The Qinghai-Tibet Plateau (QTP), known as the Earth's third pole, is highly sensitive to climate change. Various environmental degradation has occurred due to the effects of climate warming such as the degradation of permafrost and the thickening of active layers. Evapotranspiration, as a key element of hydrothermal coupling, has become a key factor of the plateau environment for deciphering deterioration, and the FAO P-M model has a good physical foundation and simple model data requirements as a primary tool to study the plateau evapotranspiration. There has been a large research base, but the estimation of evapotranspiration in alpine regions is still subject to many uncertainties. This is reflected in the fact that the classification of underlying surface types has not been sufficiently detailed and the evapotranspiration characteristics of some special underlying surface types are still unclear. Therefore, in this work, we modified the FAO P-M coefficients based on the characteristics of actual evapotranspiration measured by the Eddy covariance system and the key influencing factors to better simulate the actual evapotranspiration in alpine swamp meadow. The results were as follows: (1) Both ETa measured by the Eddy covariance system and ET0 calculated by FAO P-M showed the same trend at the daily and annual scales and hysteresis was confirmed to exist, so the error caused by hysteresis should be considered in further research. (2) The annual ETa was 566.97 mm and annual ETa/P was 0.76, and about 11.19% of ETa occurred during the night. The ETa was 2.15 during the non-growing seasons, implying that a large amount of soil water was released into the air by evapotranspiration. (3) The evapotranspiration characteristics of alpine swamp meadow are formed under the following conditions: control of net radiation (R-n) affected by VPD during the growing season and affected by soil temperature and humidity during the non-growing season. Precipitation and soil water content are no longer the main controlling factors of evapotranspiration during the growing season at the alpine swamp meadow as the volume soil water content tends to saturate. (4) The basic corrected K-c was 1.14 during the initial and mid-growing season, 1.05 during the subsequent growing season, and 0-0.25 during the non-growing season, and the correction factor process can also provide ideas for correcting the K-c of other vegetation.

Global climate change has already had observable effects on the environment. For instance glaciers have shrunk, ice on rivers and lakes is breaking up earlier, lands are deteriorating, plant and animal ranges have shifted and trees are flowering sooner. Carbon emission is considered as the strongest factor for global warming. Removing atmospheric carbon and storing it in the terrestrial biosphere is one of the cost-effective options, to compensate greenhouse gas emissions. Millions of acres of abandoned mine land throughout the world, if restored and converted into vegetative land, would solve global warming and would remediate degraded wastelands. Reclamation of mining wastelands using an integrated-biotechnological approach (IBA) has resulted in the improvement in the physicochemical properties of the soil. The findings presented in this chapter may help the industries to achieve clean development mechanism status through afforestation of degraded lands as per the guidelines of United Nations Framework Convention on Climate Change.