Improving aircraft fuel efficiency ranks #43 on the Drawdown list of climate solutions, with the potential to reduce atmospheric carbon dioxide by 5.05 gigatons by 2050. The shift would cost US$662.4 billion, but produce net savings of $3.19 trillion.
“Some 20,000 airplanes are in service around the world,” writes Drawdown, “producing at minimum 2.5% of annual emissions” [and that impact is set to rise as international aviation continues to slow-walk meaningful greenhouse gas reductions—Ed.]. With the global fleet expected to more than double by 2040, “fuel efficiency will have to rise dramatically if emissions are to be reduced.”
Drawdown concludes that “efficiency trends are headed in the right direction,” with domestic flights in the U.S. boosting fuel efficiency by 40% between 2000 and 2013. International flights became 17% more efficient over the same period.
For the next round of improvements, research is focusing on building lighter-weight engines using materials such as ceramics and carbon fibre.
“Estimates suggest more dramatic redesigns,” like moving engines to the rear of the aircraft, “would result in efficiency gains of 50 to 60%,” Drawdown states.
Beyond that, “simple operational shifts” such as treating “taxi, takeoff, and landing as uniquely fuel-consuming legs” can further trim an aircraft’s fuel consumption. MIT researchers have discovered that “taxiing on a single engine, rather than both, [is] the most effective measure for reducing fuel use on the ground, where aircraft spend 10 to 30% of their transit time.”
What is not yet off the ground, writes Drawdown, is the continuing hope for truly viable biofuel options. While work on algae-derived fuel, in particular, continues, “cost is high, supply is limited, and infrastructure is poor.”
Likewise lacking lift is industry motivation to voluntarily double down on fuel efficiency, making government regulation combined with activist, consumer, and investor pressure a key to rapidly reducing emissions.