Opinion | Singapore Airlines turbulence: how climate change has hit flight safety - South China Morning Post

Opinion | Singapore Airlines turbulence: how climate change has hit flight safety | South China Morning Post

Singapore Airlines turbulence: how climate change has hit flight safety

- Warmer air from increasing carbon emissions is changing wind speeds and likely contributing to severe turbulence
- This is just one of the climate change challenges facing airlines, as global air travel recovers from the pandemic

severe turbulence that left one passenger dead and dozens injured. While the episode has been described as a freak incident, it is making people wonder what could have caused such a serious disruption to the flight and whether climate change will worsen the frequency and intensity of turbulence during air travel.

Already, turbulence is the leading cause of non-fatal injuries in on-board accidents.

people hurtling towards the cabin ceiling and necessitated an emergency landing in Bangkok.

Most flights encounter some turbulence at some point. Strong winds near the airport cause turbulence when flights take off or land. Mainly, however, the turbulence that affects aviation can come from three sources.

The first is shear turbulence and mainly found around the jet streams that are so important to air travel. In these fast rivers of air that encircle the planet, wind shear, or an abrupt change in the direction or speed of airflow, causes turbulence.

The second is convective turbulence, caused by storms or other weather.

The third is mountain waves. In the face of mountains, not all air passes smoothly over them. Some air masses crowd against the mountains and are forced upwards, forming mountain waves that might then break up into currents of turbulence.

clear-air turbulence. According to a study published last year, significant increases in clear-air turbulence were found between 1979 and 2020. For example, severe clear-air turbulence, which is more powerful than the Earth’s gravity, became 55 per cent more frequent over the North Atlantic. Worldwide, there were comparable increases in turbulence.

Climate change is most likely to blame here because it is strengthening the jet streams that cause turbulence. Specifically, warmer air from increasing carbon emissions is changing wind speeds.

While turbulence associated with storms can be detected by radar systems and avoided, clear-air turbulence is difficult to identity. It does not show up on cockpit instruments and the only warnings are from planes that have already flown through it.

The unpredictable nature of such turbulence presents operational difficulties for airlines.

To maintain passenger comfort and safety, pilots have to navigate unforeseen rough patches, possibly changing altitudes or deviating from intended paths. This might lead to higher fuel usage and thus higher running expenses. Severe turbulence can also result in aircraft damage, and flight diversions and delays, all of which could have costly impacts.

Flight planning would be completely transformed if turbulence could be predicted accurately. The existing techniques rely on weather forecasts and pilot reports, which are useful sources of information but fall short in terms of timeliness and precision when it comes to managing turbulence effectively.

Currently, the two World Area Forecast Centres use only one turbulence index, the Ellrod and Knapp (1992) Turbulence Index 1, while other turbulence indices are included in the Graphical Turbulence Guidance forecast. Next-generation satellites, like GOES-16, have the potential to enhance turbulence nowcasting since they have higher temporal and spatial resolutions, which could help aircraft avoid turbulence on short time scales.

Meteorologists can foresee broad areas of turbulence, but they are unable to predict localised clear-air turbulence, which poses a problem to pilots.

One strategy for avoiding encounters with clear-air turbulence could be steering clear of the four main jet-stream systems encircling the planet. However, commercial airlines and pilots have been, and may continue, taking advantage of the jet-stream systems to reduce flight durations and save on fuel.

The aviation sector faces other climate change challenges, and turbulence is not the only danger. Hotter temperatures might make it more difficult for planes to take off, for example, and more passengers might have to be left on the ground.

Given that air travel is not only recovering but growing, new and better working processes could and should be devised to ensure that both the impact aviation has on the environment and the impact climate change could have on aviation are minimised.

Around the world, the demand for air travel rose last year. In India, a record 152 million passengers flew domestically in 2023.

In 2023, total traffic increased by 36.9 per cent compared to 2022. Global traffic was at 94.1 per cent of pre-pandemic levels in 2019. Traffic in December last year increased by 25.3 per cent year on year, reaching 97.5 per cent of the level recorded in December 2019. The robust recovery towards the end of the year was reflected in fourth-quarter traffic, which was at 98.2 per cent of 2019.

Rising temperatures and accompanying changes in atmospheric conditions could result in more frequent instances of severe turbulence. As we move into more turbulent times, airlines will have to make a greater effort to lessen the impact of climate change on passengers and flights. In the meantime, a regular traveller’s best bet is to buckle up and stay calm.

Kavitha Yarlagadda is an independent writer based in Hyderabad, India