This project is under the MOST Key International Program, with the largest amount of funding so far for IAP. The total fund for this project was 17 million yuan， with Academician Shi Guangyu acting as the projectleader. The China-Japan cooperation has reduced uncertainty in the study on climate change, pushed forward the control over greenhouse gases and popularization of emission reduction technologies, and provided scientific decision-making basis for controlling the air quality, dealing with climate changes and reducing emissions of greenhouse gases. This project has three major tasks : atmospheric composition and climatic changes, study on impact of climate changes, study on countermeasures for climate changes. It is intended to solve those key S&T problems, or hot or difficult national issues.