The contribution of hydrofluorocarbons (HFCs), used in refrigerators and air conditioners, to global warming by 2050 is projected to be more than that of current global CO2 emissions from houses and office buildings.
These gases are substitutes for ozone-depleting gases, but they are also strong greenhouse gases. Their contribution to global warming is currently small, but can increase to the equivalent of 9-19% (CO2-eq. basis) of projected global CO2 emissions in business-as-usual scenarios by 2050.