Propane itself is not a direct greenhouse gas (GHG) when released into the air, according to measurements reported by the Intergovernmental Panel on Climate Change. Unlike fuels such as natural gas, propane vapor is removed from the atmosphere faster than it takes for it to become well-mixed and impact the global climate. When propane is used as a fuel, it does generate small amounts of GHG emissions. However, as PERC’s study demonstrates, propane’s carbon footprint is lower than many other fuels.
| Carbon dioxide released per Btu | |
| Fuel type | kg CO2/million Btu |
| Natural Gas | 52.8 |
| Propane | 62.7 |
| Ethanol (EBS) | 66.6 |
| Motor Gasoline | 70.5 |
| Kerosene | 70.7 |
| Distillate Fuel (Diesel) | 72.5 |
| Residual Fuel (Heavy Fuel Oil) | 78.6 |
| Bituminous Coal | 92.7 |
| On-site emissions estimates based on chemical composition of the fuel with 99 percent combustion. |
| Source: U.S. Department of Energy (DOE). 1994. DOE/PO-00280 Vol. 2 (October). |