Zero emission flight, using hydrogen fuel cells or clean electricity, is still in its infancy for short haul flights and is unlikely to be viable for larger planes or for long haul before 2050, so Sustainable Aviation Fuel (SAF) will be necessary for aviation decarbonisation, particularly in the near term.

The most environmentally friendly SAF is a power-to-liquid fuel. This requires two main inputs - green hydrogen and CO2. For this solution to be CO2 neutral, the carbon needs to be sourced by Direct Air Capture (DAC). This would create no net emissions, compared to CO2 sourced from industrial gases. Waste-based SAF still produces some emissions from the burning of the waste materials. 

The £1 million competition to achieve the first transatlantic flight using 100% SAF has unlocked investment and provided a successful incentive for industry to go full throttle towards cleaner fuels. A similar competition for a commercial domestic route using zero emission aircraft by 2027 will turbocharge technological innovation.

Offsets should not be the first choice method for reaching net zero emissions in any sector. The emphasis should always be on emissions reduction first. However, aviation will be one of the hardest sectors to decarbonise and reaching absolute zero emissions by 2050 is likely impossible. High quality offsets will be necessary to limit the climate impact of flying in the short to medium term.