Fasten your seatbelts: What is clear-air turbulence and why it’s making flights bumpier

Predicted to more than double by around mid-century and affect highly popular routes from the US

Matthew McConaughey recently spoke about the sense of “suspended disbelief” that comes from hitting severe turbulence.

The actor and his wife, Camila Alves, were onboard a Lufthansa flight to Germany from Texas in March when the plane plunged 4,000ft.

“Your red wine, and the glass and the plates that your food was on are all suspended, floating, still just in the air. And to look at it for that long, which wasn’t that long – one, two, three, four – and then everything just comes crashing down,” he said during a podcast interview with TV host Kelly Ripa last week.

While that incident is still being investigated by the Federal Aviation Authority, there is growing scientific evidence that “clear-air turbulence” is becoming more common due to the climate crisis.

Clear-air turbulence happens in the absence of clouds at higher altitudes, and is down to wind shear – a change in the direction and velocity of gusts that can displace aircraft abruptly.

Global heating is causing disruptions in different layers of the atmosphere. Since 1979, wind shear in the jet stream has increased 15 per cent, Dr Paul D. Williams, a professor of atmospheric science at the University of Reading, told The Wall Street Journal.

His research projects that clear-air turbulence will more than double by around mid-century in the mid-Northern Hemisphere - affecting popular routes like New York-London and San Francisco-Tokyo, WSJ added.

Thousands of planes already experience severe turbulence every year, costing the aviation industry up to $1bn through flight delays and structural damage.

Because it can happen so suddenly it also means the potential for serious injuries to passengers and crew.

In March 2019, a Turkish Airlines flight from Istanbul to New York encountered severe clear-air turbulence over Maine, hospitalising 30 people, including a flight attendant who suffered a broken leg.

Dana Hyde, a former official in the Obama administration, died after a private plane she was travelling on experienced severe turbulence in the US Northeast last month.

Last May, 14 passengers and three cabin crew were injured on a SpiceJet flight travelling from Kolkata to Mumbai, India.

“It all happened in a span of five to seven minutes,” Hemal Rajesh Doshi, one of the passengers, told The Independent at the time.

“About an hour and a half into the flight, without any announcement, it was like the plane suddenly fell and passengers were in panic I saw about four to five passengers literally thrown into the air and some hit the flight’s roof and fell. The moment was like being on a roller coaster.”

Improved turbulence forecasting will be necessary, said Eurocontrol, an organisation which works on air traffic management across Europe.

“Avoiding unexpected turbulence can lead to route extensions and increased fuel burn/CO₂ emissions; so improving the capability to forecast turbulence means routes can be better planned and reduce additional track miles,” a spokesperson told The Independent.

Turbulence won’t be the only disruption to air travel caused by the climate crisis, scientists warn, with extreme weather events like increasingly erratic and powerful tropical cyclones also taking a toll.