Aviation’s Biggest Environmental Impact Isn’t What You Think

Condensation trails, or contrails, are the bane of nature photographers. The wispy, ice clouds produced by jet aircraft insert the unwanted hand of man into otherwise pristine, natural images. Contrails are also surprisingly bad for the environment. A study of aviation’s contribution to climate change over the last 20 years found that contrails created 56% of aviation’s impact. That’s considerably more than the carbon dioxide emissions from burning fuel. The contrails trap heat which would otherwise be released into space.

Good news, though. Contrail formation may be one of the easiest environmental problems to solve. Research has shown that 80-90% of the climate impact comes from 5-10% of all flights. Since the atmosphere must be cold and humid for contrails to form, weather prediction models can forecast the conditions that lead to their development. Simply redirecting a small portion of flights—changing the plane’s altitude or route to avoid the most at-risk parts of the atmosphere—could prevent the majority of contrail impact on the environment.

A British company, Satavia, is working with airlines to analyze their daily schedules and modify the flights of the 5% most likely to generate contrails. Their biggest challenge is working around limitations on flight time and fuel consumption. No more than five minutes may be added to the flight time and fuel consumption is kept within tenths of a percent of the original flight plan. A 0.1 or 0.2% increase in fuel consumption could potentially save hundreds of tons of carbon dioxide from being added to the atmosphere.

In the U.S., the Rocky Mountain Institute, a non-profit energy think tank, recently launched a cross-sector task force to address the contrail issue. Boeing, Airbus, American Airlines and United are among the companies already on board with them. With cooperation across the industry, 50% of contrail impact could be nearly eliminated by 2030.