## 3 Environmental Changes on Grasslands of the QTP under Global Change  
An analysis of impacts of climate change on the grassland ecosystems of the Qinghai-Tibet Plateau (QTP) shows that the grasslands are sensitive to climate change and human disturbance [20; 24]. This huge geographic region is also known as the \"Third Pole\". The ecosystems on the QTP play important roles in servicing the ecological environment and regional (SE Asian) socio-economic development and in the maintenance of biodiversity of plants and animals [39; 40]. The grasslands of the QTP are the core of the water cycle, and their health directly affects the flux of water and water conservation capacity. In terms of glacier water, the glacier area is about 49,873 km\({}^{2}\) and ice reserves about 4561 km\({}^{3}\). The frozen soil area is \(2.7\times 10^{6}\) km\({}^{2}\), accounting for 46% of the total Qinghai-Tibetan Plateau land area. The groundwater in the QTP is the source of runoff water of many surrounding low altitude areas. The lake census showed that there are 32,843 lakes with a total area of 43,151 km\({}^{2}\), which makes up 1.4% of the total area of the Plateau. Around 96% of all lakes are small, with an area \(<\)1 km\({}^{2}\), while the 1204 large lakes (\(>\)1 km\({}^{2}\)) account for a small percentage of the total area of lakes [41]. Climate change has already produced visible adverse effects on agriculture and livestock-raising sectors, manifested by increased instability in agricultural production, severe damage to crops and livestock breeding caused by drought and high temperature in some parts of the QTP. Moreover, under the background of climate change, herders have to adapt to the changes in terms of their production pattern as well as livelihood style. Therefore, understanding the effect of climate change on grassland production and response of herders to climate change is vital to improve grassland management on the QTP [1; 42; 43; 44]. From 1951 to 2009, the ground surface temperature increased on average by 1.38 \({}^{\circ}\)C in China, the warming rates is 0.23 \({}^{\circ}\)C per 10 years, which is similar to the level of global warming. The warming on the QTP was greater than in other regions, especially in winter and spring. Most regions of QTP, including Xizang (Tibet) and Qinghai Province, have a greater warming rate compared to other regions. The climate in west and north QTP has changed from warmer-wetter to warmer-dryer, however, the climate in the east and south of the QTP has changed from warmer-dryer to warmer-wetter [38; 41; 42; 43]. The precipitation on the QTP was generally rising in the 30 years ending 2012 (12.4 mm per 10 years) [42; 45; 46], in particular in the north of the QTP. The depth snow and the number of days with snow cover on the QTP increased from 1961 to 1990 and decreased from 1991 to 2005 [37; 44; 45]. IPCC [44] reported that the occurrence of extreme events is rising due to climate change. The snow disaster was also rising in recent years. Snow disaster or _dzud_ (in Mongolian language and _kengschi_ in Tibetan) is where deep snow, severe cold or other conditions make forage inaccessible or unavailable and leads to high livestock mortality. _Dzud_ is a recurring natural event that limits the growth of livestock populations on the QTP, but it also causes loss of human life and livelihoods. In the _dzud_ events of 1999-2002 and 2009-2010 the QTP lost 30% and 20% of the entire livestock flocks/herds, respectively, creating significant challenges for herders and rural communities who service the herders and their families. A herder's sole source of income can be wiped out by a _dzud_. On the QTP there are over one million herders and their families. In the 60 years ending in 2012, the snow disaster occurred 30 times in Qinghai Province, among them, severe snow disaster occurred 12 times and extreme snow disaster six times.