The immediate environmental problems facing China, from polluted water to smog-filled air, are so pressing that the longer-term issue of the impact from global warming has not often received a wide hearing.
The issue is slowly becoming more prominent, with the likely publication of Chinese government research showing that higher temperatures could reduce water supplies and seriously damage agriculture, two of the most politically sensitive subjects in the country.
At the end of last year state newspapers published highlights from a government inquiry into the probable consequences of global warming, due to be published in full this year. Rising temperatures will aggravate persistent water shortages in northern China and provoke “extreme weather events”, according to a statement from the Ministry of Science and Technology.
“The most direct impact of climate change will be on China’s grain production,” Luo Yong, the deputy director of the National Climate Centre, was quoted as saying in Science Times, a newspaper attached to the Chinese Academy of Science.
The full report could stir wider debate on the impact of climate change on China, which is the second biggest emitter of greenhouse gases after the US.
Although China has committed itself to improving its energy efficiency and has backed the UN-brokered Kyoto treaty, from whose provisions it is exempted, government officials routinely argue that primary responsibility for reducing carbon emissions lies with developed nations.
However, China’s politicians are already trying to cope with a severe water shortage, especially in the north of the country, which is the result of pollution and over-use of surface water resources.
More than a quarter of China’s land is now desert, putting greater pressure on remaining arable land, while Beijing and Shanghai have less fresh water available per capita than Israel or Jordan, according to a report by CLSA, the Hong Kong-based brokerage.
Food security, especially in grains, has long been a key strategic goal of the Chinese communists. President Hu Jintao has made raising rural incomes a priority.
In the past, Chinese scientists have been uncertain about the impact of higher temperatures on farming, especially in the northern regions where much of the country’s grain is grown.
Ren Guijie, the chief researcher at the China National Meteorological Bureau, argued last year that higher temperatures had allowed agriculture in north-east China to avoid the fierce cold and dry spells that damaged harvests in the 1960s and 1970s. Other scientists have suggested that increased rainfall might outweigh the other costs of higher temperatures. However, according to Chinese media reports, the official assessment will not be so sanguine. Mr Luo said Chinese grain output could fall by 10 per cent a year from 2030 because of climate changes, which would reduce the amount of water available and increase incidence of pests. The report also warns of the risk of more frequent flooding and landslides in southern China.
Chinese scientists warned yesterday about the impact of rising temperatures on the Qinghai-Tibet plateau – sometimes known as the “Roof of the World”.
Xu Xiangde, a researcher at the Chinese Academy of Meteorological Sciences, said warmer weather could alter the amount of water flowing into the Yangtze and Yellow rivers, which originate in the region. Changes in the amount of water vapour above the plateau could have provoked floods in other parts of the country, he said