The research explored how rising global temperatures influence jet streams at cruising altitudes commonly used by aircraft, typically around 35,000 feet or approximately 10 kilometres. Using advanced modelling techniques, scientists evaluated atmospheric conditions at these high altitudes to understand how climate change could alter air stability and turbulence patterns. The results showed that as the planet continues to warm, the skies where airplanes usually travel may become increasingly unstable, exposing aircraft to higher risks of turbulence during flights.
Researchers from the University of Reading in the UK built upon earlier work that had already highlighted a concerning trend. Their previous study demonstrated that severe turbulence had risen significantly over the past four decades, with recorded cases increasing by 55 per cent, moving from 17.7 hours in 1979 to 27.4 hours in 2020. These findings provided the foundation for the current study, which delves deeper into the mechanisms behind this growing problem.
One of the key factors identified is the strengthening of wind shear within jet streams. Jet streams are powerful air currents that flow rapidly around the globe at high altitudes, guiding weather patterns and influencing aviation routes. Climate change is now intensifying the temperature gradients that feed these air currents, thereby strengthening wind shear. This change in atmospheric dynamics has major implications for aviation safety, as stronger wind shear tends to increase turbulence.
The study, published in the Journal of the Atmospheric Sciences, projected that wind shear could intensify by as much as 16 to 27 per cent by the end of the century. At the same time, atmospheric stability at cruising levels could decline by 10 to 20 per cent between 2015 and 2100. This dual impact of stronger wind shear and reduced stability creates an environment where clear-air turbulence, or CAT, becomes more frequent and severe. Crucially, the study predicts that both hemispheres of the Earth will be affected, meaning no part of the world’s aviation routes can expect to escape these challenges.
Clear-air turbulence is particularly dangerous because it is invisible to the naked eye and cannot be detected on aircraft radar systems. Unlike turbulence caused by storms or cloud formations, CAT occurs in clear skies without visual cues, often striking planes suddenly and without warning. Lead author Joana Medeiros, a PhD researcher at the University of Reading, emphasized that this form of turbulence is especially challenging because pilots cannot easily anticipate or avoid it, making passenger safety more difficult to guarantee.
The research team relied on 26 global climate models to simulate how rising greenhouse gas emissions impact atmospheric circulation at flight altitudes. Both moderate and high-emission scenarios were analysed, but the most severe turbulence conditions were linked to the highest levels of emissions. This underscores the connection between human-driven climate change and the future safety of global air travel.
The findings clearly suggest that clear-air turbulence will become more common and more severe in the coming decades, presenting significant operational and safety challenges for the aviation industry. Airlines may need to implement stricter precautions, such as keeping seatbelt signs switched on for longer durations and suspending in-flight services more frequently. These measures, while necessary, may also affect passenger comfort and the efficiency of flight operations.
Co-author Paul Williams, a professor of atmospheric science at the University of Reading, highlighted the real-world consequences of turbulence, pointing out that recent years have already witnessed incidents leading to serious injuries and, in rare but tragic cases, fatalities. He noted that the aviation industry must adapt not only through procedural changes but also by investing in advanced technologies capable of detecting turbulence in advance. Such innovations would allow pilots to avoid dangerous air pockets and provide passengers with safer, more stable journeys, even as the skies grow increasingly turbulent due to climate change.
