Long-term aviation fuel decarbonization: Progress, roadblocks, and policy opportunities

Aviation is widely seen as the transport sector that is most difficult to decarbonize.  One option to dramatically reduce emissions within the aviation sector is through the use of low-carbon alternative fuels. This briefing paper reviews the progress and challenges to the commercialization of alternative aviation fuels and provides recommendations on policy priorities globally for the next five to 10 years.

Although some progress has been made in alternative jet fuels, significant challenges remain. The bottleneck is not just in commercializing advanced fuel conversion processes; there are barriers up and down the alternative fuel production chain, from feedstock supply to fuel conversion, upgrading, blending, and delivery.

Strong policy support for advanced fuel technologies is needed to shift from petroleum-based fuels to sustainable, low-carbon alternatives in the mid-century time frame. The most pressing challenges in supplying sustainable alternative jet fuel are common to advanced alternative road fuels. These barriers will be most effectively addressed with common policies and incentives such as mandates, fiscal incentives, and grant programs offered to all fuel types. In the near to medium term, it will also be important for governments to directly support sustainable feedstock supply chains. Programs such as long-term government procurement contracts can help bridge that uncertainty gap until strong feedstock demand is clearly established by the cellulosic biofuel industry.

More aggressive policy changes will be necessary to accelerate the advanced low-carbon fuels industry. Because it will likely take a long time to fully ramp up the advanced fuels industry to displace a high share of liquid fuel demand, stronger incentives than those under consideration by progressive countries now will be needed in the 10 to 15 year time frame.