Acknowledgements iii

Abbreviations vi

Terms and definitions x

Table of contents xxi

Foreword xxiii

Preface xxiv

Audience and focus xxv

Executive summary xxvi

Integrated action on climate and clean air is one of the highest-return investments available to governments today xxvii

Air pollution is a macroeconomic risk, not an environmental add-on xxix

Greater than the sum: integration increased returns xxxi

Time is money: delay locks in avoidable costs xxxii

The benefits materialise everywhere, across all regions and over different timescales xxxiii

Enabling conditions are as important as technology choices xxxvi

The 25 solutions deliver on governments’ existing commitments, not just future aspirations xxxvii

Call to action xxxix

Chapter 1 - Rationale for this Assessment 1

  1.1 Introduction to an integrated approach 2

  1.2 Historic emissions and concentrations 5

  1.3 Economic impacts of climate change and air pollution 8

    1.3.1 Cost and benefit valuation 8

  1.4 Past assessments of air pollution and climate change impacts 9

    1.4.1 Health impacts of air pollution 9

    1.4.2 Major impacts of climate change 12

  1.5 Introduction to the enabling environment 12

  1.6 Scope and objectives of the Assessment 13

  1.7 Guide to the Assessment 17

Chapter 2 - Scenarios and solutions 18

Key messages 18

  2.1 Introduction to scenarios and solutions 19

    2.1.1 Key features of the baseline scenario 21

  2.2 Emission outlook under the baseline scenario 24

  2.3 Key features of the integrated action scenario 25

  2.4 Emissions outlook under the integrated action scenario 29

    2.4.1 Importance of sectors for mitigation potential and regional variation 34

  2.5 Quantifying implementation costs of the scenarios 37

    2.5.1 Climate and air pollution control costs in the baseline scenario 40

    2.5.2 Costs of implementing the 25 integrated solutions 41

    2.5.3 Regional distribution of costs 42

  2.6 Unlocking the mitigation opportunities: why enabling implementation matters 43

Chapter 3 – Benefits and costs 50

Key messages 50

  3.1 Methods for quantifying air quality and climate benefits 52

    3.1.1 Exposure of people to air pollution under the baseline and integrated action scenarios 54

    3.1.2 Health impacts of air pollution under the baseline and integrated action scenarios 61

    3.1.3 Estimating the degree of climate change to 2100 under the baseline and integrated action scenarios 66

    3.1.4 Effects of climate change on human health and labour productivity under the baseline and integrated action scenarios 71

  3.2 Economic valuation of the air pollution and climate change impacts and benefits of further action 73

    3.2.1 Economic benefits from reduction in air pollution under the integrated action scenario 74

    3.2.2 Economic benefits from avoided warming under the integrated action scenario 79

    3.2.3 Combined risks from air pollution and warming on agriculture 81

  3.3 Economy-wide impacts of air pollution and climate change 82

  3.4 Benefit-cost analysis of the 25 integrated solutions 90

  3.5 Regional priorities: which solutions deliver the greatest benefits and when 93

  3.6 Further benefits and trade-offs 97

Chapter 4 - Breaking down barriers and building enabling environments for climate change and clean

air solutions 100

Key messages 100

  4.1 Introduction 101

  4.2 China 104

    4.2.1 Setting the context: integrating air pollution and climate change in China 104

    4.2.2 Transport 105

    4.2.3 Renewable and residential energy 105

    4.2.4 Waste and agriculture 106

    4.2.5 Enabling implementation and overcoming barriers in China 107

  4.3 India 107

    4.3.1 Setting the context: integrating air pollution and climate change in India 107

    4.3.2 Transport 109

    4.3.3 Renewable and residential energy 109

    4.3.4 Waste and agriculture 110

    4.3.5 Enabling implementation and overcoming barriers in India 111

  4.4 Mexico 111

    4.4.1 Setting the context: integrating clean-air and climate planning 111

    4.4.2 Transport 111

    4.4.3 Renewable and residential energy 112

    4.4.4 Waste and agriculture 113

    4.4.5 Opportunities to accelerate implementation in Mexico 115

  4.5 Nigeria 115

    4.5.1 Setting the context: integrating air pollution and climate planning in Nigeria 115

    4.5.2 Transport 116

    4.5.3 Renewable and residential energy 116

    4.5.4 Waste and agriculture 116

    4.5.5 Enabling implementation in Nigeria 117

  4.6 Towards a systemic framework for building an enabling environment 118

Chapter 5 - Conclusion and the way forward 125

  5.1 Integrated action reduces multiple forms of damage through the 25 solutions 125

  5.2 Health benefits arrive early and outweigh costs within a decade 126

  5.3 Enabling conditions determine whether and when the benefits are realised 127

  5.4 Aligning the findings with global commitments and targets 128

  5.5 Remaining challenges and the way forward 131

  5.6 What can governments and partners do now? 133

References 135