RESEARCH BRIEFINGS 01 April 2026 The contrail clouds formed by jet engines contribute to global warming. In-flight measurements of the particles emitted and contrails produced by a passenger jet show that contrails are formed through different mechanisms, depending on the soot-emission level and the fuel composition, potentially reshaping our understanding of the climate impact of aviation. This is a summary of: Voigt, C. et al . Substantial aircraft contrail formation at low soot emission levels. Nature 652 , 112–118 (2026) . doi: https://doi.org/10.1038/d41586-026-00931-z ‘Expert opinion’ and the figure are published under a CC BY 4.0 licence. References Lee, D. S. et al. Atmos. Environ. 244 , 117834 (2021). Article Google Scholar Teoh, R. et al. Atmos. Chem. Phys. 24 , 6071–6093 (2024). Article Google Scholar Kärcher, B. Nature Commun. 9 , 1824 (2018). Article PubMed Google Scholar Burkhardt, U., Bock, L. & Bier, A. npj Clim. Atmos. Sci. 1 , 37 (2018).…