Hands up everyone who loves turbulence. Anyone? No? No matter if it causes mild discomfort or severe anxiety, a bumpy flight is very few people's favorite pastime. Even more so when it becomes so severe it results in the physical injury of passengers on board the aircraft. Unfortunately, as a result of global warming, severe turbulence, including unpredictable CAT, or clear air turbulence, is set to grow two or three times in the coming decades.

Jet stream already 15% more strongly sheared since 1970s

Speaking at a panel titled "Beyond Carbon" at the Sustainable Aviation Futures Congress in Amsterdam last week, Professor of Atmospheric Science at the University of Reading in the UK, Paul Williams, said he wished to highlight how aviation will also be a victim of climate change.

One of the ways warmer temperatures will impact the industry is by placing at least 100 airports below sea level, including New York Newark and Bangkok Suvarnabhumi. Another is the substantial increase in wind shear in the jet stream that carriers rely on to get from west to east as quickly as possible. As a result, severe turbulence will become a much more frequent occurrence. Professor Williams stated,

"We have a lot of evidence that the jet stream is now 15% more strongly sheared since satellites began measuring it in the 1970s. And this is what causes a lot of turbulence, especially clear air turbulence. And the satellites show that it has become 15% stronger since the 1970s, that's a massive shift. And we understand why it's happening in terms of the physical mechanisms behind it. Our calculations indicate there is going to be twice or three times as much severe turbulence in the next few decades because of climate change."

SpiceJet Boeing 737
Photo: Boeing

Flight attendants have 24 times higher risk of injury

And the University of Reading is not alone in its calculations and conclusions. According to the US National Transportation Safety Board (NTSB), 'head-slamming' turbulence is increasing on flights. Turbulence-related injuries are the most common airline accident type, and cabin crew are 24 times more likely to be injured than passengers. In 2019, turbulence caused a flight attendant on a Turkish Airlines flight to New York JFK to break their leg and sent 28 of the passengers on board to hospital.

Turbulence is also costly for the airlines, reaching over $500 million yearly in damages and delays. Clear air turbulence, or CAT, is especially problematic as it occurs in, well, clear air. This means that, as opposed to a cloud, it is impossible to detect with the naked eye and extremely difficult to pick up using radar equipment. CAT is generated by instabilities in the jet stream because of very fast air currents at 35,000 feet.

Airplane landing at Heathrow during Storm Eunice
Several airplanes struggled to land at Heathrow during Storm Eunice. Photo: Getty Images

Motivation for the sector to decarbonize?

A stronger jet stream will have further implications than turbulence. It may speed up a journey (although make it less comfortable) when traveling eastwards. However, in the other direction, it will translate into longer flight times, delays, and more fuel burn.

Professor Williams hopes that these estimates, although grim, will,

"...doubly motivate the sector to rise to the challenge because it will suffer from the consequences if it doesn't manage to decarbonize very rapidly."

How do you react to turbulence? Any stories you'd like to share with the community and us?