Is net-zero aviation by 2050 feasible?

The expected growth in demand for air travel implies a significant rise in number of flight operations. The latter would undoubtedly cause an increase in fuel burn, jet emissions, and airport noise levels; environmental effects that regulatory bodies have been striving to limit drastically. Vehicle technologies, operational improvements and sustainable biofuels are among the solutions considered to achieve aggressive environmental targets set by the International Air Transport Association (IATA).

For 40 different scenarios considered, it was shown that for high demand growth, the IATA goals are not feasible. However, with medium and low demand growth, coupled with high technology introduction rates and faster retirement of old aircraft, it was shown that the goals are feasible.

Even before the coronavirus pandemic began, the industry was facing the challenge of reducing its carbon emissions in line with international goals to reach net-zero emissions by 2050. Forces that have buoyed the case for sustainability - including customers and regulators worried about emissions and unpredictable future carbon policies - have shifted with the pandemic, as airlines' survival seems to be at stake.

The industry has a solid record on fuel efficiency: fuel burn per passenger-kilometer has dropped by half since 1990, according to the International Air Transport Association. The current crisis could provide forward-thinking airlines with a chance to emphasize their fuel-efficiency programs and justify the retirement of older, less-fuel-efficient aircraft. Modernizing fleets and improving operational efficiency are important; however, in the best case, annual industry growth counters the emissions that they save. Carbon offsetting holds more promise, and it can help serve as a bridge while the industry takes action needed to reduce its own emissions over time.

The option that could be transformative, aligning the industry's growth ambitions with Paris Agreement targets, is sustainable aviation fuel (SAF). Compared with fossil kerosene, SAF could mean a reduction in carbon emissions of 70 per cent to almost 100 per cent. While SAF has drawbacks, including high prices and supply concerns, airline CEOs should view it as a promising tool in their decarbonization tool kits. To help push options forward, airlines can make targeted investments and purchase commitments that would increase SAF use (currently at less than 1 percent of total consumed jet fuel) while reducing costs.

Business aviation has been on a par with forecasted CO2 emissions since 2015, and it has improved its fuel efficiency by 2 per cent each year between 2010 and 2020. It is also on a trajectory to achieve carbon-neutral growth from 2020 and to accomplish a 50 per cent reduction in CO2 emissions by 2050 relative to 2005.

The bottom line is that the industry is now on track to reach about four million tonnes of CO2 emissions by 2050 as an industry, which would represent about a 70-75 per cent reduction compared to 2005.

The whole point behind SAF is to get it to a price that is comparable to that of traditional jet-A, so all of this is kind of coming together through these technical tests and seeing what is economically viable.

On the technology side, an unprecedented collaboration among OEMs helped to establish a spreadsheet to evaluate various improvements in aerodynamics, engines, and weight reduction as to their potential emissions reductions and their expected entries into service. Given the amount of competition that the industry is used to, is a great example of us being able to put this aside and really focus on what matters for the overall industry.

Use of advanced biofuels is a likely near-term solution. The technical feasibility of fuel made from vegetable or waste oils is proven, the product is certified, and some airlines use the fuel in daily operations. But getting the appropriate feedstock and supply chain in place is difficult; building production facilities and refineries is costly. Used cooking oil, a popular ingredient for biofuel, has fragmented availability and is expensive to collect. Other vegetable oils have high costs of production, collection, transportation, and conversion to fuel.