What is the impact of human activities on the change of the earth's climate?

Since the industrial revolution, the concentration of carbon dioxide (CO2) in the atmosphere has increased by about 28%. With the development of industry and agriculture, the concentrations of methane (CH4) and nitrous oxide (N2O) in the atmosphere have also increased. Their influence accounts for about 24% of the greenhouse effect, and chlorofluorocarbons (CFCs) account for about 65,438+04%. CFCs are depleting the atmospheric ozone layer.

Planktons in forests and oceans absorb carbon dioxide from the air and release oxygen. However, human beings are destroying forests at the rate of millions of hectares every year (according to the data of 1989, more than half of the global 1227km2 tropical rain forest has been destroyed). At the same time, due to the thinning of the ozone layer, holes appear in the ozone layer over some areas, which will make a large number of ultraviolet rays directly drive in and threaten the survival of animals and plants. More marine plankton were killed. On the one hand, human activities increase the release of carbon dioxide, on the other hand, human beings reduce the absorption of carbon dioxide by destroying the two main carbon dioxide absorption systems on the earth.

With the increase of global average temperature, it can be predicted that the global rainfall distribution will change widely. Although it is not yet possible to accurately predict the changes of regional precipitation patterns, some work has been done to estimate the large-scale changes. For example, a series of circulation models have been established.

Cyclic model,

GCM), trying to describe it. Among them, there are three most famous models (GCM2× CO2)-UKMO model (1988), Goddard Institute of Space Studies in New York (GISS) model (1982) and Princeton GFDL model (1985). Climate and sea level, human activities and ecosystems, with emphasis on their interaction. The results show that if the global atmospheric carbon dioxide concentration increases by 1 times, the global average temperature will increase by 4 ~ 5.2℃ and the precipitation will increase by 8% ~ 15%. 1980, Manabe and Gelade used a global climate model to test the possible climate impact of 2 times and 4 times the carbon dioxide level before the industrial revolution. The results show that: ① near 37 ~ 50 north latitude, the atmospheric surface temperature will rise by 3℃; (2) The precipitation increases in the area from 0/2 to 37 north latitude/Kloc, and decreases in the area from 37 to 50 north latitude; (3) The evaporation at various latitudes increased slightly; ④ In the south of 37 north latitude, the soil moisture will change slightly, but in the area around 37 to 47 north latitude, the soil moisture will decrease obviously. From this, we can speculate that most grain-producing areas in the United States, Canada, Europe and the former Soviet Union may become more arid and reduce production, while coastal and low-altitude plains in South Asia, East Asia, Southeast Asia, North Africa, Central Africa and the Middle East are due to sea level rise and frequent storms. In addition, the increase of atmospheric carbon dioxide concentration will lead to soil acidification and degradation, and will also change the photosynthetic efficiency, growth efficiency and water demand of different plant species to varying degrees.

Our future climate

2 1 century, the impact of human activities on climate change will become more and more serious, and the impact of climate change on human society will become more and more serious. It is predicted that the earth will continue to warm in 2 1 century, and the warming speed will be faster than that in the past 100 years, and this warming trend will continue. In 2 1 century, the global average surface temperature will increase by 65438. C the sea level will rise by 0.4 ~ 1.0m due to the rising temperature, and the volume of seawater will expand and the polar ice and snow will melt. The area of glaciers and snow will be further reduced, and the possibility of extreme weather and climate events will increase and expand. The maximum temperature in land area will become higher, the number of high temperature days will increase, the intensity of extreme precipitation may increase, and the threat of drought in some areas will increase. With the increase of social wealth, meteorological disasters may intensify.

Scientists predict that in 2 1 century, the annual average temperature in China will also increase significantly, and precipitation will also increase, but the spatial and temporal distribution will be uneven. With the climate warming, the melting of snow and ice intensifies, which leads to frequent glacier floods and mudslides, the early disappearance of snow and the intensification of spring drought, and the intensity and frequency of extreme weather and climate events in China will also be affected.