As Pinwheel has curated its project portfolio on behalf of our clients we have taken a methodical approach, focusing on project types are most likely to have impact for the planet. However, sometimes a client will suggest that we investigate an area for addition to the portfolio. We have recently had two clients ask us if our project portfolios could include activities that support the development of sustainable aviation fuels (SAFs), with the intention of supporting the decarbonisation of air travel.

Our response was to say that we don’t think so, as we have concerns that sustainable aviation fuels, if scaled, would be damaging for the planet and that any funding might not be additional – that is, it wouldn’t lead to more deployment of SAFs. However, we totally understand the logic of the request, because for many businesses, particularly service businesses, aviation makes up a significant proportion of their emissions. If there is a way for corporates to directly reduce the carbon impact of flying then it would have real appeal, so we decided to do a deep dive on SAFs.

First, we sought out some expert advice. The arguments that follow are mine, but I am indebted to the brilliant transport decarbonisation experts who gave me their time – Alethea Warrington at the climate campaign Possible, and Rachel Solomon Williams, the incoming Executive Director, at the Aldersgate Group.

The challenge of aviation decarbonisation is possibly the hardest we face. Genuinely emissions-free planes are decades away from commercial implementation, even on short-haul routes. Its not merely a question of funding or will, it is also a matter of physics that we have not yet cracked. In the long run, a mixture of green hydrogen, electric planes and efuels are likely to be a solution for low carbon flight, albeit with huge implications for electricity demand that may be insurmountable, but until then the sector has been looking for interim measures to lower the carbon intensity. That’s where SAFs come in.

It is increasingly clear that SAFs, already being deployed, will be an increasing part of the aviation fuel mix in coming years. Airlines are already purchasing SAFs, albeit in relatively small volumes, and governments around the world are basing their net zero plans and putting in place regulation to drive up deployment.