Decarbonizing Aviation Is Necessary to Achieve Climate Goals

On November 5, 2021, Forbes reported 118 private jets had landed at Glasgow and Edinburgh airports since the start of COP26, responsible for burning over 1,000 metric tons of jet fuel. In particular, English Prime Minister Boris Johnson came under fire for flying in a private jet from London to Glasgow for a dinner. 

Pundits see this as a sign that leaders are committing to big promises but little action, even eliciting critical comments from activist Greta Thunberg. Another perspective is that society is simply inefficient in its use of air travel in the short term, so stakeholders need to prioritize environmental action and conversations on decarbonization solutions.  

Airlines Experiment with Green Aviation

There is hope for a green aviation sector. Though technologies are still experimental, progress is being made. For example, Rolls-Royce recently completed a 4-hour test flight running a Boeing 747 on 100% sustainable aviation fuel (SAF). Chemically similar to fossil-based fuels and produced from a variety of renewable resources such as leftover restaurant cooking oil, SAF can be delivered and consumed within the existing aviation energy system and achieve significant greenhouse gas reductions on a gallon per gallon basis. Since 2016, over 370,000 other such flights have taken place, though usually at a blended rate of up to 50%. 

Progress is evident in several other examples as well. Airbus is investing in finding a way to make planes run on hydrogen. Other disruptive startups such as ZeroAvia are pioneering hydrogen plus electric planes. It hopes to have its first commercial offering by 2024. Another startup, Ampaire, created the Electric EEL, a hybrid-electric three-seater adapted Cessna. It has completed several flights, the first of which was in 2019. In 2021, it completed its first UK trip. 

Costs Remain a Strong Barrier

However, widespread adoption of SAF, hydrogen, or electricity in aviation is still far off. The prices of SAF and hydrogen need to be brought down to compete with fossil fuels, and battery energy density is too low to be feasible for most commercial operations. Green hydrogen costs anywhere between $3/kg and $8/kg whereas SAF costs around $2,124/ton. In comparison, jet fuel costs around $329.25/ton. To make decarbonization solutions competitive, strong policy signals are needed to encourage investment from the private sector and industry leaders. 

In a post-pandemic world, compelling enough people to fly less to make a sizeable dent in CO2 emissions is wishful thinking. Airlines are already pushing prices down to attract more customers, and countries will be keen to attract more tourists to help rebound their economies. The only way to seriously reduce emissions is to decarbonize aviation energy sources.