EXPERT REVIEW DRAFT IPCC SREX Chapter 4 1 Chapter 4. Changes in Impacts of Climate Extremes: Human Systems and Ecosystems 2 3 Coordinating Lead Authors 4 John Handmer (Australia), Yasushi Honda (Japan), Zbigniew Kundzewicz (Poland), Carlos Nobre (Brazil) 5 6 Lead Authors 7 Nigel Arnell (UK), Gerardo Benito (Spain), Jerry Hatfield (USA), Ismail Fadl Mohamed (Sudan), Pascal Peduzzi 8 (Switzerland), Charles Scawthorn (USA), Shaohong Wu (China), Boris Sherstyukov (Russia), Kiyoshi Takahashi 9 (Japan), Zheng Yan (China) 10 11 Contributing Authors 12 John Campbell (New Zealand), Adriana Keating (Australia), Adonis Velegrakis (Greece), Joshua Whittaker 13 (Australia), Anya M. Waite (Australia), Fred F. Hattermann (Germany), Reinhard Mechler (Austria), Laurens 14 Bouwer (Netherlands), Yin Yunhe (China), Hiroya Yamano (Japan) 15 16 17 Contents 18 19 Executive Summary 20 21 4.1. Introduction 22 23 4.2. Role of Climatic Extremes in Natural and Socio-Economic Systems 24 4.2.1. What is “Extreme”? 25 4.2.1.1. Role in Human Systems 26 4.2.1.2. Role in Natural Systems 27 4.2.2. Complex Interactions between Climate Events, Exposure, and Vulnerability 28 4.2.2.1. About Permafrost 29 4.2.2.2. Case Study – Forest Fires in Indonesia 30 4.2.3. How Do They Impact on Humans and Ecosystems? 31 4.2.3.1. Concepts and Human Impacts 32 4.2.3.2. Disaster 33 4.2.3.3. Impacts on Ecosystems 34 4.2.3.4. Phenomenon Induced by Climate Change that Lead to Impacts on Ecosystems 35 4.2.4. Lists of Hazards in Terms of Hazards (Climate Extremes), Sectors and Systems, Regions 36 4.2.5. Detection and Attribution of Climate Change Impacts 37 4.2.6. Comment on 4°C Rise 38 39 4.3. Observed Trends in Exposure and Vulnerability 40 4.3.1. Climate Change Contributes to and Exacerbates Other Trends 41 4.3.2. Observed Trends in Exposure 42 4.3.2.1. Human Exposure to Tropical Cyclones by Region 43 4.3.3. Observed and Projected Trends in Hazards and Impacts, Changing Frequency of Different 44 Intensities, and New Locations Affected 45 4.3.3.1. Coastal Systems: Natural and Human 46 4.3.3.2. Case Study – Long-Term Records of Flooding in Western Mediterranean 47 4.3.4. Observed Trends in Human Systems and Sector Vulnerability to all Climatic Extremes and to 48 Specific Types of Hazards 49 4.3.4.1. Vulnerability Trends 50 4.3.4.2. Global and Regional Trends in Vulnerability Factors 51 4.3.4.3. Observed Trends in Human Systems and Sector Vulnerability to all Climatic Extremes 52 and to Specific Types of Hazards 53 4.3.4.4. Case Study – Extraordinary Heat Wave in Europe, Summer 2003 54 4.3.4.5. Case Study – Glacial Retreat: Himalaya and Andes Do Not Cite, Quote, or Distribute 1 26 July 2010 EXPERT REVIEW DRAFT IPCC SREX Chapter 4 1 4.3.5. Observed Trends in Ecosystem Vulnerability to all Climatic Extremes and to Specific Types of 2 Hazards 3 4.3.5.1. Drought and Heat Wave 4 4.3.5.2. Flood 5 4.3.5.3. Storm 6 4.3.5.4. ENSO 7 4.3.5.5. Case Study – Coral Reef Bleaching 8 4.3.6. Issues of Sequencing and Frequency of Climatic Extremes 9 4.3.7. Comment on 4°C Rise 10 11 4.4. System- and Sector-Based Aspects of Vulnerability, Exposures, and Impacts 12 4.4.1. Criteria Used for the Tables in this Section 13 4.4.2. The Overall Links between Systems, Sectors, and Hazard Impacts (including Vulnerability and 14 Exposure) 15 4.4.2.1. Water 16 4.4.2.2. Ecosystems 17 4.4.2.3. Food Systems and Food Security 18 4.4.2.4. Human Settlements, Industry, and Infrastructure 19 4.4.2.5. Human Health, Well-Being, and Security 20 21 4.5. Regionally Based Aspects of Vulnerability, Exposures, and Impacts 22 4.5.1. Introduction and Overview 23 4.5.2. Africa 24 4.5.3. Asia 25 4.5.4. Europe 26 4.5.5. Latin America 27 4.5.6. North America 28 4.5.7. Oceania 29 4.5.8. Open Oceans 30 4.5.9. Polar Region 31 4.5.10. Small Island States 32 4.5.11. The Overall Links between Regions and Hazard Impacts 33 4.5.12. Comment on 4°C Rise 34 35 4.6. Total Cost of Climate Extremes and Disasters 36 4.6.1. Introduction and Conception 37 4.6.1.1. Conceptual Framework: Key Definitions 38 4.6.1.2. Framework to Identify the Cost of Extremes and Disasters 39 4.6.1.3. Different Costs in Developed Countries and Developing Countries 40 4.6.2. Methodology and Literature for Evaluating Disaster and Adaptation Costs and Impacts 41 4.6.3. Estimates of Global and Regional Costs 42 4.6.3.1. The Regional and Global Economic Loss of Climatic Disasters 43 4.6.3.2. Africa 44 4.6.3.3. Asia 45 4.6.3.4. Europe 46 4.6.3.5. Latin America 47 4.6.3.6. North America 48 4.6.3.7. Oceania 49 4.6.4. The Regional and Global Costs of Adaptation 50 4.6.5. Uncertainty in Assessing the Economic Loss of Extremes and Disasters 51 4.6.6. Comment on the Likely Impact on the Global Loss Figure of a 4°C Rise 52 53 References 54 Do Not Cite, Quote, or Distribute 2 26 July 2010 EXPERT REVIEW DRAFT IPCC SREX Chapter 4 1 2 Executive Summary 3 4 This chapter is concerned with how climate and weather events impact on human and ecological systems. This is 5 examined in terms of two distinct types of “extremes”: weather and climate extreme events, and extreme impacts on 6 human and ecological systems. Although extreme impacts often follow an extreme event, either extreme can occur 7 without the other. The impacts of weather and climate extremes on humans and ecosystems are a function of 8 exposure, vulnerability and the type and magnitude of the climate extreme. Or put another way the impacts of 9 climate events are mediated by exposure and vulnerability. Extreme impacts may become disasters, especially when 10 the impact is such that local capacity to cope is exceeded. 11 12 The chapter looks at observed and projected trends in exposure and vulnerability to, and impacts from, weather and 13 climate events. It does this by sector and by regions. The global costs of these events are estimated and where data 14 exist costs are also estimated for regions. 15 16 For practical reasons, both the concept of “extremes” and “rarity” are not amenable to precise definition. Varying 17 spatial and temporal scales, and the almost infinite variation in the attributes of the event in question – such as: 18 duration, intensity, spatial area affected, timing, frequency, onset date, whether the event is continuous or broken 19 such as a continuous drought, and antecedent conditions - mean that it is neither practical nor useful to define 20 extremes precisely. Statistical rarity is determined with respect to time and place, and subject to major changes. 21 22 Vulnerability” is defined here to mean susceptibility to harm and ability to recover. Exposures are human and 23 ecosystem tangible and intangible assets and activities in the way of weather or climate events. Assessment of 24 vulnerability and exposure should take account of temporal and spatial scales. Activities far from the site of impact 25 can be seriously impacted. Exposure can be more or less permanent or transitory: for example, exposure can be 26 increased by people visiting an area or decreased by evacuation of people and livestock after a warning. Exposure is 27 a necessary but not sufficient condition for impacts. As human activity and settlements expand in a given area, more 28 will be exposed to and affected by local climatic events. 29 30 Observed trends 31 On the global scale, annual material damage – which represents only part of the human impact - from large weather 32 events, has increased 8-fold between 1960s and 1990s, while the insured damage has risen more (17-fold in the 33 same interval) in inflation-adjusted monetary units. Attempts have been made to normalize loss records for changes 34 in exposure and vulnerability. This allows detection of observed changes in weather hazard rather than the disaster 35 impact. There is no conclusive evidence that anthropogenic climate change has lead to increasing losses, and 36 increasing exposure of people and economic assets is most likely the major cause of the long-term changes in 37 economic disaster losses. This conclusion is subject to debate and depends on the processes used to normalize loss 38 data over time. Different studies use different approaches to normalization, and to handling variations in the quality 39 and completeness of longitudinal loss data. These are areas of potential weakness in the conclusions of longitudinal 40 loss studies, and need more empirical and conceptual effort. A second area of uncertainty concerns the impacts of 41 modest weather and climate events on the livelihoods and people of informal settlements and economic sectors, 42 especially in developing countries. These impacts have not been systematically documented with the result that they 43 are largely excluded from longitudinal impact analysis. 44 45 The dramatic expansion of water demand (and water withdrawals) for food production, hygiene, human well-being 46 and industry, including by the power sector, highlights some of the complexities inherent in the weather/exposure 47 interface.