Asia’s great cities face rising flooding risks in warming world
Last updated on 26 March 2014, 8:32 am
NEWS: Draft of IPCC’s forthcoming report highlights rising seas as acute risk for China, India, Thailand and Vietnam
By Ed King
Some of Asia’s main cities could be under siege from rising sea levels by the end of the century, a UN panel of scientists is set to warn later this week.
Kolkata, Mumbai, Dhaka, Ho Chi Minh City, Shanghai, Bangkok and Rangoon are among those most at risk, drafts of the Intergovernmental Panel on Climate Change’s forthcoming report suggest.
Rice and maize yields could also decline if temperatures rise and coastal growing regions are submerged, although winter wheat yields could increase.
The findings will be discussed at a meeting of the IPCC in Yokohoma, Japan, before their final approval and publication on March 31.
Below are some of the key findings related to Asia from the IPCC draft text.
-Central Asia is expected to become warmer and increasingly arid, especially in the western parts of Turkmenistan, Uzbekistan, and Kazakhstan
-The Indo-Gangetic Plains (India), which produce about 14-15% of global wheat, could suffer significant reductions due to climate change-induced heat stress.
-The most vulnerable regions for reduced rice yield is projected for western Japan, eastern China, the southern part of the Indochina peninsula, and the northern part of South Asia.
-Sea-level rise threatens coastal and deltaic rice production areas in Asia, such as those in Bangladesh, Myanmar, and the Mekong River Delta. For example, about 7% of Vietnam’s agricultural land may be submerged due to sea-level rise.
-Winter wheat yields could increase in some areas, such as Huang-Huai-Hai Plain, China’s most productive wheat growing region, due to warmer night temperatures and higher precipitation.
-Maize yield could decrease by 25% by the 2080s (compared to 1961-1990) in the North China Plain.
– Warming ocean temperatures, ocean acidification, and the loss of coral reefs would greatly decrease the abundance of marine fisheries, negatively affecting many countries in south and southeast Asia.
– By the 2070s, the top Asian cities in terms of population exposure (including all environmental and socioeconomic factors) to coastal flooding are expected to be Kolkata, Mumbai, Dhaka, Guangzhou, Ho Chi Minh City, Shanghai, Bangkok, Rangoon, and Hai Phòng.
– The top Asian cities in terms of assets exposed are expected to be Guangdong, Kolkata, Shanghai, Mumbai, Tianjin, Tokyo, Hong Kong, and Bangkok.
Health and poverty
-Climate change impacts such as increased flooding and extreme weather events will likely lead to deteriorated drinking water quality, mosquito proliferation, increased exposure to rodent-borne pathogens and intermediate snail hosts of Schistosoma.
– Severe child stunting because of malnutrition is projected to increase by 62% in South Asia by 2050 without accelerated investment in planned adaptation.
-Mosquito-borne diseases such as dengue fever, Japanese encephalitis, and Chikungunya fever are likely to increase with warming temperatures and precipitation changes in some areas.
-If climate change reduces crop productivity, producers in food exporting countries, such as Indonesia, the Philippines, and Thailand, would benefit from global food price rises and reduce poverty, while countries such as Bangladesh would experience a net increase in poverty of 15% by 2030.
– Drought-induced fires will increase the vulnerability of agriculture, forestry and human settlements, particularly in peatland areas in Indonesia.
-Boreal forests are expected to expand northward and eastward at the expense of the tundra.
-Snow leopard habitat in the Himalayas is expected to contract by up to 30% as forests replace open habitats.
– Increased droughts will also impact lowland Southeast Asia, and together with logging and fire, could greatly increase the vulnerability of this already fragmented landscape to fire, smoke, and air pollution.
-Permafrost likely to decrease 20-90% by 2100 in North Asia and the Qinghai-Tibet Plateau.
-Sea-level rise of 0.5 m over this century is projected to erode coastlines that are composed of loose permafrost rocks, such as along the Laptev Sea, East Siberian Sea, and West Yamal in the Kara Sea.
-Climate change may further complicate the unsustainable consumption of groundwater for irrigation and other uses in some locations, such as the Indian states of Rajasthan, Punjab, and Haryana.
– Decreasing precipitation will exacerbate the growing population and expanding water withdrawal, ultimately leading to more water scarcity in northern China.