Carbon dioxide (CO2) is primarily responsible for the greenhouse effect, a natural phenomenon that warms the Earth's surface. When solar radiation reaches the planet, some of it is reflected back to space while the rest is absorbed, contributing to Earth's warmth. Greenhouse gases like CO2 trap heat in the atmosphere, preventing it from escaping into space. Human activities, particularly the burning of fossil fuels, deforestation, and industrial processes, have significantly increased CO2 levels since the industrial revolution. This rise intensifies the greenhouse effect, leading to global warming and climate change, posing significant environmental challenges.