Originally published by Dan Gage for The Transport Project – June 30, 2026
Last calendar year marked the sixth consecutive year that commercial fleets in the State of California fueled by bio-CNG (renewable natural gas, or RNG) achieved a carbon-negative transportation outcome, according to a report released today by The Transport Project (TTP), RNG Coalition, and California Renewable Transportation Alliance (CRTA).
Lowest carbon intensity fuel: -198
Renewable natural gas accounted for 98% of all on-road fuel used in natural gas vehicles in California in 2025, driven by the state’s successful Low Carbon Fuel Standard (LCFS) program. According to data from the California Air Resources Board (CARB) the annual average carbon intensity score of bio-CNG in that mix was -198.32 gCO2e/MJ.[1]
In fact, bio-CNG holds the lowest average carbon intensity of any clean fuel option on California’s roadways today and is the only fuel producing a negative carbon intensity fleet outcome in the California Low Carbon Fuel Standard (LCFS) Program, which includes ethanol, biodiesel, renewable diesel, bio-CNG, bio-LNG, electricity, alternative jet fuel, and hydrogen.
Read the full article here.