Why is global warming?
Global warming is a phenomenon related to nature, which is due to the continuous accumulation of greenhouse effect, resulting in the imbalance of energy absorbed and discharged by the geo-atmospheric system, and the continuous accumulation of energy in the geo-atmospheric system, leading to rising temperature and global warming.
Because people burn fossil fuels, these greenhouse gases have high permeability to visible light from the sun, but have high absorption to long-wave radiation emitted by the earth, and can strongly absorb infrared radiation from the ground, leading to an increase in the temperature of the earth.
Global warming is a natural phenomenon. Because people burn fossil fuels, such as oil and coal, or cut down forests and burn them, they will produce a lot of greenhouse gases, such as carbon dioxide. These greenhouse gases have strong permeability to the visible light emitted by the sun, strong absorption to the long-wave radiation emitted by the earth, and can strongly absorb the infrared radiation from the ground, leading to an increase in the temperature of the earth, which is the greenhouse effect. However, when the greenhouse effect is accumulating, the energy absorbed and discharged by the geo-atmospheric system is unbalanced, and the energy is accumulating in the geo-atmospheric system, which leads to the rise of temperature and global warming. Global warming will redistribute global precipitation, melt glaciers and frozen soil and raise sea level, which will not only endanger the balance of natural ecosystems, but also threaten human survival.
greenhouse gas
Not every gas in the atmosphere can strongly absorb the long-wave radiation on the ground. Gases that play a greenhouse role in the earth's atmosphere are called greenhouse gases, which mainly include carbon dioxide (CO2), methane, ozone, nitrous oxide, freon and water vapor. They absorb almost all the long-wave radiation emitted by the ground, and only a narrow section absorbs very little, so they are called "window areas".
It is through this window that the earth returns 70% of the heat obtained from the sun to space in the form of long-wave radiation, thus keeping the ground temperature unchanged. The greenhouse effect is mainly due to the increase of the quantity and types of greenhouse gases by human activities, which makes the value of these 70% decrease, leaving the residual heat to warm the earth.
However, although greenhouse gases such as carbon dioxide have strong ability to absorb long-wave radiation on the ground, they are very few in the atmosphere. If the atmospheric state with a pressure of one atmosphere and a temperature of 0℃ is called the standard state, then the whole atmosphere of the earth is compressed to this standard state with a thickness of 8000 meters.