greenhouse effect
The increasing carbon dioxide in the atmosphere is like a thick layer of glass, so that the sun can shine in, but the heat can not be emitted. Therefore, the earth has become a big greenhouse. This phenomenon is the "greenhouse effect". Due to the gradual increase of carbon dioxide, the greenhouse effect is also increasing. According to the analysis, in the past 2000 years, the concentration of carbon dioxide has increased by 25%, and the earth's average temperature has increased by 0.5 ℃. According to this calculation, the average temperature of the earth's surface will rise by 1.5 ℃ ~ 4.5 ℃ by the middle of this century.
The greenhouse effect will raise the surface temperature, global warming, melting ice and snow, leading to the rise of sea level, and low-lying coastal cities are in danger of being submerged. With the massive combustion of carbon containing fuels such as coal, oil and natural gas, "greenhouse effect" is becoming more and more serious.