How will aviation get low carbon flying off the ground?
It is common knowledge that transportation is responsible for 16% of carbon emissions right now, and flying is a big part of that. Flying is also one of the fastest-growing sources of greenhouse gas emissions. And as those gases tend to get released directly into the upper atmosphere (where planes fly), they can be even more potent than other emissions.
Currently, flights make up 3% of total global emissions, however only 20% of the population have ever been on a flight. It is still a preserve of the wealthy, but the desire to fly is increasing rapidly as the global middle class expands. If we do not fix aviation emissions, flights could make up 25% of emissions by 2050.
Aviation is an extremely difficult sector to decarbonise. While the pandemic has shown that a lot of international work can be done digitally, if someone really needs to fly, there is no viable alternative yet.
Short versus long haul
For short-haul flights, there are encouraging developments around zero-emission planes running on electric - you may be boarding one quite soon? Scandinavia are leading the way - Denmark and Sweden have announced plans to make all domestic flights fossil fuel free by 2030. Electric planes are proving to be more economical for airlines too, with reduced expenses around fuel and maintenance. So as consumers we can expect lower costs over time too.
These are positive developments but only half of the flight routes operated worldwide today are less than 500 miles. Making long distance flights carbon-neutral is much more challenging. The batteries required for a long haul electric flight would have to be too big and heavy for the size of the aircraft that is why they are not being built.
What are the airlines doing?
Multiple airline companies have announced programmes to become more sustainable. Delta Air Lines has committed $1 billion to become carbon neutral by 2030. JetBlue pledged to get there by 2040, and United Airlines by 2050. Many others have made similar promises. A lot of this currently relies on carbon offsets, but more direct solutions are in development.
The most common method is switching from traditional fossil-derived jet fuels to ones that are made from renewable sources. Sustainable Aviation Fuels (SAFs) or drop in fuels (fuels that can work with existing jet engines) need to have similar properties to jet fuel. They often blend them with conventional jet fuel. Most SAFs need to be blended 50:50. And even though some SAFs boast significant emission reductions, none of them are being produced at scale yet. Most are based on biofuels, which are an imperfect solution even if they are far better than regular fossil fuels. (When the fuel source is a food crop, the process still contributes to deforestation because land is needed to grow the additional crops). It is going to take another three to five years more development time to create 100% SAF fuels.
Airlines are also looking at new materials and coating technologies to make planes lighter, more aerodynamic, and more resistant to wear and tear. Meanwhile, a few airlines, such as United, think they can get to carbon neutrality by reintroducing supersonic flight. The jury is still out on that one though.
Some companies, such as Airbus, are looking to hydrogen as a fuel, since it combusts to produce water vapour. But developing H2-burning engines is still in its early stages.
Looking to 2050, air travel is one of those areas which is going to need some serious research and innovation. Hybrid-electric technology, which combines batteries with traditional jet fuel engines, is another promising strategy, with companies like California-based startup Ampaire and France’s VoltAero already developing hybrid planes. Hybrid flights will offer fuel and energy savings, emissions reductions, and help us get used to the idea of electric flights, quite similar to what the Toyota Prius did for EVs.
Consumer purchasing power
But we must remember that as businesses and consumers we hold the purchasing power to help drive a greener aviation industry. We must demand cleaner, greener, quieter, lower-cost ways to fly. To tackle the out-of-control emissions from the aviation sector there needs to be more flight reductions, short-haul flight bans, and investment in alternative greener modes of transport, such as rail.
Without wide scale and urgent action greener fuels or electric planes will only provide emissions cuts that are far too little or far too late for today’s demand.
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