The primary purpose of the greenhouse effect is to regulate Earth's temperature, making it habitable for living organisms. It occurs when certain gases in the atmosphere, known as greenhouse gases (such as carbon dioxide and methane), trap heat from the sun. This natural process maintains a stable temperature range, but human activities, like burning fossil fuels, increase these gases, leading to climate change. Understanding the greenhouse effect is critical for addressing environmental issues and informing policies aimed at reducing greenhouse gas emissions.