Sustainable Aviation Fuel (SAF) Emissions Life Cycle

WHAT IS SAF?

Sustainable Aviation Fuel (SAF) is jet fuel made from sustainable feedstock rather than petroleum. Some examples of sustainable feedstocks include plant oils, waste oils, crop sugars, municipal solid waste, and agricultural residues, among others. As a drop-in fuel, SAF can be used on our existing aircraft and engines, up to a blend of 50% with conventional jet fuel. The blend limit is expected to increase substantially in coming years.

SAF is better for the environment because it has a lower life-cycle carbon intensity compared to petroleum fuel. A fuel’s ‘life cycle’ (see page 18) includes all of its associated GHG emissions, starting with sourcing feedstock, through refining, distribution and combustion. Although SAF and conventional jet fuel release the same GHG emissions in the combustion phase, carbon from petroleum jet fuel had been stored underground for millions of years, while carbon from SAF was recently absorbed from the atmosphere by feedstock through photosynthesis, meaning its intensity nets to zero during the combustion phase.