How to treat the frequent occurrence of extreme weather in the world?

The so-called extreme weather and climate events refer to small probability weather and climate events that occur less frequently than the same period in history. It usually means that the state of weather (climate) seriously deviates from its average state, which is statistically unlikely. Generally speaking, extreme weather and climate events refer to small probability events that occur once in 50 years or once in 100 years, and the probability of occurrence is often less than 10%.

From the perspective of probability theory, if the temperature in a certain area or place is normally distributed under the average condition for many years, the probability of weather is the highest, the probability of hot and cold weather is small, and the probability of extremely cold or hot weather is even smaller. However, due to the influence of global warming, the average temperature in this area will rise, and the probability of high temperature weather will increase obviously. Extremely hot weather, which was rarely seen before, may also appear frequently now, and extreme events such as high temperature heat waves will become frequent. If the variance of temperature changes increases, extreme weather will occur more frequently.

Scientists believe that the causes of extreme weather are the combined effects of internal and external factors, such as the increase of greenhouse gas concentration, global warming, El Ni? o phenomenon, the dynamic movement of the earth itself, human intervention in nature, changes in solar radiation, and the deviation of the earth's orbit. According to the data of the World Meteorological Organization (WMO), the global surface temperature (representing winter) in June and April of 20 16 was 1.89 and 1.37℃, respectively, which were higher than the average level in the same period in history and exceeded the highest level in history 1998. From June to July, 2007, the national average temperature was 195 1, which was a continuous high temperature year since1/year. Global warming can not only change the average temperature, but also increase the variability of climate, that is, increase the gap between the highest and lowest values. The increase of average temperature and temperature variability may lead to extreme weather and climate events.

According to the principle of meteorology, global warming makes the surface temperature rise, the water surface evaporation increases, the total amount of water vapor evaporated into the atmosphere increases, and the water cycle accelerates. With the increase of atmospheric water content, precipitation will increase in a short time. Extreme precipitation events such as heavy rain, blizzard and local floods occur frequently. Strong convective weather such as tornadoes, thunderstorms, storms and hail will also increase in some areas. In addition, the evaporation of plants, soil, lakes and reservoirs is accelerating, and the depletion of water is increasing. As the temperature rises, some areas will suffer more frequent, more lasting or more serious droughts.

Dieter Gerten, a German climatologist, said that the increase of "extreme events" is "what we see in climate model prediction". Computer models show that more places in the world will break records more frequently. Johannes Shi Ying, a meteorologist at the University of Leipzig, said, "This will become the new normal." Although scientists are evaluating the extent to which extreme weather can be attributed to climate change, a series of so-called rapid attribution studies point out that global warming is a major factor. Such studies compare real-time data with models that simulate carbon-free emissions.

As predicted by scientists, more extreme events will occur frequently, which will have a more serious impact on global economic and social development and natural ecosystems. The frequent occurrence of extreme weather and climate events will become a new challenge for us to cope with global climate change!