The main gas that causes global warming is carbon dioxide (CO2). While other greenhouse gases, such as methane and nitrous oxide, also contribute to warming, carbon dioxide is the most significant due to its abundance and long atmospheric lifespan. It is primarily produced by burning fossil fuels, deforestation, and various industrial processes. As carbon dioxide levels rise, they trap heat in the atmosphere, leading to changes in climate patterns, sea levels, and ecosystem dynamics. Efforts to mitigate global warming often focus on reducing CO2 emissions through renewable energy, energy efficiency, and reforestation initiatives.