The lines observed behind planes are simply ice crystals. Aircraft contrails represent about 35% of the aviation-related warming effect, according to calculations made by the IPCC, though there is a lot of uncertainty behind the numbers.
But Why Are Aircraft Contrails Responsible for Warming?
Contrails emit a certain amount of sunlight during the day, thus having some cooling effect but, in turn, have a greater warming effect during the night. Contrails created by the small percentage of flights, 2-10% of total flights, are responsible for around 80% of warming.
Is There a Way for Flight. Pilots to Avoid Them?
American Airlines conducted 70 test flights in 2023 based on AI forecasts that resulted in 54% less contrails formed while using 2% more fuel. A study of 2400 flights in 2025 showed that the method can actually help lower the contrails formation by 62%, with dispatchers using the method in less than 1% of flights.
What Happens Next in This Sphere?
The UK and Google are trying to change the altitude on hundreds of flights above the north-east Atlantic; this method should effectively lower the costs of the impact to the climate.
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