Take sustainable aviation fuel (SAF). This government, and the Conservatives before them, proudly announced their aim by 2030 is for SAF to constitute 10% of all the fuel powering flights departing the UK. A lofty ambition, but how realistic is it?

According to travel intelligence specialist Mabrian, European aviation’s carbon footprint grew by 16% in 2023, with the UK accounting for 18% of Europe’s aviation-related emissions. This footprint will no doubt have grown in 2024 and will do so again in 2025 judging by the capacity hikes we are seeing.

We need – and deserve – to know how much an airline’s emissions will grow when it announces capacity increases. How much of this growth in emissions will be mitigated by the tiny amount of SAF mandated between now and 2030?

NGOs warn all is not what it seems regarding messaging around SAF. What will count is how it is manufactured, and what proportion of it will come from feedstock and e-fuels – synthetic fuels made using renewable energy sources like wind or solar, or carbon capture.

If SAF comes from fossil fuels, these will release as much CO2 as kerosene. There will no doubt be scepticism about the sustainability of e-fuel production too.

It’s all very technical and confusing, and transparency is sadly lacking. We all want to grow, but we need to know exactly what damage we are causing by doing so. Airlines obviously want government to step in and increase funding for the manufacture of SAFs because, being more expensive than kerosene, fares will have to rise.

Then there’s the question of whether it’s right prices should rise if this is part of a mechanism to slow aviation growth until we crack these issues – CO2 and methane emissions, contrails, etc.

I recently read we can drastically reduce emissions by flying slower, and that contrails can be reduced by flying around certain weather patterns rather than in a straight line – how true are these claims?

It seems to me we are rushing to find answers when, in the short-term, the best solution would be to moderate growth rather than be hell-bent on flying from every regional airport in the UK to every resort airport in Europe. It’s as if our industry is going for broke before government finally restricts capacity when emissions get out of hand.

And it’s not just aviation. Pollution from cruise ships is also increasing. Lobby group Transport & Environment says Europe’s cruise ships now emit more sulphur oxides (SOx) than a billion cars.

A study by the group found that Venice’s decision in 2021 to ban large cruise vessels resulted in an 80% reduction in SOx emissions. By contrast, in Barcelona, cruise ships emit three times more SOx than all the cars in the city, despite far stricter limits on SOx emissions from cars than cruise ships.

Even those in the industry are worried. In December 2023, Hurtigruten chief Daniel Skjeldam said the industry had its head in the sand. So what, and who, do we believe? Surely we can’t just turn a blind eye and carry on regardless?

Noel Josephides is chair of Sunvil.