Greenhouse gas (GHG) emissions are the main cause of global warming and climate change. While you can take steps to lower the amount of GHG you cause in your daily life, it’s impossible to avoid polluting altogether. Your contribution to GHG pollution is known as a carbon footprint because most pollutants are carbon compounds. Your footprint is the total amount of greenhouse gases like carbon dioxide (CO2) released into the atmosphere due to your activities. In addition to carbon, you could also cause the release of methane and nitrous oxide.