Why is it too hot?

Because the greenhouse effect refers to the effect that the atmosphere makes the temperature in different parts of the earth relatively stable by capturing radiation.

Many studies have pointed out that human factors have strengthened the greenhouse effect on the earth and led to global warming effect.

principle

Solar radiation is mainly short-wave radiation, while ground radiation and atmospheric radiation are long-wave radiation. The atmospheric absorption of long-wave radiation is strong, and the absorption of short-wave radiation is weak.

During the day: when the sun shines on the earth, part of the energy is absorbed by the atmosphere, part of it is reflected back to the universe, and about 47% of the energy is absorbed by the earth's surface.

Night: At night, the earth's surface radiates the heat absorbed during the day into the universe in the form of infrared rays, and some of it is absorbed by the atmosphere.

The atmosphere is like a greenhouse covered with glass, which holds a certain amount of heat, so that the temperature of the earth will not rise sharply when it is irradiated by the sun and drop sharply when it is not irradiated by the sun, like the moon without atmosphere. However, due to the increase of greenhouse gases, the heat energy retained by the whole earth has increased.

affect

Without the greenhouse effect, the earth would be too cold for human habitation. It is estimated that without the atmosphere, the average temperature of the earth's surface would be-18 degrees Celsius. It is the greenhouse effect that keeps the average temperature of the earth at 15 degrees. However, excessive greenhouse gases cause the average temperature of the earth to be higher than 15 degrees.

At present, human activities have increased the content of greenhouse gases in the atmosphere. Gases emitted by burning fossil fuels, such as water vapor, carbon dioxide, methane and chlorofluorocarbons, are absorbed by infrared radiation to retain energy, which leads to the increase of global surface temperature, the intensification of greenhouse effect and global warming. In order to solve this problem, the United Nations has formulated the Framework Convention on Climate Change to control the emission of greenhouse gases and prevent the earth's temperature from rising and affecting the ecology and environment.