Contrails, Aviation, and Climate Change

Magazine article, 2025

Aviation impacts the climate in several ways. In addition to carbon dioxide (CO2) emissions from the combustion of jet fuel, there are also the climate impacts of nitrogen oxides, particles, water vapor, and condensation trails, or contrails, white cloudlike streaks sometimes visible in the sky. Out of the non-CO2 effects, contrails are the most important, and in terms of climate impacts, they are broadly comparable to the carbon dioxide emissions from aviation.

How are contrails formed? How do they affect the climate? And what can be done to reduce them? In this paper, we try to answer these questions.