropogenic 

emissions in 2005: 43 per cent from agriculture, including 

livestock rearing and rice production; 34 per cent from 
8 Near-term Climate Protection and Clean Air Benefits – POLICIES AND MEASURES TO REDUCE SHORT-LIVED CLIMATE FORCERS

Figure 3.1: Emissions of black carbon (top) and methane (bottom) for the baseline year 2005, and projections for 2030 based upon the 

UNEP/WMO assessment reference scenario for five different world regions (see Chapter 2 of UNEP/WMO, 2011). The emissions are 

broken down by major sector.

Note: shipping and aviation are not included in this regional analysis

0.0

0.5

1.0

1.5

2.0

Black carbon emissions for baseline year (2005) and reference 

(2030) scenario (millions of tonnes black carbon)

Africa Latin America 

and Caribbean

North America

and Europe

North East Asia, 

South East Asia 

and Pacific

South, West 

and Central Asia

2005 2030 2005 2030 2005 2030 2005 2030 2005 2030

0

20

40

60

80

100

120

Africa Latin America 

and Caribbean

North America

and Europe

North East Asia, 

South East Asia 

and Pacific

South, West 

and Central Asia

Methane emissions for baseline year (2005) and reference 

(2030) scenario (millions of tonnes methane)

2005 2030 2005 2030 2005 2030 2005 2030 2005 2030

Agriculture

Waste/landfill

Fossil fuel extraction and 

distribution

Transport 

Residential-commercial 

combustion

Industrial processes

Large-scale combustion 
POLICIES AND MEASURES TO REDUCE SHORT-LIVED CLIMATE FORCERS – Near-term Climate Protection and Clean Air Benefits 9

fossil fuel production and distribution; and 17 per cent 

from municipal waste and wastewater management. Asia 

accounts for 46 per cent of global methane emissions 

compared with 28 per cent in North America and Europe, 

14 per cent Latin America and 12 per cent in Africa. 

Without further mitigation efforts, baseline methane 

emissions are expected to grow by about 25 per cent 

by 2030, with no significant changes in the regional and 

sectoral contributions.

At the global level, anthropogenic emissions of 

black carbon are dominated by residential-commercial 

combustion and transport sources that make up nearly 80 

per cent of the total. Another 14 per cent originates from 

industrial production and the open burning of agricultural 

waste. There are significant regional differences in the 

importance of particular sectors – residential-commercial 

combustion dominates anthropogenic emissions of black 

carbon in Africa and Asia, while transport is currently a key 

contributor in North America and Europe. In Latin America 

and the Caribbean, both sectors are equally important 

black carbon sources. Industrial processes (e.g. production 

of bricks and coke in traditional kilns and ovens) are 

significant sources of emissions in some developing 

countries. As a global total, the reference scenario does 

not show a large change in total black carbon emissions 

by 2030 (Figure 3.1). However, significant regional 

and sectoral shifts are expected with, for example, 

declining shares from North America and Europe where 

emissions are estimated to fall by about half, primarily 

due to measures implemented in the transport sector. 

Meanwhile, the share of emissions from South, West and 

Central Asia and Africa increases significantly because of 

increases from the transportation and residential sectors.

Combustion within the residential-commercial sector is 

expected to remain an important emission source over 

the next two decades. 

3.4 Identifying key methane measures

Seven out of the 16 identified measures are focussed 

on reducing methane emissions (Table 3.1) from three 

sectors: fossil fuel production and transport, waste 

management, and agriculture. 

The impact of these measures on emissions of 

methane relative to the reference scenario in 2030 is 

shown in Figure 3.2, assuming full implementation of 

measures in each region.

The identified measures are expected to reduce 

reference methane emissions by about 38 per cent in 

2030 (Figure 3.2). A third of that figure is achieved by 

reducing emissions from oil and gas production in North 

America and Europe, Africa and South, West and Central 

Asia. Another third of the potential can be reduced from 

coal mining, especially from North East Asia, South East 

Asia and the Pacific region. The improved management of 

municipal waste could contribute one fifth of the potential 

reduction, half of which could be achieved in North 

America and Europe. Lastly, the agricultural measures 

considered here could account for about one tenth of 

global methane reductions in 2030.

A more detailed discussion of the measures and their 

application to different sectors is presented in Section 5.2.

3.5 Identifying key black carbon measures

Nine out of the 16 identified measures are focussed on 

reducing black carbon emissions (Table 3.2) from four 

sectors: transport, residential, industry and agriculture.

The impact of the identified measures on reference 

scenario emissions in 2030 is shown in Figure 3.3, again 

assuming full implementation of the measures in each 

region. The impact of the measures on emissions of other 

substances is given in the on-line Appendix.

These key measures achieve about 77 per cent of the 

potential emission reduction for black carbon in 2030 (i.e. 

Table 3.1: Key methane abatement measures identified for this report (after UNEP/WMO, 2011)

Measure Sector

Extended pre-mine degasification and recovery and oxidation of methane from ventilation air from coal mines Fossil fuel 

production 

and transport Extended recovery and utilization, rather than venting, of associated gas and improved control of unintended 

fugitive emissions from the production of oil and natural gas

Reduced gas leakage from long-distance transmission pipelines

Separation and treatment of biodegradable municipal waste through recycling, composting and anaerobic 

digestion as well as landfill gas collection with combustion/utilization

Waste 

management

Upgrading primary wastewater treatment to secondary/tertiary treatment with gas recovery and overflow control

Control of methane emissions from livestock, mainly through farm-scale anaerobic digestion of manure from cattle 

and pigs

Agriculture

Intermittent aeration of continuously flooded rice paddies
10 Near-term Climate Protection and Clean Air Benefits – POLICIES AND MEASURES TO REDUCE SHORT-LIVED CLIMATE FORCERS

Figure 3.2: Methane emission reductions in 2030 achieved with the identified measures in Table 3.1 compared to the reference scenario 

in 2030 (in millions of tonnes of methane)

-40

-30

-20

-10

0

Africa

Latin America 

and 

Caribbean

North 

America

and Europe

North East 

Asia, South 

East Asia 

and Pacific

South, West 

and Central 

Asia

Change in methane emissions in 2030 compared to the 2030 reference 

scenario (millions of tonnes of methane)

Intermittent aeration of continuously 

flooded rice paddies

Reduced methane emissions from 

livestock by anaerobic digestion of 

manure

Upgrading primary wastewater 

treatment with gas recovery

Separation and treatment of 

biodegradable municipal waste

Reduced gas leakage from 

long-distance transmission pipelines

Extended methane recovery/utilization 

and reduced fugitive emisions from oil 

and gas production

Pre-mine degasification and recovery 

of methane from coal mine ventilation 

air

Table 3.2: Key black carbon abatement measures identified for this report (after UNEP/WMO, 2011)

Measure Sector

Standards for the reduction of pollutants from vehicles (including diesel particle filters), equivalent to those included 

in Euro-6/VI standards, for road and off-road vehicles

Transport

Elimination of high-emitting vehicles in road and off-road transport

Replacing lump coal by coal briquettes in cooking and heating stoves Residential

Pellet stoves and boilers, using fuel made from recycled wood waste or sawdust, to replace current wood burning 

technologies in the residential sector in industrialized countries

Introduction of clean-burning (fan-assisted) biomass stoves for cooking and heating in developing countries1, 2

Substitution of traditional biomass cookstoves with stoves using clean-burning fuels (liquefied petroleum gas (LPG) or 

biogas)1, 2

Replacing traditional brick kilns with vertical shaft brick kilns3 Industry

Replacing traditional coke ovens with modern recovery ovens

Ban on open burning of agricultural waste1 Agriculture

 1. Motivated in part by its effect on health and regional climate including its impact on areas of ice and snow

 2. For cookstoves, given their importance for black carbon emissions, two alternative measures are included

 3. Zig-zag brick kilns would achieve comparable emission reductions to vertical-shaft brick kilns
POLICIES AND MEASURES TO REDUCE SHORT-LIVED CLIMATE FORCERS – Near-term Climate Protection and Clean Air Benefits 11

Figure 3.3: Black carbon emission reductions in 2030 achieved with the identified measures in Table 3.2 compared to the reference 

scenario in 2030 (in millions of tonnes of black carbon)

-1.5

-1.2

-0.9

-0.6

-0.3

0.0

Africa

Latin America 

and 

Caribbean

North 

America

and Europe

North East 

Asia, South 

East Asia 

and Pacific

South, West 

and Central 

Asia

Change in black carbon emissions in 2030 compared to the 2030 reference 

scenario (millions of tonnes of black carbon)

Ban of open burning of agricultural 

residues

Additional reduction from Euro-6/VI 

vehicle standards (including DPF) after 

elimination of high-emitters

Elimination of high-emitting vehicles

Replace lump coal with coal briquettes 

in cooking and heating stoves

Replace current residential wood 

burning technologies with pellet stoves 

and boilers (in industrialized countries)

Switch from traditional biomass cookstoves to stoves fueled by LPG or biogas 

or to fan-assisted biomass stoves (in 

developing countries)

Replace traditional coke ovens with 

modern recovery ovens 

Replace traditional brick kilns with 

vertical shaft kilns 

Note: for biomass cookstoves, only the effect of substitution with LPG and biogas stoves is shown for clarity; with 100 per cent substitution with fanassisted biomass cookstoves, the emissions reduction would be about 6 per cent less

compared to all 2000 measures). Black carbon measures 

also have a significant effect on various co-emitted 

substances. For example, they reduce organic carbon 

emissions, which is an important consideration when 

assessing the net change in climate impact caused by the 

measures. They also reduce a number of ozone precursors 

- carbon monoxide, non-methane volatile organic 

compounds and nitrogen oxides – and therefore have the 

effect of reducing tropospheric ozone concentrations (see 

the on-line Appendix).

Measures addressing traditional biomass cookstoves 

would reduce emissions mostly in Africa and Asia, whilst 

those addressing emissions from the transport sector, 

especially by implementing Euro-6/VI vehicle-emission 

standards that include diesel particle filters, would bring 

about the largest reduction in black carbon emissions in 

Latin America and the Caribbean. In regions other than 

North America and Europe, eliminating high emitting 

vehicles would also have a significant beneficial impact 

on black carbon emissions. In North America and Europe, 

the largest black carbon emission reductions would come 

from replacing current wood-burning technologies in the 

residential sector with pellet stoves and boilers or another 

technology with equally low emissions. 

Regionally, the potential to implement the measures 

differs depending on the source structure and the state 

of emission legislation. A broader discussion on the 

measures and their potential application to different 

sectors is presented in Section 5.2.
This chapter focuses on the costs and benefits of black 

carbon and methane emission reduction measures. By 

articulating which measures in different sectors will bring 

the largest benefits in particular regions, it goes beyond 

the global analysis in the Integrated Assessment of Black 

Carbon and Tropospheric Ozone (UNEP/WMO, 2011). 

Information is provided about benefits to human health 

and crop yields due to the reduction of air pollution, as 

well as about benefits to global and regional climate. 

Information is provided for the following aggregation of 

countries: Africa; North East Asia, South East Asia and the 

Pacific; Latin America and the Caribbean; North America 

and Europe; and South, West and Central Asia (Figure 4.1 

and more detail in on-line Appendix).

4.1 Costs of implementing the measures 

There are many examples of the suggested measures 

already being implemented around the world, mainly in 

developed countries, not only for air pollution control, 

but also for occupational safety, climate protection and 

other reasons. Hence, ample experience regarding direct 

implementation costs already exists for many of the 

measures. Indirect costs, such as the cost of enforcing 

regulations, and the valuation of benefits associated 

with the measures are difficult to quantify. Investment 

and operating costs are fairly well known for measures 

to reduce methane emissions from coal mining, oil and 

gas production and distribution in some OECD countries. 

It is possible to extrapolate costs from OECD countries, 

but this has to be done cautiously because of differences 

between countries, especially between developed and 

developing countries. 

Uncertainty is higher for cost data from the domestic 

sector (such as for cookstoves), agriculture and industry 

(such as for brick kilns) because these data are often 

drawn from a limited number of existing applications or 

specific installations. This data limitation makes it difficult 

to accurately reflect specific local-scale circumstances in a 

global assessment.

For measures that require improved governance rather 

than application of new technologies alone, it is difficult 

to quantify the costs of overcoming implementation 

Chapter 4:

Costs and Benefits of Implementing 

the Measures: A Regional Analysis

Figure 4.1: The aggregation of countries into the five regions used in this report

12 Near-term Climate Protection and Clean Air Benefits – COSTS AND BENEFITS OF IMPLEMENTING THE MEASURES
COSTS AND BENEFITS OF IMPLEMENTING THE MEASURES – Near-term Climate Protection and Clean Air Benefits 13

barriers and associated monitoring and enforcement. An 

example of this is the cost associated with regulations to 

stop such practices as the open burning of agricultural 

crop residues. 

An initial global estimate of implementation costs has 

been developed using the GAINS model which contains 

cost data for the major emission reduction technologies, 

and uses calculation routines that consider the impacts of 

important local factors on emission control costs (Amann 

et al., 2011; Höglund-Isaksson et al., 2009 - see on-line 

Appendix for further details). 

Cost estimations were carried out from two 

perspectives– that of a ‘social planner’ and that of a 

‘private investor’:

i) The ‘social planner’ perspective considers 

investments in terms of the best use of resources 

to promote development for the long-term benefit 

of society; hence, the cost estimation assumes 

that costs and cost savings are discounted over the 

full technical lifetime of the equipment with a low 

assumed discount rate of 4 per cent. 

ii) The ‘private investor’ perspective incorporates 

expectations about short-term profits. The rates 

of return on capital are required to compete with 

potential gains from alternative investments, for 

example, in the stock market. An assumed discount 

rate of 10 percent is used. 

Table 4.1 provides cost estimates for the 16 identified 

measures, computed with the GAINS model for the year 

2030. The measures were grouped into four categories 

according to their relative cost. Although key factors, 

such as labour costs, that allow estimation of differences 

in emission-control costs between countries were taken 

into account, the cost estimates calculated by the GAINS 

model are preliminary as reliable data are not always 

available for all local factors. Due to the differences in 

economic structures, costs vary widely between regions as 

can be seen in Table 4.1. 

Group 1 in Table 4.1 includes measures that result 

in net cost savings or low costs over their full technical 

lifetime (taking into account the ranges given in the 

table). Initial investments are offset by subsequent cost 

savings, for example from reduced fuel use or utilization 

of recovered gas. It must be noted that the cost estimates 

do not take into account any monetary valuation of health 

and crop-yield benefits. While the Group 1 measures are 

economically profitable and would pay for themselves 

from a social planner’s perspective, many are less 

attractive for private investors. As a consequence, these 

measures are less likely to be adopted by relying on 

market forces alone.

Although the exact quantification of costs depends on 

the chosen perspective, measures of Group 1 are the least 

costly from both perspectives and would realize more 

than half of the temperature reduction potential in 2050. 

About half of the emission reductions of both methane 

and black carbon could be achieved by these measures 

that would deliver financial cost savings over the lifetime 

of the measures (as a global average, and for the ‘social 

planner’s’ perspective).

Group 2 contains measures that do not result in net 

savings from the social planner’s perspective. Although 

these measures will incur costs over the lifetime of the 

measure, they also enhance human welfare by protecting 

health and crop yields and slowing down global warming. 

On the other hand, the Group 2 measures would be 

competitive on a global carbon market for less than 75 

US $/CO2

e, if costs are calculated from a private investors 

perspective. These measures would collectively achieve 

about 18 per cent of the potential temperature reduction 

in 2050.

Group 3 includes other measures for which costs can 

be quantified. They appear less cost-effective to society 

when their costs are considered solely in terms of their 

climate benefits. Still, these measures have been widely 

implemented around the world, mainly in more wealthy 

countries, although usually for other purposes such as 

occupational safety, public health, groundwater protection 

and sanitation. Group 3 measures would achieve about 17 

per cent of the potential temperature reduction in 2050.

Finally, Group 4 contains measures where the costs 

are difficult to quantify – a ban on open burning of 

agricultural waste and elimination of high-emitting 

vehicles. These two measures, in particular, depend on 

strong governance and regulatory frameworks for their 

successful implementation. It is difficult to quantify 

the costs of overcoming implementation barriers, and 

subsequent monitoring and enforcement. However, there 

are many instances around the world where such bans 

or removal of polluting vehicles have been successfully 

implemented, suggesting that the costs are not a major 

barrier. About 12 per cent of the potential temperature 

reduction is linked to this group.

The influence of costs on implementation

As mentioned, about half of the temperature reduction 

would emerge from Group 1 measures, which result in net 

cost savings to society over their full technical lifetime. 

However, the required up-front investments over an 
14 Near-term Climate Protection and Clean Air Benefits – COSTS AND BENEFITS OF IMPLEMENTING THE MEASURES

Table 4.1: Overview of costs of methane (CH4) and black carbon (BC) measures. Emission reduction potentials are shown together with 

the per cent share of temperature reduction in Figure 4.2 achieved by each measure. Also shown are preliminary cost estimates of 

methane and black carbon measures in terms of costs per tonne of methane or black carbon. Two cost perspectives are shown, that 

of the ‘social planner’, and that of the ‘private investor’. See text. These are preliminary cost estimates. The uncertainty is higher for 

measures related to technologies that are not traded globally. All costs are in US$.

Emission 

reduction 

potential 

in 2030 1)

Global climate 

benefits 

expressed as 

share of total 

temperature 

reduction from 

SLCFreductions 

in 2050 

(based on 

GTP2

) 

Costs per tonne 

reduced1, 5

(‘social 

planner’s’ 

perspective; 

global mean 

value; variation 

across the 

regions shown 

in parentheses)

Equivalent 

carbon price2, 

5, 6 (private 

investor’s 

perspective; 

global mean 

value; variation 

across the 

regions shown 

in parentheses). 

Non-climate 

benefits of 

measure

A B C D E

GROUP 1: Cost Savings or Low Cost 

Cooking and heating with biomass 

in developing countries:

- clean burning stoves instead of 

conventional stoves and/or

- clean fuel (LPG/biogas) instead of 

biomass stoves. 

1.8 Mt BC 24.8%

-10,100 $/t BC

(-12,000 to -5,000)

-200 $/t BC

(-240 to -100)

-6 $/t CO2e

(-7 to -3)

7 $/t CO2

e

(6 to 14)

Health protection, 

indoor air quality,

crop protection4

Recovery and utilization of vented 

associated gas during oil production. 

30.6 Mt 

CH4

10.8% -150 $/t CH4

(-730 to 480)

70 $/t CO2

e

(32 to 92)

Energy efficiency,

crop protection

Separation and treatment of 

biodegradable municipal waste with 

no biodegradable waste disposed of 

to landfill. 

27.8 Mt 

CH4

9.7% -1,650 $/t CH4

(-1,840 to -1,450)

29 $/t CO2

e

(12 to 53)

Improved waste 

management,

energy efficiency,

crop protection

Replacing coal with coal briquettes 

in cooking and heating stoves in 

developing countries.

0.4 Mt BC 3.9% Approximately 

zero $/t BC

Approximately 

zero $/t CO2

e

Health protection, 

crop protection

Reduced leakage during gas pipeline 

transmission.

6.7 Mt CH4 2.3% -190 $/t CH4

(-259 to 4,120)

27 $/t CO2

e

(21 to 382)

Long-term 

economics,

energy efficiency,

crop protection

Recovery and utilization of 

vented associated gas during gas 

production. 

2.4 Mt CH4 0.85% -690 $/t CH4

(-721 to -632)

-7 $/t CO2

e

(-8 to -6)

Long-term 

economics, 

energy efficiency,

crop protection

Farm-scale anaerobic digestion 

on large farms with liquid manure 

management.

2.2 Mt CH4 0.7% -400 $/t CH4

(-2,320 to +1,250)

34 $/t CO2

e

(17 to 81)

Energy efficiency, 

crop protection

Replacing traditional brick kilns with 

more efficient kilns.

0.04 Mt BC 0.5% -5,500 $/t BC

(-5,600 to -4,400)

-7 $/t CO2

e

(-5 to -8)

Improved quality 

of bricks,

health protection,

energy efficiency,

Total for Group 1 53.6%

GROUP 2: Moderate Cost

Coal mines: oxidation of ventilation 

air methane including improvements 

in ventilation air systems.

25.0 Mt 

CH4

8.7% 280 $/t CH4

(222 to 2,820)

13 $/t CO2

e

(11 to 137)

Occupational 

safety
COSTS AND BENEFITS OF IMPLEMENTING THE MEASURES – Near-term Climate Protection and Clean Air Benefits 15

1. For the main substance affected (methane – CH4, or black carbon - BC)

2. Taking into account impacts of co-emitted species

3. For Euro-6/VI, these are additional reductions after elimination of high-emitting vehicles

4. ‘Crop protection’ implies reduced ozone impacts on crop yields

5. The cost ranges represent regional differences in initial conditions, cost of labour, etc

6. Costs per equivalent CO2

 emission are calculated using the GWP100 metric

Coal mines: recovery of pre-mine 

degasification emissions. 

17.5 Mt 

CH4

6.1% 1,300 $/t CH4

(500 to 10,500

74 $/t CO2

e

(37 to 445)

Occupational 

safety,

energy efficiency

Feed changes for dairy and nondairy cattle.3.9 Mt CH4 1.3% 1,330 $/t CH4

(1,090 to 1,880)

53 $/t CO2

e

(44 to 75)

Improved meat 

quality 

Replacing traditional coke ovens 

with modern recovery ovens.

0.2 Mt BC 1.6% 190 $/t BC

(140 to 500)

0.4 $/t CO2

e

(0.3 to 1.1)

More cost-effective 

production,

energy efficiency

Total for Group 2 17.7%

GROUP 3: High Cost

Euro VI/6 standards (incl. DPF) for 

heavy duty vehicles

0.3 Mt 

BC 3)

3.1% 145,000 $/t BC

(120,000 to 

200,000) 

300 $/t CO2

e

(240 to 410)

Health protection,

crop protection

Euro VI/6 standards 

for light duty vehicles:

- with diesel particle filters.

0.1 Mt 

BC 3)

1.0% 80,000 $/t BC 

(36,000 to 

150,000)

180 $/t CO2

e 

(80 to 350)

Health protection,

crop protection

Euro VI/6 standards (incl. DPF) for 

off-road mobile machinery.

0.3 Mt 

BC 3)

3.1% 570,000 $/t BC

(225,000-

815,000) 

1,400 $/t CO2

e

(500 to 2,000)

Health protection,

crop protection

Intermittent aeration of 

continuously flooded rice paddies. 

9.1 Mt CH4 3.2% 3,160 $/t CH4

(1,750 to 35,300)

130 $/t CO2

e

(70 to 1,410)

Crop protection

Control of unintended leakages 

during oil production.

5.7 Mt CH4 2.0% 3,410 $/t CH4

(1,310 to 22,800)

140 $/t CO2

e

(52 to 913)

Energy efficiency,

occupational safety

Pellet stoves and boilers replacing 

current wood burning technologies 

in industrialized countries.

0.2 Mt BC 1.8% 320,000 $/t BC

(200,000 to 

400,000)

710 $/t CO2

e

(440 to 880)

Energy efficiency,

health protection

Control of unintended leakages 

during gas production. 

4.3 Mt CH4 1.5% 3,390 $/t CH4

(1,300 to 10,300)

160 $/t CO2

e

(72 to 428)

Energy efficiency,

occupational safety

Upgrading of primary to secondary/

tertiary wastewater treatment. 

3.9 Mt CH4 1.4 % 4,090 $/t CH4

(2,990 to 6,420)

430 $/t CO2

e

(335 to 633)

Improved water 

quality

Total for Group 3 17.1%

GROUP 4: Difficult to Quantify

Elimination of high-emitting 

vehicles.

0.4 Mt BC 6.6% Health protection,

energy efficiency

Ban of field burning of agricultural 

waste.

0.4 Mt BC 5.2% Health protection,

crop protection,

improved visibility

Total for Group 4 11.8%
16 Near-term Climate Protection and Clean Air Benefits – COSTS AND BENEFITS OF IMPLEMENTING THE MEASURES

assumed 20 years implementation period do constitute 

a considerable barrier to implementation. Prevailing 

short-term profit expectations of private investors make 

these measures less attractive to the market. For example, 

implementation of the recovery and utilization of vented 

methane and other gases in oil production would pay for 

itself in about ten years and would be desirable from a 

social planner’s perspective, even without considering 

health and climate benefits. In contrast, the large capital 

investment associated with this measure makes it quite 

expensive for a private investor.

The separation and treatment of biodegradable waste 

is the measure requiring the second highest capital 

investment within Group 1. It is estimated to have a 

pay-back period of four to six years, if the methane 

derived from the waste treatment process is utilized. 

However, this measure requires adequate coordination 

between the public sector responsible for setting up 

needed infrastructures and private households, who 

will be required to separate their waste at source. This 

requirement may pose a barrier to implementation, 

especially in countries where waste separation is not a 

common practice. 

Capital investments for clean cookstoves are 

substantially lower than those measures already 

mentioned above and also provide a short pay-back 

period. However, because this measure applies to poor 

people in developing countries a major issue is how 

to meet up-front costs for new stoves. For all Group 1 

measures, targeted interventions or appropriate financing 

mechanisms could help to overcome implementation 

barriers. In comparison, measures of Group 2, which could 

potentially be competitive on a carbon market, require 

much lower up-front investments, especially for methane 

recovery in coal mines.

Overall, the largest upfront investments would be 

required for worldwide introduction of diesel particle 

filters to achieve the Euro-6/VI emission standards for 

road vehicles and non-road mobile machinery. One 

way to shortcut this high cost and yet achieve similar 

environmental benefits would be to replace diesel 

powered light duty vehicles with gasoline powered ones 

through natural fleet turnover. This can be encouraged 

by changing the taxes for diesel and gasoline fuels, or by 

modifying emission standards for diesel and gasoline lightduty vehicles. It must be noted however that reducing 

emissions from light-duty vehicles only covers a small 

fraction of the climate benefit from introducing Euro-6/

VI, as most of the benefits are projected to come from 

reducing the emissions from heavy-duty trucks which will 

continue to use diesel fuel.

Some of the more costly measures for controlling SLCFs 

are often/usually implemented for other developmentrelated objectives. For example, the upgrading of 

wastewater treatment is contained in the list of 16 SLCF 

measures because it can be an effective way of reducing 

methane emissions. But, of course, wastewater treatment 

is usually upgraded in order to safeguard sanitation, 

protect public health, and protect aquatic ecosystems. 

In this particular case the benefits of reducing methane 

emissions articulated in this report provide additional 

arguments for going ahead with the upgrading of 

wastewater treatment. 

4.2 Quantifying the climate and air quality 

benefits of regional implementation of 

measures

In the Integrated Assessment of Black Carbon and 

Tropospheric Ozone (UNEP/WMO, 2011) the climate, 

health and crop-yield benefits that would be achieved 

from the implementation of the 16 measures were 

quantified or described, mainly from a global perspective. 

These included a substantial reduction in global warming 

in the near-term, about 2.4 million fewer premature 

deaths (range of 0.7-4.6 million), and about 52 million 

tonnes of crop losses avoided (range of 30-140 million 

tonnes) each year. It was also noted there that, the 

health and crop-yield benefits of emission reductions 

would mostly be realised in the regions that reduce their 

emissions. 

In this report the analysis is taken a step further by 

describing the regional benefit from each of the 16 

measures. For each region, the effectiveness of the 

selected measures in reducing emissions has already been 

shown in Chapter 3. This chapter shows the regional and 

global climate benefits of these measures in 2050, as well 

as the health benefits, estimated in terms of the reduction 

in number of premature deaths per year in 2030, and the 

crop-yield benefits estimated as avoided crop-yield losses 

per year for four staple crops, also in 2030. 

In the UNEP/WMO (2011) assessment the global 

climate benefits were calculated using output from 

two global climate/chemical composition models – the 

NASA-GISS model (Shindell et al., 2006) and the ECHAM 

model (Pozzoli et al., 2008). These models were used 

to compute the change in global temperature as shown 

earlier in Figure 1.1. For the purposes of this report it was 

not possible to run these models for each region and for 

each measure because of the long time required to run 

the models and process their output. Therefore, in order 

to quantify the regional benefits for each measure, the 
COSTS AND BENEFITS OF IMPLEMENTING THE MEASURES – Near-term Climate Protection and Clean Air Benefits 17

TM5-FASST10 rapid assessment tool has been used for this 

report developed at the European Union Joint Research 

Centre at Ispra, Italy (a more detailed description of TM5-

FASST is given in the on-line Appendix). 

4.2.1 Global and regional climate benefits from 

implementing measures in the regions

In the next sections we explain how the global and 

regional climate benefits from implementing the 

different measures were estimated, and then compare 

the potential effectiveness of the different measures in 

different regions in achieving these benefits. 

Estimating global climate benefits

An important indicator of the global climate benefits of 

SLCF reductions is the slowing of global warming over the 

next two to four decades. The TM5-FASST model used in 

this report computes that the increase in temperature 

between 2010 and 2050 will be 0.4°C below the reference 

scenario under the full implementation of the 16 SLCF 

measures (range of 0.1 - 0.6°C). Put another way, the 

SLCF measures will slow global warming between 2010 

and 2050 by 0.4°C. This benefit is not quite as large as 

the 0.5°C reduction by 2050 computed in the UNEP/

WMO (2011) assessment with the NASA-GISS and ECHAM 

models, which reflects the differences between models. 

Of importance to this report, the TM5-FASST tool was 

used to calculate the contribution of each measure within 

each region to this 0.4°C reduction. It was assumed that 

the measures were introduced beginning in 2010, fully 

implemented by 2030 and then maintained up to 2050. 

For each measure, and for each of the five regions, the 

global temperature potential (GTP) metric (see glossary) 

was used to translate the resultant change in emissions 

for each year between 2010 and 2050 into a change in 

temperature by 2050. The percentage contribution of 

each measure in each region to the total 0.4°C reduction 

of global warming was then computed (Figure 4.2). 

For the black carbon measures, the individual radiative 

forcing of all relevant co-emitted species, both cooling 

and warming ones, were taken into account. The range of 

temperature reduction shown for black carbon in Figure 

4.1 mainly reflects the uncertainty associated with the 

impact of black carbon on radiative forcing. 

Across the regions, the most important methane 

measures for near-term climate protection are those 

focusing on coal mines, the oil and gas industry and 

municipal waste (Figure 4.2, upper graph). For methane 

measures the largest single benefit calculated for any region 

is from the implementation of methane capture in coal 

mines in North East Asia, South East Asia and the Pacific. 

However, within the other four regions, extended utilization 

and recovery of methane from oil and gas production 

would bring the greatest near-term climate benefit. Also, 

reducing methane leakage from transmission in longdistance gas pipelines in Europe and North America would 

provide a significant near-term global climate benefit. 

Across Asia, intermittent aeration of continuously flooded 

paddy fields also provides a significant climate benefit.

The black carbon measure likely to bring the greatest 

near-term global climate benefit is that addressing 

domestic cooking with biomass fuel, especially in Africa, 

but also in Asia and in Latin America and the Caribbean 

(Figure 4.2, lower graph). The benefit would come from 

substituting biomass fuels with cleaner-burning fuels 

such as biogas or liquefied petroleum gas (LPG), or from 

a complete switch to fan-assisted improved biomass 

cookstoves, or by some combination of these options. 

It should be borne in mind, that the climate impact of 

emissions from cookstoves are subject to a particularly 

high degree of uncertainty concerning the relative 

emissions of warming substances – black carbon, carbon 

monoxide, non-methane volatile organic compounds and 

methane – and cooling ones – especially organic carbon. It 

should also be noted that a wholescale switch away from 

using traditional biomass stoves, although technically 

feasible, would represent an enormous challenge in these 

regions. In Europe and North America, replacing current 

residential wood-burning stoves with pellet stoves and 

boilers would bring the largest climate benefit among 

black carbon measures in 2030. 

10. The TM5-FASST (Fast Scenario Screening Tool) model (described in detail in the on-line Appendix) is a linearized source-receptor model derived 

from the full chemical transport model TM5-CTM. TM5-CTM is a state of the art global chemical transport model for gaseous pollutants and 

atmospheric aerosols (particulate matter) which has been used in numerous multi-model exercises and intercomparisons, including HTAP and 

AEROCOM (Krol et al., 2005; Dentener et al., 2006; Stevenson et al., 2006; Eyring et al., 2007; Anenberg et al., 2009; Fiore et al., 2009; Jonson et 

al., 2010). Radiative forcing by aerosols is pre-calculated for a reference scenario with the off-line radiative Transfer Model (OTM) described and 

implemented by Marmer et al. (2007). The normalized forcings from a reference scenario were stored and scaled with aerosol columns from actual 

scenarios. Radiative forcing for ozone was approximated by using the forcings obtained for the scenario results by Dentener et al. (2005), based on 

Edwards and Slingo (1996), and scaling them with ozone columns resulting from actual scenarios. The TM5-FASST model simulates well the TM5 

results for concentrations of black carbon, organic carbon, sulphate, ozone and PM2.5 and results are conformable to the results of the GISS model 

used in the UNEP/WMO assessment (on-line Appendix), which gives confidence in using this simplified tool to give a realistic estimate of the different 

benefits of implementing measures in different regions. However, it should also be pointed out that the approximations of the TM5-FASST model add 

additional uncertainties to modelling by TM5 alone.
18 Near-term Climate Protection and Clean Air Benefits – COSTS AND BENEFITS OF IMPLEMENTING THE MEASURES

Figure 4.2: The impact of methane (top) and black carbon (bottom) measures on global temperature expressed as their percentage share 

of the global 0.4°C (TM5-FASST estimate) temperature benefit delivered by the sum of all 16 measures in 2050 (left-hand axis) and in 

terms of absolute temperature change (right-hand axis). When added together, the bars for both methane and black carbon add up to 

100% of the temperature benefit. Vertical grey bars indicate the uncertainty range in absolute temperature change due to the likely range 

of the radiative forcing of methane and of black carbon and co-emitted substances

*Note: For clarity, only the effect of substitution with LPG and biogas stoves is shown in the black carbon graph for biomass cookstoves. With 100% 

substitution by fan-assisted biomass stoves, the reductions would be slightly lower (i.e. the lengths green bars would be 6% shorter). (Detailed values for all 

measures are given in the on-line Appendix)

Ban of open burning of agricultural 

residue

Additional reduction from Euro-6/VI 

vehicle standards (including DPF) after 

elimination of high-emitters

Elimination of high-emitting vehicles

Replace lump coal with coal briquettes 

in cooking and heating stoves

Replace current residential wood 

burning technologies with pellet stoves 

and boilers (in industrialized countries)

Switch from traditional biomass 

cookstoves to stoves fueled by LPG 

or biogas or to fan-assisted biomass 

stoves (in developing countries)

Replace traditional coke ovens with 

modern recovery ovens 

Replace traditional brick kilns with 

vertical shaft kilns 

Africa

Latin 

America and 

Caribbean

North 

America

and Europe

North East 

Asia, South 

East Asia 

and Pacific

South, West 

and Central 

Asia

-0.11

-0.09

-0.07

-0.05

-0.03

-0.01

0%

5%

10%

15%

20%

25%

30%

Share of the SLCF global temperature reduction benefit achieved by 

black carbon measures in 2050

Change in temperature by 2050 due to black carbon measures (°C)

Africa

Latin America and 

Caribbean

North America

and Europe

North East Asia, 

South East Asia 

and Pacific

South, West 

and Central 

Asia

0.00

-0.01

-0.02

-0.03

-0.04

-0.05

-0.06

-0.07

-0.08

Share of the SLCF global temperature reduction benefit achieved by 

methane measures in 2050

Change in temperature by 2050 due to methane measures (°C)

0%

2%

4%

6%

8%

10%

12%

14%

16%

18%

20%

22%

Intermittent aeration of continuously 

flooded rice paddies

Reduce methane emissions from 

livestock by anaerobic digestion of 

manure

Upgrading primary wastewater 

treatment with gas recovery

Separation and treatment of 

biodegradable municipal waste

Reduced gas leakage from 

long-distance transmission pipelines

Extended methane recovery/utilization 

and reduced fugitive emisions from oil 

and gas production

Pre-mine degasification and recovery 

of methane from coal mine ventilation 

air
COSTS AND BENEFITS OF IMPLEMENTING THE MEASURES – Near-term Climate Protection and Clean Air Benefits 19

Globally, the next most important black carbon 

measures after addressing biomass cookstoves are those 

tackling emissions from the transport sector, that is, 

eliminating high-emitting vehicles and introducing Euro6/VI vehicle standards which include the use of diesel 

particle filters. Indeed, compared with black carbon 

measures in other sectors, the transport measures 

account for the greatest contribution to short-term climate 

benefit both in South, West and Central Asia, as well as 

being second in importance in the other four regions.

Estimating the near- and long-term climate benefits of 

reducing short-lived climate forcers 

Comparing the impact of SLCFs to that of carbon dioxide 

(CO2

) on global temperatures over the long term is difficult 

because of the difference in the atmospheric lifetimes of 

the two kinds of substances. SLCFs have short lifetimes and 

mainly affect the near-term temperature in the first few 

decades after being emitted, while CO2

 has a much longer 

lifetime and, once emitted, continues to have a major 

influence on the global temperature for centuries. 

Put another way, the shorter atmospheric lifetimes of 

SLCFs means that their reductions in any particular year 

will have a much smaller effect on global warming over the 

long run as compared to reducing CO2

 or other long-lived 

greenhouse gases. Consistent with this, it is estimated 

that the package of SLCF reduction measures in this report 

will have only a modest effect on reducing the estimated 

6 to 11 Gt CO2

e ’emissions gap’ in 2020 (UNEP, 2011b). 

This is because the emissions gap has to do with the long 

term goal of keeping the increase in global temperature 

below 2°C up to the end of the century and beyond. Added 

together, the black carbon and methane measures, if they 

were all implemented in 2020, would reduce the gap in 

that year by an equivalent of about 1.1 Gt of CO2

 emissions 

(range: 0.4-1.7 Gt CO2

e) using the metric of ‘global 

temperature potential’ with a one-hundred year time 

horizon (see methane plus black carbon for GTP100 in Table 

4.2). Although this will help narrow the gap, it is clear that 

it does not go far enough, and it confirms that the main 

way of staying within the 2°C limit has to be reducing CO2

and other long-lived greenhouse gases. As shown in Table 

4.2 reductions in SLCFs from implementing both black 

carbon and methane measures will have a much larger 

impact on temperatures if a 20 year time-frame is used 

(i.e. shown by using the GTP20 metric), compared to using a 

100 year time-frame (using GTP100).

Table 4.2 gives an estimation of the equivalent CO2

emissions of implementing all black carbon and methane 

measures in 2020 on global warming in a 20 and 100 year 

time-frame, using the global warming potential and global 

temperature potential metrics (see glossary). The GWP 

values are higher than GTP values and are considered 

to be an overestimate of the temperature reduction. 

The range of values, shown in parentheses, reflects the 

range of radiative forcing of black carbon, its co-emitted 

substances, and methane. The effect of nitrogen oxides 

on methane over 20 or 100 years and the removal of 

the cooling aerosols such as organic carbon or sulphur 

compounds can lead to the negative values shown.

Regional Climate Benefits 

There is ample scientific evidence that SLCFs have impacts 

on regional climate. One such impact is the effect of SLCFs 

on cloud formation and precipitation. Both ozone and 

black carbon, as well as other particles, can influence 

many of the processes that lead to the formation of 

clouds and precipitation (Jacobson, 2002; Ramanathan 

and Carmichael, 2008; Penner et al,. 2006 and Chen et 

al., 2010). They affect evaporation, cloud formation and 

cloud lifetime, rainfall and weather patterns. They can also 

change wind patterns by affecting the regional temperature 

contrasts that drive the winds, influencing where rain and 

snow fall. These effects are both local and distant. 

Several studies indicate that changes in radiative 

forcing caused by absorbing particles can substantially 

alter precipitation patterns within a given region 

(Ramanathan and Carmichael, 2008; Wang et al., 2009; 

Meehl et al., 2006 and Menon et al., 2002). The black 

carbon measures reduce atmospheric energy absorption 

by particles most strongly in South Asia and also in other 

parts of Asia and central Africa (Figure 4.3), as this is 

where the measures cause the greatest reductions in the 

emissions of black carbon. Hence the emission reductions 

may have a substantial effect on the Asian monsoon and 

on central African rainfall, and may lessen the disruption 

of traditional rainfall patterns. 

The fact that the changes to both tropospheric ozone 

and particle concentrations mainly occur in the northern 

hemisphere means that they also alter the differences 

in temperature between hemispheres. This in turn may 

cause shifts in rainfall patterns throughout the tropics. 

Several studies have shown that such changes can have 

Table 4.2: Converting black carbon and methane emission 

reductions from implementing the 16 measures to CO2

equivalents, over a twenty and one hundred-year time frame. 

Units: Gt CO2

e

Black carbon measures Methane measures

 GTP100 0.5 (0.0 to 0.8) 0.61 (0.43 to 0.69) 

 GTP20 3.8 (-0.6 to 6.5) 9.0 (6.3 to 10)

 GWP100 3.6 (-0.2 to 5.9) 4.0 (2.8 to 4.6)

 GWP20 13 (0.2 to 20) 11 (7.6 to 12) 
20 Near-term Climate Protection and Clean Air Benefits – COSTS AND BENEFITS OF IMPLEMENTING THE MEASURES

large impacts in regions such as the Sahel (Ackerley et al., 

2011; Biasutti and Giannini, 2006; Rotstayn and Lohmann, 

2002). Therefore the benefits of mitigating black carbon 

may be realized in distant locations as well (Shindell and 

Faluvegi, 2009).

Another regional impact of SLCFs is their effect on 

accelerating the melting of ice and snow. Firstly, ozone 

and black carbon warm the atmosphere and therefore 

promote melting of ice and snow in the Arctic and in 

heavily glaciated parts of elevated regions, such as the 

Himalayas. The UNEP/WMO (2011) assessment concluded 

that by 2040 atmospheric warming could be reduced by 

about 0.7°C in the Arctic by implementing black carbon 

and methane measures, two thirds of the warming 

projected for that region in that year. It also concluded 

that this benefit was larger in the Arctic compared to the 

average global climate benefit.

Secondly, the deposition of black carbon has the 

additional effect of accelerating melting by darkening 

snow and ice surfaces. This increases their absorption of 

sunlight leading to further warming of the near-surface 

atmosphere as well as contributing to early melting of 

snow and ice. This melting in turn exposes the below 

darker surfaces, which then absorb more sunlight and 

further accelerate the local warming process. Snow- and 

ice-covered regions exposed to sunlight are thus especially 

vulnerable to accelerated warming from SLCFs. 

Increased early melting of glaciers also has subsequent 

effects on water supplies downstream. Glaciers and 

seasonal snowpacks in the Himalayas, the Tibetan Plateau,

the Hindu Kush and the Karakoram region provide water to 

a large number of people and are near to large black carbon 

sources in Asia. Vulnerability in this region is enhanced 

because of the high levels of solar radiation striking the 

surface as a result of the low latitude, high altitude, and low 

vegetation cover. A small body of peer-reviewed literature 

suggests that black carbon is driving significant warming 

and increased snow and ice melt in this region (Flanner et 

al., 2007; Kopacz et al., 2011), thus increasing the risks of 

flooding by outbursts from glacial lakes (Box 4.2).

4.2.2 Estimating health benefits

Quantitative health benefits of implementing black carbon 

measures are estimated from the resulting reduction in 

exposure to outdoor PM2.5 concentrations (particulate 

matter with a diameter less than 2.5 microns). Health 

benefits of ozone concentration changes are not included 

as these were found to be an order of magnitude 

lower than the health benefits from particulate matter 

reductions in the UNEP/WMO (2011) assessment. The 

changes in regional PM2.5 by each individual measure 

were calculated from changes in black carbon, organic 

carbon, other PM2.5 emissions, and sulphate, nitrate 

and ammonium concentrations, estimated using the 

TM5-FASST tool. This change in concentration was then 

used to scale the premature death estimates from the 

ECHAM model results reported in the UNEP/WMO (2011) 

assessment for each region (more details are given in the 

on-line Appendix). 

Figure 4.3: Change in atmospheric forcing in the year 2030 due to the full implementation of the black carbon measures relative to 

the reference case (emissions following current policies) in the two GCM models of the UNEP/ WMO (2011) assessment. The greatest 

benefit for regional climate would be expected where there is greatest change in atmospheric forcing (darker areas in the graphs), where 

reduced disruption in the distribution of rainfall would be expected. The results from two models, using the same input data, are shown 

and they show similar results, despite there being different treatment of aerosols in the models

Source: UNEP/WMO, 2011

50

0

-50

-20 -10 -4 -3 -2 -1 1

-100 0 100 -100 0 100

50

0

-50

W/m2

GISS ECHAM
COSTS AND BENEFITS OF IMPLEMENTING THE MEASURES – Near-term Climate Protection and Clean Air Benefits 21

It is important to note that the impact of indoor air 

pollution is not included. This has been estimated globally 

as causing a greater number of premature deaths than 

outdoor air pollution – 1.97 million deaths worldwide 

for indoor air pollution compared to 1.15 million deaths 

from outdoor air pollution in urban areas (WHO, 2009). 

Note that the method used in this report uses population 

estimates for 2030 and includes both urban and rural 

exposure which is why the number of avoided premature 

deaths, 2.4 million, is higher than the total number of 

deaths from PM2.5 exposure reported by WHO. Health 

benefits in terms of reduced chronic morbidity are also 

not indicated and these would be substantially larger than 

the number of premature deaths. 

The health benefits from the reduction in outdoor 

PM2.5 concentrations of different measures are shown 

in Figure 4.4. The uncertainty shown for each regional 

mortality estimate is calculated from the uncertainty in the 

concentration-response relationships of PM2.5 only, and does 

not include uncertainties in estimating PM2.5 concentrations 

themselves. The percentage values show that nearly all 

health benefits will be realised in the same region that 

implements the measures (more than 90% of the benefits in 

the case of Asia, Africa, Europe and North America). 

A total of 2.4 million fewer premature deaths (within 

a range of 0.7-4.6 million) could be realized globally each 

year by 2030 from the widespread implementation of black 

carbon measures. The biggest health benefits would be felt 

in Asia, with 1.9 million premature deaths avoided annually 

(Figure 4.4). In Africa, Asia and in Latin America and the 

Caribbean, improved biomass cookstoves would deliver the 

greatest health benefit although the benefits from reduced 

emissions from transport would also be substantial. In 

Europe and North America, the largest health gains would 

come from switching to pellet stoves from current domestic 

wood-burning technologies. In most regions there would 

also be a significant, though smaller, health benefit from 

banning the burning of agricultural crop residues.

4.2.3 Estimating crop-yield benefits

Figure 4.5 shows the estimated crop-yield benefits for 

wheat, rice, maize and soybean from reductions in 

concentrations of tropospheric ozone that result from 

the implementation of the 16 black carbon and methane 

In large parts of the Hindu Kush-Himalaya region, 

glaciers are thinning and retreating as a result of global 

warming, leading to the creation of many glacial lakes 

(Mool et al., 2001). Glacial lakes are potentially unstable 

because their end moraines are composed of unsorted 

and unconsolidated boulders, gravel, sand and clay. 

Furthermore, they are frequently reinforced by frozen 

cores (permafrost) that, like the glaciers themselves, 

are now beginning to melt. As the volume of a lake 

accumulating behind an end moraine increases, it 

Box 4.2: Glacial Lake Outburst Floods (GLOFs)

becomes less stable and the end moraine may fail, 

releasing much or all of the lake water. The ensuing 

outbreak can be sudden and highly dangerous to people 

and infrastructure located downstream. In October, 1994 

a part of the moraine holding back a glacial lake in Bhutan 

burst, and a wave of water swept downstream killing 21 

people and leaving a path of destruction as it travelled 

204 km before dissipating. At least 35 glacial lake outburst 

floods events have occurred over the last century in 

Nepal, Pakistan, Bhutan and China (UNEP, 2010b).

                               Land Sat MSS of 1975: development of a glacial lake at the tongue 

of Imja glacier in Dudh Koshi basin of Nepal

ALOS, AVNIR-2 March 2009: growing Imja glacial lake in Dudh 

Koshi basin of Nepal

Source: Ives et al., (2010) and ICIMOD (2011)
22 Near-term Climate Protection and Clean Air Benefits – COSTS AND BENEFITS OF IMPLEMENTING THE MEASURES

measures. These benefits arise because the measures 

reduce atmospheric levels of methane and other ozone 

precursors (carbon monoxide, nitrogen oxides and nonmethane volatile organic compounds). The changes in 

ground-level ozone concentrations were calculated by 

the TM5-FASST tool which used the same concentrationresponse relationships that were used in the UNEP/

WMO (2011) assessment. These relationships are 

based upon the average exposure of the crops to ozone 

during daylight hours in the growing season (see on-line 

Appendix)11. Estimates of avoided impacts are considered 

conservative because only four staple crops were 

assessed, and the analysis does not take into account 

additional benefits from avoided regional climate change 

(from reduced drought and heat stress). 

As was found in the UNEP/WMO (2011) assessment, 

different models have slightly differing approaches to 

ozone modelling and come up with different responses 

to changes in precursor emissions. This was observed in 

the result of the three models: GISS, ECHAM and TM5. 

Therefore, the total avoided crop yield losses calculated 

using TM5-FASST were 32 million tonnes per annum 

(range of 21-57 million tonnes) globally, compared with 

the average of 52 million tonnes per annum (range of 30-

140 million tonnes) obtained using GISS and ECHAM.

Globally, the positive impacts of SLCF measures 

on crop-yield is more or less evenly split between the 

methane and the black carbon measures, reflecting their 

similar impact on ozone formation (Figure 4.5). However, 

the methane measures tend to influence ozone formation 

at long distances from methane sources, because 

methane has a longer atmospheric lifetime than other 

ozone precursors and consequently becomes globally 

mixed. Therefore, the benefits of methane measures are 

less clearly confined to the regions implementing the 

measures. However, the black carbon measures affect the 

co-emitted pollutants: nitrogen oxides, carbon monoxide 

and non-methane volatile organic compound emissions, 

and these give rise to ozone formation closer to the 

sources of pollution. Hence, a greater proportion of the 

benefit of avoided crop-yield losses is felt in the regions 

that implement the black carbon measures (Figure 4.5). 

The greatest crop benefit from methane measures 

comes from reducing emissions from coal mines, especially 

in North East Asia, South East Asia and the Pacific, from 

oil and gas production in all regions, and reduced gas 

Figure 4.4: The annual reduction in premature deaths from the implementation of black carbon measures in each region in 2030. The 

percentages given above each bar indicate the proportion of deaths that would be avoided within the region that implements the measures. 

Vertical grey bars indicate the uncertainty range in the mortality figures based on the uncertainty of concentration-response relationships

11. The calculation of ozone concentrations using the TM5-FASST tool assumes a linear approximation to a non-linear ozone formation process. It should be 

noted that the uncertainties arising from this linear approximation are probably not significantly larger than the differences observed between the results 

of state-of-the-art non-linear models.

Ban of open burning of agricultural 

residue

Additional reduction from Euro-6/VI 

vehicle standards (including DPF) after 

elimination of high-emitters

Elimination of high-emitting vehicles

Replace lump coal with coal briquettes 

in cooking and heating stoves

Replace current residential wood 

burning technologies with pellet stoves 

and boilers (in industrialized countries)

Switch from traditional biomass cookstoves to stoves fueled by LPG or biogas 

or to fan-assisted biomass stoves (in 

developing countries)

Replace traditional coke ovens with 

modern recovery ovens 

Replace traditional brick kilns with 

vertical shaft kilns 

0

500

1000

1500

2000

2500

Total premature mortality avoided in 2030 due to black carbon measures 

(1000s of deaths)

Africa Latin America

and Caribbean

North America

and Europe

North East Asia, 

South East Asia

and Pacific

South, West and 

Central Asia

93% in 

region

87% in 

region

95% in 

region

98% in 

region

99% in 

region
COSTS AND BENEFITS OF IMPLEMENTING THE MEASURES – Near-term Climate Protection and Clean Air Benefits 23

Figure 4.5: Annual avoided crop-yield losses in 2030 from methane measures (in the upper graph) and from black carbon measures (in 

the lower graph - from reduced nitrogen oxides, volatile organic compounds, methane and carbon monoxide emissions). The percentage 

above each bar indicates the crop-yield loss avoided in the region that implements the measures. Vertical grey bars indicate the 

uncertainty range in the crop-yield loss figures based on the uncertainty in the concentration-response relationships alone

Intermittent aeration of continuously 

flooded rice paddies

Reduce methane emissions from 

livestock by anaerobic digestion of 

manure

Upgrading primary wastewater 

treatment with gas recovery

Separation and treatment of 

biodegradable municipal waste

Reduced gas leakage from 

long-distance transmission pipelines

Extended methane recovery/utilization 

and reduced fugitive emisions from oil 

and gas production

Pre-mine degasification and recovery 

of methane from coal mine ventilation 

air

Global crop yield loss avoided in 2030 due to methane measures 

(millions of tonnes)

Africa Latin America

and Caribbean

North America

and Europe

North East Asia, 

South East Asia

and Pacific

South, West and Central 

Asia

0

1

2

3

4

5

6

7

8

4% in 

region

8% in 

region

55% in 

region

23% in 

region

12% in 

region

Ban of open burning of agricultural 

residue

Additional reduction from Euro-6/VI 

vehicle standards (including DPF) after 

elimination of high-emitters

Elimination of high-emitting vehicles

Replace lump coal with coal briquettes 

in cooking and heating stoves

Replace current residential wood 

burning technologies with pellet stoves 

and boilers (in industrialized countries)

Switch from traditional biomass cookstoves to stoves fueled by LPG or biogas 

or to fan-assisted biomass stoves (in 

developing countries)

Replace traditional coke ovens with 

modern recovery ovens 

Replace traditional brick kilns with 

vertical shaft kilns 

0

2

4

6

8

10

12

14

16

Global Crop yield loss avoided in 2030 due to black carbon measures 

 (millions of tonnes)

Africa Latin America

and Caribbean

North America

and Europe

North East Asia, 

South East Asia

and Pacific

South, West and 

Central Asia

23% in 

region

81% in 

region

84% in 

region

81% in 

region

81% in 

region

leakage from long-distance transmission in pipelines in 

North America and Europe. Next are the benefits from the 

improved treatment of municipal waste and, in Asia, the 

intermittent aeration of continuously flooded paddy fields. 

The crop-yield benefits from black carbon measures 

stem largely from measures implemented in the transport 

sector, especially the wider implementation of Euro-6/VI 

standards. There is also a smaller benefit from addressing 

biomass cookstoves in Asia and Africa and from banning 

the burning of agricultural residue in all regions. 

4.2.4 Uncertainty of the benefit estimation

Previous sections of the report describe emission 

reduction measures that provide a range of benefits to 

health, crops and climate. While the magnitudes of these 

benefits are uncertain, there is much higher certainty 

that some degree of benefit will accrue. For example, it 

is quite certain that measures for reducing black carbon 

will lower ambient levels of PM2.5 and thereby protect 

health. Likewise, it is quite certain that black carbon and 

methane measures will reduce tropospheric ozone levels 
24 Near-term Climate Protection and Clean Air Benefits – COSTS AND BENEFITS OF IMPLEMENTING THE MEASURES

and thereby help to protect health and crop yields. Finally, 

the climate benefits of reducing methane emissions are 

quite clear. More uncertain are the global climate benefits 

of reducing black carbon emissions. On the other hand, 

the level of confidence is quite high that reducing black 

carbon emissions will have regional climate benefits. 

In sum, the remaining uncertainties in the effectiveness 

of emission control measures should not be seen as a 

barrier to action. The science is sufficiently robust for 

action to be taken to reduce SLCFs. 

4.3 Comparing costs and benefits 

The costs of implementing the measures can be compared 

to the regional and global benefits described in this 

chapter. As said earlier, an investment which would 

implement all of the measures in all regions by 2030 

would achieve about 2.4 million fewer premature deaths 

annually, and avoid global annual crop yield losses for four 

staple crops of about 32 million tonnes (according to the 

TM5-FASST model assessment). Full implementation of 

the SLCF measures would also reduce the projected nearterm temperature increase by about 0.4°C (according to 

the TM5-FASST model) in 2050. However, the unit costs of 

the measures to achieve these benefits vary.

About half of the near-term temperature benefit could 

be achieved through measures that would result in net cost 

savings in the long run, even without accounting for their 

health and ecosystems benefits. But prevailing short-term 

profit expectations make these measures less profitable 

for private investors. Hence, it is unlikely that the measures 

would be implemented solely through market forces. 

Another 18 per cent of the temperature benefit could 

be realized through measures that would be competitive 

on a global carbon market for less than US$75 per tonne 

of CO2

e. A further 17 per cent would come from measures 

that seem less cost-effective to society when their costs 

are compared solely to their climate benefits. These 

measures are already widely implemented in developed 

countries around the world, although this is usually for 

other purposes. The remainder, approximately 12 per 

cent of the temperature benefit, would require improved 

environmental governance (for example, by implementing 

bans on open-burning of agricultural crop residues) for 

which costs are difficult to quantify. 

Nearly all of the health benefit, 87-99 per cent, would 

be realized within the same regions that implement the 

measures, which is worth considering when deciding 

on national actions to reduce SLCFs. It also provides 

an argument for including black carbon and methane 

measures in action plans to reduce air pollution and its 

impacts on health and crops. Furthermore, it should be 

recalled that these estimates are conservative since they 

do not include the likely benefits of reduced indoor air 

pollution or the chronic health impacts that, in number, 

will be much greater than avoided premature deaths. 

The impact of black carbon on the regional climate and 

weather patterns, including rainfall, is also an important 

benefit felt closer to the regions where measures are 

implemented. Also, the global climate benefits of 

reducing SLCFs are substantial, offering an opportunity 

to reduce the rate of global warming in the near term 

to complement necessary carbon dioxide emission 

reductions to mitigate long-term temperature increase. 

As well as providing economic benefits, the 

measures will also help in the attainment of Millennium 

Development Goals (MDGs) related to health, including 

reducing premature child mortality, and the environment. 

24 Near-term Climate Protection and Clean Air Benefits – COSTS AND BENEFITS OF IMPLEMENTING THE MEASURES
There is a wide spectrum of actions that can be taken 

to reduce short-lived climate forcers (SLCFs) and in the 

following chapters reasons for pursuing them at all levels 

– national, regional and global - are explained. That being 

said, there are also good arguments for giving special 

priority to the national level. Firstly, the greatest public 

health benefits will accrue close to emission sources. 

Secondly, each country has its own particular mix of 

emission sources and acting at the national level can best 

take into account this unique mix. Thirdly, many countries 

already have institutions that deal with air pollution 

and climate change, and these institutions can serve as 

effective platforms for action on SLCFs. Fourthly, policies 

and measures for reducing SLCFs can, and should, be 

linked to national priorities for sustainable development. 

On the other hand, acting at the national level does not 

preclude regional or global action. In fact, regional and 

global actions can strongly support national activities as 

explained in following two chapters.

Many countries have already seen the added value 

of acting nationally. In the United States of America, 

the Congress has requested that the US Environmental 

Protection Agency prepare a ‘Report to Congress on 

Black Carbon’12. Meanwhile, India has justified a new 

programme of cookstove replacement13 based on the 

public health threat posed by black carbon and particulate 

matter emissions, and their link to regional climate issues. 

South Africa has taken the lead with legislation that 

allows integration of air pollution and climate policies14

and Mexico is promoting an SLCF-mitigation plan to 

accompany its greenhouse gas reduction plans15.

This chapter reviews a variety of topics important to 

national action on SLCFs. It first explains why action on 

SLCFs should be integrated into existing national policy 

frameworks. It then reviews the opportunities and barriers 

to implementing a wide range of practical measures for 

reducing black carbon and methane emissions, including 

the 16 measures introduced earlier in Chapter 3. It 

then lists some of the enabling activities that can help 

overcome the identified financial, institutional, and sociopolitical barriers, and presents other considerations that 

should be taken into account when planning national 

actions. Finally, it presents the basic outline of possible 

national action plans that would consolidate activities for 

mitigating SLCFs.

5.1 Integrating SLCFs into existing policy and 

regulatory frameworks

In most countries various decision-making processes and 

policy and regulatory frameworks already exist within 

which SLCF mitigation could be incorporated. These 

include: 

i) air quality management institutions and programmes; 

ii) national climate change programmes; and 

iii) sectoral and cross-sectoral policies and plans.

Countries need to determine which of these processes 

and frameworks offer the best opportunity to implement 

SLCF measures. In some countries it may be necessary 

to enhance governance systems, for instance, by 

strengthening coordination among agencies.

For countries with effective environmental governance 

and regulatory systems, a natural choice might be 

to locate SLCF policy coordination in their air quality 

management institutions and to integrate SLCF mitigation 

in existing air quality legislation and regulations, because 

Chapter 5:

National-scale Action

12. Interior Department and Further Continuing Appropriations, Fiscal Year 2010, Public Law 111–88—Oct. 30, 2009, at p. 36. Available from: <http://

www.gpo.gov/fdsys/pkg/PLAW-111publ88/pdf/PLAW-111publ88.pdf>

13. Ministry of New and Renewable Energy, India. Available from: <http://mnre.gov.in/press-releases/press-release-02122009.pdf>

14. National Environmental Management: Air Quality Act, No. 39 of 2004. Available from: <http://www.info.gov.za/view/DownloadFileAction?id=67978>

15. Also see Co-Chairs Summary, Ministerial Meeting on Short Lived Climate Forcers from <http://mce2.org/SLCF workshop>

NATIONAL-SCALE ACTION – Near-term Climate Protection and Clean Air Benefits 25
26 Near-term Climate Protection and Clean Air Benefits – NATIONAL-SCALE ACTION

these are likely to already address black carbon and 

methane emissions as part of their management of 

particulate matter and ground-level ozone. These 

institutions and regulatory instruments provide a 

good platform for SLCF mitigation because: (i) they 

typically regulate the issuance of permits to significant 

emission sources, as well as include regular inspection 

and monitoring, (ii) they sometimes provide economic 

instruments and education and behavioural change 

programmes to support emission reductions.

While one option is to embed SLCF policies within 

air quality management programmes, another option 

is to incorporate these policies into national climate 

action plans. They could also be included in ‘Nationally 

Appropriate Mitigation Actions’ (NAMAs)16. 

Considering the development co-benefits that 

are associated with SLCF mitigation, there could be 

opportunities to incorporate some measures into 

national development planning. For instance, methane 

capture in waste-water treatment, waste management 

and agriculture could lead to economic gains and result 

in renewable and decentralized energy production 

opportunities. Replacing traditional biomass cookstoves 

with cleaner burning cookstoves will reduce exposure to 

particulate matter with its consequent health risks, and 

thereby remove a barrier to economic development. 

Replacement stoves will also be more fuel efficient leading 

to reduced time spent collecting firewood.

Introducing certain SLCF mitigation measures as 

part of broader development processes would also 

encourage the involvement of all concerned actors 

and facilitate access to multiple sources of funding. For 

example, any action including restrictions on the burning 

of agricultural residues would require the involvement 

of the Ministry of Agriculture. Even if a national action 

plan is formulated outside the development planning 

process, many of the proposed actions will still need to be 

consistent with development goals. Hence, it is advisable 

that the development of a national SLCF action plan be 

coordinated with broader national development planning.

5.2 Implementing emission reductions: 

opportunities and barriers

A wide range of opportunities exist for reducing black 

carbon and methane emissions. In this section we review 

these opportunities in seven sectors, and identify some of 

the barriers that could slow implementation. 

5.2.1 Residential combustion

Globally, developing countries account for the largest total 

emissions of black carbon and co-emitted pollutants from 

cooking and heating using biomass. However, in a number 

of developed countries, the use of biomass for heating has 

increased, making it the largest projected source of black 

carbon emissions in North America and Europe in 2030 

(Chapter 3). 

In developing countries, two tracks are being pursued 

for reducing black carbon emissions from household 

stoves. Firstly, there are programmes that promote the 

replacement of stoves with improved ones having better 

fuel efficiency and lower emissions (World Bank, 2011). 

Secondly, there are programmes to replace stoves using 

‘dirty’, smoke-producing fuels (fuelwood, charcoal, crop 

residues and dung) with stoves that use ‘cleaner’ fuels 

(e.g. liquefied petroleum gas (LPG) or renewable options 

such as biogas, solar cookers or renewably produced 

electricity) that produce less fumes and smoke and would 

almost eliminate black carbon emissions. While such a 

strategy is a massive undertaking, given the billions of 

people using biomass, if achieved it would greatly reduce 

the major public health risk posed by smoky cookstoves, 

especially in Africa and Asia. 

The promotion of cleaner substitute fuels for 

households has been a common strategy among many 

developing countries, most commonly implemented in the 

form of a fuel and/or equipment subsidy, but experience 

has been mixed. Attempts to increase the use of LPG and 

kerosene in Africa have largely failed due to costs and 

complexities, including fuel supply, transport and use. Even 

in fossil-fuel-rich countries of Africa, such as Nigeria, Gabon 

or Angola, biomass and fuelwood accounts for the bulk 

of energy consumption (IEA, 2009a). But there are also 

success stories. For example many households in urban 

areas of Botswana, Ghana, and Senegal, have successfully 

shifted from charcoal to LPG for cooking. By 2000 most 

households in Dakar and other main urban areas of 

Senegal owned LPG stoves. This was achieved by lowering 

costs, initially by exempting butane stoves from customs 

duties, and later with fuel subsidies. Another feature of the 

successful projects was that the technology supplied was 

adapted to the local conditions and situations. 

Factors that will facilitate switching to cleaner fuels 

include:

• a long-term information and awareness-raising 

campaign;

16. Nationally Appropriate Mitigation Action (NAMA) refers to mitigation action by developing countries and was first introduced in the Bali Action Plan as 

part of the Bali Road Map agreed at the United Nations Climate Change Conference in Bali in December 2007, which in particular referred to “Nationally 

appropriate mitigation actions by developing country Parties in the context of sustainable development, supported and enabled by technology, financing 

and capacity-building, in a measurable, reportable and verifiable manner”.
NATIONAL-SCALE ACTION – Near-term Climate Protection and Clean Air Benefits 27

• linking improved cookstove programmes to national 

goals of poverty alleviation and greater access of the 

poor to modern energy sources;

• political will and long-term political commitment;

• the adoption of technology appropriate to local 

conditions; 

• the implementation of regulations and appropriate price 

and fiscal policies;

• attractive incentives for the various stakeholders 

involved;

• the guarantee of a reliable and effective supply system; 

• monitoring and evaluation of the impacts of 

implemented policies; and

• building required capacity for successful implementation.

Pellet stoves and boilers in the residential sector in 

industrialized countries

One way to hasten the replacement of old stoves and 

boilers with newer equipment would be to implement 

a stringent emission standard for black carbon together 

with appropriate enforcement mechanisms. This should 

be implemented alongside public awareness campaigns 

and financial incentives to assist the transition to cleaner 

technologies. This is likely to require a high level of 

political commitment, which international cooperation, 

through the Convention on Long-range Transboundary Air 

Pollution, the European Union or the Arctic Council, could 

help achieve (Chapter 6).

5.2.2 Agriculture and forestry

The technical mitigation options offering the greatest 

methane reduction potential in agriculture include 

measures for livestock, manure management, and 

intermittent aeration of continuously flooded rice paddy 

fields. 

For black carbon, banning or limiting open-field 

burning of agricultural residues and the introduction of 

no-burn methods, such as conservation tillage or soil 

incorporation, have been demonstrated as effective 

means of reducing associated emissions. Similarly, a 

campaign on the prevention of wildfires and management 

of prescribed forest and other vegetation burning, 

and greater resources devoted to fire monitoring and 

prevention would result in reduced emissions of black 

carbon and co-emitted substances.

Banning the field burning of agricultural residue 

In the 1970s a number of European countries implemented 

regulations limiting and prohibiting open burning of 

Ethanol cleaner cookstove

Fan-assisted biomass cookstove

Cleaner cooking and heating stoves 

Several regional programmes, introduced primarily in 

response to health concerns, have demonstrated the 

technical feasibility of introducing cleaner biomass 

cooking and heating stoves in Africa and Asia. Hundreds 

of millions of stoves have been introduced globally in 

countries such as China and India; but success in terms of 

a sustainable change has proven difficult in many regions 

due to cultural and financial barriers at the household 

level (World Bank, 2011). Some recent projects are 

explicitly considering black carbon emissions (Box 5.1).

Achieving wider deployment of cleaner-burning 

biomass cookstoves is likely to require more effective and 

widespread public awareness of the health impacts of 

emissions from traditional practices and other benefits 

such as reduced fuelwood usage. Financing schemes 

are also needed to overcome up-front capital costs. 

In addition, it is necessary to ensure that the designs 

adapted are effective in reducing black carbon emissions, 

such as fan-assisted models.

Photograph courtesy of Surya project

Photograph courtesy of Gaia Association
28 Near-term Climate Protection and Clean Air Benefits – NATIONAL-SCALE ACTION

agricultural crop residues. Wider implementation of such 

bans in other countries can be successfully achieved, but 

will require awareness raising, investment by farmers, 

and adoption of appropriate technology. In Brazil's largest 

sugar cane producing state, São Paulo, the daytime 

burning of cane fields has been banned from 1 June to 

30 November because of human health concerns18. In 

China, implementation of regulations to ban open-biomass 

burning is supported by a website and satellite-derived 

images which can identify fire spots on a day-to-day basis 

during harvest seasons (SEC, 2011). When it is strictly 

enforced, the regulation has been effective at reducing 

crop residue burning around large cities.

Intermittent aeration of continuously flooded rice 

paddies

Examples demonstrate that it is technically feasible 

to apply intermittent aeration – at least one aeration 

period of more than three days during the cropping 

season – to rice fields that are currently continuously 

flooded as a methane mitigation measure (IPCC, 1996). 

As with field burning of agricultural residues, however, 

widespread implementation may require demonstration 

projects, outreach programmes and attention to other 

crop management issues. For example, visible success 

of a water saving technology called alternate ‘wet-dry 

irrigation’ in pilot farms and specific training programmes 

for farmers in the Philippines have helped dispel the 

widespread misconception of possible yield losses in nonflooded rice fields (Bouman et al., 2007).

Methane emissions from livestock and manure

One of the available measures to control methane 

emissions in the agricultural sector is anaerobic digestion 

of manure from cattle and pigs. Anaerobic digestion, 

together with feed modification, is a readily available 

option to reduce methane emissions, mainly in intensive 

agriculture in North America and Europe. In Africa, for 

example, applying anaerobic digestion may be applicable 

to large farms; but there is also the potential to more 

broadly reduce methane emissions, with the added 

benefit of improving the quality and quantity of milk and 

meat production by improving the diet of livestock. In 

addition, examples from developing countries suggest 

that household-size anaerobic digesters with utilization of 

the generated biogas for cooking stoves are a promising 

option that also would reduce emissions from biomass 

burning, making this a ‘win-win’ solution. 

Barriers to wider methane capture from manure 

management include lack of information, high up-front 

capital costs, unsatisfactory reliability of technology, 

and low rates paid by some utilities for the electricity 

generated through the recovered methane. For example, 

there are relatively few anaerobic digesters in the United 

States of America mainly due to their high capital costs. 

Policies to promote these measures should therefore 

consider development of demonstration projects, 

outreach, capacity building and appropriate financing. 

Some other mitigation measures from the agricultural 

sector, such as reducing emissions from the digestion 

process of ruminant animals, are proving more difficult 

to realise and are not included as measures in this report. 

17. http://www.projectsurya.org

18. http://www.enn.com/top_stories/article/37041

One of the most innovative cleaner cookstove projects 

in the world is Project Surya in India, which began 

in 2009 in the state of Uttar Pradesh and combines 

cookstove replacement with innovative data collection 

and monitoring techniques. Project Surya is part of 

the second phase of UNEP’s Atmospheric Brown Cloud 

project. Unlike other similar initiatives, Surya documents 

the impact on climate forcing, regional air quality, and 

indoor and outdoor human exposure to particulate 

matter by using advanced surface, balloon and satellite 

monitoring platforms17.

Box 5.1: Project Surya

Photograph courtesy of Surya project
NATIONAL-SCALE ACTION – Near-term Climate Protection and Clean Air Benefits 29

Some progress could be achieved by changes in people’s 

diets leading to a reduction in livestock numbers and 

changing animal feed from roughage to a cereal-grain base, 

although this introduces other issues such as greenhouse 

gas emissions related to increased cereal production.

5.2.3 Industrial processes

Brick and coke production in small-scale traditional kilns 

and ovens has been estimated to contribute a sizable 

fraction of black carbon emissions in, for example, South 

Asia. Furthermore, poor quality coal, fuelwood, and 

waste are used to fuel these inefficient kilns resulting in 

high pollutant emissions. Viable mitigation options are 

available and have been demonstrated for both activities. 

Replacing traditional brick kilns with cleaner and more 

efficient kilns

Traditional brick kilns, such as clamp kilns, are still 

widespread in South Asia and Central and South America. 

They are based on old technology and are inefficient, in 

addition to being labour intensive and a health risk to 

workers. A number of Asian countries including China and 

Vietnam have managed a successful transition to much 

cleaner and more fuel efficient brick-kiln technologies, 

for example, vertical shaft, zig-zag, and Hoffman kilns. 

Demonstration projects have also been implemented in 

India and Bangladesh. In Latin America, Brazil’s recent 

programme of modernization is seen as a successful 

example of what can be achieved through training and 

technology transfer.

Although the number of brick kilns in some regions is 

large, it is possible to achieve rapid progress in shifting 

to cleaner technology. Readily available, cost-effective 

technical solutions could be deployed in developing 

countries, through, in some cases, the transfer of 

technology and exchange of experience between 

countries. Furthermore, the number of stakeholders that 

need to be involved in such a shift is relatively small. In 

addition to promoting the shift to cleaner technology in 

this sector, for example by using mandatory standards, 

governments could also consider training and awarenessraising programmes for those involved in brick production 

and distribution. Governments and other institutions could 

also help establish mechanisms to finance cleaner kilns. 

Replacing traditional coke ovens with modern recovery 

ones 

Clean production of coke has been demonstrated in 

industrial countries over the past few decades. Currently, 

major coke producing capacity exists in China where 

many coke plants are still using old, polluting technology. 

However, fast-growing demand has already resulted in 

rapid technological development and new plants are now 

built to international standards. Speeding the phaseout of old, polluting technology by regulation or use of 

incentives appears to be a promising option.

5.2.4 Transport

The most promising approaches for national action on 

black carbon in the transport sector are the elimination of 

high emitting vehicles from the diesel road- and non-roadvehicle fleet and the introduction of Euro-6/VI emissions 

standards for new vehicles, which include the use of diesel 

particle filters. Other measures are to adopt policies that 

promote petrol or ethanol vehicles, rather than diesel 

vehicles, or to introduce electric cars which would also 

eliminate particulate emissions.

Elimination of high-emitting vehicles 

Numerous studies show that in many countries a small 

share of the vehicle fleet – high polluting vehicles or 

‘super-emitters’ – causes a high proportion of total 

emissions. In several countries, such vehicles are being 

phased out through a combination of import restrictions 

on second-hand vehicles and engines, restricting access of 

high-emitting vehicles to urban areas, engine replacement 

Between 1980 and 2000, shifting to the practice of 

draining rice paddies mid-season has already reduced 

methane emissions from China’s rice fields by about 

5 million tonnes each year (Li et al., 2002). It is also 

practised in other Asian countries including the Philippines 

and Japan.

Box 5.2: Rice paddy mid-season drainage

Photograph courtesy of UN photo/S. Rotner
30 Near-term Climate Protection and Clean Air Benefits – NATIONAL-SCALE ACTION

and conversions, and scrappage programmes. The most 

appropriate policy mechanism to control emissions from 

vehicles currently in use is the wider adoption of vehicle 

inspection and maintenance programmes. Many countries 

have such programmes, but their establishment and/or 

effectiveness in other countries are hampered by the lack 

of enforcement, infrastructure and institutional capacity.

Diesel particle filters for road and off-road vehicles

Current legislation in many industrialized countries 

requires installation of diesel particle filters on diesel 

cars, buses and trucks and, more recently, also on nonroad machinery as a measure to reduce particulate 

matter emissions, including black carbon. Diesel particle 

filters can be built into new vehicles or retrofitted on to 

currently - used vehicles and machinery. Their relatively 

high costs have not inhibited their introduction in 

industrialized countries because of the significant health 

benefits resulting from emission reductions. 

A prerequisite for introducing diesel particle filters is 

the use of fuel that meets certain standards, in particular 

diesel with 50 ppm sulphur or less. This fuel standard is, 

for instance, required under Euro-4/IV, and even lower 

sulphur levels are required under the more stringent Euro5/V (15 ppm) and Euro-6/VI (10 ppm) standards. 

Initiatives to reduce air pollution from traditional 

kilns, through a combination of health regulations and 

economic incentives, have proven effective. For example, 

Box 5.3: Improved brick kilns

in Ciudad Juarez, Mexico, improved kiln designs boosted 

fuel efficiency by 50 per cent and reduced particulate 

pollution by 80 per cent (TCEQ, 2002; Bruce et al., 2007).

A traditional brick kiln (left) and an improved kiln (right) operating in Mexico

Virtually all new diesel trucks for use on-road in the 

United States of America, as of 2007, have been equipped 

with diesel particle filters. The USEPA estimates that the 

new standards under the Clean Air Non-road Diesel Rule 

will cut particulate and black carbon emissions from offroad diesel engines by over 90 percent19.

Box 5.4: Big reductions from the transport sector

19. http://www.epa.gov/nonroaddiesel/ Photograph courtesy of Robert Marquez

Photograph courtesy of Alba Corral Avitia

UNEP Photo
NATIONAL-SCALE ACTION – Near-term Climate Protection and Clean Air Benefits 31

Standards for the reduction of pollutants from vehicles 

have long been present in some countries and regions 

(e.g. a series of standards, up to the current Euro-6/

VI in the European Union). The key issue now is the 

adoption of vehicle emission standards worldwide. Many 

developing countries are introducing Euro standards 

to varying degrees. The progress achieved in this area 

in the European Union over several decades is now 

being repeated in some developing countries within 

the span of about ten years. To guide governments in 

improving standards and seeking regional alignment, 

the Roadmap for Cleaner Fuels and Vehicles in Asia

was prepared through a multi-stakeholder approach 

involving government agencies, oil companies, vehicle 

manufacturers and other institutions20.

Introducing more stringent emission standards for 

new vehicles is attractive because compliance monitoring 

of these standards would be relatively easy. However, 

there are problems to be overcome. One is the cost of 

upgrading refineries to produce fuel to the required 

standards, and another is setting up proper inspection 

and maintenance programmes to ensure that emission 

standards are achieved in practice. Efforts should thus 

focus on overcoming these barriers through collaboration 

between different countries and stakeholder groups.

Shipping

There is only limited experience with measures that 

reduce black carbon emissions from ship engines. 

However, a recent review by Corbett et al., (2010) indicates 

a range of options available in the next decade ranging 

from existing slide-valve technology to diesel particle 

filters. The International Convention for the Prevention of 

Pollution from Ships (MARPOL) does not expressly cover 

black carbon emissions. However, developments are taking 

place in this area as discussed in Chapter 7.

5.2.5 Fossil-fuel production and distribution

Addressing the fossil-fuel production and distribution 

sector presents important opportunities for large 

reductions in methane emissions. Several effective 

measures have been identified (see Chapter 3, Table 3.1).

In many industrialized countries more than 90 percent 

of the methane associated with oil and gas production 

is recovered and used. However, due to the necessary 

significant up-front investments, this percentage is 

typically less than 20 percent in developing countries, 

although it would be technically feasible in these 

countries to recover the gas at large-scale facilities and 

control fugitive emissions (EIA, 2010).

In addition to the introduction of relevant regulations, 

partnerships between governments and the private sector 

can offer an important opportunity to reduce emissions 

from fossil-fuel production and distribution. These are 

usually restricted to a limited number of facilities in 

each country, which are often owned by multi-national 

companies with access to the necessary financial and 

technical resources. 

Pre-mining degasification of surface and underground 

coal mines, especially as a measure to ensure 

occupational safety, is currently applied at large scale 

facilities in many industrialized countries, including the 

United States of America, European Union countries 

and Australia. Given its success in many regions, there 

are opportunities for widespread implementation of 

this measure. It is considered technically feasible to 

control about 50 per cent of the ventilation-air methane 

(VAM) emitted from underground coal mines in many 

countries. Due to increasing demand for methane as a 

fuel, especially in the rapidly developing countries of Asia, 

methane extraction from coal mines is an increasingly 

valuable resource.

There may also be opportunities for reducing black 

carbon emissions by controlling gas flaring. Although 

emissions from this sector are very uncertain, the few 

available measurements (Johnson et al. 2011), remote 

sensing data (Elvidge et al. 2009) and GAINS model 

estimates indicate it could be a significant source. Existing 

practice on improving flare performance, for example, 

from Norway and other countries, could be used to assess 

20. Road Map for Cleaner Fuels and Vehicles in Asia; Clean Air Initiative for Asian Cities, 2008. Available from: http://cleanairinitiative.org/portal/node/3632

Gas flaring in Nigeria

UNEP Photo
32 Near-term Climate Protection and Clean Air Benefits – NATIONAL-SCALE ACTION

the potential and means for future reductions of these 

emissions.

Barriers to controlling gas flaring include legal issues, 

high capital costs for equipment, low electricity prices 

for produced energy, and restricted pipeline capacity for 

transporting recovered methane. However, these barriers 

are surmountable, as has been demonstrated in India and 

other countries. 

There may also be considerable opportunities for further 

reductions of gas leakage from long-distance transmission 

pipelines through the implementation of improved 

equipment and inspection and maintenance programs.

5.2.6 Waste management

Landfill

Significant methane reductions can be achieved through 

waste management measures, including landfill gas 

collection (see Chapter 3, Table 3.1). While in most 

countries regulations are in place for large landfills, many 

smaller ones are not yet regulated. In many developed 

countries, however, voluntary programmes are in place 

such as the ‘landfill methane outreach program’ in 

the United States of America. These programmes are 

designed to encourage industries to capture and sell 

methane for energy production, and have achieved some 

level of success in slowing the rate of emission increases. 

Barriers to additional landfill-gas capture may include high 

capital costs, low rates paid for the gas captured and/or 

electricity generated, complex permit requirements, and 

liability concerns. Further regulation may therefore be 

needed to support wider implementation of this measure.

Separation and treatment of biodegradable municipal 

waste

Broader measures in the field of waste management, 

including a comprehensive cradle-to-grave approach 

that promotes recycling and composting, especially of 

biodegradable municipal waste, would achieve multiple 

environmental benefits in addition to reducing methane 

emissions. Many countries have introduced legislation 

to divert biodegradable waste from landfills through 

separation and treatment by recycling, composting 

or incineration and to equip existing landfills with gas 

recovery. Based on this wide experience, diversion of 

all biodegradable waste away from landfills should 

Countries like India, Mexico and the United States of 

America are investigating further reductions in coal-mine 

methane emissions. China is a leader in coal-mine methane 

projects with 39 registered with the Clean Development 

Box 5.5: Coal mine methane

The BENLESA plant, the first renewable energy project 

in Mexico using the biogas from landfill as fuel, has 

an installed capacity of 17 MW and by February 2010 

had avoided the release of more than 81 000 tonnes 

of methane, equivalent to the reduction in emissions 

of 1.7 million tonnes of carbon dioxide. The project is 

a partnership between the government and a private 

company22.

Box 5.6: Landfill gas capture

Photograph courtesy of J. Saldaña

              

21. http://cdm.unfccc.int/Projects/projsearch.html

22. http://seisa.com.mx/index.php?option=com_content&task=view&lang=en&id=54&Itemid=65

Mechanism, including the world’s largest at the Sihe Mine 

in Jincheng City, Shanxi Province21, which is projected to 

avoid around 3 million tonnes of carbon dioxide equivalent 

of methane emissions per year (IEA, 2009b).
NATIONAL-SCALE ACTION – Near-term Climate Protection and Clean Air Benefits 33

be technically feasible in many countries. Wider 

implementation requires sufficient financial resources and 

functioning institutions – clearly a challenge in countries 

lacking the necessary infrastructure.

Upgrading primary wastewater treatment 

Primary treatment of centrally collected wastewater is 

carried out to varying extents in both developed and 

developing countries and can be a major source of 

methane emissions. It should be technically possible 

by 2030 to upgrade all primary wastewater treatment 

to secondary or tertiary treatment including methane 

recovery, which reduces emissions considerably, 

although the costs may be high. Municipalities around 

the world are applying biogas-treatment technologies to 

wastewater, such as anaerobic-aerobic activated sludge 

processes, to mitigate methane emissions and generate 

energy. For example, wastewater methane reduction 

projects under the Clean Development Mechanism23 have 

been undertaken in India, Indonesia, Morocco (UNEP/

WMO, 2011).

5.2.7 Other sources

There are a large number of control measures that reduce 

particulate matter emissions from large-scale combustion 

and production processes, including electrostatic 

precipitators and fabric filters, but in most cases the 

sources concerned emit only small amounts of black 

carbon (Bond et al., 2004). 

Stationary diesel generators are another source of 

black carbon which are frequently operated in harsh 

conditions and are rarely subject to regulation of 

emissions. Emissions can be reduced by retrofitting or 

replacing engines. However, the emission reduction 

potential is quite uncertain because of the lack of 

statistical data on fuel consumption and actual equipment 

in use. Lastly, some additional black carbon sources, such 

as open domestic waste burning, could in the future 

become targets for mitigation.

5.3 Enabling activities

The previous sections of this chapter have described many 

opportunities for introducing SLCF mitigation measures in 

different sectors at the national level. They also described 

some of the barriers that may hinder their widespread 

implementation and possible ways to surmount these. 

Table 5.1 summarizes the 16 identified priority measures 

with their attendant barriers and proposed enabling 

activities. Note that the set of financial, institutional, and 

socio-cultural barriers in Table 5.1 is not exhaustive. For 

example, it does not include technical barriers, which 

in many situations could be important. It should also be 

noted that socio-cultural barriers in particular are often 

not anticipated. Nevertheless, they may become extremely 

important if they surface in the form of public opposition to 

an emission reduction measure. Successful implementation 

requires that community concerns be understood and 

addressed through outreach and awareness-raising 

activities. Moreover, outreach should be a two-way 

street: it is equally important to adapt technologies to 

the needs of the communities as it is to communicate the 

potential benefits of new technologies to communities. 

This exchange will yield the best results if it is based on 

sustained interactions between communities and outreach 

providers and wide public participation in decision-making. 

The last column of Table 5.1 provides a long, but not 

exhaustive, list of enabling activities that would help 

surmount the barriers identified. One lesson from the 

implementation experience described in Section 5.2 is 

that benefits from SLCF policies and measures will only be 

realized if they are embedded in an enabling environment 

that can overcome financial, institutional, and sociocultural barriers.

5.4 Other considerations for national actions

National governments have a wide choice of mitigation 

options for SLCFs, and a wide choice in the ways they 

can be implemented and the policies that would 

encourage their implementation. This section draws on 

the international experience reviewed in this chapter to 

suggest a number of general conclusions and implications 

that could provide a starting point for national strategies 

and action plans. 

Developed countries have already accomplished 

substantial reductions in black carbon and methane 

emissions but mainly as a positive side-effect of other 

actions, for example, improving energy efficiency or 

reducing particulate matter pollution. This situation is 

expected to continue. However, some emission sources 

are not being reduced on their own, and require specific 

policy attention. Included here are wood burning stoves, 

as an example.

Overall, however, barriers to further mitigation of black 

carbon emissions in developed countries are not major. 

Furthermore, the climate for further mitigation continues 

to be good as industrial processes are upgraded, vehicle 

fleets are replaced, and new technology spreads. The 

23. http://cdm.unfccc.int/Projects/Validation/index.html
34 Near-term Climate Protection and Clean Air Benefits – NATIONAL-SCALE ACTION

Table 5.1: Major measures, barriers and enabling reforms to facilitate implementation of the package of 16 SLCF mitigation measures

Sectors Measures Barriers Enabling activities

Residential 

combustion

Fuel switching • High fuel and technology costs 

• Limited fuel supplies

• Tax incentives, subsidies

• Facilitated access to alternative fuels

Improved cookstoves • Low awareness of health impacts of 

established cooking practices 

• Limited durability of improved 

stoves 

• High cost of technology for the poor 

• Awareness raising and community outreach 

• Improved technology 

• Subsidies or loans

Pellet stoves/boilers 

industrialized countries

• Lack of awareness 

• Lack of harmonised standards

• Public education and outreach

• Introduce harmonised black carbon 

emission standards

Agriculture 

and forestry

Banning the burning of 

agricultural residues

• Weak enforcement of regulations • Enhanced enforcement capacity 

Intermittent aeration of 

continuously flooded 

rice paddies

• Low stakeholder awareness • Outreach and demonstration projects

Emissions from manure 

(farm-scale anaerobic 

digesters)

• Adherence to traditional practices • Outreach and demonstration projects 

Methane emissions 

from livestock

• High costs of modified feed • Economic incentives

Industrial 

processes

Cleaner and more 

efficient brick kilns

• Limited access to finance and skilled 

personnel

• Economic incentives

• Capacity building and training

Modernisation of coke 

ovens

• Limited community awareness

• Lack of relevant regulation and 

enforcement

• Outreach and demonstration projects 

• Issuance of relevant regulation

• Enhanced enforcement capacity

Fossil fuel 

industry

Pre-mine gasification • High upfront investment • Economic incentives

Oxidation of ventilation 

air methane from coal 

mines

• Technical constraints • Improved technology

• Technology transfer

Recovery of vented 

methane from 

production of oil and 

natural gas

• Lack of infrastructure

• Lack of nearby markets 

• Economic incentives

Reducing leaks from 

long-distance natural 

gas transmission 

pipelines

• Cost of monitoring and maintenance • Strengthened regulations and enforcement 

procedures

• Enhanced enforcement capacity

Transport Diesel particle filter 

as part of Euro 6/VI 

standards

• Unavailability of ultra-low sulphur 

fuels

• Government regulations to require ultra-low 

sulphur fuels

Removing high-emitting 

vehicles

• Lack of regular inspection/

enforcement

• Introduction and enforcement of inspection 

and maintenance programmes

• Scrappage schemes

Waste 

management

Separation of biodegradable solid waste, 

and generation and 

recovery of methane

• High capital costs

• Low prices for methane

• Complex permitting schemes and 

liability issues

• Economic incentives including financial 

mechanisms

• Introduction of clear legislation 

Upgrading primary 

wastewater treatment 

• High cost • Further legislation requiring secondary or 

tertiary treatment
NATIONAL-SCALE ACTION – Near-term Climate Protection and Clean Air Benefits 35

potential gains from controlling black carbon and methane 

emissions could even be seen on the national level as a 

new impetus for further accelerating these processes.

The reduction of methane emissions in the energy, 

mining, landfill and agricultural sectors represents a 

major opportunity to achieve benefits from voluntary 

programmes, partnership schemes and tighter 

regulations. Particularly rapid progress can be achieved 

when the application of best technologies and practices is 

required across an industry. 

Addressing agricultural methane emissions, especially 

from livestock and, in Asia, continuously flooded 

rice paddies, is another important area for action, 

notwithstanding the possible difficulties in the near term 

due to the traditionally slower development pace of 

agricultural technology and practices. While benefits from 

changes in management and husbandry of livestock may 

be relatively limited, they may become more important 

with the expected increases in consumer demand 

for meat products. Clearly, any overall reductions in 

meat consumption could have an immediate effect on 

emissions. However, other opportunities are more readily 

available in the agricultural sector to reduce black carbon 

emissions, notably through banning or restricting open 

burning of agricultural crop residues, and introducing 

waste management measures to create viable alternatives 

to such practices.

In many developing countries the effectiveness of 

options and strategies will depend on a different set 

of factors: limited resources and competing priorities, 

lack of appropriate infrastructure, and institutional and 

regulatory challenges, such as how to adequately monitor 

and enforce regulations to control emissions. However, 

at all stages of development there are cost-effective 

measures that can be implemented successfully, so long 

as they take into account local culture and sustainability 

priorities, and are aligned with national development 

goals for such issues as energy, transport and agriculture. 

In developing countries, SLCF strategies can also 

take advantage of the pivotal role that major cities play 

in environmental concerns. Urban centres can benefit 

from the fact that they provide a critical mass of people 

and know-how to rapidly diffuse new technologies and 

new management approaches. Particularly in Asia and 

Latin America, cities have become proving-grounds for 

advancements in air quality management. For example, 

Beijing and Shanghai have introduced tighter vehicle 

emission standards some years ahead of the rest of China. 

The same pattern has been observed in Indian cities, 

particularly with respect to the introduction of cleaner 

fuels. Some cities in Latin America, including São Paulo, 

Santiago de Chile and Mexico City have pioneered effective 

controls of air pollution sources (Molina et al., 2004).

5.5 Elements of a national action plan

As shown in previous chapters, the current state of 

knowledge is sufficiently robust to justify immediate 

action at the national scale to reduce SLCF-related 

emissions. Countries can be confident that multiple 

benefits will be achieved if they begin now to implement 

reduction measures for obvious emission sources. Of 

the many steps that can be taken on the national level, 

one of the most useful might be to develop a National 

Action Plan which would consolidate and prioritize a 

larger number of national actions. The action plan would 

build on existing institutions and policies, including those 

concerned with air quality management and climate 

policy. The plan would have specific connections to other 

country-wide plans for sustainable development and other 

national priorities. A National Action Plan could include:

• Characterizing sources and opportunities for emission 

reductions. Countries with well- functioning air quality 

management institutions could add the assessment 

of SLCF-related emissions to their activities. Those 

countries without such institutions could set up a special 

expert group(s) to carry out this work. 

• Planning awareness-raising activities to inform 

government, business, and civil society about the 

benefits and costs of controlling SLCFs and the steps to 

implement measures.

• Assessing the relative benefits and costs of action,

either based on international analyses, such as the 

ones outlined in this report, or by conducting economic 

analysis to develop more local/national estimates.

• Determining the political feasibility of implementation

to identify which options are likely to be easiest to 

implement, and which will require additional effort.

• Undertaking an inventory of current policy and legislation

that is already used to implement related measures. 

• Identifying further policies, where there are gaps, to 

make more rapid progress in implementing the control 

of SLCF-related emissions. 

• Taking cost-effective action on obvious SLCF sources.

While there are many good arguments for giving priority 

to national actions, these actions can also be supported 

by other policies and measures at the regional and global 

scales. That is the subject of the next two chapters.
Regional-level cooperation and support can enhance the 

successful implementation of national-level actions and is 

the most effective scale at which regional transboundary 

problems can be addressed. To date, there has been 

little regional action on SLCFs, in contrast to air pollution 

which has well-developed regional initiatives and 

intergovernmental agreements. Similar initiatives on 

SLCFs could complement and support national emission 

reduction efforts. This chapter discusses options for action 

at the regional level: it reviews the existing major regional 

agreements and other mechanisms and then discusses 

options for regional activity to further the understanding 

of regional impacts and build consensus around regional 

objectives.

One major initiative, carried out in Asia over the last 

ten years, is the Atmospheric Brown Cloud (ABC) project 

(Ramanathan et al., 2008). Although not originally aimed 

specifically at SLCFs, the ABC project made important 

findings relevant to these issues. More recent examples 

of efforts specifically focusing on SLCFs include scientific 

assessments carried out by international organizations, 

including with a regional focus, such as the United 

Nations Environment Programme (UNEP) and the Word 

Meteorological Organization (WMO), the Ad Hoc Expert 

Group on Black Carbon of the Convention on Long-Range 

Transboundary Air Pollution (CLRTAP), and the Arctic 

Council, as further detailed in the following sections. 

There are four reasons why action at the regional level 

could add value to, or stimulate, national actions:

• The impacts of SLCFs often go beyond the national 

level and occur at the regional level, and therefore SLCF 

mitigation is best addressed at this level. Examples 

include: the health impacts from particulate matter 

transported across national boundaries; regional 

impacts of tropospheric ozone on crops; long-range 

transport and impact of black carbon on the Arctic and 

the Himalayas, and disruption of weather patterns on all 

continents.

• Economies of scale or other benefits that arise 

from pooling and sharing of scientific expertise and 

knowledge, joint research and capacity building and 

technical assistance programmes. This is particularly 

important in regions where the pollution problems 

extend across national boundaries and where resources 

may be scarce. Raising awareness of the impacts of SLCFs 

and sharing knowledge within regional groupings could 

also facilitate joint or complementary policy solutions 

and help overcome barriers to delivery. It is also arguable 

that it is easier to reach consensus on policies at a 

regional, rather than a global, scale.

• Common clean technology standards can be developed 

at the regional level, and can serve as models to other 

nearby countries, ensuring the more cost-effective use of 

scarce human and technical resources.

• Accountability may be enhanced by the presence of a 

regional forum to which progress on emission reductions 

is reported. Such shared accountability has the potential 

to provide further incentives for action at a national level.

This chapter examines the existing regional initiatives 

in terms of the following three categories:

i) Regional entities with established infrastructure and 

a policy focus: in some regions detailed regional legal 

instruments and infrastructure have been established. 

The most established example is the CLRTAP, which 

mandates legally-binding national emission ceilings 

for different pollutants, and the European Union (EU) 

which issues legislation on emissions, ambient air 

quality and climate change.

ii) Regional entities with permanent structure and 

a science focus: though not based on legallybinding agreements, other regional entities do have 

permanent structures (e.g. a secretariat) but focus 

largely on developing a regional scientific base, 

for example by promoting or undertaking regional 

monitoring and modelling. Examples include the Acid 

Deposition Monitoring Network in East Asia (EANET) 

and the Malé Declaration on Control and Prevention 

of Air Pollution and its Likely Transboundary Effects 

for South Asia (Malé Declaration).

Chapter 6:

Regional-scale Action

36 Near-term Climate Protection and Clean Air Benefits – REGIONAL-SCALE ACTION
REGIONAL-SCALE ACTION – Near-term Climate Protection and Clean Air Benefits 37

iii) Other initiatives: which have no permanent 

structures, but provide viable policy making fora for 

regional cooperation. Examples include:

• in Sub-Saharan Africa, ministerial declarations 

(also known as ‘agreements’) were recently 

adopted, such as the Lusaka Agreement for 

southern Africa, the Nairobi Agreement for 

eastern Africa, and the Abidjan Agreement for 

west and central Africa. These declarations lay out 

common policy, set regional priorities and offer a 

framework for future cooperation;

• in Latin America and the Caribbean: the 

Intergovernmental Network on Air Pollution in 

Latin America and the Caribbean was created 

and given a mandate from the Regional Forum of 

Environment Ministers of Latin America and the 

Caribbean to develop a regional work plan;

• in Asia and the Pacific, regional cooperation has 

been enhanced through a new Joint Forum on 

Atmospheric Environment Issues in Asia and the 

Pacific, drawing together several institutions and 

intergovernmental initiatives.

In addition to these three categories this chapter also 

considers the role that economic integration organizations 

and other relevant regional and subregional organizations 

could play in developing action on SLCFs.

6.1 Potential for action through regional 

entities with established infrastructure and a 

policy focus

The three inter-governmental bodies that currently 

address short-lived climate forcers are the United Nations 

Economic Commission for Europe (UNECE) Convention 

on Long-Range Transboundary Air Pollution (CLRTAP), the 

European Union (EU) and the Arctic Council.

6.1.1 Convention on Long-Range Transboundary Air 

Pollution 

The Convention on Long-Range Transboundary Air 

Pollution (CLRTAP)24 and its protocols have resulted in 

specific measures to be taken at national level to cut 

emissions of air pollutants. In particular, it mandates 

national emission ceilings of pollutants that cause acid 

rain, eutrophication (excess nutrient deposition), and 

tropospheric ozone in its 1999 Gothenburg Protocol 

to Abate Acidification, Eutrophication and Groundlevel Ozone. The Task Force on Hemispheric Transport 

of Air Pollution (TFHTAP) is undertaking modelling of 

tropospheric ozone including the role of methane and 

other ozone precursors, such as carbon monoxide. CLRTAP 

is currently incorporating SLCFs into its activities, taking 

an initial step to include consideration of black carbon as 

a component of particulate matter (PM) in the process 

of the revision of the Gothenburg Protocol, probably in 

the form of ceilings for PM2.5. Some areas of discussion on 

black carbon within the context of CLRTAP include:

i) improving measurement coverage of black carbon 

across the region, and clarifying the definition of 

black carbon;

ii) developing guidelines for black carbon emission 

inventories; and

iii) prioritizing reductions of primary particulate matter 

emissions in sectors with high black carbon to organic 

carbon ratios, recognizing that black carbon is only 

emitted in conjunction with other pollutants such as 

organic carbon which is a cooling agent25.

CLRTAP has considerable potential to address the 

linkages between air pollution and climate change, 

including continuation of its work to integrate black 

carbon in the next phase of the Gothenburg Protocol. 

Methane could also be included in the Protocol, informed 

by the findings of the TFHTAP. There is also the possibility 

that expertise within the CLRTAP region could be shared 

with other world regions to make policy makers aware of 

options to mitigate SLCFs. The sharing of information and 

knowledge could build on the linkages that have already 

been established with regional air pollution networks in 

Asia and Africa, in the area of scientific research.

6.1.2 European Union

The European Union (EU) Directive 2001/81/EC of the 

European Parliament and of the Council on National 

Emissions Ceilings for Certain Atmospheric Pollutants 

Directive, known as the National Emission Ceilings (NEC) 

Directive, sets emission ceilings for member states 

for sulphur dioxide, nitrogen oxides, volatile organic 

24. The Convention on Long-Range Transboundary Air Pollution (CLRTAP) was signed in 1979 and entered into force in 1983. It has 51 parties, with a 

geographical coverage extending from North America to Europe. www.unece.org/env/lrtap/welcome.html

25. Decision 2010/2 by the Executive Body on Implications of the reports of the Task Force on Hemispheric Transport of Air Pollution and the Ad hoc Experts 

Group on Black Carbon (document ECE/EB.AIR/106/Add.1), decided to “include consideration of black carbon, as a component of particulate matter (PM), 

in the process of the revision of the 1999 Gothenburg Protocol”. In addition, also see the Report by the Co-Chairs of the Ad Hoc Expert Group on Black 

Carbon, available from: http://www.unece.org/env/lrtap/ExecutiveBody/welcome.28.html
38 Near-term Climate Protection and Clean Air Benefits – REGIONAL-SCALE ACTION

compounds and ammonia, some of which are precursors 

of tropospheric ozone. The European Union also supports 

action by appropriate international fora to reduce the 

effects of emissions of greenhouse gases, black carbon 

and other SLCFs in the Arctic. In January 2011 the 

European Parliament stated that it ‘...recognises the 

disproportionately large Arctic warming impact caused 

by black carbon emissions in the EU and other regions 

in the northern hemisphere, and stresses the need for 

inclusion of black carbon emissions in the relevant UNECE 

and EU regulatory frameworks, such as the Convention 

on Long-Range Transboundary Air Pollution and the 

National Emissions Ceilings Directive’26. In September 

2011 the Parliament further came forward with two 

resolutions calling for more action on SLCFs, in particular on 

hydrofluorocarbons, black carbon and tropospheric ozone27.

The European Union formulates its own air quality and 

climate change legislation and has just begun a review 

of its air quality legislation, aiming to conclude by 2013. 

At present it is not clear to what extent this will result in 

further action on SLCFs although the European Union is 

likely to incorporate particulate matter emissions in the 

NEC Directive, following the indication by the Parliament 

referred to above.

European Union legislation also has the potential 

to affect other regions as the motor-vehicle emission 

standards set by the EU (the Euro standards) have 

been taken up by both India and China amongst others 

(Chapter 5).

6.1.3 Arctic Council

The Arctic nations28 may play a special role in 

demonstrating a strong resolution to reduce emissions of 

SLCFs, and most of these countries are highly motivated 

by the fact that the Arctic, is warming at a higher rate than 

the global average. The Arctic Council was an early actor 

on SLCFs, publishing two reports in 2008 on science and 

mitigation29 and an SLCF task force is further exploring 

policy and mitigation options30, while the Arctic Council’s 

Arctic Monitoring and Assessment Programme (AMAP) is 

continuing to develop the science of SLCFs and assessing 

their Arctic impacts. In addition, the council’s Arctic 

Contaminants Action Program (ACAP) working group has 

begun coordinating demonstration projects funded by 

member governments aimed at sources of black carbon in 

Arctic nations, initially focusing on stationary and mobile 

diesel sources but potentially including other important 

sources such as residential stoves and open-field and 

forest burning31.

The Arctic Council is a high level intergovernmental 

forum to provide a means for promoting cooperation, 

coordination and interaction among the Arctic 

States; the recent signing in 2011 of the first legally 

binding agreement, the Agreement on Cooperation 

on Aeronautical and Maritime Search and Rescue in 

the Arctic32 may open the door to additional future 

agreements. The Arctic Council’s own analysis indicates 

that the eight member nations are responsible for 

more than half of the black carbon affecting the Arctic, 

demonstrating the potential benefits of a regional Arctic 

agreement that could serve as a model for others. The 

Arctic nations could also spearhead more global efforts 

such as those aimed at methane abatement or oil and gas 

SLCF emissions. Such actions, even if taken outside the 

Arctic region, could benefit Council members by mitigating 

some of the more extreme impacts of rapid warming there.

6.1.4 Commission for Environmental Cooperation

Since 1994, Canada, Mexico and the United States of 

America have been collaborating in protecting North 

America’s environment through the North American 

Agreement on Environmental Cooperation (NAAEC), 

which is the environmental side agreement to the North 

American Free Trade Agreement (NAFTA). NAAEC created 

a framework to better conserve, protect and enhance 

the North American environment through cooperation 

and effective enforcement of environmental laws. The 

Commission for Environmental Cooperation (CEC) was 

also established in the context of the NAAEC in order to 

address regional environmental concerns. Ongoing CEC 

26. European Parliament resolution of 20 January 2011 on a sustainable EU policy for the High North (2009/2214(INI)). The full text of the Resolution is 

available from: <http://www.europarl.europa.eu/sides/getDoc.do?type=REPORT&reference=A7-2010-0377&language=EN>

27. European Parliament resolution of 14 September 2011 on a comprehensive approach to non-CO2

 climate-relevant anthropogenic emissions. The text of 

the Resolution is available from: <http://www.europarl.europa.eu/sides/getDoc.do?type=TA&language=EN&reference=P7-TA-2011-0384>

28. The Arctic nations include: the Russian Federation, Canada, the United States of America, Sweden, Norway, Denmark, Finland and Iceland.

29. Arctic Monitoring and Assessment Programme (AMAP): http://www.amap.no/

30. The task force provided recommendations to ministers at the 2011 ministerial meeting in Nuuk, Greenland, which focused primarily on black carbon, and 

will continue its work in the coming years on black carbon as well as methane and tropospheric ozone, with Sweden joining as a co-chair. Nuuk Declaration 

(2011) Seventh Ministerial Meeting of the Arctic Council, Nuuk, Greenland. http://arctic-council.org/filearchive/Nuuk%20Declaration%20FINAL.pdf

31. Funding for these various projects is approaching US$10 million.

32. The Agreement will strengthen cooperation between the Arctic states and improve the way Arctic countries respond to emergency calls in the region.
REGIONAL-SCALE ACTION – Near-term Climate Protection and Clean Air Benefits 39

programmes, as well as new strategic priorities, present a 

good opportunity to integrate SLCF mitigation in its work.

6.2 Potential for action through regional 

entities with permanent structure and a 

science focus

6.2.1 Malé Declaration in South Asia

The Malé Declaration on Control and Prevention of 

Air Pollution and Its Likely Transboundary Effects for 

South Asia was adopted at the Seventh meeting of the 

Governing Council of SACEP in 1998. The main objective 

of the Malé Declaration programme is to promote the 

establishment of a scientific base for prevention and 

control of transboundary air pollution in South Asia to 

encourage and facilitate coordinated interventions of 

all the stakeholders on transboundary and shared air 

pollution problems at national and regional levels33. It 

already includes consideration of the air quality impacts of 

tropospheric ozone, especially on crops, and the impact of 

particulate matter pollution on health. Activities include 

developing emission inventories, integrated assessment 

modelling and consideration of policies and measures to 

reduce air pollution. Sharing practices and experiences 

from countries within this region on emission reduction 

policies and measures is already an important part of 

this forum and could be further expanded to key sources 

of black carbon and tropospheric ozone precursors, 

including methane. Priority sources for this region include 

transport, cookstoves, brick kilns and agricultural residue 

burning, all of which are included in the Declaration. 

Assessment and action on these issues could be promoted 

through awareness raising and appropriate financing of 

the Malé Declaration activities.

6.2.2 EANET – Acid Deposition Monitoring Network in 

East Asia

The Acid Deposition Monitoring Network in East Asia 

(EANET) was established in 1998 as an inter-governmental 

initiative to create a common understanding of the state 

of acid deposition problems and to provide inputs into the 

decision-making process34. The focus at this stage is chiefly 

scientific and concerned with the pollutants involved 

in acid deposition but includes a group of countries 

with some of the largest emissions of SLCFs. Many of 

the key countries involved are promoting national cobenefit strategies that enhance the synergy between air 

pollution and climate policy and it would be important to 

investigate the potential of this forum to focus on SLCF 

issues.

6.2.3 ASEAN Agreement on Transboundary Haze 

Pollution in South East Asia

The governments of the ten member countries of the 

Association of South East Asian Nations (ASEAN) signed an 

Agreement on Transboundary Haze Pollution in 200235. 

It is the first regional agreement in the world that binds 

a group of contiguous states to tackle transboundary haze 

pollution resulting from land and forest fires36. It arose as 

a result of the transboundary transport of particles from 

forest-fire outbreaks that has significant health impacts 

in countries thousands of kilometres from the source 

of emissions. As outdoor burning of biomass is a major 

source of SLCFs, the agreement could provide an excellent 

opportunity in the region to discuss wider measures that 

reduce particulate matter pollution and SLCF emissions.

6.2.4 The Central Asian Environment Convention

Countries of Central Asia have made a political 

commitment on air pollution issues under the 2006 

Framework Convention on Environmental Protection for 

Sustainable Development in Central Asia37. This offers an 

opportunity for these countries to address SLCFs.

6.2.5 Other Initiatives in Asia

There are other regional initiatives, such as the Tripartite 

Environmental Ministers’ Meeting (TEMM) among China, 

Japan and Republic of Korea38 and ASEAN+3 Meeting39, 

which might be effective in addressing the issues of 

transboundary air pollution and its link with climate 

change, including aspects related to various SLCFs. 

33. The Malé Declaration covers Bangladesh, Bhutan, India, Iran, the Maldives, Nepal, Sri Lanka and Pakistan.

34. Thirteen countries participate in EANET: Cambodia, China, Indonesia, Japan, Lao PDR, Malaysia, Mongolia, Myanmar, Philippines, Republic of Korea, 

Russia, Thailand and Vietnam. UNEP is the Secretariat and the Asia Centre for Air Pollution research, located in Japan is the Network Centre for EANET.

35. ASEAN is the Association of South East Asian Nations, a geopolitical and economic organization of ten countries originally formed in 1967 involving 

Indonesia, Malaysia, the Philippines, Singapore and Thailand. Membership then expanded to include Brunei, Myanmar, Cambodia, Laos and Vietnam.

36. The Agreement entered into force in 2003 and was ratified by nine of the ten ASEAN countries. See: http://haze.asean.org/hazeagreement/

37. See http://www.ecolex.org/ecolex/ledge/view/RecordDetails;document_Framework%20Convention%20on%20Environmental%20Protection%20

for%20Sustainable%20Development%20in%20Central%20Asia.html?DIDPFDSIjsessionid=20D91EE559E0718840CF60B3AFCE560A?id=TRE143806&index=treaties . The agreement has been signed only by Kyrgyzstan, Tajikistan and Turkmenistan.

38. http://www.env.go.jp/earth/coop/coop/english/dialogue/temm.html

39. ASEAN+3 includes the ASEAN countries plus China, Japan and Republic of Korea. http://www.aseansec.org/4918.htm
40 Near-term Climate Protection and Clean Air Benefits – REGIONAL-SCALE ACTION

The Clean Air Initiative for Asian Cities (CAI-Asia) is a 

partnership40 that actively promotes policies to address 

air pollution and climate change in an integrated fashion, 

and, given the opportunity of policy development at 

city scale in rapidly industrializing countries in Asia, it 

focuses on how urban centres could help be a catalyst 

for enhanced implementation of the black carbon and 

methane measures.

The Asian Co-benefits Partnership41 was officially 

launched in November 2010 and serves as an informal and 

interactive platform to improve knowledge management 

and stakeholder cooperation on co-benefits in Asia. The 

SLCF issue is central to this partnership.

The Asian Development Bank (ADB) has a number 

of programmes and initiatives for Asia and the Pacific 

that are relevant to SLCFs and the measures required 

to control them. These include the Climate Change 

Programme, Clean Energy Programme, Energy Efficiency 

Initiative, Energy for All Initiative, and Sustainable 

Transport Initiative. The Cities Development Initiative 

for Asia (CDIA) may also be relevant to SLCF mitigation, 

as it provides assistance to medium-sized Asian cities to 

bridge the gap between their development plans and the 

implementation of their infrastructure investments42.

6.3 Potential for action on SLCFs through 

other initiatives

6.3.1 Africa

Regional cooperation on air pollution was initiated by 

the Air Pollution Information Network for Africa (APINA) 

in 1997 culminating in the adoption by the Southern 

African Development Community (SADC) Ministers of the 

Regional Policy Framework on Air Pollution, known as 

the Lusaka Agreement in 2008. APINA has also worked in 

partnership with UNEP’s Partnership for Clean Fuels and 

Vehicles (PCFV)43, the USEPA, the World Bank and others 

since 2006 on better air quality for African cities44. This 

process has resulted in further regional instruments on 

air pollution adopted at the ministerial level, the Eastern 

Africa Regional Framework Agreement on Air Pollution, 

known as the Nairobi Agreement (2008), the West and 

Central Africa Regional Framework Agreement on Air 

Pollution, known as the Abidjan Agreement (2009)45, and 

a draft regional framework in northern Africa. All these 

regional instruments specifically mention air pollution 

and climate change co-benefits. Elements of the Lusaka 

Agreement have been considered for inclusion in the SADC 

environment protocol that is currently being developed. 

UNEP has been encouraging national governments to 

implement measures outlined in the regional agreements 

across Africa, through the Partnership for Clean Fuels and 

Vehicles (PCFV) initiative, on unleaded petrol and low 

sulphur fuel. There is considerable potential for these 

processes to promote action on SLCFs. Investments in these 

regions to develop stable institutional structures would 

promote progress and provide a platform for coordinating 

SLCF activities. Including the issues addressed in these 

declarations into the discussions at the African Ministerial 

Conference on Environment (AMCEN) could provide 

an opportunity to elaborate a regional framework and 

strategy on SLCF mitigation.

6.3.2 Asia

Regional cooperation in Asia has been enhanced through 

a new Joint Forum on Atmospheric Environmental Issues 

in Asia and the Pacific convened by UNEP. The Forum 

draws together ASEAN, the Malé Declaration, EANET, 

CAI-Asia, the Central Asian Environment Convention, the 

Pacific Regional Environment Programme (SPREP), the 

South Asia Cooperative Environment Programme (SACEP) 

and the governmental meetings on Urban Air Quality in 

Asia. Although in its early stages, the Joint Forum has 

the potential to promote action on SLCF through the 

exchange of information across the region. It could also 

provide a focus for inter-regional scientific collaboration 

on SLCF issues, awareness raising and capacity 

enhancement.

6.3.3 Latin America and the Caribbean

In 2008, the XVI Forum of Ministers of the Environment 

of Latin America and the Caribbean secured support in 

principle for the establishment of an Inter-Governmental 

40. CAI-Asia leads efforts to enable Asia’s 2500 cities to reduce both air pollution and CO2 emissions. http://cleanairinitiative.org/portal/node/2288

41. http://www.iges.or.jp/en/cp/co-benefits.html

42. http://www.cdia.asia/about-cdia/

43. www.UNEP.org/PCFV/

44. The Better Air Quality in Sub-Saharan Africa (BAQ-SSA) policy dialogue was held in July 2006 with participation by forty nine sub-Saharan countries and 

Ministers of Environment of thirty of them. See: www.gapforum.org for details.

45. Lusaka Agreement: (2008) - Southern African Development Community (SADC) Regional Policy Framework on Air Pollution’. See: www.gapforum.org for 

details. Nairobi Agreement: (2008) http://www.unep.org/urban_environment/PDFs/EABAQ2008-AirPollutionAgreement.pdf, Abidjan Agreement: http://

www.unep.org/urban_environment/PDFs/BAQ09_AgreementEn.Pdf
REGIONAL-SCALE ACTION – Near-term Climate Protection and Clean Air Benefits 41

Network on Air Pollution in Latin America and the 

Caribbean. The initiative is being promoted by the Global 

Atmospheric Pollution (GAP) Forum46 and includes 

recognition of air pollution climate change issues. 

Although the inter-governmental network is still in its 

infancy, and will require further financial commitment, 

it does have enormous potential to promote action on 

SLCFs. Draft Elements of a Framework Agreement on 

Atmospheric Pollution in Latin America and the Caribbean 

has been discussed at the Seventeenth Meeting of the 

Forum of Ministers of Environment of Latin America 

and the Caribbean in 201047. Bilateral donors have also 

supported SLCF mitigation in the region. For example, 

the Swiss Development Agency for Development and 

Cooperation established a project to increase the 

energy efficiency of artisanal brick kilns in seven Latin 

American countries. The project promotes the reduction 

of greenhouse gas emissions through the use of more 

energy-efficient technologies and processes, and the use 

of less polluting fuels.

The Inter-American Development Bank (IDB) has a 

sustainable energy and climate change initiative and 

also finances several climate change and sustainable 

energy efforts such as a climate change programme in 

Latin America including the Biodigester Network and 

Knowledge Sharing Platform (BioLAC).

The WMO Global Atmospheric Watch (GAW) Urban 

Research Meteorology and Environment (GURME) project 

addresses both air quality and climate change48 and is an 

initiative that could be approached to promote the science 

around SLCFs across Latin America and the Caribbean.

6.3.4 Other Relevant Initiatives

Environmentally sustainable transport (EST) forums were 

established for Asia and Latin America by the United 

Nations Centre for Regional Development (UNCRD), 

bringing together senior transport and environment 

sector government officials each year to share experience 

and discuss strategies for making transport more 

sustainable. In Asia, the Fifth Regional Environmentally 

Sustainable Transport Forum held in Bangkok in August 

2010, adopted the Bangkok Declaration for 2020, in 

order to demonstrate their ‘renewed interest in, and 

commitment to, realizing a promising decade (2010-

2020) of sustainable actions and measures for achieving 

safe, secure, quick, reliable, affordable, efficient and 

people-centric and environment friendly transport in 

rapidly urbanizing Asia’49. The Latin America Forum (Foro 

de Transporte Sostenible para América Latina) held a 

meeting in Bogota, Colombia in June 2011 and adopted 

the Bogota Declaration, which outlines common goals on 

environmentally sustainable transport in Latin America 

until 2020. These forums could provide an avenue to 

promote SLCFs measures in the transport sector.

6.4 Economic groupings 

In addition to the atmosphere-based groupings discussed 

above, there are also economic integration organizations 

and other regional and sub-regional organizations that 

potentially could play a role in SLCF mitigation. The role 

of some of them, such as SADC and ASEAN, has already 

been discussed in this chapter. Organizations covering 

other sub-regions could also become active on SLCF 

mitigation. These could include for instance Mercosur in 

Latin America50, the South Asian Association for Regional 

Cooperation (SAARC)51 and the Economic Community of 

West African States (ECOWAS)52. ASEAN, in addition to 

being the forum under which the Haze Agreement was 

adopted, hosts formal meetings of senior officials from 

national ministries, such as the ASEAN Senior Transport 

Officials Meeting, that are relevant to the SLCF issue. It 

also has several working groups that could be relevant 

to the SLCF policies and measures, amongst others on 

transboundary air pollution, environmentally sustainable 

cities, agriculture and training extension and multilateral 

environment agreements.

6.5 Possible options for progress at a regional 

Level

This chapter shows that throughout the world there are 

now regional inter-governmental networks and initiatives 

that can provide a basis for cooperative action on SLCFs, 

as well as enhancing and supporting national activity. At 

present their scale and effectiveness vary significantly, and 

46. A global forum of regional atmospheric initiatives. www.gapforum.org.

47. http://www.pnuma.org/forumofministers/17-panama/FORO%20DE%20MINISTROS%202010%20VERSIONES%20FINALES/EXPERTOS/DE%20

TRABAJO%20INGLES/UNEP-LAC-IGWG-XVII-%206%20Draft%20Elements%20Framework%20Agreement%20Atmospheric%20Pollution.pdf

48. http://mce2.org/wmogurme/

49. http://www.uncrd.or.jp/env/5th-regional-est-forum/index02

50. Involving Argentina, Brazil, Paraguay and Uruguay. See www.mercosur.int

51. http://www.saarc-sec.org/

52. http://www.ecowas.int/
42 Near-term Climate Protection and Clean Air Benefits – REGIONAL-SCALE ACTION

although some are still at an early stage of development, 

they are developing rapidly. These initiatives can provide 

a useful platform for awareness raising, capacity building, 

technical cooperation and financing at the regional level.

6.5.1 Awareness of the benefits

A key requirement for going forward with SLCF 

mitigation is to adequately inform decision makers. It 

should be made clear that many benefits, especially 

for human health, will accrue to the populations of 

regions and individual countries that take action. While 

the responsibility to select and implement measures 

to mitigate SLCFs could lie primarily with national 

governments, it should be made clear that co-ordinated 

regional action is indispensible if certain key impacts – for 

instance on the Arctic, the Himalayas and the South Asian 

Monsoon – are to be effectively addressed.

6.5.2 Technical knowledge

Existing agreements and their institutions and 

partnerships could be used to raise awareness, improve 

scientific understanding, facilitate the transfer of 

technology, and develop capacity as prerequisites for 

policy makers to take action on SLCFs.

Regional instruments and initiatives such as CLRTAP, 

the Malé Declaration, EANET and others could be involved 

in a series of regional meetings or workshops, which could 

be tailored to the needs of the different regions. The 

meetings could be linked to the development of regionspecific SLCF assessment reports. In an initial phase, these 

meetings could involve scientists and decision makers to 

define the scope of the issues at stake, refine priorities, 

promote capacity building and scientific research and lay 

the foundations for policy action at regional or national 

levels. Inviting participants from other regions to these 

meetings could promote cross-fertilization and the sharing 

of experiences.

The more developed institutions, as well as countries, 

individually or jointly, could play an important role in 

capacity building and awareness raising. The CLRTAP 

and the EU, for example, can offer their experience in 

formulating mitigation policies and in particular offer 

examples of how science informs and drives policy 

development in these areas, as well as help disseminate 

scientific findings related to SLCFs.

South-south cooperation also can increase the flow 

of information, resources, expertise, technology and 

knowledge among developing countries. One example 

is UNEP’s efforts to actively promote the streamlining 

of approaches to south-south cooperation in the 

implementation of the capacity-building components of 

its biennial programmes of work53.

6.5.3 Financing and enabling mechanisms

Regional and sub-regional development banks, such as 

the Asian and African Development Bank, the European 

Bank for Reconstruction and Development and the InterAmerican Development Bank, as well as other similar 

institutions, could play a strong role in supporting regional 

activities. Regional initiatives have already received 

support from the regional development banks, such as 

through the Clean Air Initiative for Asian Cities, but these 

institutions could play a bigger role through funding and 

promoting additional initiatives such as high-level dialogue 

among governments in their respective regions. Increased 

knowledge and awareness among countries about funding 

opportunities and other enabling mechanisms available 

through these institutions in the field of SLCFs would also 

be useful to advance mitigation efforts.

6.5.4 Further regional development to enable SLCF 

Action

In order to move forward, it is important to capitalize on 

the important role played by regional networks, which are 

able to address the circumstances of individual regions and 

catalyze policy discussion and promote action. 

Some of the declarations and other instruments 

emerging in Africa and Latin America and the Caribbean 

and other developments mentioned in this chapter offer 

the prospect of moving to effective collaborative action in a 

relatively quick fashion. A positive aspect of some initiatives 

is their close alignment with regional development 

communities such as the SADC (in the case of the Lusaka 

Agreement) and ASEAN (in the case of the ASEAN 

Haze Agreement) which could offer an opportunity for 

mainstreaming near-term climate and air-quality protection 

into development.

Building on the successes of the network of wellestablished institutions and agreements at the regional 

level, as well as promoting collaboration among them, can 

offer an effective way to strengthen on-going efforts to 

mitigate SLCF emissions. It can also offer the opportunity to 

incorporate SLCF mitigation into existing air quality policies 

where this has not yet happened.

53. See: http://www.unep.org/south-south-cooperation/; this also closely links with some aspects of the North-South cooperation and the so-called 

triangular cooperation.

42 Near-term Climate Protection and Clean Air Benefits – REGIONAL-SCALE ACTION
Efforts at the global level can catalyze action at the 

national and regional scales and help promote widespread 

implementation of black carbon and methane mitigation 

measures. Global cooperation can also provide needed 

support to help achieve development goals, including 

the Millennium Development Goals. A global strategy to 

attain widespread mitigation of SLCFs could be based on 

common objectives, include priorities set at the regional 

level, and build upon existing instruments, initiatives 

and organisations. A systematic international approach 

would help ensure the efficient use of scarce resources 

and support integrated policy development at the global 

level. While the implementation of SLCF mitigation 

measures needs to occur primarily at the national level, 

the international community could have an important role 

in putting in place the enabling conditions for this to take 

place. 

This chapter considers the following major global 

approaches for promoting the mitigation of SLCFs: 

i) building upon existing legal instruments;

ii) promoting further efforts by international 

organisations and cooperative mechanisms, including 

partnerships and networks; and 

iii) putting enabling mechanisms in place at the global 

scale to facilitate the national implementation of 

black carbon and methane mitigation measures. 

These include: awareness raising; technical 

assistance, technology transfer and capacity building; 

and financing.

This chapter focuses on early opportunities rather than 

longer-term efforts, and therefore does not include 

negotiation of new multilateral environmental agreements 

or the amendment of existing ones, but also does not 

preclude such action. 

7.1 Building upon existing legal instruments

Global strategies to mitigate SLCF emissions need to be 

based on action that can be implemented in the next 

couple of decades if their potential to improve public 

health, crop yields and slow the rate of climate change is 

to be realised in the near term. While there is currently 

no dedicated global regime to regulate SLCFs per se,

rapid progress might be possible by building on existing 

instruments, initiatives and organisations as outlined in 

this and the previous chapter. 

Considering the interconnected nature of 

environmental problems across the globe, it is important 

that a holistic and synergistic approach is taken to tackle 

these emissions. Benefits could therefore be realised 

by associating SLCF mitigation with other related issues, 

including climate and air pollution, and also through 

global agreements that address specific sectors and 

sources of emissions such as the MARPOL Convention 

(Box 7.1). 

It may be beneficial to have some level of connection 

between SLCF mitigation and the global climate regime. 

Methane, one of the substances that is the subject 

of this report is in fact already covered by this regime 

and is one of the six greenhouse gases addressed by 

the Kyoto Protocol. It is also likely to be included in 

any successor agreement, although currently there is 

no specific emission reduction target for methane and 

the other gases covered in the Kyoto Protocol. Instead, 

the protocol requires that Annex I parties limit their 

aggregate greenhouse gas emissions in accordance with 

their respective commitments54. Additional efforts to 

specifically address methane emissions could be helpful to 

achieve the full health, environmental and development 

benefits of its mitigation. These could include using 

existing vehicles or avenues within the climate regime.

Chapter 7:

Global-scale Action

54. Kyoto Protocol, Article 3(1). The relevant commitments are set out in Kyoto Protocol, Annex B. Gases controlled by the Kyoto Protocol are set out in 

Kyoto Protocol, Annex A. http://unfccc.int/kyoro_protocol/items/2830.php

GLOBAL-SCALE ACTION – Near-term Climate Protection and Clean Air Benefits 43
44 Near-term Climate Protection and Clean Air Benefits – GLOBAL-SCALE ACTION

Information exchange could be promoted under 

the framework of the climate regime, for example by 

building upon the work of subsidiary bodies of the 

UNFCCC, especially the Subsidiary Body for Science and 

Technological Advice (SBSTA) which has already discussed 

the results of the UNEP/WMO (2011) assessment, as 

well as the impact of SLCFs on sensitive areas such as the 

Arctic. 

The Intergovernmental Panel on Climate Change (IPCC) 

will have an important role through its development of 

its Fifth Assessment Report (AR5) to further expand the 

scientific understanding of SLCF issues. The IPCC Task 

Force on National Greenhouse Gas Inventories could 

further consider developing guidelines on emissions 

reporting, initially voluntary, to encompass black carbon, 

possibly in conjunction with air quality experts in the 

Arctic Council and United Nations Economic Commission 

for Europe Convention on LRTAP.

However, notwithstanding the linkages between 

climate protection and the reduction of SLCF-related 

emissions, it is important that any strategy to mitigate the 

emissions of these SLCFs is treated as complementary to 

the primary efforts being undertaken to stabilize longlived greenhouse gases under the global climate regime.

Benefits could also be realised by integrating SLCF 

mitigation into air pollution efforts taking place in the 

context of global agreements that address specific sectors 

and sources of emissions such as the MARPOL Convention 

(Box 7.1). 

7.2 Promoting further efforts by international 

organisations and cooperative mechanisms

International organizations, such as FAO, ICAO, IMO, 

UNDP, UNEP, WHO, WMO and the World Bank among 

others, have institutional air-quality or climate mandates 

relevant to SLCFs. Several global networks, partnerships 

and associations also exist that are already active in 

the field of air quality, or that address sectors that can 

generate SLCFs. 

Many of these organizations and cooperative 

mechanisms have already undertaken action to address 

SLCFs, and these could be enhanced and coordinated to 

promote much wider implementation of the identified 

black carbon and methane mitigation measures. This 

should be done in cooperation with relevant stakeholders, 

including national governments, regional bodies and civil 

society organisations.

International organizations and their partners could 

promote the generation and sharing of knowledge and 

awareness raising, design and implement technical 

assistance and capacity building programmes, and 

facilitate technology transfer. In addition, relevant 

international organizations could play a key role in 

facilitating financing. These enabling measures are 

discussed in section 7.3. 

International organizations and cooperative 

mechanisms are also well placed, especially if they work in 

a coordinated manner, to undertake or strengthen existing 

initiatives to: 

The International Maritime Organization’s (IMO) MARPOL 

Convention regulates air pollution from ships in its 

Annex VI, which entered into force in 2005 and limits 

the main air pollutants contained in ships’ exhaust gas 

and prohibits deliberate emissions of ozone-depleting 

substances. It also regulates shipboard incineration and 

the emissions of volatile organic compounds from tankers. 

A revised Annex VI, containing a progressive reduction 

globally in emissions of sulphur dioxide, nitrogen oxides 

and particulate matter and introducing Emission Control 

Areas (ECAs), was recently adopted and entered into 

force in 2010. International maritime shipping is not one 

of the sectors addressed by the 16 measures identified 

in Chapter 3, but probably emits significant quantities of 

black carbon close to sensitive regions. Shipping traffic in 

Box 7.1: Opportunities to build on the International Convention for the Prevention of Marine 

Pollution from Ships (MARPOL)

the Arctic is anticipated to grow substantially as the area 

of summer sea ice diminishes and new major sea lanes 

open up in the region, thereby increasing the impact of 

black carbon from shipping on the Arctic environment 

(IMO, 2010). In 2011, the IMO’s Marine Environment 

Protection Committee (MEPC) agreed to address the 

impact of black carbon emissions in the Arctic, investigate 

appropriate control measures to reduce the impacts of 

such emissions in the Arctic and establish mandatory 

energy efficiency standards for international shipping 

(IMO, 2011). These are expected to help reduce emissions 

from the projected increase under a “business as usual” 

scenario. These developments underscore the way in 

which national and regional efforts on SLCFs can also lead 

to action on a global scale. 
GLOBAL-SCALE ACTION – Near-term Climate Protection and Clean Air Benefits 45

• convene stakeholders around a shared vision and global 

strategy to mitigate SLCFs; 

• develop common standards and guidelines;

• promote policy integration through existing inter-agency 

coordination mechanisms; and

• encourage joint actions amongst and between the 

private sector, civil society and governments, including 

the promotion of best practices and improvement of 

technology. 

7.2.1 Facilitating a shared SLCF vision and global strategy 

Convening different international organizations around 

common near-term climate protection objectives could be 

a powerful way of integrating various initiatives, reducing 

duplication, and inefficient use of resources, and leading 

to more effective implementation of SLCFs mitigation 

measures in different sectors worldwide. A variety of 

organizations have already begun initiatives that directly 

or indirectly affect SLCFs, such as the World Bank on gas 

flaring, ICAO on air pollution, UNEP on the Atmospheric 

Brown Cloud and other initiatives discussed in the 

following sections. 

7.2.2 Developing common standards and guidelines for 

SLCFs

Sector-specific emission standards could be modified 

to more clearly and comprehensively include SLCFs. 

Examples, which range from mandatory to voluntary 

standards and guidelines, applied to emissions, products 

and concentrations, are given here from the oil and gas, 

aviation, road transport and cookstoves sectors.

Current research points to gas flaring possibly being a 

large source of black carbon emissions; gas venting and 

inefficient seals on pipelines are also known to be a large 

source of methane emissions. The World Bank Global Gas 

Flaring Reduction Partnership (GGFR)55 is a public-private 

partnership launched at the World Summit on Sustainable 

Development in Johannesburg in 2002. It supports the 

efforts of oil producing countries and companies to reduce 

flaring and venting and increase the use of associated 

natural gas. Global Gas Flaring Reduction partners have 

established a collaborative global standard for gas flaring 

reduction, which provides a framework for governments, 

companies, and other key stakeholders to consult with 

each other, take collaborative actions, expand project 

boundaries, and reduce barriers associated with gas 

utilization.

The International Civil Aviation Organization (ICAO) has 

issued standards and recommended practices on aircraft 

engine emissions56. The standards regulate, inter alia, 

particulate matter and the tropospheric ozone precursor 

carbon monoxide (UNEP/WMO, 2011). Although the initial 

focus was on improving air quality in the vicinity of airports 

by regulating emissions during landing and take-off, ICAO 

is considering developing the standards further to regulate 

emissions during the cruise phase of flights (ICAO, 2010).

The Global Alliance for Clean Cookstoves (GACC)57, a 

public-private partnership initiated by the UN Foundation 

in 2010, is currently working with several governments 

and organizations to develop international cookstove 

standards and guidelines that will incorporate standards 

for black carbon. 

The development of other SLCF-focused guidelines 

in other sectors could be spearheaded by relevant 

international organizations to address all major sources 

of SLCF emissions that require international regulation 

(World Bank, 2011), and could constitute a reference in 

the development of national standards. 

WHO’s air quality guidelines for particulate matter, 

ozone, nitrogen dioxide and sulphur dioxide, are intended 

to provide guidance to policy makers in developing 

measures to reduce impacts of air pollutants on human 

health and ecosystems (WHO, 2006). Furthermore, 

WHO is preparing new indoor air quality guidelines for 

household fuel combustion, which are also relevant to 

SLCF reduction58. 

International organizations, individually or jointly, could 

also initiate the development of guidelines to assist policy 

makers in developing national action plans to address 

SLCFs (see Chapter 5).

7.2.3 Promoting policy integration through existing interagency coordination mechanisms 

Cooperation mechanisms have been established to 

promote integrated policy making within the United 

Nations system to ensure enhanced coherence in 

global policy-making, linking together the environment, 

development and other areas of international 

55. Global Gas Flaring Reduction Partnership. http://go.worldbank.org/NEBP6PEHS0

56. International Civil Aviation Organization. Environment Branch: Air Emissions. http://www.icao.int/icao/en/Env2010/Aee.htm

57. http://cleancookstoves.org/overview/

58. http://www.who.int/indoorair/interventions/CHEA_brochure_rev.pdf
46 Near-term Climate Protection and Clean Air Benefits – GLOBAL-SCALE ACTION

cooperation. These mechanisms can be used to promote 

the progressive integration of decision making on issues 

related to climate change mitigation, air pollution 

prevention and control, ecosystems management, 

agriculture, food security and, more broadly, development 

including through the angle of SLCF mitigation. Examples 

of coordination measures include:

• The High-Level Committee on Programmes (HLCP) to the 

Chief Executives Board for Coordination (CEB), which 

fosters coherence, cooperation and coordination on 

programme dimensions of strategic issues for the United 

Nations system. 

• The United Nations Development Group (UNDG) to 

the Chief Executive Board that unites the 33 United 

Nations funds, programmes, agencies, departments, 

and offices that play a role in development, with a 

common objective to deliver more coherent, effective 

and efficient support to countries seeking to attain 

internationally agreed development goals, including the 

Millennium Development Goals.

• The Environment Management Group (EMG), 

established by the United Nations General Assembly as 

a UN system-wide coordination body. Its membership 

consists of its specialized agencies, programmes and 

organs including the secretariats of the Multilateral 

Environmental Agreements, and is chaired by the 

Executive Director of UNEP59.

These and other mechanisms could be used to enable 

continued dialogue and ensure that SLCF policy 

development and implementation in areas ranging from 

climate change, environment, public health, agriculture 

and development are undertaken in a coherent way 

encompassing multiple benefits. In addition, ministerial 

and other meetings of high-level representatives of 

interested governments, and global meetings such as the 

Rio+20 meetings in June 2012, could provide a vehicle 

for drawing high-level global attention to SLCFs and the 

imperative of addressing near-term climate change, with 

its air quality, sound economic development and poverty 

alleviation benefits.

7.2.4 Encourage joint actions amongst and between the 

private sector, civil society and governments

Further action and enhanced collaboration on SLCF 

mitigation could be sought through existing global 

networks, partnerships and associations, such as the 

Global Atmospheric Pollution Forum (GAP Forum), the 

Atmospheric Brown Cloud (ABC) project and others 

outlined in Chapter 6. Several of these groups focus 

specifically on air quality, whereas others focus on specific 

sectors, such as transport or cookstoves. Such fora can 

catalyze regional and global coordination and synchronize 

action. 

Public-private partnerships, which promote joint 

action by public institutions and the private sector for the 

achievement of common objectives, engage the affected 

industries in a way that can accelerate the rate and the 

scale of abatement of SLCFs and assist the public sector in 

overcoming market barriers. They can also establish best 

practices, guidelines and voluntary industry standards. 

The UNEP Partnership for Clean Fuels and Vehicles (PCFV), 

for example, is a public-private partnership made up of 

over 120 partners worldwide, with the shared goal of 

reducing air pollution in developing countries through 

technological improvements within the transport sector 

and the adoption of clean fuel and vehicle strategies60.

Multi-sector initiatives such as the Global Methane 

Initiative (GMI) provide a basic framework for multistakeholder cooperation on one particular SLCF. The 

GMI brings together resources and technical expertise 

to enable methane emission abatement projects in a 

voluntary action network. The USEPA has also established 

the SmartWay Partnership with the private sector, 

initially as a national programme to advance green 

freight practices that improve fuel efficiency and reduce 

emissions. It includes a supply chain partnership of 

over 2,000 shippers (manufacturers) and carriers, and 

programmes concerned with technologies, financing and 

marketing61. 

7.3 Enabling mechanisms at the global scale 

to facilitate implementation of national SLCF 

mitigation 

Adequate institutional and legal frameworks are essential 

in achieving SLCFs mitigation, but to be effective they 

need to be accompanied by adequate human, technical 

and financial resources. While efforts to secure adequate 

resources need to occur primarily at the national level, 

they can be supported through a variety of ways at 

the global level. Overcoming financial challenges, for 

instance, requires readily accessible financing systems 

59. UN Systems High-Level Committee on Programmes (HLCP): http://hlcp.unsystemceb.org/, United Nations Development Group: http://www.undg.org/, 

Environment Management Group: http://www.unemg.org/

60. http:// www.unep.org/transport/pcfv

61. http://www.epa.gov/smartway
GLOBAL-SCALE ACTION – Near-term Climate Protection and Clean Air Benefits 47

at the national level such as incentive schemes, existing 

credit institutions, the Clean Development Mechanism, 

among others, which can entirely originate and be 

funded through national sources, or be supported by 

external sources, including bilateral and multilateral 

donors. Similarly, strengthening national capacities and 

institutions, and access to technology, can be supported 

by global programmes. Awareness raising is also essential 

to mobilize political support and wide acceptance of, and 

participation in, mitigation efforts at national level. This 

need is discussed at length in Chapter 5, in relation to the 

specific sectors addressed, and Chapter 8. 

7.3.1 Technical assistance, technology transfer and 

capacity building

International organizations and donors can play an 

important role in facilitating access to appropriate 

technology, information, knowledge and data and 

can support national efforts to strengthen institutions 

and capacities to implement measures to reduce SLCF 

emissions. An example is the Global Fuel Economy 

Initiative by UNEP and other partners to promote 

fuel-efficient vehicles, with the co-benefit of reducing 

emissions of black carbon62. Other examples are the 

institutional strengthening projects funded under the 

multilateral fund for the implementation of the Montreal 

Protocol, which support ozone units in relevant ministries 

worldwide in their efforts to implement national measures 

to phase out ozone depleting substances63. 

While technical assistance and capacity building 

programmes to support SLCF mitigation are already being 

implemented by various organizations, a more coherent, 

coordinated SLCF-specific approach based on synergies 

among existing programmes and plans for future activities 

would be beneficial. 

7.3.2 Financing SLCF mitigation

Given the multitude of conflicting and often pressing 

development and economic priorities facing decision 

makers, investment in SLCF mitigation may not be the 

immediately preferred choice, and only those measures 

that provide an increase in earnings in the relatively nearterm will directly appeal to the private sector (Chapter 4). 

So, when cost savings can only be realised over the longterm, the resources required for the up-front investment 

need to be found in other ways. 

Action to mitigate SLCFs can be funded through a wide 

range of sources from the national to the global level and 

from micro-finance to large-scale funding. Creative ways 

to generate and access funding have already been devised 

and continue to evolve, in addition to traditional official 

development assistance (ODA) and multilateral funding 

mechanisms. 

Considering the development co-benefits of mitigating 

SLCFs, a more comprehensive approach to policy on 

SLCFs that takes such co-benefits fully into account could 

positively affect funding to address SLCF concentrations. 

The links between the impacts of near-term climate 

change and poverty eradication, for example, need to be 

drawn more clearly both at national and international 

levels.

Mechanisms specifically funding SLCFs

One initiative aimed at specifically reducing an SLCF is the 

Prototype Methane Financing Facility (PMFF)64, introduced 

by the Methane Blue Ribbon Panel and supported by 

UNEP and several donor and recipient countries. The 

PMFF provides a guaranteed floor price for certified 

emission reductions (CERs) arising from qualified methane 

projects, especially in least developed countries, and for 

cookstoves projects that abate methane. Financing is 

expected to arise from guarantees issued by governments, 

and therefore would not require extensive additional 

funding; if successful, this model could be used to target 

other SLCFs as well. Proposals also exist for a more 

extensive price floor mechanism that would actually 

purchase and retire the CERs, rather than using them as 

offsets in meeting climate obligations. Several private 

methane funds also exist, targeted specifically at methane 

abatement activities.

The PMFF is an example of a ‘forcer fund’ approach, 

with the focus on an individual SLCF. Another option 

would be for groups of donors, both government and 

private actors, to take a sectoral approach instead of 

focusing on individual forcers. The Global Alliance for 

Clean Cookstoves (GACC) has for example encouraged 

donors to set aside development loan guarantees for 

cookstove manufacturers. This approach could be used 

for other sectors impacting SLCF emissions as well, such 

as oil and gas, brick-making kilns, diesel combustion or 

agricultural waste burning.

62. http://www.globalfueleconomy.org/Pages/Homepage.aspx

63. http://www.multilateralfund.org/default.aspx

64. Methane Blue Ribbon Panel, A Fast-Action Plan for Immediate Methane Abatement. http://www.globalmethanefund.org/
48 Near-term Climate Protection and Clean Air Benefits – GLOBAL-SCALE ACTION

Multilateral environmental agreement-related funds 

Many financial mechanisms have been established to help 

implement multilateral environmental agreements. While 

some are trust funds that support the operation of the 

agreement’s secretariats, others aim to support parties in 

their implementation of the agreement’s obligations. In 

particular, several funds have been established under the 

United Nations Framework Convention on Climate Change 

to finance projects both for adaptation and mitigation 

including technology transfer and capacity building in 

various sectors. 

In addition to the two funds specifically established 

to assist with the implementation of the Convention and 

the Protocol, three special funds have been established 

under the climate regime: the Special Climate Change 

Fund (SCCF); the Least Developed Countries Fund (LDCF), 

both under the Convention; and the Adaptation Fund 

(AF), under the Kyoto Protocol. The SCCF, in particular, was 

established to finance projects in the fields of adaptation 

and mitigation, including technology transfer and capacity 

building in various sectors (energy, transport, industry, 

agriculture, forestry and waste management, and 

economic diversification)65. These funds could be explored 

as possible avenues for financing activities that also result 

in SLCF mitigation. In addition to managing specific funds 

established under relevant multilateral environmental 

agreements, the Global Environment Facility (GEF), which 

is replenished every four years, and is currently operating 

under GEF V (1 July 2010 - 30 June 2014), provides grants 

and concessional funding to meet the incremental costs 

of measures needed to achieve global environmental 

benefits in agreed focal areas, including climate change. 

The following objectives apply to the climate change focal 

area for the current funding window:

• demonstration, deployment and transfer of innovative, 

low-carbon technologies;

• market transformation for energy efficiency in the 

industrial and buildings sectors;

• investment in renewable energy technologies;

• energy-efficient, low-carbon transport and urban 

systems;

• conservation and enhancement of carbon stock through 

sustainable management of land use, land-use change 

and forestry;

• support for enabling activities and capacity building66.

Subject to countries own choice and to applicable 

funding policies, GEF allocations could be used to 

support SLCF work, if proposed projects respond to the 

above objectives or fall under one of its cross-cutting 

areas, especially for pollutants such as black carbon and 

tropospheric ozone that are not traditionally considered 

primary climate forcers. In addition, future replenishment 

periods - GEF VI and beyond - could provide an additional 

opportunity for the GEF to specifically target SLCFs 

emissions.

The Clean Development Mechanism and new Green 

Climate Fund

Other mechanisms associated with the global climate 

regime, including the ‘Fast Track Fund’ and the Clean 

Development Mechanism (CDM), could be explored for 

their potential to facilitate SLCF mitigation. 

Under the ‘Fast Track Fund’, developed countries have 

pledged to provide US$ 30 billion by 2012 for adaptation 

and mitigation. This funding is supposed to increase to 

US$ 100 billion annually by 2020. Some or all of these 

resources will be allocated through a ‘Green Climate Fund’ 

that could provide an opportunity in the future for further 

SLCF mitigation67. 

Although not technically financial mechanisms, the 

CDM and other flexible mechanisms can play an important 

role in channelling funds to mitigate SLCFs - especially 

methane - but also to some degree black carbon and 

other ozone precursors. This is because many of the 

measures for SLCFs also abate Kyoto Protocol gases and 

therefore are eligible for credits under such financing 

schemes68.

 Unfortunately, however, the system does not 

fully cater to the needs of SLCFs mitigation, and some 

methane projects, such as those associated with landfills 

and wastewater, present challenges that make them 

less likely to attract investment. This is also due to the 

way by which carbon credits such as Certified Emissions 

Reductions (CERs) are calculated.

The CDM could do more to reduce methane emissions 

but further incentives need to be put in place to this 

end, and especially to promote small-scale projects such 

as municipal waste management. One such incentive 

mechanism is the Prototype Methane Financing Facility, 

described above.

65. http://unfccc.int/cooperation_and_support/financial_mechanism/items/2807.php

66. GEF Secretariat (2010). GEF-5: Programming Document, available from: http://www.thegef.org/gef/sites/thegef.org/files/documents/GEF.R.5.31.pdf

67. Fast-start finance: http://unfccc.int/cooperation_support/financial_mechanism/fast_start_finance/items/5646.php, Green climate fund: http://unfccc.

int/cooperation_and_support/financial_mechanism/green_climate_fund/items/5869.php

68. About CDM: http://cdm.unfccc.int/about/index.html
GLOBAL-SCALE ACTION – Near-term Climate Protection and Clean Air Benefits 49

Emissions of methane and black carbon often 

arise from multiple small sources such as cookstoves, 

diesel engines, brick kilns and agriculture, and may 

need to be addressed through ‘Programmatic CDM’ 

methodologies designed to cover these multiple small 

sources. Programmatic CDM projects, while proving at 

times difficult to implement, tend to be associated with 

significant development benefits, especially in least 

developed countries. The United Nations Framework 

Convention on Climate Change, UNEP and individual 

governments could work with the CDM Executive Board to 

facilitate the approval of such projects and work to shape 

new CDM methodologies or its eventual successor in the 

context of the new climate regime that include mitigation 

of SLCFs and air quality as an important co-benefit.

Integrating SLCFs into development assistance and other 

funding 

Incorporating SLCF mitigation as an integral part of 

national development and poverty reduction strategies, 

particularly in relation to public health and food security, 

would be beneficial to eventually attract additional 

resources. To encourage this, the connection between 

poverty reduction, air pollution and near-term climate 

change needs to be made more explicit. The fact that 

reducing the risk of environmental impacts that would 

result from near-term climate change will create large 

cost savings and overall promote economic development, 

needs to be more widely appreciated. 

Bilateral and multilateral donors, including multilateral 

development banks, could choose to finance SLCF 

abatement activities directly for the specific purpose of 

near-term climate benefit to sensitive areas such as the 

Himalayas and the Arctic, or they could add and integrate 

black carbon and tropospheric ozone precursor reduction 

projects into their existing development assistance 

portfolios. Funding programmes would need to be 

tailored to support the specific SLCF mitigation measures 

applicable in a given country or region, and build on the 

relevant key sectors. For many countries, for example, 

SLCF mitigation could be integrated into improved 

cookstoves and waste management projects, while in 

other countries a good avenue could be provided by 

wastewater, transport and landfill infrastructure or brick 

kiln projects. 
The previous chapters have outlined the benefits for 

health, crop yields and near-term climate protection of 

taking action, starting now, on short-lived climate forcers 

(SLCFs). Other chapters discussed the options to promote 

implementation of identified black carbon and methane 

emission control measures at national, regional and global 

scales. The challenge for the international community is 

to put these measures in place quickly, as effective action 

must be taken over the next two decades to achieve the 

full potential for the near-term benefits outlined in this 

document. This will be influenced by the very diverse 

starting points of different governments and regional and 

international organizations. In order for SLCF mitigation to 

be successful, implementation of the key measures needs 

to be integrated into national programmes according to 

national priorities. Fortunately, there is a substantial basis 

on which to build national strategies. Chapter 5 indicates 

the need to take full advantage of the wide range of 

policy measures and instruments which have already 

been developed to address air pollution, as well as the 

potential to integrate SLCF mitigation- when appropriate 

- into sustainable development planning, and sectoral 

and climate-related policies. The principal instruments 

available are regulation of emission levels, bans of 

substances or particular processes, and deployment of 

cleaner technology (e.g. cookstoves). These approaches 

can usefully be complemented by a wide range of tools, 

including economic incentives, technology transfer, 

awareness raising, capacity enhancement and education.

A suitable starting point is the identification of relevant 

sources and measures that can achieve the emission 

reduction goals, are sustainable in the circumstances of 

the country, can be readily introduced and effectively 

implemented, and where success can be measured and 

assessed. It is especially important that the selected 

measures are cost-effective, generating positive short-term 

returns on capital expenditure and have low maintenance 

costs. This work can be consolidated into national action 

plans or other planning or strategy documents. 

Although the principal route for abating SLCFs is 

through national programmes, cooperative action at 

regional and global scales will also be required. This 

is because, like all air pollutants, some SLCFs are also 

transported at regional, hemispheric or even global 

scales. For the same reasons, different SLCFs may require 

different approaches. Measures to reduce black carbon 

emissions may be motivated by important local health 

benefits alone, even though they also have regional 

benefits in ice- and snow-covered areas and limit 

global temperature increases. Measures to address 

tropospheric ozone, a regional and hemispheric pollutant, 

may require cooperation at those scales to effectively 

reduce concentrations. Methane is globally mixed in the 

atmosphere, so methane abatement lends itself to global 

cooperation. Global- and regional-scale efforts will also 

help widespread implementation of national-level actions 

and allow the development of a more coordinated and 

comprehensive approach. 

Existing international and regional instruments and 

policies can provide a useful foundation on which to 

anchor an SLCF strategy, without having to create costly 

and time-consuming new ones. SLCF policy development 

can build on existing processes to promote cross-cutting 

activities such as awareness raising, agenda setting, policy 

formulation and monitoring. It is also important to focus 

on what could be implemented within current sustainable 

development pathways and existing air quality and 

climate change programmes, expanding and accelerating 

those efforts that will have significant development cobenefits. 

The above considerations are based on the fundamental 

premise that addressing near-term climate change by 

interventions that reduce concentrations of SLCFs is time 

sensitive. The opportunity to achieve near-term global 

and regional climate benefits and significantly reduce the 

rate of climate change needs to be realised within the 

next two decades if changes already seen in sensitive and 

at-risk regions, such as the Himalayas and the Arctic, are to 

Chapter 8:

A Way Forward

50 Near-term Climate Protection and Clean Air Benefits – A WAY FORWARD
A WAY FORWARD – Near-term Climate Protection and Clean Air Benefits 51

be slowed. This near-term climate strategy complements 

the long-term climate strategy of reducing long-lived 

greenhouse gases, especially carbon dioxide. If taken in 

conjunction with the necessary carbon dioxide reductions, 

reducing SLCFs increases the chance of remaining below 

the 2°C temperature increase target during this century.

8.1 The need for awareness raising

Mobilizing political support to address environmental 

concerns has always depended on raising general 

awareness of the problem both within government and 

among the public. It also means seeing the benefits of 

taking action and the negative impacts of inaction. The 

attention given to the need for SLCF mitigation, and 

consequent decision-making, can only derive from a 

firm grounding in science and knowledge of the impact 

that these substances have on climate, public health, 

agricultural crop yields, ecosystems and development. 

Despite some progress in the understanding of these 

issues among both governments and the public, there 

is a need for greater recognition of the urgency of the 

near-term climate situation and the potential threats 

of continued rapid temperature increase in the coming 

two to four decades. In addition, the ready availability of 

SLCF-reduction measures and their health, environment, 

climate and development co-benefits need to be 

emphasised and brought to the attention of the public. 

This needs to be coupled with efforts to advance scientific 

and technical knowledge on SLCFs and their potential for 

achieving near-term climate and air-quality gains.

Awareness-raising efforts should target a broad 

spectrum of actors across multiple sectors. At the 

global level, raising political awareness at such suitable 

international forums as UNEP’s Governing Council, the 

Commission for Sustainable Development and United 

Nations Framework Convention on Climate Change 

meetings is an essential aspect of developing a framework 

for international cooperation on SLCFs. To achieve the 

scale of intervention needed to rapidly reduce SLCFs, the 

discussion of the issues must occur beyond air-pollution 

circles and also be considered together with climatechange policies at global, regional and national levels. This 

discussion should also move into broader development 

circles, such as through the United Nations Development 

Programme, the World Bank, regional development banks, 

and the Global Environment Facility. The policy challenges 

resulting from the convergence of climate change and airquality objectives are complex and the ability of outreach 

campaigns to influence action at all levels will depend 

on their ability to highlight the cost-effective, ‘win-win’ 

nature of SLCF reduction measures. 

Governments could also initiate or support joint 

activities to promote awareness raising, information 

exchange and other enabling actions to facilitate 

implementation of policy measures. Technical meetings 

and policy dialogues with national and sub-national 

authorities and stakeholders are essential to raise 

awareness and facilitate subsequent implementation of 

mitigation measures in any country. Such meetings would 

foster an understanding of the available implementation 

options and mechanisms, highlight available 

internationally transferrable experience, and facilitate the 

building of political support and funding. Organizing such 

meetings would also promote information sharing and 

greater coordination.

Coordinated awareness-raising efforts at global, regional 

and national scales involving governments and other key 

stakeholders, including the public, would increase political 

support for the implementation of SLCF measures. 

8.2 Setting the agenda

While raising awareness is the first step required to put 

SLCFs on to governments’ agendas, the widespread 

adoption and implementation of policies at global, 

regional and national levels will depend to a large extent 

on a willingness to set an agenda that clearly identifies 

priorities for the course of action. Policy development 

at all levels needs to be based on the science and 

understanding of SLCFs. Government officials also 

require cost-benefit analyses to define the most costeffective measures for their country’s circumstances, as 

well as the means to measure and evaluate the success 

of implementation. The natural way to achieve this is 

through national action plans as discussed in Chapter 5.

The knowledge represented by Integrated Assessment 

of Black Carbon and Tropospheric Ozone (UNEP/WMO, 

2011), together with this and other recent reports, 

provide a concrete basis for policy-making and action to 

mitigate SLCFs. The involvement of key governments in 

developing these reports, and high-level policy dialogues 

in different regions, will further the development of an 

effective agenda at national, regional and global levels. 

At the global level, SLCF mitigation needs to be placed 

on the international agenda so that governments can 

address this issue in a coordinated manner. This requires 

wider acceptance of the problem and an appreciation of 

how the mitigation of SLCFs can assist countries to meet 

their immediate air-quality and development goals, as 

well as helping to solve their short- and medium-term 

climate change challenges. A key point at this stage is to 

enhance understanding of the need to act quickly and 

build on existing policies and processes.
52 Near-term Climate Protection and Clean Air Benefits – A WAY FORWARD

Agenda setting at the regional level could build 

on the existing regional initiatives, agreements and 

networks already responsible for addressing air quality. 

Incorporating SLCFs into regional agendas will require that 

the issues are elevated to the level where the authority 

exists to address them, for example at ministerial 

meetings. Due to its convening power, the United Nations 

Environment Programme (UNEP) and its regional offices 

can play an important role here because many of the 

existing instruments were originally promoted through 

UNEP cooperation and awareness-raising projects.

Setting priorities at the regional level will face 

underlying challenges, related to the fact that the 

development of transboundary air pollution agreements 

is still a work-in-progress in many regions. There may be 

resistance to move away from traditional air pollution 

approaches, as closer association with climate issues 

might be perceived as adding further complexity; similar 

challenges may also be faced at the national level. 

Near-term and regional benefits, and opportunities to 

realise co-benefits, may however remove part of that 

reluctance. To achieve this, it will be important to have 

a clear understanding of the costs and benefits of SLCF 

mitigation, and financial and other forms of support 

that could assist implementation of SLCF mitigation 

activities. Therefore, successful agenda setting will 

require early engagement with stakeholders active in air 

pollution, climate and development policy, to enhance 

understanding of the added value of linking air pollution 

with near-term climate mitigation in the context of 

development. At the national level, policy makers need to 

be aware that national efforts are not only possible, but 

implementable at marginally increased costs to existing 

efforts.

8.3 Establishing an effective governance 

framework

An adequate governance framework is important for 

ensuring coordinated efforts among governments and 

international agencies. It is also important to ensure the 

delivery of the required enabling activities and financing, 

and for monitoring progress.

The challenge for SLCF mitigation is that while specific 

policies can be initiated by building on existing policies 

and processes, it still is a cross-cutting issue that falls 

outside the scope of any single existing regime or 

governance framework that would specifically address 

this problem in a dedicated and cohesive manner. An 

international governance framework is required that 

can coordinate and collaborate with existing initiatives, 

and be recognized by them as the primary framework. 

However, the framework must be flexible and framed in 

a way that will allow it to take quick and effective action 

working through the entire United Nations system, as 

well as at regional and national levels. Because of these 

requirements, an ad hoc arrangement might be best 

suited for moving forward on SLCFs. 

One important role for a global initiative would be to 

provide a menu of policies and measures that countries 

could use to develop national actions on SLCFs. Such a 

menu, along with some understanding of best practices, 

could be an important tool for assisting countries in 

developing their own national strategy and could become 

part of an action plan on near-term climate protection and 

clean-air benefits.

International organizations with relevant mandates 

could individually or jointly facilitate a global initiative 

on SLCFs, or provide secretariat functions, in addition 

to other roles they can play as outlined in chapter 7. 

An organization like UNEP could provide a platform 

for cooperation under such an initiative as a global 

organization that deals with environmental issues across 

different levels and sectors, including those most relevant 

to an effective SLCF strategy – climate change, ecosystems 

management, and transboundary air pollution, and due to 

its regional presence. 

A model for a global initiative could be a voluntary 

partnership of committed governments and other major 

stakeholders, led by a small steering committee of country 

champions working together with a small secretariat. The 

initiative could: 

• identify opportunities for enhanced international 

coordination and outreach;

• report on domestic activities; 

• identify knowledge gaps and human and financial 

resource requirements; 

• raise public awareness of the problem and opportunities, 

and discuss common approaches to taking new action or 

promoting and reinforcing action in other organizations; 

• serve as a forum for increasing awareness of, and 

participation in, existing efforts; 

• promote the development of national or regional 

action plans, tracking progress of programmes and 

commitments, and mobilizing funding commitments for 

SLCF mitigation; 

• aim to provide up-front finance to help create the 

necessary enabling environments for action, as well as to 

provide funds to leverage private sector investments in 

SLCF mitigation. 

The initiative could further task relevant international 

organizations to work through regional ministerial forums 

to develop awareness, set agendas and facilitate regional 

and national actions or promote the establishment of 
A WAY FORWARD – Near-term Climate Protection and Clean Air Benefits 53

regional structures where they are missing. The initiative 

could include an inter-agency mechanism for collaborative 

activities, a system-wide strategy and governance 

arrangements that would allow the types of partnerships 

that are needed to instigate and enable policies.

When establishing such a governance framework it 

would be important to achieve:

• a critical mass of countries across regions that will take 

leadership;

• recognition of the legitimacy of the global initiative by 

key actors and organizations in the climate and airpollution arenas;

• access to funding to kick-start early actions, e.g. pilot 

projects; and

• implementable and realistic action to achieve the agreed 

global agenda.

With these elements, the opportunities that SLCF 

mitigation presents for near-term climate change 

mitigation and for air-quality benefits can be utilized to 

their fullest extent and not be lost. 

The imperative for early action seems clear. The 

co-benefits to human development and environmental 

health, and avoidance of risks associated with existing 

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