Remy Gabalda/AFP/Getty Images

More and more research is showing that as the planet becomes warmer due to climate change, there will be an increase in turbulence by the middle of this century, especially in the Northern Hemisphere, scientists say.

"Climate change is strengthening the north-south temperature difference that drives the jet stream," Dr. Paul Williams of the University of Reading told CNN. "A stronger jet stream is less stable and means more clear-air turbulence." Clear-air turbulence is caused by quick changes in the speed or direction of air movement, and it most commonly takes place in and around the jet stream, an invisible current of fast-moving air that can be found around 30,000 to 40,000 feet above the ground.

Last month in the journal Advances in Atmospheric Sciences, Williams and his team published research using model simulations of a warming climate that showed increases in turbulence of all types, but especially "severe turbulence," CNN reports. "Increases in light and moderate turbulence will not injure anyone, but they will cause anxiety amongst nervous fliers," Williams said. "On the other hand, the 149 percent increase in severe turbulence that we have calculated does have the potential to cause more serious injuries." For more on how the jet stream affects turbulence and how this could lead to higher ticket prices and longer trips between North America and Europe, visit CNN.