The gas produced when burning fossil fuels is primarily carbon dioxide (CO2). Fossil fuels, such as coal, oil, and natural gas, release CO2 when they are combusted for energy. This process occurs in power plants, vehicles, and industrial facilities, contributing significantly to the greenhouse gases in the atmosphere. The increase in CO2 levels is a major factor driving climate change and global warming, prompting efforts to transition to cleaner energy sources and enhance sustainability practices globally.