Altering flight routes may cut climate impact: study

Airlines could reduce their climate impact by up to 10 per cent by making small changes to some flight routes, a new study has found.
The study by researchers at by University of Reading in the UK shows airlines could make a large positive impact on climate change by altering flight routes to avoid areas where emissions have the largest impact.
The changes would be comparatively small - resulting in only around a one per cent increase in operating costs.
"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," said Professor Keith Shine from Reading's Meteorology Department.

"With more targeted research, it could become a reality in the next 10 years," said Shine.
"Around 5 per cent of man-made climate change is caused by global aviation, and this number is expected to rise. However, this impact could be reduced if flights were routed to avoid regions where emissions have the largest impact," said Volker Grewe, Professor at the Delft University of Technology in The Netherlands.

"Aviation is different from many other sectors, since its climate impact is largely caused by non-CO2 effects, such as contrails and ozone formation. These non-CO2 effects vary regionally, and, by taking advantage of that, a reduction of aviation's climate impact is feasible.

"Our study looked at how feasible of such a routing strategy is. We took into account a representative set of weather situations for winter and summer, as well as safety issues, and optimised all trans-Atlantic air traffic on those days," said Grewe.
Using calculations of emissions, climate change functions, and air traffic simulations, the research team evaluated 85 alternative routes (17 horizontal and five vertical) for each of the roughly 400 flights crossing the North Atlantic in either direction each day.
"Our results show that under appropriate framework conditions and regulations, cost-effective climate-optimised routing has the potential to significantly reduce the climate impact from aviation," Grewe said.

"We adopted a detailed modelling framework to estimate the benefits and costs of air traffic routing options over the North Atlantic.
The results for five representative winter and three representative summer situations show the potential to reduce the climate impact of aviation by roughly 10 per cent at relatively low costs of 1 per cent," said Grewe.
The study showed that, in all-weather situations, routes could be found that reduced the climate impact at low costs, though the intensity in climate impact reduction varied.
The research was published in the journal Environmental Research Letters.