Changes to some airline flight routes could reduce aviation’s climate impact by 10% at minimal incurred cost, say European scientists.

Researchers analyzed 85 alternative routes for each of about 400 daily trans-North Atlantic flights in either direction. Simulations of a climate-optimized routing strategy for five representative winter and three representative summer days show potential to reduce the climate impact of aviation by roughly 10% at costs of around 1%.

This cost-efficient reduction in the climate impact is mostly achieved by avoiding the formation of warming contrails and by producing cooling contrails, the researchers say. The low cost increase, primarily attributed to fuel use, could be compensated by market-based measures, if costs for non-CO₂ climate impacts were included.

The scientists say that additional research is needed to assure that calculation of the climate change functions are robust and fast enough to become operational. Consensus should be achieved on the extent to which additional contrail formation be allowed, they say. The implications on air traffic management must also be identified, and a market-based measure or alternative measures should be developed to foster climate-optimal routing.

Participating in the study were scientists from the University of Reading (UK), DLR Institute of Atmospheric Physics (Germany), Eurocontrol (Belgium), and the Center for International Climate and Environmental Research (Norway).