Gasoline and diesel make up this category, which is focused on fueling household vehicles. These liquid fuels are distinct from home fuels because they are rarely delivered to your home or consumed inside the house. Carbon dioxide forms when these fuels are burned. Their contribution to your household carbon footprint begins at the source.
Both gasoline and diesel come from crude oil (petroleum). Crude oil is a mixture of liquid hydrocarbons found in natural underground deposits. Small amounts of volatile hydrocarbons like natural gas may be present with the oil. If no gas-gathering system exists at the production site, those gases will be flared (burned on-site). Even though flaring natural gas adds a little CO2 to your carbon footprint, it’s much better than releasing it as natural gas, which has a greenhouse gas value more than 20 times greater than CO2.
Biofuels are processed from biomass (plant matter)—typically corn for ethanol and soybeans for biodiesel. The growing of the plant material for ethanol and biodiesel requires the operation of farm implements (e.g., diesel-powered tractors) and fertilizers (e.g., mining,manufacturing) that contribute to their carbon footprint.