This post was originally published by Business Green.
Although flying is one of the most carbon intensive activities a person can do, and despite growing focus on polluting behaviours in recent years, emissions from aviation have more than doubled since 1990. Air passenger numbers have risen drastically, and the Department for Transport (DfT) projects this will go on rising over the next thirty years, to reach 74 per cent greater than 1990 levels by 2050.
As a sector, aviation has so far got off lightly in the push to meet net zero. There has been little policy to address the uptake of sustainable technologies: jet fuel isn’t taxed in the same way as road fuel, and no VAT is applied to airline tickets.
The government is paying attention though and its Jet Zero strategy has started to set out a plan but, as Transport Minister Grant Shapps recently said, “We will still fly on holiday, but in more efficient aircraft, using sustainable fuel.” What he didn’t say was that zero emission aircraft are unlikely to penetrate the market in a meaningful way for another couple of decades. Even if all UK domestic routes switched to hydrogen or battery electric airplanes in 2040, it would only address around three per cent of the UK’s aviation emissions.
One solution for decarbonising this sector in the shorter term is by using sustainable aviation fuel (SAF). One SAF, power-to-liquid fuel (PtL), offers 100 per cent reduction in carbon emissions if it is produced using direct air capture of carbon and green hydrogen. Both industries need to be significantly ramped up to make it possible.
The brilliant thing about growing these industries to make PtL, is that they can also be useful elsewhere in the economy; if, in fifty years’ time, we really are flying in zero emission aircraft, the infrastructure developed to make PtL in the meantime will not have been a wasted investment. Direct air capture can be used as a removal technology, while green hydrogen is valuable in clean steel production, shipping and the manufacture of hydrogen fuel cells.
New research published by Green Alliance shows that, if PtL was added to jet fuel, emissions from aviation could be 50 per cent lower than the Climate Change Committee’s projection under its ‘balanced pathway’ scenario, which is its blueprint for a fully decarbonised UK by 2050.
DfT has already committed to a SAF mandate, obliging fuel suppliers to use a certain amount of SAF in the sale of jet fuel from 2030. Alongside this, it should introduce additional requirements specifically for PtL in the jet fuel mix from 2025-50, as the only carbon neutral SAF option.
To achieve this scaling up of more sustainable fuel, the government needs a plan to also increase the necessary feedstocks for production, which means a strategy for expanding green hydrogen and direct air capture.
As green hydrogen for PtL production needs a large amount of renewable energy, decisions will have to be made about how much of the available capacity aviation deserves. And there are currently no operational direct air capture (DAC) plants in the UK, although there has been some recent progress: in 2021, Carbon Engineering and LanzaTech won DfT’s Green Fuels Green Skies competition to carry out a feasibility study to produce PtL fuel using DAC technology.
The cost of producing SAF is a contentious issue; even with economies of scale, fossil fuel kerosene is still likely to be cheaper than SAF in 2050 without help. Despite the government’s reliance on SAFs and technological advances to reduce the climate impact of flying, there are no funding mechanisms in place to accelerate the use of alternative fuels. And it’s still unclear whether the costs involved would be shouldered by the taxpayer or by industry. Historically, aviation has not been held to the polluter pays principle. DfT needs to consider if it’s finally time to use taxes, such as a kerosene tax, to stimulate the shift to more sustainable flying, or if the sector can be relied on to fund the changes needed. A recent report from Possible, however, highlights the industry’s past record on meeting climate targets, and it isn’t encouraging reading.
The risk of some sectors, like aviation, not doing their fair share in meeting economy-wide climate targets, means pressure will be felt elsewhere in the economy to decarbonise faster. If PtL production could be accelerated, it offers aviation the chance to bring about faster and more significant emissions reductions in the short to medium term. But, for this to happen, serious efforts need to begin now.