Global warming is one of the greatest challenges of our time. As the world comes together to reduce greenhouse-gas emissions and limit global warming to 1.5 degrees compared with pre-industrial levels, the World Economic Forum’s Clean Skies for Tomorrow (CST) Coalition has set out to identify and address the challenges of decarbonizing the aviation sector (see sidebar, “About Clean Skies for Tomorrow”).
Closing the gap to a 1.5-degree pathway as outlined in the Paris Agreement will require rapid decarbonization in every industry. Transportation—which contributes nearly a quarter of total energy-related CO2 emissions—is falling behind, while other sectors are on track to meet EU climate targets.
The time to act is now. As travel and tourism ramp up, aviation will again produce about 3 percent of total carbon emissions, plus other greenhouse gases that contribute to global warming. Hybrid-electric and hydrogen-powered aircraft could help the industry reach the next efficiency horizon, but developing them could take ten to 20 years, and the technology will be initially limited to smaller aircraft.
To reduce the industry’s carbon emissions, the CST Coalition’s leaders aim to scale the most promising option: sustainable aviation fuel (SAF). Synthesized from renewable feedstocks—such as municipal waste, agricultural residues, and waste lipids—SAF has already fueled more than a quarter million commercial flights. In addition, it is fully compatible with existing aircraft and fuel infrastructure.
Indeed, a transition to SAF is in reach: enough feedstock will likely be available to fuel all aviation by 2030.
Ramping up production will require the industry to scale new technologies that run on less-constrained feedstocks. To create commercial quantities of power-to-liquid fuels or e-fuels that are made only from CO2 and green electricity, technology will need to mature, and much more renewable electricity must be available.
In 2019, fewer than 200,000 tons of SAF were produced globally, a tiny fraction of the roughly 300 million tons of jet fuel used by commercial airlines. If announced SAF projects are completed in the next few years, capacity will scale to at least four million tons—about 1 percent of global jet fuel demand in 2030. In the near term, hydroprocessed esters and fatty acids fuels (produced from waste lipids) will contribute most of the capacity buildup, though smaller companies are now testing and refining alternative pathways that will take longer to scale up.
As the SAF industry innovates, costs will decline. Facilities will scale, technologies will mature, and inputs such as green electricity will become less costly. There is no silver bullet, however—no single feedstock or production pathway will be practical in every geography or yield enough SAF to meet all demand. Even as costs fall, SAF will almost certainly remain more expensive to produce than fossil fuel.
To make SAF economically viable and scale production, several advances will be required: a supportive regulatory framework, measures to stimulate demand from corporate and private customers, and innovative ways to finance the transition. The CST Coalition is debating how to meet these challenges and help aviation earn its right to keep growing.
Stakeholders that propose to conduct business as usual and wait for a technological miracle must change their mindset. The long-term effects of climate change are already underway. And hope is not a strategy.
Download Clean Skies for Tomorrow: Sustainable aviation fuels as a pathway to net-zero aviation, the full report on which this article is based (PDF–9.02MB).