When the global average temperature rises 1℃, great changes will take place: sea level rises, alpine glaciers retreat, and the snow area shrinks. As the global temperature rises, it will lead to uneven precipitation, with precipitation increasing in some areas and decreasing in some areas. For example, the drought in the Sahel region of West Africa has been severe since 1965; Since 1965, the precipitation in North China has decreased year after year. Compared with 1950s, the precipitation in North China decreased by 1/3, and the water resources decreased by 1/2. The drought-stricken area in China is about 400 million mu every year. In normal years, irrigation areas in China lack 30 billion cubic meters of water every year, and cities lack 6 billion cubic meters of water. With the temperature rising 1℃, the population lacking water will increase by 400 million, reaching1700 million, some infectious diseases and allergic pollen will increase, and some amphibians will disappear.

Due to the rising temperature, the global sea level has been rising at a rate of 1-2 mm per year in the past 100 years. It is predicted that the sea level will continue to rise by 30-50 cm by 2050, which will flood a large number of low-lying areas along the coast. In addition, climate disasters such as drought, flood and low temperature are aggravated by climate change, resulting in tens of billions of dollars in global economic losses every year.