Is Turbulence Getting More Intense?

Recently, there have been alarming reports of severe turbulence. Notably, a Hawaiian Airlines flight from Phoenix to Honolulu last December resulted in 36 injuries requiring medical attention. In March, a Lufthansa flight from Austin to Frankfurt had to be rerouted to Washington Dulles after experiencing intense turbulence, leading to seven passengers being hospitalized for minor injuries.

Reports of turbulent flights have gained traction due to video clips (and celebrity accounts) circulating on social media, raising concerns among travelers about these recent incidents—and whether they signify an increase in dangerously turbulent conditions on commercial flights.

Passengers have valid reasons to be anxious. Research indicates that turbulence is being influenced by climate change—and not positively. However, whether this translates to a higher frequency or severity of turbulence during passenger flights remains uncertain. Here’s what you need to know about turbulence changes in a climate-altered world and their potential impact on your upcoming flights.

Is turbulence worsening?

Turbulence has existed for as long as air travel has. It refers to the movement of air caused by variations in atmospheric pressure, jet streams, mountain winds, weather fronts, or thunderstorms, as defined by the Federal Aviation Administration (FAA).

The FAA notes, “Turbulence can cause a sudden jolt in an airplane.”

Research increasingly shows that climate change directly impacts atmospheric conditions that lead to turbulence, resulting in more frequent and severe occurrences—particularly of a type known as clear-air turbulence.

According to Isabel Smith, a meteorologist pursuing a PhD at the University of Reading, clear-air turbulence is especially hazardous because it’s invisible to onboard radar systems. She explains that “the main issue is that it can appear unexpectedly, catching passengers, pilots, and crew off guard.”

Smith highlights that the rise in clear-air turbulence is linked to shifting temperatures affecting jet streams, which are narrow corridors of strong winds that usually travel from west to east around the globe. There are four primary jet streams on Earth: two polar jet streams near the poles and two subtropical jet streams closer to the equator.

As the troposphere (the layer of the atmosphere where we reside) warms rapidly, the stratosphere (the layer where commercial aircraft typically fly) is actually cooling at a comparable rate. This cooling occurs because the rise in greenhouse gases traps heat in the troposphere, contributing to global warming, which would otherwise have been released into the stratosphere. As a result, the temperature difference—or gradient—between these two layers is becoming more pronounced.

Smith states, “Jet streams are intensifying due to this temperature gradient, leading to increased turbulence. At the fringes of these jet streams, chaotic air swirls outward, resulting in the clear-air turbulence you may experience.”

In March 2023, Smith and Dr. Paul Williams, a professor of atmospheric science at the University of Reading, published a report revealing that, traditionally, winter has been the most turbulent season. However, climate change models suggest that summer and fall are expected to see the greatest rise in clear-air turbulence occurrences. Their research predicts that “by 2050, summers may be as turbulent as winters were in 1950.”

This follows a 2017 report from Williams, which indicated that all forms of clear-air turbulence, from mild to severe, are likely to increase, with severe clear-air turbulence projected to rise the most—by 149 percent—if atmospheric carbon dioxide levels were to double.

Dr. Robert Sharman, a project scientist at the National Center for Atmospheric Research (NCAR), notes that his research suggests there will likely be an upward trend in other turbulence types due to climate change, including mountain-wave turbulence caused by airflow over mountains and turbulence generated above clouds due to convection below.

He remarks, “Much of the heightened focus on climate change and turbulence seems to stem from several recent incidents,” referencing well-publicized events like the Hawaiian and Lufthansa flights mentioned earlier. However, he adds, “These instances were linked to in-cloud turbulence, not clear air. There is, nonetheless, some evidence suggesting an increase in turbulence caused by convective clouds as well. Ultimately, it’s difficult to determine whether these specific occurrences are tied to global warming or merely due to unfortunate circumstances.”

Are flights becoming more turbulent?

Research indicates that climate change is influencing the frequency and severity of turbulence in the atmosphere, but it remains uncertain if turbulence is affecting a greater number of flights. This uncertainty arises from the absence of clear year-over-year data to indicate a definitive trend.

The National Center for Atmospheric Research reports that, on average, there are 65,000 pilot-reported instances of moderate or greater turbulence annually in the United States, alongside about 5,500 reports of severe or greater turbulence each year. However, NCAR does not provide comparative year-over-year data.

Currently, the only year-over-year data available pertains to serious in-flight injuries caused by turbulence, and these figures have fluctuated in recent years, complicating any conclusive analysis. For example, serious turbulence injuries in the United States from 2009 to 2022 ranged from as few as 5 or 6 (noted in 2013, 2014, 2020, and 2021) to a maximum of 17 or 18 (recorded in 2009, 2011, and 2022), according to a Federal Aviation Administration report released in March 2023, which is based on data from the National Transportation Safety Board (NTSB). The NTSB mandates that airlines report “serious injuries and fatalities,” defining a serious injury as one requiring hospitalization for more than 48 hours, or resulting in a bone fracture or significant internal damage.

Although the 17 serious turbulence injuries reported in 2022 marked the highest count since 2011, when 18 were noted, U.S. airlines transported 853 million passengers in 2022 (compared to 804 million in 2011), according to the Bureau of Transportation Statistics. Thus, these 17 serious injuries account for a tiny percentage of the total passenger volume. Furthermore, the years 2020 and 2021 reported only 5 and 6 serious turbulence injuries, respectively, coinciding with the pandemic when significantly fewer passengers were traveling.

“Injuries related to turbulence don’t indicate a clear recent trend,” states Kristy Kiernan, associate director at the Boeing Center for Aviation and Aerospace Safety.

Will there be more in-flight turbulence in the future?

The possibility of more turbulence in the atmosphere leading to increased in-flight turbulence for passengers in the near to midterm remains uncertain. This is attributed to various flight planning and safety measures implemented both before and during flights to minimize turbulence encounters.

“In aviation, the focus is on risk mitigation,” Kiernan explains.

Much of the risk management concerning turbulence takes place even before the flight departs, as air traffic controllers and airlines examine weather patterns and utilize radar and LIDAR technology (the latter employing lasers instead of radio waves) to identify environmental changes that aircraft can adjust to in order to evade turbulent air.

“When it comes to planning flight routes to steer clear of turbulence, we currently have the most effective tools available,” explains Kiernan. “Climate models enable us to forecast where rapid shifts in wind speed and direction are likely to occur. This information, relayed to dispatchers, can be invaluable for planning routes at various altitudes or adjusting navigation strategies to avoid those areas.”

However, there is a notable complication in route planning to avoid clear-air turbulence. The airline industry is heavily investing in emission reductions—the very emissions that contribute to climate change and consequently increase turbulence—and one method to cut emissions is to fly shorter, more efficient routes.

“It’s a complex dilemma,” states Smith from the University of Reading. “The challenge is that you are likely to encounter turbulence on the most efficient flight paths.” In a genuine climate change Catch-22, to minimize turbulence, airlines may need to opt for longer, less efficient routes to navigate around these rough patches.

In the interim, the air travel sector is diligently working to develop and enhance systems that would improve turbulence detection and management during flights—potentially helping to avoid the necessity for those longer, less turbulent flight paths.

Although clear-air turbulence cannot be detected by current onboard radar systems, Smith points out that some studies indicate LIDAR technology may be capable of identifying it. Whether the industry will choose to equip commercial aircraft with LIDAR for improved navigation around such turbulence remains uncertain. However, it could also assist ground teams in circumventing specific clear-air turbulence areas before takeoff.

Pilots have access to additional tools, including real-time turbulence-sharing data systems.

“Many commercial aircraft are outfitted with systems that automatically log any instances of vertical acceleration that surpass a certain threshold, indicating turbulence. This data is then transmitted to a third-party provider, which notifies subscribing airlines and relays turbulence information to the cockpit about affected areas,” explains Kiernan.

The International Air Transport Association (IATA) operates one such data-sharing system called Turbulence Aware. Other systems include SkyPath and NASA’s Turbulence Auto-PIREP System, known as TAPS.

She also mentions, “Another method, albeit very traditional and old-fashioned, involves pilot reports. Pilots will relay ride reports to air traffic control.” She elaborates that other pilots flying through the same region can then “request ride reports from air traffic control to help them steer clear of turbulent areas.”

Kiernan explains that when pilots find themselves facing unavoidable severe turbulence, they typically reduce their speed to prevent overstressing the aircraft. They may also choose to change their altitude to steer clear of turbulent conditions.

With the increase in turbulence, is it still safe to fly?

Despite the current measures to circumvent turbulent areas, turbulence continues to be the primary cause of injuries among cabin crew and passengers during nonfatal flight incidents, according to IATA.

However, Kiernan emphasizes that turbulence alone is “not going to bring down an airplane.” The likelihood of turbulence causing a commercial aircraft to crash is extremely low, she asserts.

So, when does turbulence become dangerous? “Turbulence poses a serious risk if you are not secured in your seat. It’s significant from an internal standpoint, but it doesn't harm the aircraft. Therefore, as long as passengers are buckled in and there are no loose items around them during turbulence, they are safe,” Kiernan clarifies.

When moderate to severe turbulence occurs, three groups of individuals on the aircraft face increased risk:

Flight attendants

Flight attendants are often moving throughout the cabin, making them less likely to be buckled in compared to passengers. This increases their chances of injury during turbulence. For this reason, pilots instruct flight attendants to take their seats during instances of moderate to severe turbulence, ensuring they can buckle up and stay safe.

Lap children

While U.S. airlines permit infants and small children under two to fly as “lap babies,” the FAA recommends that the safest position for a child under two on an airplane is in an approved car seat, rather than in a parent's lap. “Your arms aren’t able to securely hold your lap child, particularly during sudden turbulence, which is the leading cause of pediatric injuries in-flight.” However, the challenge lies in the fact that lap children fly free, while using a car seat requires purchasing an additional seat. The Association of Flight Attendants has recently advocated for banning lap babies due to the rising instances of severe turbulence and the associated risks for unsecured small children.

Individuals who neglect to wear their seat belts

For passengers who opt not to buckle up during most of the flight, Kiernan states, “It’s their own decision. However, they risk becoming a projectile. Personally, I can’t fathom why anyone wouldn’t be buckled up unless they’re using the restroom or retrieving something from the overhead compartment. Just buckle up; it’s a simple measure to ensure your safety.”

Echoing Kiernan’s views, Dr. Sharman from the National Center for Atmospheric Research remarked: “Ultimately, [turbulence] forecasts are not foolproof, and it’s always wise to stay buckled.”