接 UN DPI/NGO部主任Jeffery Huffines博士来函, 本所潘根兴教授代表中国科协系统科学家为联合国６０届非政府组织年会"气候变化如何影响我们"撰写的"Danger of Climatic Change to China’s agriculture and Environmental Protection: Accelerating the vulnerability of food production and Economy＂一文已经被选编大会论文出版, 这是中国唯一的一篇非政府科学家对气候变化问题的见解的论文。
论文内容如下：
Danger of Climatic Change to China’s agriculture and Environmental Protection: Accelerating the vulnerability of food production and Economy
Pan Genxing(1) Yu Xiaoxiao(2)
1, Inst. Resources and Environment of Agricukture, Nanjing Agric. University, Nanjing, 210095-China; 2, Department of International Cooperation, Chinese Association for Science and Technology, 3 Fuxing Road, Beijing 1000863- China(yuxiaoxiao@cast.org.cn)
The issue of Global Climate change has been widely introduced and the damages caused by or related to climate change have been frequently experienced in China. Climate change has impacted the vulnerability of agriculture in China. Rapid and frequent changes in rainfall and temperature caused greater variability of cereals production in China in the last 10 years. Some of the effort of increasing input for enhancing the productivity has been probably offset by the climate change. As recorded in Atlas of China’s Agriculture, the mean cereals production by per kg of fertilizer nutrient input declined to 11.8 kg in the last 10 years from 14.6 kg in 1990-1995. While the rice production of whole China has kept relatively constant, the variability of other cereals production has been greatly increased under the impact of climate changes. The yield of wheat and corn, mostly produced in North and Northeast China with sensitivity to global climatic change, varied at a deviation of 22% and 30% in last 10 years compared to 18% and 19% in 1990’s respectively. However, a study on the sustainability of rice paddy under different fertilization by Nanjing Agric. University in a long-term agro-ecosystem experiment has proven a trend of decreasing rice yield stability over the last 10 years even in the Tai Lake region where paddy rice has been very high-yielding and kept generally constant. Rice yield has been decreased to 6.69±1.40t/ha under chemical fertilization and 8.45±1.23t/ha under combined fertilization of organic and inorganic fertilizers in 1996-2006 from 7.91±0.98 t/ha and 8.62±1.15t/ha in 1987- 1995 respectively. Thus, it could be expected that the climatic change would inevitably enhance the vulnerability of China’s agriculture superimposing the problems of decline in good quality arable lands and water shortage. Struggle for stabilizing higher yield of cereals will be a long term challenge for China for feeding its increasing huge population.
Climate change has also caused unexpected problems of water scarcity in China’s agriculture, particularly of South China where total annual rainfall are generally high. Due to the increasing frequency of El Nino events, severe droughts and water scarcity from early autumn to late spring have happened in southern China executively in the years of 2003-2007. Predictions reported by USA meteorological agencies on potential huge drought disasters in South China around 2010 has introduced a huge threaten to Chinese farmers concerning the survival of rice-based agriculture. As an example, a severe drought in 2003 which was the biggest one in the last 50 years has damaged croplands of 3.7Mha and 3.7M people in shortage of drinking water. Again in 2007, a drought in spring over the extensive areas of southern China has caused damage to 2.6 Mha of crops and nearly 10 M people in shortage of drinking water. The problem of drought and drinking water scarcity has greatly increased the cost-off of the agricultural production and living expenses for farmers and thus, will further enhance the poverty of the farmers particularly in the provinces such as of Hunan, Jiangxi and Chongqing with less developed economy. As a countermeasure, small dams are extensively under construction in local areas of southern China for storage and reallocation of water resources, and tap water pipelines are extending from the city and towns to countryside villages. These are among the capacity building facilities for improving the ability of farmers to fight against the meteorological disasters due to climate change in the future.
Pollution and eutrophication of waters has been Accelerated for the last years as affected by the drought and warming in early spring due to El Nino in southern China especially in the region of northern subtropical region of the Yangtze and Huai River valleys. In these regions, water pollution and eutrophication disasters have happened increasingly since 1990’s as an increasing trend of early spring air and water temperature has been observed, facilitating the nutrient release from terrestrial and benthic soils and the vigorous growth of blue algae. In the Tai Lake, water temperature was increased to 19.6 centigrade in late April (highest over the last 25 years), blooming of blue algae became extended on the declining water body due to the spring drought. Scientist attributed the severe water pollution from blue algae blooming in spring of 2007 to the interactive effects of warming, spring drought on the concentrated with N and P in waters, all of which could be related to global climate change. This problem has impacted on drinking water scarcity in both urban and rural regions of Yangtze valley in 2007 and caused a uncountable economic loss due to cost-off of enhanced water treatment and decline of fishery production and tourism. In the future, the climate change induced or related pollution of waters may become an increasing threaten to the public society superimposing the spring drought and the summer flood in the Yangtze and Huai River valleys. A state project to assess the overall effect of global climate change on the economical sectors in the Yangtze valley has been initiated for developing relevant countermeasures to diminishing such dangers.
