So Williams ran a climate model that looked at the atmosphere over the Atlantic Ocean, which currently sees about 600 flights per day. He factored in the sort of doubled carbon dioxide, warmer climate conditions that are expected in coming decades. What he looked for, in particular, were changes in the stratosphere's jet stream that could lead to more areas of turbulence.
One of the biggest signs of more turbulence is more wind shear, which is where fast-moving air is roaring right alongside a layer of slower moving air. That sort of situation creates unstable air and turbulence.
"Climate change is increasing the destabilizing influence," said Williams, whose work is published in the April 8 issue of the journal Nature Climate Change.
Long-term climate models and even daily aviation weather models can't predict the turbulence itself, but they can predict the conditions that are known to be associated with clear air turbulence, explained John Knox, a clear air turbulence forecast researcher at the University of Georgia. It's the same thing that's done in forecasting tornadoes.