What is the greenhouse effect?

The greenhouse effect refers to the process where certain gases in Earth's atmosphere, known as greenhouse gases, trap heat from the sun. This process is essential for maintaining the planet's temperature and supporting life. When sunlight reaches the Earth, some of it is absorbed, and the rest is reflected back into space. Greenhouse gases, such as carbon dioxide, methane, and water vapor, then absorb some of this outgoing heat and re-radiate it, effectively warming the atmosphere.

This natural phenomenon allows Earth to sustain a temperature range that is suitable for ecosystems to thrive. Without the greenhouse effect, the planet would be too cold to support life as we know it. Understanding this effect is crucial for addressing concerns related to climate change and human impact on the atmosphere.

In contrast, the other choices describe different environmental phenomena that do not accurately describe the greenhouse effect itself. For example, the cooling of Earth's atmosphere does not involve the trapping of heat by greenhouse gases, while ozone depletion pertains to the thinning of the ozone layer due to certain chemicals, and the reduction of carbon emissions focuses on actions taken to mitigate climate change rather than the natural process of heat retention.