Carbon dioxide (CO2) is a climate-altering gas that naturally occurs in our atmosphere; its very high concentration contributes to global warming. However, CO2 is not the only gas responsible for the greenhouse effect, which is also caused, for example, by nitrous oxide (N2O), methane (CH4) and sulfur hexafluoride (SF6). CO2 equivalent (CO2eq) describes the impact of greenhouse gases in a single unit. For any quantity and type of greenhouse gas, CO2eq indicates the amount of CO2 that would have an equivalent impact on global warming