The greenhouse effect is a natural process by which certain gases in the Earth's atmosphere trap heat, sustaining temperatures necessary for life. This mechanism involves the absorption and subsequent re-emission of longwave infrared radiation. Specific atmospheric gases, known as greenhouse gases, absorb outgoing thermal energy from the planet's surface and re-radiate it in all directions, warming the lower atmosphere. While a natural process vital for maintaining habitable conditions, increasing concentrations of these gases, due to various activities, enhance this warming effect, leading to changes in global climate patterns.