Expect Long Delays Before Green Airlines Take Off, Say Researchers

The aviation industry is responsible for 2.4% of global greenhouse gas emissions and 8% of UK emissions. As governments and the aviation industry work to reduce the climate impacts of traditional kerosene fuel, sustainable fuel is key to reaching "jet zero" flying by 2050. However, according to the Royal Society, there is currently no single, clear alternative to traditional fuel. 

The report looked at four options for greener fuels to replace the 12.3m tonnes of jet fuel used annually in the UK. The authors concluded that none could replace fossil jet fuel in the short term. Some airlines use biofuel, largely made from crops, but London Heathrow is the largest global user of biofuels, accounting for just 0.5% of the airport's fuel. To produce enough to supply the UK aviation industry would require half of Britain's farming land, putting pressure on food supplies, according to the Royal Society. 

Another option is fuel made from hydrogen produced with green electricity. However, the UK does not generate enough renewable electricity to make enough green hydrogen. Another major barrier is that existing plane engines cannot use hydrogen-based fuel. Ammonia and synthetic fuels are also under consideration, but they need even more green hydrogen, and it is unclear if existing planes could use them. 

The trade body for UK airlines, Airlines UK, said in response that sustainable fuels were safe and increasingly commonplace, and that the sector was committed to the 2050 "jet zero" target. "There is no magic bullet, but by modernising airspace to make flying more efficient, by introducing new zero emission technology like hydrogen aircraft and by upscaling the use of sustainable aviation fuels this decade, it can be achieved," it said in a statement. 

Regarding the Royal Society's assertion that sufficiently supplying the UK aviation industry with sustainable fuels would put pressure on food supplies, Airlines UK said the UK had sufficient feedstocks, that they would be drawn initially from household, commercial, agricultural and forestry waste and waste industrial gases, and that they did not compete with food crops. 

Environmental campaigners say the government must also encourage people to fly less. "Not all aspects of modern life in Western nations have an easy 'technofix' for the damage they do to the environment, and nowhere is this truer than for air travel," suggests Leo Murray, director of innovation at climate charity Possible. His organisation wants the government to tax frequent flyers, the small number of people who take around 70% of flights from UK airports. 

The Department for Transport said that the UK's Sustainable Aviation Fuels programme is one of the most comprehensive in the world, and sustainable aviation fuels and hydrogen are key elements of this. They will ensure that there is no impact on food crops. 

In conclusion, while sustainable fuel is key to reaching the "jet zero" target, the Royal Society concludes that there is currently no single, clear alternative to traditional fuel. The aviation industry is committed to the target and continues to work on developing greener fuel options. However, environmental campaigners suggest that the government must also encourage people to fly less, and the Department for Transport said that they will ensure that there is no impact on food crops.