Severe turbulence has increased 55% since 1979 thanks to climate change, study finds

Whether it’s delayed departures, lost luggage or long lines at security checks, flying has long presented countless challenges.

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

The British researchers have 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 in the jet stream — the narrow stream of fast-moving air that planes fly past to get a speed boost.

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

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

Tens of thousands of aircraft experience severe turbulence each year, with estimated costs to the global aviation industry of up to £826 million ($1 billion) 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 Survey Letters.

“After 10 years of research showing that climate change will increase clear-air turbulence in the future, we now have evidence to suggest that the increase has already begun,” said study co-author Professor Paul Williams.

“We should invest in improved turbulence prediction and detection systems to prevent the rougher air from translating into bumpier flights in the coming decades.”

Some aircraft turbulence occurs in well-defined 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 trail using remote sensing methods and a challenge for aviation meteorologists to predict.

At a typical point over the North Atlantic – one of the world’s busiest flight paths – the total annual duration of severe turbulence increased by 55 percent from 17.7 hours in 1979 to 27.4 hours in 2020, the study found. research.

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

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

“The best way I think pilots know about it is when another pilot has flown through and sent radios back to let them know the location.

“You can try to predict it statistically, but you can’t predict it case by case because it’s a random process and the sky looks clear and harmless – hence the name.”

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

We use a data set called ERA5,” said study co-author Mark Prosser, a meteorologist at the University of Reading.

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

‘Although automatically recorded information from aircraft ends up in this dataset, other observations – such as those from satellites and weather balloons – do the same.’

At a typical point over the North Atlantic – one of the world’s busiest flight paths – the total annual duration of severe turbulence increased by 55 percent from 17.7 hours in 1979 to 27.4 hours in 2020, the study found. research.

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.

While the US and the North Atlantic experienced the largest increases, the experts found 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 “justifies further investigation.”

According to the team, their study represents “the best evidence yet” that turbulence in clear skies has increased over the past few decades, consistent with increasing global warming.

Previous research from the University of Reading showed that flights are two to three times more likely to encounter severe air turbulence if emissions are not reduced.

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

Another study by the team found that aircraft can reduce their CO2 emissions by riding the jet stream more often.