Replacing conventional jet fuels with climate-friendly alternatives derived from plants would cost up to $60 billion a year from 2020 to 2050, the UN’s aviation body has estimated.
Around 170 new bioenergy refineries would need to be built every year through to mid-century, catering for annual growth of 4% through 2030 and beyond.
Meeting this target would require a “large share” of bioenergy resources to be devoted to the aviation sector, said the International Civil Aviation Organisation (ICAO) report.
“Even under this scenario, achieving carbon neutral growth exclusively from the use of sustainable alternative fuels is unlikely to happen in 2021 or shortly thereafter as for the production of alternative fuels an initial ramp-up phase is required before production can reach the levels mentioned above,” it reads.
Many hunger campaigners already oppose current levels of biofuels, arguing they use farmlands in poorer parts of the world that could supply food to millions.
The study suggests the industry will rely heavily on offsetting its greenhouse gas emissions from 2020, the year countries have committed to carbon neutral aviation growth.
By the end of the decade CO2 emissions from flying are likely to hit 682-755 megatonnes, says ICAO. By 2050 that figure could hit 2,500 MT.
Better engines, paints, flying techniques and improvements to infrastructure could knock off just under 1,000MT a year, leaving a gap of 1,039MT.
“Sustainable alternative drop-in fuels are the only practical renewable energy option available for aircraft today,” says Boubacar Djibo, head of ICAO’s airport transport bureau in the report.
“While the technical feasibility, environmental impacts and safety of biofuels have been well-demonstrated, integrated thinking is now required to accompany their large-scale deployment.”
Aviation accounts for 2% of global emissions of carbon dioxide, but it’s a figure expected to rise as the industry expands through Asia, Africa and South America.
Malawi, Uganda, Serbia, Sierra Leone, Vietnam and Ethiopia are among countries projected to see 7-8% growth in flights each year.
Talks on developing a market-based mechanism to tackle aviation emissions are ongoing, with a UN deal expected in Montreal this October.
But given projected emissions growth, costs of offsetting emissions are likely to be steep, ranging from US$1.5-6.2 billion in 2025 to $5.3 to 23.9 billion in 2035, depending on carbon prices.
“Putting in perspective with the reality of the business, the analysis also shows that the cost of carbon offsetting for operators would range from 0.2 to 0.6 % of total revenues from international aviation in 2025; and 0.5 to 1.4 % of total revenues from international aviation in 2035,” says the report.
Last week the US government signalled its intention to deliver a UN deal in the autumn, releasing a study warning of the climate and health risks posed by aviation emissions.