Annex one: sustainable aviation fuels compared

Emissions reductions Power-to-liquid fuel

99 per cent (100 per cent if the supply chain is fully decarbonised)38 70-90 per cent39 As this displaces emissions from fossil fuel waste, there are no emissions reductions in overall lifecycle (unless mixed with biogenic material)

Environmental impacts Water and power use, some small land use required for DAC plants and electrolysers If sourced incorrectly, can cause land degradation and harm to biodiversity. Also requires high land use40 May continue to prop up the fossil fuel market into the future, undermining decarbonisation efforts in other sectors41

Costs Highly variable costs (renewable electricity) and high first of a kind costs for new power plants

Scalability No scalability limit but dependent on availability of renewable energy, hydrogen and DAC Waste-based biofuel Recycled carbon fuel

Most cost effective fuel for near term carbon abatement (cooking oil derived)

Limited availability for jet fuel as it is currently used in road transport There is a marginal additional cost of obtaining feedstock, but with diminishing returns in future as fossil fuels are phased out Only scalable if the fossil fuel industry scales up