What natural phenomenon involves the retention of heat in Earth's atmosphere by gases such as carbon dioxide and methane?

The phenomenon that involves the retention of heat in Earth's atmosphere by gases such as carbon dioxide and methane is known as the greenhouse effect. This process occurs when these greenhouse gases trap heat from the sun in the atmosphere, preventing it from escaping back into space. As a result, the Earth's surface and lower atmosphere warm, which is essential for maintaining temperatures that can support life.

The greenhouse effect plays a crucial role in regulating the planet's climate. Without it, Earth would be too cold to sustain the diverse forms of life we experience today. Human activities, particularly the burning of fossil fuels and deforestation, have increased the concentration of these gases, enhancing the greenhouse effect and contributing to global warming.

The other terms in the options refer to different environmental concepts. The ozone layer relates to a layer of ozone in the atmosphere that protects Earth from harmful ultraviolet radiation. Climate change is a broader term referring to long-term alterations in temperature and weather patterns, which can be influenced by the enhanced greenhouse effect but is not the specific mechanism itself. Acid rain refers to precipitation that has been acidified due to atmospheric pollution, particularly sulfur and nitrogen compounds, and does not directly pertain to the heat retention by gases in the atmosphere.