WG II Impacts, Adaptation and Vulnerability

*Table SPM-2:* Regional adaptive capacity, vulnerability, and key concerns.^a,b

Region	Adaptive Capacity, Vulnerability, and Key Concerns

Africa	Adaptive capacity of human systems in Africa is low due to lack of economic resources and technology, and vulnerability high as a result of heavy reliance on rain-fed agriculture, frequent droughts and floods, and poverty. [5.1.7] Grain yields are projected to decrease for many scenarios, diminishing food security, particularly in small food-importing countries (medium to high confidence⁶). [5.1.2] Major rivers of Africa are highly sensitive to climate variation; average runoff and water availability would decrease in Mediterranean and southern countries of Africa (medium confidence⁶). [5.1.1] Extension of ranges of infectious disease vectors would adversely affect human health in Africa (medium confidence⁶). [5.1.4] Desertification would be exacerbated by reductions in average annual rainfall, runoff, and soil moisture, especially in southern, North, and West Africa (medium confidence⁶). [5.1.6] Increases in droughts, floods, and other extreme events would add to stresses on water resources, food security, human health, and infrastructures, and would constrain development in Africa (high confidence⁶). [5.1] Significant extinctions of plant and animal species are projected and would impact rural livelihoods, tourism, and genetic resources (medium confidence⁶). [5.1.3] Coastal settlements in, for example, the Gulf of Guinea, Senegal, Gambia, Egypt, and along the East-Southern African coast would be adversely impacted by sea-level rise through inundation and coastal erosion (high confidence⁶). [5.1.5]

Asia	Adaptive capacity of human systems is low and vulnerability is high in the developing countries of Asia; the developed countries of Asia are more able to adapt and less vulnerable. [5.2.7] Extreme events have increased in temperate and tropical Asia, including floods, droughts, forest fires, and tropical cyclones (high confidence⁶). [5.2.4] Decreases in agricultural productivity and aquaculture due to thermal and water stress, sea-level rise, floods and droughts, and tropical cyclones would diminish food security in many countries of arid, tropical, and temperate Asia; agriculture would expand and increase in productivity in northern areas (medium confidence⁶). [5.2.1] Runoff and water availability may decrease in arid and semi-arid Asia but increase in northern Asia (medium confidence⁶). [5.2.3] Human health would be threatened by possible increased exposure to vector-borne infectious diseases and heat stress in parts of Asia (medium confidence⁶). [5.2.6] Sea-level rise and an increase in the intensity of tropical cyclones would displace tens of millions of people in low-lying coastal areas of temperate and tropical Asia; increased intensity of rainfall would increase flood risks in temperate and tropical Asia (high confidence⁶). [5.2.5 and Table TS-8] Climate change would increase energy demand, decrease tourism attraction, and influence transportation in some regions of Asia (medium confidence⁶). [5.2.4 and 5.2.7] Climate change would exacerbate threats to biodiversity due to land-use and land-cover change and population pressure in Asia (medium confidence⁶). Sea-level rise would put ecological security at risk, including mangroves and coral reefs (high confidence⁶). [5.2.2] Poleward movement of the southern boundary of the permafrost zones of Asia would result in a change of thermokarst and thermal erosion with negative impacts on social infrastructure and industries (medium confidence⁶). [5.2.2]

Australia and New Zealand	Adaptive capacity of human systems is generally high, but there are groups in Australia and New Zealand, such as indigenous peoples in some regions, with low capacity to adapt and consequently high vulnerability. [5.3 and 5.3.5] The net impact on some temperate crops of climate and CO₂ changes may initially be beneficial, but this balance is expected to become negative for some areas and crops with further climate change (medium confidence⁶). [5.3.3] Water is likely to be a key issue (high confidence⁶) due to projected drying trends over much of the region and change to a more El Niño-like average state. [5.3 and 5.3.1] Increases in the intensity of heavy rains and tropical cyclones (medium confidence⁶), and region-specific changes in the frequency of tropical cyclones, would alter the risks to life, property, and ecosystems from flooding, storm surges, and wind damage. [5.3.4] Some species with restricted climatic niches and which are unable to migrate due to fragmentation of the landscape, soil differences, or topography could become endangered or extinct (high confidence⁶). Australian ecosystems that are particularly vulnerable to climate change include coral reefs, arid and semi-arid habitats in southwest and inland Australia, and Australian alpine systems. Freshwater wetlands in coastal zones in both Australia and New Zealand are vulnerable, and some New Zealand ecosystems are vulnerable to accelerated invasion by weeds. [5.3.2]

Europe	Adaptive capacity is generally high in Europe for human systems; southern Europe and the European Arctic are more vulnerable than other parts of Europe. [5.4 and 5.4.6] Summer runoff, water availability, and soil moisture are likely to decrease in southern Europe, and would widen the difference between the north and drought-prone south; increases are likely in winter in the north and south (high confidence⁶). [5.4.1] Half of alpine glaciers and large permafrost areas could disappear by end of the 21st century (medium confidence⁶). [5.4.1] River flood hazard will increase across much of Europe (medium to high confidence⁶); in coastal areas, the risk of flooding, erosion, and wetland loss will increase substantially with implications for human settlement, industry, tourism, agriculture, and coastal natural habitats. [5.4.1 and 5.4.4] There will be some broadly positive effects on agriculture in northern Europe (medium confidence⁶); productivity will decrease in southern and eastern Europe (medium confidence⁶). [5.4.3] Upward and northward shift of biotic zones will take place. Loss of important habitats (wetlands, tundra, isolated habitats) would threaten some species (high confidence⁶). [5.4.2] Higher temperatures and heat waves may change traditional summer tourist destinations, and less reliable snow conditions may impact adversely on winter tourism (medium confidence⁶). [5.4.4]

Latin America	Adaptive capacity of human systems in Latin America is low, particularly with respect to extreme climate events, and vulnerability is high. [5.5] Loss and retreat of glaciers would adversely impact runoff and water supply in areas where glacier melt is an important water source (high confidence⁶). [5.5.1] Floods and droughts would become more frequent with floods increasing sediment loads and degrade water quality in some areas (high confidence⁶). [5.5] Increases in intensity of tropical cyclones would alter the risks to life, property, and ecosystems from heavy rain, flooding, storm surges, and wind damages (high confidence⁶). [5.5] Yields of important crops are projected to decrease in many locations in Latin America, even when the effects of CO₂ are taken into account; subsistence farming in some regions of Latin America could be threatened (high confidence⁶). [5.5.4] The geographical distribution of vector-borne infectious diseases would expand poleward and to higher elevations, and exposures to diseases such as malaria, dengue fever, and cholera will increase (medium confidence⁶). [5.5.5] Coastal human settlements, productive activities, infrastructure, and mangrove ecosystems would be negatively affected by sea-level rise (medium confidence⁶). [5.5.3] The rate of biodiversity loss would increase (high confidence⁶). [5.5.2]

North America	Adaptive capacity of human systems is generally high and vulnerability low in North America, but some communities (e.g., indigenous peoples and those dependent on climate-sensitive resources) are more vulnerable; social, economic, and demographic trends are changing vulnerabilities in subregions. [5.6 and 5.6.1] Some crops would benefit from modest warming accompanied by increasing CO₂, but effects would vary among crops and regions (high confidence⁶), including declines due to drought in some areas of Canada's Prairies and the U.S. Great Plains, potential increased food production in areas of Canada north of current production areas, and increased warm-temperate mixed forest production (medium confidence⁶). However, benefits for crops would decline at an increasing rate and possibly become a net loss with further warming (medium confidence⁶). [5.6.4] Snowmelt-dominated watersheds in western North America will experience earlier spring peak flows (high confidence⁶), reductions in summer flows (medium confidence⁶), and reduced lake levels and outflows for the Great Lakes-St. Lawrence under most scenarios (medium confidence⁶); adaptive responses would offset some, but not all, of the impacts on water users and on aquatic ecosystems (medium confidence⁶). [5.6.2] Unique natural ecosystems such as prairie wetlands, alpine tundra, and cold-water ecosystems will be at risk and effective adaptation is unlikely (medium confidence⁶). [5.6.5] Sea-level rise would result in enhanced coastal erosion, coastal flooding, loss of coastal wetlands, and increased risk from storm surges, particularly in Florida and much of the U.S. Atlantic coast (high confidence⁶). [5.6.1] Weather-related insured losses and public sector disaster relief payments in North America have been increasing; insurance sector planning has not yet systematically included climate change information, so there is potential for surprise (high confidence⁶). [5.6.1] Vector-borne diseases -- including malaria, dengue fever, and Lyme disease -- may expand their ranges in North America; exacerbated air quality and heat stress morbidity and mortality would occur (medium confidence⁶); socioeconomic factors and public health measures would play a large role in determining the incidence and extent of health effects. [5.6.6]

Polar	Natural systems in polar regions are highly vulnerable to climate change and current ecosystems have low adaptive capacity; technologically developed communities are likely to adapt readily to climate change, but some indigenous communities, in which traditional lifestyles are followed, have little capacity and few options for adaptation. [5.7] Climate change in polar regions is expected to be among the largest and most rapid of any region on the Earth, and will cause major physical, ecological, sociological, and economic impacts, especially in the Arctic, Antarctic Peninsula, and Southern Ocean (high confidence⁶). [5.7] Changes in climate that have already taken place are manifested in the decrease in extent and thickness of Arctic sea ice, permafrost thawing, coastal erosion, changes in ice sheets and ice shelves, and altered distribution and abundance of species in polar regions (high confidence⁶). [5.7] Some polar ecosystems may adapt through eventual replacement by migration of species and changing species composition, and possibly by eventual increases in overall productivity; ice edge systems that provide habitat for some species would be threatened (medium confidence⁶). [5.7] Polar regions contain important drivers of climate change. Once triggered, they may continue for centuries, long after greenhouse gas concentrations are stabilized, and cause irreversible impacts on ice sheets, global ocean circulation, and sea-level rise (medium confidence⁶). [5.7]

Small Island States	Adaptive capacity of human systems is generally low in small island states, and vulnerability high; small island states are likely to be among the countries most seriously impacted by climate change. [5.8] The projected sea-level rise of 5 mm yr^-1 for the next 100 years would cause enhanced coastal erosion, loss of land and property, dislocation of people, increased risk from storm surges, reduced resilience of coastal ecosystems, saltwater intrusion into freshwater resources, and high resource costs to respond to and adapt to these changes (high confidence⁶). [5.8.2 and 5.8.5] Islands with very limited water supplies are highly vulnerable to the impacts of climate change on the water balance (high confidence⁶). [5.8.4] Coral reefs would be negatively affected by bleaching and by reduced calcification rates due to higher CO₂ levels (medium confidence⁶); mangrove, sea grass bed, and other coastal ecosystems and the associated biodiversity would be adversely affected by rising temperatures and accelerated sea-level rise (medium confidence⁶). [4.4 and 5.8.3] Declines in coastal ecosystems would negatively impact reef fish and threaten reef fisheries, those who earn their livelihoods from reef fisheries, and those who rely on the fisheries as a significant food source (medium confidence⁶). [4.4 and 5.8.4] Limited arable land and soil salinization makes agriculture of small island states, both for domestic food production and cash crop exports, highly vulnerable to climate change (high confidence⁶). [5.8.4] Tourism, an important source of income and foreign exchange for many islands, would face severe disruption from climate change and sea-level rise (high confidence⁶). [5.8.5]
^a Because the available studies have not employed a common set of climate scenarios and methods, and because of uncertainties regarding the sensitivities and adaptability of natural and social systems, the assessment of regional vulnerabilities is necessarily qualitative. ^b The regions listed in Table SPM-2 are graphically depicted in Figure TS-2 of the Technical Summary.

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