More bumpy flights: Researchers say climate change is increasing turbulence

Flights are getting bumpier according to a new analysis of turbulence over the past four decades, a trend that scientists say is caused by a warming climate.

Researchers at the University of Reading in the UK found clear-air turbulence is 55% more frequent today than it was in 1979.

"Basically, we're seeing a large increase in turbulence across all the seasons," said Isabel Smith, one of the researchers for the study.

In the U.S., severe clear-air turbulence has increased by 41% since 1979. While there is variability year-over-year, scientists say there's a clear long-term upward trend, consistent with the expected effects of climate change.

Researchers say increases in this invisible and hazardous turbulence are due to greenhouse gasses trapping heat in the lower-level troposphere, widening the gap in temperature with the higher stratosphere.

"So, it's this temperature gradient that's increasing over time and it's leading to a faster and more chaotic jet stream, which is then leading to more instances of clear-air turbulence," Smith said.

Researchers predict frequency of this turbulence will continue to rise, impacting airlines and passengers.

"Because we're trying to avoid the turbulence and jet stream as much as possible, there are likely to be more delays and more convoluted flight routes, which will lead to more emissions," Smith said.

Clear-air turbulence also present safety risks, because it can be difficult for current equipment and pilots to see and avoid.

"Encounters with severe turbulence can be quite serious and dangerous," Smith said. "A good reminder to always wear your seat belt when flying."