Carbon dioxide (CO2) is the primary greenhouse gas driving climate change, released mainly through burning fossil fuels (coal, oil, natural gas) for energy and transportation. CO2 traps heat in the atmosphere, causing global temperatures to rise. While carbon dioxide occurs naturally in the atmosphere and is essential for plant growth, human activities have increased atmospheric concentrations by about 50% since pre-industrial times. Reducing CO2 emissions is the central focus of climate policy. Strategies include transitioning to renewable energy, improving energy efficiency, electrifying transportation, and changing land use practices. Carbon dioxide can remain in the atmosphere for centuries, making emission reductions urgent.