China Water Resources

In understanding the effect of human activity on the global climate change for recent 100 years, IPCC (Intergovernmental Panel on Climate Change) has played a key role. During 17 years from 1990, IPCC has continuously gained insight into better understanding on the global climate change during the recent 100 years mainly caused by human activity, with its four assessment reports. This achievement has been made with provision of three aspects of evidences: (1) rapid increase in greenhouse gases since preindustrial era (after 1750); (2) temperature rise or warning of surface, tropospospere and oceans; (3) 100-yr climate simulations since 1900 for detection and attribution of the past climate change. These results have shown that recent 100-yr warming is jointly caused by natural climate fluctuation and anthropogenic activity, but most of recent 50-yr climate change is caused by the authropogenic activity. The present paper has first reviewed this issue. Then, the debates and uncenrtainties of global climate change issue have been discussed. The global climate change has had a significant impact on global water resources and management. This issue is further discussed based on changes in temperature, precipitation, sea level rise and evapotranspiration, which may be a necessary scientific basis for adaptation.