Small tweaks to flight paths could reduce the effects that aircraft have on climate by as much as 10%, a new study shows. For a roughly 1% increase in operating costs, airlines could make significant climate change cuts by optimising their routes according to the weather, time of day and time of year.
Aircraft affect Earth’s climate by emitting greenhouse gases, and creating contrails, which alter the way radiation is reflected back to space. An estimated 5% of manmade climate change is caused by global aviation, and this number is expected to rise. But Keith Shine, a meteorologist at the University of Reading, and his colleagues show this could be reduced if flights were routed to avoid the regions where their emissions have the greatest effect on climate.
The scientists modelled routings for 800 daily transatlantic flights, under typical winter and summer weather patterns. Using a chemistry climate model, they investigated 85 flight path variations, and worked out which were most ‘climate-friendly’.
Their results, which are published in Environmental Research Letters, found that some routes had a much larger effect on climate than others. For example, contrails (which usually cause warming by trapping radiation) could be reduced by avoiding regions where the atmosphere is saturated with ice crystals, because these conditions encourage the formation of contrails.
The increased fuel and staff costs (associated with rerouting) would add about 1% to operating costs, the scientists calculate. “Climate-friendly routing of aircraft has an exciting potential to decrease the climate impact of aviation, without the need for costly redesign of aircraft, their engines and airports. With more targeted research, it could become a reality in the next 10 years,” says Shine.