For the climate, it matters when and where you fly

Climate Progress

As fall begins its descent, and people start pulling sweaters out from the backs of closets, the sun-seekers among us are already online browsing flights to warmer climes. For the climate conscious, flying has always been a guilty pleasure, but nowresearch from MIT may help those bitten by the travel bug avoid the most climate polluting flights.

Out of 83,000 flight routes studied by the researchers from MIT’s aeronautics department, flights to and from Australia and New Zealand in October were guilty of creating the highest amounts of a potent global warming pollutant – tropospheric ozone. Tropospheric ozone is created when nitrogen oxides, released during the burning of jet fuel, react with carbon monoxide and other chemicals in the presence of sunlight.

The area around the Solomon Islands in the Pacific was found to be the most sensitive to airplane emissions. Here, just 1 kilogram of nitrogen oxide emissions can cause an additional 15 kilograms of tropospheric ozone annually. A flight from Sydney to Mumbai results in an extra 25,000 kilograms of tropospheric ozone.

This isn’t the first research to recommend rerouting certain flight paths. Last December, researchers from Stanford published data showing how flying around, rather than over the Arctic could help preserve precious climate stabilizing polar ice for a bit longer, buying the world more time. While skirting the Arctic would increase the total amount of fuel burned, the researchers argued that it would mean that aviation emissions would be dumped in a less stable part of the atmosphere where precipitation would quickly wash climate-damaging black carbon out of the air.

Worldwide, aviation is a huge source of greenhouse gas pollution. Every year, commercial planes account for two percent of global carbon dioxide emissions and dump enormous amounts of short-lived but highly potent black carbon high up in the atmosphere. Moreover, aviation has the fastest-growing emissions of any transportation sector. By 2050, theEuropean Commission predicts that emissions from international flights will have grown by 300 to 700 percent.

At the end of the month, the International Civil Aviation Organization(ICAO) is scheduled to meet in Montreal to discuss mechanisms for reducing aviation-related greenhouse gas emissions. The U.S. has already legislated to protect itself from the European Union’s plan to charge a fee for aviation emissions on all flights originating or ending in Europe.