LONDON -- Tourists, exchange students, masters of the financial universe and other business travelers: It's time to buckle up.
More pollution is likely to mean bumpier flights for trans-Atlantic travelers, researchers say, predicting increased turbulence over the North Atlantic as carbon dioxide levels rise.
"We looked at the effect of climate change on aviation," he said.
In a paper published Monday in the journal Nature Climate Change, Joshi and colleague Paul Williams ran a climate simulation that cranked up the level of carbon dioxide in the atmosphere to twice its preindustrial level -- roughly 50 percent more than now. Williams said they ran a series of turbulence-predicting algorithms for the North Atlantic winter period and compared the results to preindustrial rates.
Queasy fliers need read no further.
Williams said the results showed a 10-to-40 percent increase in the median strength of turbulence and a 40-to-170 percent increase in the frequency of moderate-or-greater turbulence. He described the latter as shaking that is "strong enough to force the pilot to switch on the seat-belt sign, knock over drinks, and make it difficult to walk."
The explanation is that some models predict that global warming will draw the jet stream further north, creating more of the vertical wind shear that causes turbulence.
Joshi said choppier skies might prompt pilots to reroute their flights. But the North Atlantic is a busy place for air travel, with an average of 960 flights a day last week, according to aviation data companies mas Flight and OAG. Pilots interviewed by The Associated Press said -- in such a crowded air corridor -- planes were just as likely to simply power through.
"You just got to grin and bear it," said Steven Draper, a retired airline pilot and a spokesman for the British Airline Pilots Association. Although there's no clear evidence of rougher skies just yet, Draper did say he'd seen worse weather -- like storms -- near the end of his career.
"My experience was that they were increasing in intensity and frequency," he said.
Academics who weren't involved in the research praised it.
University of Birmingham climatologist Gregor Leckebush said there weren't any substantial holes that he could see, although he did note that it relied on a single climate model.
Rob MacKenzie, a professor of atmospheric science at Birmingham, said additional models might have refined the researchers' results but their overall conclusion -- "a really neat piece of work" -- was not in doubt.
The aviation industry is the world's fastest-growing source of carbon dioxide emissions, a major factor in human-driven climate change. Solutions including plant-based jet fuels and carbon offsets have been considered, but politicians, aviation companies and international travelers have so far failed to significantly blunt the environmental impact of air travel.
Werner Krauss, a social anthropologist and the author of "The Climate Trap," said he doubted that the prospect of a more turbulent New York-to-London flight would jolt anyone into action.
"For decades now, environmentalists and climate scientists [have confronted] us on an almost daily basis with doom scenarios," said Krauss. "Do people still listen? I am not sure, and I am afraid bumpy air travel . . . won't come as a shock."