Singapore Airlines tragedy: Is climate change worsening air turbulence?

Geoff Kitchen and his wife Linda were en route to a six-week holiday spanning South Asia and Australia. Ten hours into their journey aboard Singapore Airlines flight SQ321 from London to Singapore, amidst the breakfast service, the Boeing 777-300ER suddenly descended 6,000 feet (1,800 meters) within minutes. The aircraft, carrying 211 passengers and 18 crew members, was forced to make an emergency landing in Bangkok. Tragically, Kitchen suffered cardiac arrest and passed away. Additionally, at least 71 individuals sustained injuries, with 20 remaining in intensive care units in Bangkok.

How Common are Injuries in Air Travel?

In comparison to the vast number of flights worldwide (forecasted at 40.1 million for 2024), incidents like the one on SQ321 are rare.

In the United States, the largest air travel market globally, only 163 injuries requiring hospitalization were reported between 2009 and 2022, according to the Federal Aviation Administration.

According to the National Transportation Safety Board, there hasn't been a single turbulence-related fatality on a large-body aircraft during that timeframe.

Instances of turbulence leading to aircraft crashes are exceedingly rare. In 2001, American Airlines flight 587 from New York's JFK to Santo Domingo, Dominican Republic, crashed due to a technical error rather than turbulence directly causing the accident. The NTSB confirmed that turbulence led to a failure in the aircraft's vertical stabilizer.

What causes Turbulence?

Turbulence occurs due to disruptions in the air, with various types and causes. Natural features such as mountains can alter airflow, leading to air rising over terrain, creating waves that trigger turbulence.

While weather phenomena can contribute to turbulence, clear-air turbulence (CAT) is of particular concern.

“It can be caused by what are called gravity waves that cause undulations in the air that you can’t see. The only way pilots know about it is to hear about it from a previous pilot. Pilots often listen to what a person who took that same flight path a few minutes earlier say. That’s the best way to detect these turbulence events,” Ramalingam Saravanan, head of the department of atmospheric sciences at Texas A&M University.

Have Occurrences of Turbulence Risen, and is Climate change Accountable?

A recent study conducted by the University of Reading in England, published last year, revealed that clear-air turbulence increased by 55 percent over the North Atlantic, a crucial flight route, between 1979 and 2020. This surge is attributed largely to warmer temperatures impacting wind patterns, with greenhouse gas emissions identified as a primary factor, according to the report.

This assertion is corroborated by researchers at the University of Chicago, who predict that rising temperatures could result in higher wind speeds within the fastest upper-level jet stream. Their study suggests that for every degree Celsius of global warming, wind speeds could rise by 2 percent, a trend expected to continue if greenhouse gas emissions persist at current levels, potentially leading to a 4-degree Celsius increase by the end of the century.

Since the pre-industrial era, the global temperature has escalated by at least 1.1 degrees Celsius, with the most significant rise occurring since 1975, as reported by NASA.

In anticipation of record-breaking wind speeds, airlines may need to reduce flight speeds to mitigate the safety risks associated with turbulence, according to the University of Chicago researchers.

The North Atlantic, a vital route between North America and Europe, is expected to experience the most significant increase in turbulence. Additionally, substantial surges are anticipated in southeast China, the western Pacific, and northern India. A study by Nanjing University in China, conducted in 2021, forecasts a 15 percent rise in clear-air turbulence occurrences by 2059.

The escalating turbulence in the Asia Pacific region poses a growing concern for the airline industry, especially considering that China is projected to surpass the United States as the world's largest air travel market by passenger volume by 2037.

Who Suffers the Most when Aircraft Encounter Turbulence?

The concerns surrounding turbulence primarily revolve around the safety of passengers and crew rather than the aircraft itself, particularly when individuals are not properly secured in their seats.

Flight crew members bear the brunt of turbulence-related injuries, accounting for 79 percent of all such incidents.

"Turbulence poses a significant workplace safety challenge for Flight Attendants," remarked Sara Nelson, president of the Association of Flight Attendants-CWA, AFL-CIO, in a statement.

"While details regarding Singapore Flight 321 are still emerging, initial reports suggest clear-air turbulence, which is the most perilous type. It is invisible and nearly impossible to detect with current technology. One moment, everything is calm; the next, passengers, crew, and unsecured items are tossed around the cabin," Nelson added.

Does Turbulence Impact Airline Profits?

Despite the rarity of turbulence-related disasters, turbulence incurs substantial costs for the airline industry, amounting to up to $500 million annually. This figure encompasses damage to aircraft and cabins, flight delays, and occasional liability payments. As turbulence is expected to become more frequent in the coming years, these costs are anticipated to escalate.

Who Bears the Brunt of Turbulence-related Liabilities, according to the 1999 Montreal Convention?

Under the 1999 Montreal Convention, airlines are held financially responsible for injuries sustained on board due to turbulence, including damage to luggage, personal injury, and even death.

"The convention delineates the jurisdictions where plaintiffs can file their cases, varying based on each passenger's circumstances. They are entitled to full compensatory economic damages," explained Ladd Sanger, managing partner of Slack Davis Sanger, a Texas-based personal injury law firm specializing in aviation accidents.

Airlines are obligated to comply with these regulations and compensate affected passengers using special drawing rights (SDRs), a reserve asset established by the International Monetary Fund. Depending on the injured party's nationality, SDRs can be exchanged for their respective currency.

However, airlines may contest claims if they can demonstrate that an injury resulted from passenger negligence. Each carrier may have slightly different policies regarding liability.

Singapore Airlines, for instance, states in its terms of service that there are no financial limits for death or bodily injury. For damages up to 113,100 SDR (equivalent to US$149,720.22 today), the carrier cannot dispute compensation claims. Beyond that amount, the carrier may defend itself by proving it was not negligent or at fault.

While many of these cases are settled out of court, they impose financial strains on airlines, particularly given the industry's narrow profit margins. In December, the International Air Transport Association (IATA) projected record profits for the year at a 2.7 percent profit margin, underscoring the industry's delicate financial balance.

Despite challenges, most major financial firms on Wall Street have yet to downgrade Boeing's stock, suggesting a level of confidence in the company's ability to weather these issues, despite negative consumer perceptions.