2.2 Impact of Climate Change on China
2.2.1 Impacts on agriculture and livestock industry
Climate change has already had certain impacts on agriculture and livestock industry in China, primarily shown by the two-to-four-day advancement of spring phenophase since the 1980s. Future climate change can affect agriculture and livestock industry in the following ways: increased instability in agricultural production, where the yields of three main crops, i.e. wheat, rice and maize, are likely to decline if no proper adaptation measures are taken; changes in distribution and structure of agricultural production as well as in cropping systems and varieties of the crops; changes in agricultural production conditions that may cause drastic increase in production cost and investment need; increased potential in aggravation of desertification, shrinking grassland area and reduced productivity that result from increased frequency and duration of drought occurrence due to climate warming; and potentially increased rate in disease breakout for domestic animals.
2.2.2 Impact on forest and other natural ecosystems
Climate change has brought impacts on forests and other natural ecosystems in China. For example, the glacier area in the northwestern China shrunk by 21 percent and the thickness of frozen earth in Qinghai-Tibet Plateau reduced a maximum of four to five meters in the recent 50 years. Future climate change will continue to impact these ecosystems to some extent. Firstly, the geographical distribution of major forest types will shift northward and the vertical spectrum of mountain forest belts will move upward. The distribution range of major tree species for afforestation or reforestation and some rare tree species is likely to shrink. Secondly, forest productivity and output will increase to different extents, by 1-2 percent in tropical and subtropical forests, about 2 percent in warm temperate forests, 5-6 percent in temperate forests, and approximately 10 percent in cold temperate forests. Thirdly, the frequency and intensity of forest fires and insect and disease outbreaks are likely to increase. Fourthly, the drying of inland lakes and wetlands will accelerate. A few glacier-dependent alpine and mountain lakes will eventually decrease in volume. The area of coastal wetlands will reduce and the structure and function of coastal ecosystems will be affected. Fifthly, the area of glaciers and frozen earth is expected to decrease more rapidly. It is estimated that glacier in western China will reduce by 27.7 percent by the year 2050, and the spatial distribution pattern of permafrost will alter significantly on Qinghai-Tibet Plateau. Sixthly, snow cover is subjected to reduction largely with significantly larger inter-annual variation. Seventhly, biodiversity will be threatened. The giant panda, Yunnan snub-nose monkey, Tibet antelope and Taiwania flousiana Gaussen are likely to be greatly affected.
2.2.3 Impact on water resources
Climate change has already caused the changes of water resource distribution over China. A decreasing trend in runoff was observed during the past 40 years in the six main rivers, namely the Haihe River, the Huaihe River, the Yellow River, the Songhuajiang River, the Yangtze River, and the Pearl River. Meanwhile, there is evidence for an increase in frequency of hydrological extreme events, such as drought in the north and flood in the south. The Haihe-Luanhe river basin is the most vulnerable region to climate change, followed by the Huaihe River basin and the Yellow River basin. The arid continental river basins are particularly vulnerable to climate change. In the future, climate change will have a significant impact on water resources over China: in the next 50-100 years, the mean annual runoff is likely to decrease evidently in some northern arid provinces, such as Ningxia Hui Autonomous Region and Gansu Province, while it seems to increase remarkably in a few already water-abundant southern provinces, such as Hubei and Hunan provinces, indicating an increase of flood and drought events due to climate change; the situation of water scarcity tends to continue in the northern China, especially in Ningxia Hui Autonomous Region and Gansu Province, where water resource per capita is likely to further decrease in the future 50-100 years; providing that water resources are exploited and utilized in a sustainable manner, for most provinces, water supply and demand would be basically in balance in the future 50-100 years. However, gap between water resource supply and demand might be expanded in Inner Mongolia Autonomous Region, Xinjiang Uygur Autonomous Region, Gansu Province and Ningxia Hui Autonomous Region.
2.2.4 Impact on the coastal zone
Climate change has brought certain impacts on the coastal environment and ecosystems of China to some extent, mainly represented by the accelerating trend of sea level rise along the Chinese coast in the past 50 years, which resulted in coastal erosion and seawater intrusion, as well as mangrove and coral reef degradation. The future climate change will have even greater impact on the sea level and coastal ecosystems of China. Firstly, the sea level along the Chinese coast will continue to rise. Secondly, the frequency of typhoon and storm surge will increase, aggravating the hazards induced by coastal erosion. Thirdly, some typical marine ecosystems, including coastal wetlands, mangroves and coral reefs, will be further damaged.
2.2.5 Impacts on other sectors
Climate change may increase the frequency and intensity of the heat waves, hence increase deaths and serious diseases induced by extreme high temperature events. Climate change is likely to stimulate the emergence and spread of some diseases and to increase the magnitude and scope of diseases like cardiovascular diseases, malaria, dengue fever and heatstroke, endangering human health. Meanwhile, climate change tends to increasingly impact China's medium-sized to large projects, due to the increase of extreme weather and climate events and related hazards. Similarly, climate change may greatly harm natural and human tourism resources, as well as tourism security in some areas. In addition, global warming will exacerbate the increasing trend of electricity consumption for air conditioning and impose greater pressure to electric power supply.