The ecological security in Tibetan plateau is the important part of state ecological security, which is also a main ecological protective screen for our country and even Asia. However, the ecological environment in Tibetan plateau is very sensitive, so scientists from Cold and Arid Regions Environmental and Engineering Research Institute (CAREERI) used the method of the ecological footprint to summarize the processes and characteristics of the ecological change in the Tibetan plateau. 

The research on ecological footprint and carrying capacity is a crucial basis for the settlement of environment deterioration and the realization of regional sustainable development. Based on ecological footprint models, this research estimated the ecological footprint and carrying capacity of Tibet during 2005-2010. 

According to the land use properties in Tibet, the following six types were categorized: fossil fuel land, arable land, grassland, woodland, waters and construction area. Scientists found that the average ecological footprint per capita of Tibet increased from 0.34 hm²per capita in 2005 to 0.83 hm²per capita in 2010. Among the above six land use types, woodland consumption was the most important part, accounting for 39.8% of the total consumption. The average arable land consumption per capita stayed relatively stable, from 0.18 to 0.2 hm²per capita in 2010. The ecological caring capacity per capita of woodland, grassland and fossil fuel lands accounted for 95% of the total capacity, and those of the former two and the arable land tended to decrease slowly during the study period. The average ecological caring capacity per capita of water area did not very much. The average ecological surplus per capita is relatively large, though it decreased from 14.44 hm²per capita in 2005 to 12.94 in 2010. 

The largest part of Tibetan ecological surplus was observed in woodland in which drastic fluctuations in ecological footprint were found. The ecological footprint of woodland and grassland accounts for 1%-30% and 5% of the overall carrying capacity, respectively. The ecological footprint of water area can be negligible due to its small amount. In all, the ecological footprint is much lower while the carrying capacity is much higher than the average values of China or the whole world, indicating that the economic development level of Tibet is still in a primary stage and there still exist great development potential. 

However, the ecological surplus tended to decrease during the last six years, suggesting that the environment deterioration does occur in some regions where the ecosystem maybe vulnerable. Therefore, when we are concentrating on the economic development of Tibet, we should pay close attention to the dangers brought by environment deterioration, which will ensure the sustainable development of resources and environment. 

This research is financially supported by the Major National Scientific Research Projection Global Change(Grant No. 2010CB951702) and the Strategic Leading Science and Technology Projects of the Chinese Academy of Sciences (B type) (Grant No. XDB03030100). This paper has been published on the journal of Acta Ecologica Sinica, Vol. 34, No. 4, Feb., 2014.