Weather always makes good news, but the role of climate change in altering weather, especially extreme weather, has made the subject a lightning rod for unease.
A case in point this week: A heat wave is triggering record temperatures in the Southwest. American Airlines reported having canceled up to 50 flights at Phoenix’s Sky Harbor airport, where the temperature has neared 120 degrees in recent days.
Flight cancellations are a perfect foundation for climate-change panic. Commercial air travel is an aspect of ordinary life that touches everyone: Travelers can’t help but worry that their mobility will be impacted by near- and long-term effects of climate change. Much of the coverage tracking the American Airlines cancellations pegs climate change as a direct or indirect cause of the disruption.
That account isn’t wrong. But it doesn’t tell the full story, either.
When I asked, American Airlines cited a 118 degree “maximum operating temperature” for the flights in question, and confirmed that “the heat has impacted some of our regional flights.” But airplanes don’t exactly have such neat and tidy maximum temperatures. Temperature limits might affect avionic systems—the electronics that run communication, navigation, and so forth—but temperatures interact with airplane performance more than they allow or prohibit flight itself. Density altitude, which can change in part based on temperature, affects aerodynamic performance of specific aircraft, but that performance also interacts with other factors, including weight.