Winter in Hunan is not so cold this year. Why?

Probably because of the greenhouse effect, global warming.

Global warming is due to the greenhouse effect.

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.

Extended data:

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.