Severe turbulence has increased by 55% since 1979 due to climate change, research shows

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Whether it's delayed departures, lost luggage or long lines at security checkpoints, flying has long presented numerous challenges.

But now scientists are pointing to perhaps an even bigger concern: an increase in severe turbulence that could cause sudden changes in altitude and nasty injuries.

The British researchers found that severe turbulence has increased by 55 percent since 1979, and is likely to become even more common as the planet warms.

Global warming is causing disruptions to the jet stream – the narrow stream of fast-moving air that planes fly past to get a speed boost.

Air passengers are increasingly capturing terrifying images of extreme turbulence on their smartphones, sending flight attendants and hot drinks flying.

Severe turbulence requires forces stronger than gravity – and these are strong enough to hurl people and luggage through the cabin of an aircraft

In rare cases, turbulence can even be fatal, as was demonstrated earlier this year when it caused the death of a passenger on a business jet.

Tens of thousands of aircraft experience severe turbulence every year, with an estimated cost to the global aviation industry of as much as £826 million ($1 billion) in costs from injuries, aircraft structural damage and flight delays.

The new study was conducted by researchers at the University of Reading and published today in Geophysical research letters.

“After a decade of research showing that climate change will increase clear-sky turbulence in the future, we now have evidence to suggest the increase has already started,” said study author Professor Paul Williams.

“We need to invest in improved systems for predicting and detecting turbulence to prevent rougher air from translating into bumpier flights in the coming decades.”

Some aircraft turbulence occurs in specific locations, such as over mountain ranges or near convective storms, and is largely avoidable.

However, a certain type of turbulence, called clear air turbulence (CAT), is invisible and is caused when air masses moving at different speeds meet.

CAT is difficult to observe ahead of an aircraft's trajectory using remote sensing methods and challenging for aviation meteorologists to predict.

At a typical point over the North Atlantic Ocean – one of the busiest flight lanes in the world – the total annual duration of severe turbulence has increased by 55 percent, from 17.7 hours in 1979 to 27.4 hours in 2020, the study found. the research. This figure refers to the square above the North Atlantic Ocean

Vertical wind shear – the increase in wind speed at higher altitudes – causes invisible clear-air turbulence, or CAT (file photo)

'The main problem [with CAT] is that you can't see it,” said Ramalingam Saravanan, a professor in the Department of Atmospheric Sciences at Texas A&M University, who was not involved in the study.

How does climate change worsen turbulence?

Commercial aircraft fly in jet streams: narrow streams of fast-flowing air in the Earth's atmosphere.

As Earth's atmosphere warms, these jet streams become stronger and wavy.

This is because the jet stream is driven by temperature differences, and as global temperatures rise, these differences become greater.

This means that planes are more likely to experience turbulence when flying through the jet stream.

“I think pilots are best informed when another pilot has flown through and calls back to let them know the location.

'You can try to predict it statistically, but you can't predict it on an individual case basis because it's a random process and the sky looks clear and harmless – hence the name.'

For the study, the team from the University of Reading analyzed atmospheric data between 1979 and 2020 to find out whether CAT has already started to increase.

“We used a dataset called ERA5,” study author Mark Prosser, a meteorologist at the University of Reading, told MailOnline.

'This dataset contains information about the atmosphere from the past – for example temperature, wind speed – which we used as a basis for this research.

'Although information automatically recorded from aircraft ends up in this dataset, other observations – such as those from satellites and weather balloons – do so too.'

Moderate turbulence increased 37 percent from 70.0 to 96.1 hours, and light turbulence increased 17 percent from 466.5 to 546.8 hours.

Although the US and the North Atlantic experienced the largest increases, the experts noted that other busy flight paths over Europe, the Middle East and the South Atlantic also saw significant increases in turbulence.

Interestingly, there is a greater increase in CAT in the Northern Hemisphere than in the Southern Hemisphere, which 'warrants further investigation'.

According to the team, their research represents “the best evidence yet” that air turbulence has increased in recent decades, in line with increases in global warming.

Previous research from the University of Reading has found that flights will experience two to three times more severe open-air turbulence if emissions are not reduced.

The Study from 2017 calculated that climate change will significantly increase the amount of severe turbulence worldwide sometime between the 2050s and 2080s.

Another study by the team showed that planes could reduce their CO2 emissions by hitching a ride on the jet stream more often.

How could global warming worsen air turbulence?

New research from the University of Reading shows that clear air turbulence, which is invisible and dangerous to aircraft, has increased in several regions around the world.

The researchers say this increase has occurred in parallel with the increase in global warming – and that the two are linked.

Isabel Smith, a PhD candidate in the university's meteorology department, told MailOnline: 'Clear air turbulence (CAT) is generated by wind power and so has a strong link with jet streams, which are fast-flowing wind bands that propagate around the Earth. world.

'Global warming refers to the rapid warming of the lowest layer of the atmosphere in which we live, the troposphere.

'There are different layers in the atmosphere and the layer above the troposphere is the stratosphere.

The troposphere is where people live and weather exists, with the lower layer extending for about six miles

'The increase in greenhouse gases traps heat in the troposphere, which is normally emitted to the stratosphere.

'Therefore, the stratosphere is cooling at a rate comparable to the warming of the troposphere.

'This creates a strong temperature difference vertically through the atmosphere.

'A stronger vertical temperature gradient will lead to a stronger and more chaotic jet stream.

“As the jet streams strengthen, it becomes more chaotic and unstable and the number of CAT encounters increases.”