What caused the extreme weather on the earth?

Scientific research has confirmed that global warming caused by the increase of atmospheric greenhouse gas concentration caused by human activities can change the frequency, intensity, spatial range and duration of extreme weather events, and may lead to unprecedented extreme events. The latest research results show that the frequency of extreme weather events will increase significantly when the average climate state changes. If the average temperature moves in the warm direction, the extremely cold weather will decrease and the frequency of extremely warm events will increase significantly, and vice versa.

In addition, climate change will also change the large-scale circulation pattern, air-sea interaction, ground-air interaction, etc., and then affect the occurrence of extreme weather and climate events in different regions. Take the El Nino phenomenon in the equatorial Pacific as an example. Global warming will enhance the air-sea exchange, and the ocean will also absorb the increased greenhouse gases in the atmosphere, which will lead to the warming of seawater. Extreme events and disasters caused by El Ni? o will increase accordingly, such as floods in southeastern South America and western North America, and droughts in India and Australia.

At the same time, global warming has also led to the accelerated melting of Arctic sea ice. In recent 30 years, the minimum coverage area of sea ice in summer has been reduced by half, and its direct consequence is that it changes the atmospheric circulation in the northern hemisphere in winter by affecting the Siberian high, which in turn leads to a significant increase in the frequency of extreme low temperature events in the middle and high latitudes of Eurasia.

In recent years, extreme weather and climate events related to global warming have become increasingly frequent, which has brought many adverse effects on social economy, ecological environment and human health. According to authoritative statistics, from 1980 to 20 13, there were 22,000 natural disasters in the world, resulting in economic losses of about 3.8 trillion US dollars. About 87% of natural disasters and more than 70% of economic losses are directly related to climatic disasters or meteorological conditions such as drought, flood, tropical cyclone, high-temperature heat wave and low-temperature chilling injury.

In the final analysis, whether people freeze to death or die of heat is closely related to global warming. If human beings are not committed to curbing the trend of climate change, by the end of 2 1, the probability of high-temperature heat wave events in land areas will be 5- 10 times that of now; The global extreme low temperature events will decrease on average; In most parts of the world, the frequency of extreme precipitation events will increase.