Climate Change over the Qinghai-Tibet Plateau and Its Impacts on Local Agriculture and Animal Husbandry in the Last 50 Years

Annual average trends of average temperature, minimum temperature, maximum temperature, and precipitation on a daily timescale from 47 stations across Qinghai and Tibet during the period 1961-2010 were analyzed using the least square method. Impacts on local agriculture and animal husbandry caused by changes in temperature, precipitation, and other climatic factors were discussed. In general, the Qinghai-Tibetan plateau showed an increasing trend in temperatures, with the magnitude of increase in average daily minimum temperature greater than that of average daily maximum temperature. In addition, annual average temperature increased during the past five decades. There was a small increase of 0.3℃/10a in southeast Tibet. Northern Tibet, and southern and northern Qinghai showed a (0.3~0.4)℃/10a increasing trend. A increasing rate of (0.5~0.9)℃/10a occurred in Lhasa and Nagqu in central Tibet, and Golmud and Mangya in northwestern Qinghai. There was an increasing trend of (0.4~0.5)℃/10a at Banma and other observational stations across southeast Qinghai. The amount of precipitation in the Tibetan Plateau gradually declined from southeast to northwest, mainly concentrated in the south-eastern Tibetan Plateau, Brahmaputra valley agricultural areas, and forestry areas in eastern Tibet. Southeast and northwest Qinghai showed an increase in precipitation of less than 5 mm/10a. Northern Tibet and southern and northern Qinghai ranged (5~10)mm/10a. Over central Tibet and north-central of Qinghai, precipitation mainly increased at rates of (10~20)mm/10a. Individual sites over the southeastern Tibetan Plateau showed increasing trends in precipitation larger than 20 mm/10a. However, most parts of the northwest of the entire Tibetan Plateau did not have rainfall, with the rainfall being in accordance with the distribution of pastures in the plateau. Climate warming would lead to increases in evapotranspiration from agriculture and ecological systems. Changes in spatial and temporal distributions of precipitation would change effective utilization of vegetation, thereby affecting agricultural and ecological purposes. The permafrost was reducing regionally as well as plateau wetlands. Increased winter temperatures, on the one hand, would accelerate the growth rate of winter wheat. On the other hand, rising temperatures would lead to increased demand for agricultural water use. Degrading capacity to adapt to climate change due to desertification of pastures, degradation of wetland permafrost, increases in unstable climatic factors, and abnormal weather would lead to significant adverse effects to agriculture and animal husbandry over the study regions.