New Energy World™
New Energy World™ embraces the whole energy industry as it connects and converges to address the decarbonisation challenge. It covers progress being made across the industry, from the dynamics under way to reduce emissions in oil and gas, through improvements to the efficiency of energy conversion and use, to cutting-edge initiatives in renewable and low-carbon technologies.
Blue sky thinking: fighting climate change by avoiding contrails
15/10/2025
8 min read
Feature
Recent evidence suggests that civil aviation harms the climate not only through carbon emissions, but also by creating cloud layers that trap the sun’s heat like a blanket. Work done as part of European research is finding ways to reduce their effect by preventing these clouds forming in the first place. Technology currently in trial phase is proving able to reduce the climate effects of aviation by nearly 25%, for an additional fuel cost of 3%, or less, finds New Energy World Senior Editor Will Dalrymple.
Exhaust plumes stream out the back of aeroplanes, drawing straight white lines across the blue vault of the sky. Known as contrails, these artificial clouds are made of ice crystals that coalesce around particles of soot from engine emissions. Under certain conditions of temperature and humidity, these formations don’t dissipate into thin air but broaden out and hang around for hours.
But at the edges of these clouds is a silver lining. First, the effect is uncommon; although all flights emit soot, only a few percent cause planet-heating contrails. Second, meteorologists understand much about cloud formation, the atmospheric parameters which are required for damaging contrails to form (cool and moist). Apparently, those zones with the atmospheric conditions most prone to creating contrails can be pancake-shaped: if not necessarily round, they spread over a wide area but are not very deep.
Taken together, this atmospheric data and analysis suggests that where a contrail risk zone occurs, aeroplanes can avoid creating contrails simply by avoiding a certain volume of air.