IPCC Fourth Assessment Report: Climate Change 2007
Climate Change 2007: Working Group II: Impacts, Adaptation and Vulnerability

Executive summary

New evidences show that climate change has affected many sectors in Asia (medium confidence).

The crop yield in many countries of Asia has declined, partly due to rising temperatures and extreme weather events. The retreat of glaciers and permafrost in Asia in recent years is unprecedented as a consequence of warming. The frequency of occurrence of climate-induced diseases and heat stress in Central, East, South and South-East Asia has increased with rising temperatures and rainfall variability. Observed changes in terrestrial and marine ecosystems have become more pronounced (medium confidence). [10.2.3, 10.2.4]

Future climate change is likely to affect agriculture, risk of hunger and water resource scarcity with enhanced climate variability and more rapid melting of glaciers (medium confidence).

About 2.5 to 10% decrease in crop yield is projected for parts of Asia in 2020s and 5 to 30% decrease in 2050s compared with 1990 levels without CO2 effects (medium confidence) []. Freshwater availability in Central, South, East and South-East Asia, particularly in large river basins such as Changjiang, is likely to decrease due to climate change, along with population growth and rising standard of living that could adversely affect more than a billion people in Asia by the 2050s (high confidence) [10.4.2]. It is estimated that under the full range of Special Report on Emission Scenarios (SRES) scenarios, 120 million to 1.2 billion will experience increased water stress by the 2020s, and by the 2050s the number will range from 185 to 981 million people (high confidence) []. Accelerated glacier melt is likely to cause increase in the number and severity of glacial melt-related floods, slope destabilisation and a decrease in river flows as glaciers recede (medium confidence) [,]. An additional 49 million, 132 million and 266 million people of Asia, projected under A2 scenario without carbon fertilisation, could be at risk of hunger by 2020, 2050 and 2080, respectively (medium confidence) [].

Marine and coastal ecosystems in Asia are likely to be affected by sea-level rise and temperature increases (high confidence).

Projected sea-level rise is very likely to result in significant losses of coastal ecosystems and a million or so people along the coasts of South and South-East Asia will likely be at risk from flooding (high confidence) []. Sea-water intrusion due to sea-level rise and declining river runoff is likely to increase the habitat of brackish water fisheries but coastal inundation is likely to seriously affect the aquaculture industry and infrastructure particularly in heavily-populated megadeltas (high confidence) [,]. Stability of wetlands, mangroves and coral reefs around Asia is likely to be increasingly threatened (high confidence) [, 10.6.1]. Recent risk analysis of coral reef suggests that between 24% and 30% of the reefs in Asia are likely to be lost during the next 10 years and 30 years, respectively (medium confidence) [].

Climate change is likely to affect forest expansion and migration, and exacerbate threats to biodiversity resulting from land use/cover change and population pressure in most of Asia (medium confidence).

Increased risk of extinction for many flora and fauna species in Asia is likely as a result of the synergistic effects of climate change and habitat fragmentation (medium confidence) []. In North Asia, forest growth and northward shift in the extent of boreal forest is likely (medium confidence) [10.4.4]. The frequency and extent of forest fires in North Asia is likely to increase in the future due to climate change that could likely limit forest expansion (medium confidence) [10.4.4].

Future climate change is likely to continue to adversely affect human health in Asia (high confidence).

Increases in endemic morbidity and mortality due to diarrhoeal disease primarily associated with climate change are expected in South and South-East Asia (high confidence). Increases in coastal water temperature would exacerbate the abundance and/or toxicity of cholera in south Asia (high confidence). Natural habitats of vector-borne and water-borne diseases in north Asia are likely to expand in the future (medium confidence). [10.4.5]

Multiple stresses in Asia will be compounded further due to climate change (high confidence).

It is likely that climate change will impinge on sustainable development of most developing countries of Asia as it compounds the pressures on natural resources and the environment associated with rapid urbanisation, industrialisation and economic development. Mainstreaming sustainable development policies and the inclusion of climate-proofing concepts in national development initiatives are likely to reduce pressure on natural resources and improve management of environmental risks (high confidence) [10.7].