According to Radio France Internationale, the UN expert group on climate change launched its assessment report on the global climate situation in Copenhagen, the capital of Denmark, on November 2. The report warned with extraordinary strong words that in the face of the risk of rapid deterioration of the earth's ecological environment, governments of all countries must act as soon as possible to reduce greenhouse gas emissions and reduce greenhouse gas emissions to zero by 2100, Otherwise, it may lead to ecological and social disasters. At the same time, the report also points out that emission reduction can not harm economic growth.

According to the report, the 40 page summary report indicates that mankind is changing the earth's climate system. Global warming has led to more frequent extreme high temperatures, rainstorms, ocean acidification and sea-level rise. The three main greenhouse gases, carbon dioxide, methane and nitrous oxide, caused by global warming, have reached the concentration since 800000 years.

Pachauri, chairman of the Intergovernmental Panel of experts on climate change, said that we "still have time, but there is little time left" to control the earth's temperature rise below 2 degrees Celsius. He warned that if the trend of global warming continues, the surface temperature will rise by 4 degrees Celsius in 2100 compared with that before industrialization, which will lead to irreparable consequences such as the melting of Greenland's huge ice sheet, the rise of the sea surface and the flooding of coastal areas.

The report proposes that in order to achieve the goal of maintaining the rise of surface temperature no more than 2 degrees Celsius, global emissions should be reduced by 40% to 70% between 2010 and 2050 and "close to zero or lower" by 2100.

The report also pointed out that between 1880 and 2012, the average surface temperature increased by 0.85 degrees Celsius, while from 1901 to 2010, the global sea level increased by 19 cm.

The report said that this is the Fifth Research Report on global climate change proposed by the United Nations panel of experts on climate change since its establishment in 2008, and it is also a complete assessment report. UN Secretary General Ban Ki Moon attended the release ceremony on that day. It is reported that the report has been approved and authorized by more than 120 governments and will be used as the main reference of 200 governments. It will also become an important basis for the 2015 Paris climate summit. The Paris climate summit will face the arduous task of adopting a global agreement to combat climate warming. On the 2nd, foreign minister Fabius of the host country France and environment minister Royal jointly called for immediate and comprehensive action to combat the great threat to human beings in ecology, food safety and health.

US Secretary of State John Kerry also said after the release of the UN report that ignoring climate science will endanger future generations. Non governmental organizations have also responded to the United Nations environmental report, including Greenpeace and the nature fund, which proposed to give up the use of ancient fossil fuels such as coal and oil as energy as soon as possible, and proposed that the use of renewable energy is a fast and clean way to reduce emissions.