FIRST-ORDER DRAFT IPCC WGII AR5 Chapter 19 1 Chapter 19. Emergent Risks and Key Vulnerabilities 2 3 Coordinating Lead Authors 4 Michael Oppenheimer (USA), Maximiliano Campos (Costa Rica) 5 6 Lead Authors 7 Joern Birkmann (Germany), George Luber (USA), Brian O’Neill (USA), Kiyoshi Takahashi (Japan), Rachel Warren 8 (UK) 9 10 Contributing Authors 11 Franz Berkhout (Netherlands), Pauline Dube (Botswana), Wendy Foden (South Africa), Stefan Greiving (Germany), 12 Solomon Hsiang (USA), Klaus Keller (USA), Joan Kleypas (USA), Robert Kopp (USA), Carlos Peres (UK), Jeff 13 Price (UK), Alan Robock (USA), Wolfram Schlenker (USA), Richard Tol (UK) 14 15 Review Editors 16 Mike Brklacich (Canada), Sergey Semenov (Russian Federation) 17 18 Chapter Scientist 19 Solomon Hsiang (USA) 20 21 22 Contents 23 24 Executive Summary 25 26 19.1. Purpose, Scope, and Structure of the Chapter 27 19.1.1. Historical Development of this Chapter 28 19.1.2. The Special Report on Managing the Risks of Extreme Events and Disasters to Advance Climate 29 Change Adaptation (SREX) 30 19.1.3. New Developments in this Chapter 31 32 19.2. Framework for Identifying Key Vulnerabilities, Key Risks, and Emergent Risks 33 19.2.1. Risk and Vulnerability 34 19.2.2. Criteria for Identifying Key Vulnerabilities and Key Risks 35 19.2.2.1. Criteria for Identifying Key Vulnerabilities 36 19.2.2.2. Criteria for Identifying Key Risks 37 19.2.3. Criteria for Identifying Emergent Risks 38 19.2.4. Identifying Key and Emergent Risks under Alternative Development Pathways 39 19.2.5. Assessing Key Vulnerabilities and Emergent Risks 40 41 19.3. Emergent Risk: Multiple Interacting Systems and Stresses 42 19.3.1. Limitations of Previous Approaches Imply Key Risks Overlooked 43 19.3.2. Emergent Risks 44 19.3.2.1. Emergent Risks Arising from the Effects of Degradation of Ecosystem Services by 45 Climate Change 46 19.3.2.2. Emergent Risk Involving Non-Climate Stressors: the Management of Water, Land, and 47 Energy 48 19.3.2.3. Emergent Risks Involving Health Effects and Disease Emergence 49 19.3.2.4. Spatial Convergence of Multiple Impacts: Hotspots 50 19.3.2.5. Maladaptation 51 52 19.4. Emergent Risk: Indirect, Trans-Boundary, and Long-Distance Impacts 53 19.4.1. Indirect, Trans-Boundary, and Long-Distance Impacts of Climate Change Impacts on Agricultural 54 Yields: Food Trade Patterns, Prices, Malnutrition Do Not Cite, Quote, or Distribute 1 11 June 2012 FIRST-ORDER DRAFT IPCC WGII AR5 Chapter 19 1 19.4.2. Indirect, Trans-boundary, and Long-Distance Impacts of Adaptation 2 19.4.2.1. Human Migration and Displacement 3 19.4.2.2. Conflict and Insecurity 4 19.4.2.3. Species Range Shifts: Consequences 5 19.4.3. Indirect, Trans-Boundary, and Long-Distance Impacts of Mitigation Measures 6 19.4.3.1. Effects on Biodiversity 7 19.4.3.2. Effects on Human Systems 8 19.4.3.3. Indirect Effects of Biofuels Production via Markets 9 10 19.5. Other Emergent Risks 11 19.5.1. Risks from a Large Temperature Rise 12 19.5.2. Risks from Ocean Acidification 13 19.5.3. Risks from CO2 Health Effects 14 19.5.4. Risks from Geo-Engineering (Solar Radiation Management) 15 16 19.6. Key Vulnerabilities, Key Risks, and Reasons of Concern 17 19.6.1. Key Vulnerabilities 18 19.6.1.1. Dynamics of Vulnerability 19 19.6.1.2. Differential Vulnerability 20 19.6.1.3. Trends in Vulnerability 21 19.6.1.4. Risk Perception 22 19.6.2. Key Risks 23 19.6.2.1. The Role of Adaptation and Alternative Development Pathways 24 19.6.2.2. Relationship between Adaptation, Mitigation, and Residual Impacts at Regional and 25 Sectoral Levels 26 19.6.3. Updating Reasons for Concern 27 19.6.3.1. Unique and Threatened Systems 28 19.6.3.2. Extreme Events 29 19.6.3.3. Distribution of Impacts 30 19.6.3.4. Aggregate Impacts 31 19.6.3.5. Large-Scale Singular Events: Physical, Ecological, and Social System Thresholds and 32 Irreversible Change 33 19.6.3.6. Variations in RFCs across Socio-Economic Pathways 34 35 19.7. Assessment of Response Strategies to Manage these Risks 36 19.7.1. Relationship between Adaptation Efforts, Mitigation Efforts, and Residual Impacts 37 19.7.2. Limitations of Response Strategies 38 19.7.2.1. Limits to Mitigation 39 19.7.2.2. Limits to Adaptation 40 19.7.3. Avoiding Thresholds, Irreversible Change, and Large-Scale Singularities in the Earth System 41 19.7.4. Avoiding Tipping Points in Social/Ecological Systems 42 19.7.5. Governance and Adaptation Strategies 43 44 Frequently Asked Questions 45 46 References 47 48 49 Executive Summary 50 51 A focal point of this chapter is the interaction of the changing physical characteristics of the climate system with 52 evolving characteristics of socioeconomic and biological systems (exposure and vulnerability) to produce risk. 53 Do Not Cite, Quote, or Distribute 2 11 June 2012 FIRST-ORDER DRAFT IPCC WGII AR5 Chapter 19 1 Key risks arise from high probability of occurrence of a substantial physical impact of climate change or a high 2 degree of exposure and vulnerability to an impact, or both. 3 4 Emergent risks are risks which have only recently emerged in the scientific literature in sufficient detail to permit 5 assessment and which have the potential to become key risks as additional understanding accumulates, i.e. those 6 relevant to interpreting Article 2 of the UN Framework Convention on Climate Change (UNFCCC). 7 8 Key vulnerabilities arise in systems due to one or more of the following characteristics: exposure to physical climate 9 changes, probability of major harm due to exposure, importance of exposed system, limited ability to cope with 10 impacts, limited adaptation capacity, persistence of conditions of high susceptibility to climate stressors, cumulative 11 and interactive stresses. 12 13 Existing frameworks, such as Reasons for Concern and Key Vulnerabilities, for evaluating risks pertinent to Article 14 2 of the UNFCCC are updated here in light of the advances in SREX and the current report’s discussions of 15 vulnerability, human security, and adaptation. 16 17 Alternative development paths influence risk by changing both the likelihood of physical impacts (through their 18 effect on greenhouse gas emissions) and by altering vulnerability and exposure. 19 20 Interactions among climate change impacts in various sectors and regions, and between these impacts and human 21 adaptation in other sectors and regions, as well as interactions between adaptation and mitigation actions, are 22 generally not included, or not well integrated, into projections of climate change impacts. These interactions create 23 emergent risks and/or key vulnerabilities not previously recognized. 24 25 Among these are interactions of climate change with other non-climate factors such as land management, water 26 management, air pollution (which has drivers in common with climate change), energy production (including 27 cultivation of biofuel feed stocks) and diseases. 28 29 A key interaction is that between the impacts of climate change on biodiversity and the impacts of climate change on 30 human systems, where the effects on human systems are increased by the loss of ecosystem services that 31 biodiversity provides such as water and air purification, protection from extreme weather events, preservation of 32 soils, recycling of nutrients, and pollination of crops. 33 34 Spatial convergence of impacts in different sectors can create impact ‘hotspots’ involving new interactions. 35 36 Adaptation designed for one sector interacting with functioning of another sector can create risks (e.g. increasing 37 irrigation to crops in response to a drying climate can exacerbate water stress in downstream areas such as wetlands, 38 in cases where the latter provide important water cleaning services) 39 40 Risks emerge from indirect, trans-boundary, and long-distance impacts of climate change acting on agricultural and 41 energy sectors among others. Impacts of climate change may be transmitted by human responses such as migration 42 and via global markets. An emergent risk is the association of climate change, acting through uncertain channels, 43 with conflict. 44 45 Other emergent risks relate to ocean acidification, geo-engineering, temperature increases above 40C, and indirect 46 health impacts of high ambient concentrations of CO2. 47 48 A large number of key vulnerabilities, key risks, and emergent risks follow from the assessments of individual 49 chapters of this report. Many of these reflect differential vulnerability between groups due to age, wealth, or income 50 status, and deficiencies in governance. 51 52 In updating and revising the Reasons for Concern framework, we find that since AR4, there is new and stronger 53 evidence to support the previous judgment of high confidence that “a warming of up to 2°C above 1990-2000 levels 54 would result in significant impacts on many unique and vulnerable systems, and would likely increase the Do Not Cite, Quote, or Distribute 3 11 June 2012 FIRST-ORDER DRAFT IPCC WGII AR5 Chapter 19 1 endangered status of many threatened species, with increasing adverse impacts (and increasing confidence in this 2 conclusion) at higher temperatures”. 3 4 Based largely on the findings from SREX, we assess that the overall risk from physical climate characteristics of 5 extreme events has not changed significantly since AR4. However, there is a new appreciation for the importance of 6 exposure and vulnerability, in both developed and developing countries. 7 8 New methods for estimating aggregate impacts have emerged. Consistent with AR4, we judge that there remains 9 high confidence that globally aggregated figures underestimate damages because they cannot include many non- 10 quantifiable impacts and there is very high confidence that aggregate estimates of costs mask significant differences 11 in impacts across sectors, regions, countries and populations.