In recent 100 years, the global climate and environment have greatly changed, with the global warming as its main feature. These changes have exerted significant impacts on the climate and environment changes in China. More than 100 Chinese scientists in areas of climate change, environment, ecology, oceanography, economics and social sciences have assessed the climate and environment changes in China and their impact on natural ecosystem and socioeconomic sectors. On the basis of scientific assessment, response strategy to the adaptation and mitigation of climate change has been put forward. The present paper is the first part of this scientific assessment report , mainly dealing with the climate and environment changes. And the future projections of climate change have been provided.

The negotiation of the international climate regimes is a highly complicated process. Nevertheless, the determinants for beyond 2012 commitments rely on the political will, economic interest and scientific knowledge of the global powers. The vehicles for post-Kyoto negotiations will be not only confined to the UNFCCC process, but bilateral, multilateral and even unilateral commitments outside the UNFCCC are also likely to take place. Furthermore, the contents of agreements will cover mitigation, adaptation, technologies, and low carbon development. In the end, it is possible that a basket of agreements will be concluded under the overall framework of sustainable development. In the next 20 years or so, China will be in the process of large-scale and rapid industrialization and urbanization. The choice by China for climate agreements will have to consider the reduction of possible risks, avoidance of inflexible restrictions, and active participation in the negotiation and making of international regimes, so as to safeguard and promote sustainable development in China.