Through systematic comparison of the total emissions, per capita emissions and emission intensity of CO_2 in the major countries, the characteristics of carbon emission in developed countries are summarized, and the carbon emissions history and its causes of each stage in China is analyzed. Through the comparative analysis of the relevant policies to address climate change between developed countries and developing countries, combined with the characteristics of carbon emissions in China and abroad, the main problems in China's carbon emissions and climate change mitigation are also summarized. At last, we put forward countermeasures for China to deal with climate change under the new normal, including actively participating in climate negotiations, and promoting the development of low carbon of the international community at the international level; while at the level of China, effectively changing the economic growth mode, and leading the development of low carbon economy in China.