Net-zero aviation needs up to $1 trillion in carbon offsets by 2050
Growing demand for air travel is counteracting the aviation industry push to achieve net-zero emissions by 2050. Carbon offsets will be necessary – or fewer passengers
30 January 2023
Surging global demand for air travel and air freight transport means that the aviation industry would need to spend $1 trillion in carbon offsets by 2050 to achieve net-zero climate impacts – unless both the industry and frequent fliers abandon the business-as-usual approach.
The estimate comes from a study of pathways the aviation industry could take to reach net zero. The industry’s climate impacts include carbon emissions from burning jet fuel – aviation contributed 3 per cent of global carbon emissions from burning fossil fuels in 2019 – and even bigger factors such as aircraft contrails that can create more heat-trapping clouds within the earth’s atmosphere.
Steven Davis at the University of California, Irvine, and his colleagues modelled nine scenarios to map out the carbon cost of aviation until 2050. Even the rosiest of them – which envisioned lower demand for aviation, significant improvements in energy efficiency and high usage of sustainable aviation fuels – found that the aviation industry would still need to spend at least $60 billion on carbon offsets by 2050.
“The industry cannot achieve net-zero climate impacts without some [carbon] removal,” says Davis.
Some airlines may be tempted to generally buy carbon offsets rather than directly reduce their climate impacts if that proves the cheapest route. But “there is a lot of debate regarding carbon removals” and whether they have a meaningful impact, says Candelaria Bergero at the University of California, Irvine.
Reduced demand for air travel could make a significant contribution toward net-zero aviation – but the trends are pointing in the opposite direction. “Changes in demand could be a really important source of emissions reductions, but all of our scenarios anticipate overall increases in demand by mid-century given expected growth in global population and affluence,” says Davis.
Substituting biofuels or synthetic fuels can help, but only up to a point. Without extreme reductions in aviation demand, the demand for sustainable aviation fuels in all scenarios would be more than double the total global production of biofuels in 2019. Doubling the production of biofuels would require the world to set aside as much as 3 million square kilometres of land for crops – equivalent to one-third the size of the US.
And despite the fanfare around hydrogen-powered aircraft or electric planes with improved batteries, such technologies are unlikely to contribute significantly to reducing aviation climate impacts because they can only power smaller aircraft and sustain short flights, says Davis.
The aviation industry has an ambitious target of improving aircraft energy efficiency by 2 per cent or more per year, which alone could offset more than half of future growth in demand for air travel, says Davis.
“The cost reduction of zero-emission aviation requires new technologies with greatly improved efficiencies both in fuel production and in aircraft propulsion,” says Grigorii Soloveichik, a former program director for the US Advanced Research Projects Agency-Energy.
Meanwhile, companies making conscious business travel decisions could encourage the industry to move toward net-zero aviation. “I see real opportunities for corporate action that prefers more efficient aircraft, low-contrail flights and especially increased demand for sustainable aviation fuels,” says Davis.
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