Prepare for take-off: decarbonising aviation

What’s happening? UK Export Finance (UKEF), which provides loans, insurance and guarantees to help British firms grow abroad, has supported the aviation industry with billions of pounds since the Paris climate agreement, according to research from DeSmog and the Guardian. More than 50% of the support provided by UKEF since 2015 has gone to aviation – some of the firms benefitting the most include Rolls-Royce, Airbus, Boeing and British Airways. Out of the 62 deals listed in annual reports, just one contained climate-related conditions. Sam Pickard, a research associate at the ODI, said that the UKEF’s continued support for the expansion of the aviation industry is locking us into more carbon emissions for the coming decades. (The Guardian)

Why does this matter? As a global sector, transport is falling behind in reaching global climate targets. Within transport, the aviation sector is one of the main underachievers – last year a report found that UK airlines have missed all but one of the climate targets they set since 2000.

The global aviation industry is currently responsible for around 2% of all global CO2 emissions, but the industry’s climate impact is more substantial when other gases are considered. Research from the EU regulator EASA analysed the impact of non-CO2 aviation emissions, including nitrogen oxide, soot particles, oxidised sulphur and water vapour. It found that when the impact of such non-CO2 particles is included, the sector is responsible for “warming the climate at approximately three times the rate of that associated with aviation CO2 emissions alone”.

The government’s climate targets rely on airlines achieving their own targets and their failure to do so undermines the government’s climate strategy. It also emphasises the importance for the UKEF to put conditions on contracts that would force the aviation sector to decarbonise.

What technologies can be used? The three most popular technologies being used to decarbonise the aviation sector include hydrogen, sustainable aviation fuels (SAFs) and electric-powered planes. Most recently, a group of companies including Bank of America, JPMorgan Chase and Meta have said they are working together via the Sustainable Aviation Buyers Alliance (SABA) to scale access to SAFs.

The issues with SAFs – The two main types of SAFs include biofuel and synthetic electrofuel – both have major problems. For instance, biofuel crops use large quantities of energy and fertilisers, which are a major source of nitrous oxide. Some biofuels may also come from crops such as palm oil, rapeseed or soy that contribute to deforestation and biodiversity loss. Additionally, SAFs are nearly three times more costly than conventional jet fuel.

It’s also worth noting that even if aviation transitions to using SAF and achieves net-zero CO2 emissions, the industry could still increase global temperatures by up to 0.4C. This is due to the contrails produced by burning jet fuel, which would still be produced by SAF and which warm the atmosphere.

Limitations of electric power – While several companies have been developing electric-powered aircraft, most of these are small aircraft with room for just a few passengers. The batteries needed to power electric-powered planes capable of transporting around 200 passengers would weigh about 40 times more than the amount of jet fuel needed. This makes electric-powered planes impractical without significant leaps in battery technology. However, there is scope for hybrid-electric aircraft, with Ampaire completing the longest nonstop hybrid-electric flight last year.

Challenges with hydrogen – A recent report from the Royal Society estimated that using hydrogen as jet fuel would require nearly double the amount of renewable energy the UK is currently producing. Additionally, the German environmental institute Öko-Institut has estimated that for all current flights to be operated with e-fuels, more than the existing renewable electricity of the whole world would be needed.

The degrowth of aviation – One of the most effective ways for the aviation sector to effectively cut emissions is to reduce air transport. Earlier this year a study found that business-as-usual levels of air travel could cause climate pollution from aviation to triple by 2050. The report said that keeping the growth in air travel flat through 2050 may avoid 60% of these emissions and that a further 27% of emissions could be prevented by increased energy efficiency.

In 2019 the group Stay Grounded discussed the degrowth of aviation in a report which can be found here.