Singapore Airlines flight: Climate change is making turbulence more severe - and experts say it may get worse

Climate change could double or even triple the amount of severe turbulence on flights in the coming decades, experts warn.

On Tuesday (21 May), a Singapore Airlines flight from London Heathrow to Singapore encountered what authorities described as “severe turbulence”. A British national, 73-year-old Geoff Kitchen, died of a suspected heart attack during the incident, while 30 others onboard were injured - as the plane dropped sharply from an altitude of 37,000 feet to just 6,000.

University of Reading atmospheric science expert, Professor Paul Williams, said that while the cause of the turbulence involved in Tuesday’s fatal incident would take some time to determine, turbulence on flights was usually caused by storms, mountains, or strong air currents called jet streams. “In this last case, it is called clear-air turbulence, and it can be difficult to avoid because it doesn't show up on the weather radar in the flight deck.

“The last fatality caused by clear-air turbulence on a commercial flight occurred on 28 December 1997, on a United Airlines flight from Tokyo to Honolulu,” he continued. “Other forms of turbulence have caused more recent fatalities, but as far as I am aware there has not been a turbulence fatality on a commercial flight since 2009.”

But Professor Williams warned we now had “strong evidence” that turbulence was increasing, because of climate change. “We recently discovered that severe clear-air turbulence in the North Atlantic has increased by 55% since 1979,” he said. “Our latest future projections indicate a doubling or trebling of severe turbulence in the jet streams in the coming decades, if the climate continues to change as we expect.”

How does climate change impact turbulence?

Research from the University of Reading in June 2023 found that the skies aircraft traverse are significantly bumpier today than they were four decades ago. Over the North Atlantic - one of the world’s busiest flight routes - the total time spent experiencing severe turbulence in a year increased by 55%, from 17.7 hours in 1979 to 27.4 hours in 2020, the study found.

On top of that, moderate turbulence increased 37% - from 70.0 to 96.1 hours - and light turbulence increased 17% - from 466.5 to 546.8 hours. The increases were consistent with the effects of climate change, researchers noted.

Basically, turbulence is created when two different wind or air flows meet, creating disruption. Jet streams are fast air currents high above the Earth’s surface, which planes frequently use to travel more quickly, CQUniversity Australia aviation professor Doug Drury wrote on the Conversation.

Warmer air, caused in part by greenhouse gas emissions (such as carbon dioxide), increases the amount of wind shear in jet streams. This means the small amount of turbulence you’d usually experience moving in and out of jet streams (where planes encounter a difference in air flow) will likely increase.

Climate change is cooling what experts call the ‘polar lower stratosphere’ and warming the ‘tropical upper troposphere’ around the world’s upper-level jet stream - strengthening it. Lower down in the atmosphere, global warming’s amplified effect on the Arctic is changing weather patterns in a way that weaken the upper-level jet stream. Scientists say this creates “a closely balanced tug-of-war” between two competing effects at different altitudes - meaning a more stark difference as planes move up and down.

With the world just experiencing its warmest year on record, Reading PhD researcher Mark Prosser said of his 2023 study that airlines would need to start thinking about how they will manage the increased turbulence, which already costs the industry US$150–500m (£118-£393m) annually in the USA alone. “Every additional minute spent travelling through turbulence increases wear-and-tear on the aircraft, as well as the risk of injuries to passengers and flight attendants.”

Amber Allott is NationalWorld’s environment and sustainability specialist, covering all things green - from climate to conservation. If you liked this article you can follow Amber on X (Twitter) here and sign up for the free daily NationalWorld Today newsletter here - with Amber bringing you the UK's most important, pressing, weird and wonderful environmental stories every Tuesday.