As climate change continues to have an effect on global temperatures and weather patterns, commercial airlines are having to adapt their flight schedules to ensure their passengers’ safety, reports Zach Wichter for The New York Times. Planes rely on the density of air molecules beneath their wings to take off, but the rise in temperature means thinner air and less lift. With extreme heat, like that experienced this week in Phoenix, Arizona, flights will cancelled because planes will not be able to take off. Climate change threatens to ground more and more planes in the future, and airports will have to adapt, whether that means cancelling mid-day flights or extending runways when possible.

The jet stream has also been affected by climate change, and west-bound flights have gotten noticeably longer over the past decade. Flying into a headwind takes longer and burns more fuel, forcing some planes to make unplanned landings to refuel before reaching their final destination. A stronger jet stream also leads to more turbulence, making flights less comfortable and more dangerous for passengers. As the planet warms, these problems pose a greater threat, and airlines are starting to recognize it.