All the world’s planes consumed roughly 100 billion gallons of jet fuel as they crisscrossed the planet in 2024. Only about 0.5% of it was something other than fossil fuel. That could soon change.
Alternative jet fuels could slash aviation emissions—which have caused about 4% of global warming to date. These new fuels can be made with materials like used cooking oils, crop residue, industrial waste, and carbon dioxide captured from the air. Depending on the source, they can reduce emissions by half or nearly eliminate them. And they can generally be used in existing planes, which could enable quick climate progress.
More governments are now setting targets or passing legislation requiring airlines to begin using these alternative fuels (sometimes called sustainable aviation fuels, or SAFs). Starting this year, alternative fuels must make up at least 2% of the fuel used at airports in the European Union and UK. That mandate will ramp up in the coming decades, reaching 70% in the EU by 2050.