The gas primarily responsible for the greenhouse effect is carbon dioxide (CO2). This colorless gas is produced by natural processes such as respiration and volcanic eruptions, but human activities—particularly the burning of fossil fuels and deforestation—have significantly increased its concentration in the atmosphere. CO2 traps heat from the sun, preventing it from escaping back into space, which contributes to global warming and climate change. Other greenhouse gases include methane and nitrous oxide, but carbon dioxide remains the most significant. Efforts to reduce CO2 emissions are critical in combating climate change, emphasizing the importance of sustainable practices and renewable energy sources.