turbulence-getting-worse-but-deaths-are-very-rare-what-to-know

One person is dead, and 30 are injured after a Singapore Airlines flight hit severe turbulence.

"We can confirm that there are injuries and one fatality on board the Boeing 777-300ER," said SIA said in a statement. "There were a total of 211 passengers and 18 crew on board."

Flight SQ321 departed from London's Heathrow Airport on a Boeing 777-300ER on Monday and was supposed to land in Singapore, but instead was diverted to Thailand at 3:45 local time on Tuesday after requesting an emergency landing.

According to updates the airline posted on its Facebook page, the rest of the passengers, the majority of whom were from Australia, the United Kingdom and Singapore, and the crew were being evaluated and treated as needed by medical personnel at the airport.

Turbulence is getting worse, and that trend is likely to continue because of climate change.

Here's what climate and aviation experts said about the worsening turbulence trends.

What causes turbulence?

There are different kinds of turbulence, and they're caused by different things:

• Mountain wave turbulence, as the name suggests, happens when the wind hits a mountain and is forced upward off its blustery path. That's why it's common to hit some bumps when you're flying over the Rockies on a transcontinental flight.
• Convective turbulence is generally associated with storms and is caused by warm air rising.
• Clear-air turbulence can be caused by a number of factors and is generally harder to predict than the other two types, but it is also the most likely kind to affect aircraft. And because it's harder to predict, it can also be harder to avoid.

How clear-air turbulence occurs

Pockets created by jet streams traveling at different speeds and directions cause clear-air turbulence. The phenomenon often happens at 15,000 feet or higher, where clouds aren't present to offer clues of the unstable air. Clear-air turbulence is also invisible on conventional radar.

Among three causes of turbulence, clear-air is the hardest to predict, and it's the most likely to affect aircraft.

Is climate change making turbulence worse?

Yes, at least with clear-air turbulence.

According to Paul Williams, a professor of atmospheric science at the University of Reading, there's no clear data on how climate change is affecting mountain waves or convective turbulence, but clear-air turbulence is definitely becoming more frequent and intense.

"It's going up because of climate change," Williams told USA Today last year. "The atmosphere is getting more turbulent; there will be more severe turbulence in the atmosphere."

Williams co-authored a 2023 study examining increases in clear-air turbulence, which intrigued Noboru Nakamura, a professor of atmospheric science at the University of Chicago.

"Using different metrics, they looked at the observational data over the last 40 years, as well as computer simulations of the future, hypothetically warmer world with increased carbon dioxide," said Nakamura, who is a faculty member in the Department of the Geophysical Sciences. "They found that the risk for the frequency and magnitude of clear-air turbulence have indeed increased observationally over the last four decades, and will continue to do so as the climate keeps warming."

Although the research is ongoing, Nakamura described the theoretical underpinning as "very robust and reliable."

Southern Illinois University aviation professor and safety officer Michael Robertson agreed that climate change affecting clear-air turbulence is a possibility.

"But we're also seeing more and more flights," he said. "It's hard to compare the data coming from aircraft today versus 50 years ago because of the number of flights that we do daily. So, there's going to be more chances that you're going to run into [turbulence] just because there's more traffic."

How many deaths has turbulence caused?

Deaths from turbulence are extremely rare.

In the U.S., the Federal Aviation Administration reported 163 passengers and crew have been seriously injured by turbulence between 2009 and 2022.

Can planes withstand turbulence?

Yes, planes are designed to withstand even extreme turbulence, so it may be uncomfortable for passengers, but it almost never puts the plane itself in physical danger, according to Guinn.

Even with the potential increase in clear-air turbulence, experts say the likelihood of encountering the condition is still very small, and passengers should not be overly concerned, as long as they buckle up when instructed.

"You might be flying along and hit this pocket of air where you encounter some type of downdraft or updraft, and if you're not belted in, you could have some injury," Robertson said. "That's why they're always saying, even when you're seated, still wear your belt. ... I wouldn't want this to increase everybody's fear about the safety of flying because it's the still one of the safest forms of travel."

The bigger problems, Guinn said, are the other operational complications turbulence can cause.

"If you can climb above it or go below it, that fixes things, but that costs a lot of fuel," Guinn said. "Prolonged exposure to turbulence for a pilot is fatiguing. Pilots are going to have to deal with that as well."

Robertson said technology, such as aircraft automation, can help pilots combat stress and fatigue. He also said they can ask air traffic controllers for alternate altitudes upon encountering turbulence.

But that can add to the workload of the air traffic controllers, according to Williams.

Despite these concerns, Robertson said he doesn't think people will be deterred from becoming pilots. He cited increases in starting pay and engaging with students early in their college careers as solutions to pilot shortages.

"You're always going to have that population that has a passion for aviation that wants to pursue it," he said.

Contributing: Stephen J. Beard and Ramon Padilla, USA Today; and Erica Thompson, Chicago Sun-Times