What natural phenomenon retains heat in the Earth's atmosphere through gases such as carbon dioxide and methane?

The greenhouse effect is a natural phenomenon that occurs when certain gases in the Earth's atmosphere, such as carbon dioxide and methane, trap heat. This process is essential for maintaining the Earth's temperature, making the planet habitable. Solar radiation enters the atmosphere, and some of it is absorbed by the Earth's surface. The Earth then re-radiates this energy back into the atmosphere in the form of infrared radiation. Greenhouse gases absorb and re-radiate this infrared energy, effectively preventing it from escaping into space and thus warming the atmosphere.

This is crucial for supporting life because it helps to keep the average global temperature at a level conducive to life. The greenhouse effect is a balance that is naturally occurring; however, human activities have significantly increased the concentrations of these gases, which can enhance the greenhouse effect and lead to global warming. Understanding this process is key in addressing climate change and its impacts on global ecosystems.