Lowering aircraft altitude could reduce aviation's climate impact by 59%, study finds

Aviation Updates Philippines – As climate change becomes harder to ignore, aviation experts have been pushing the use of low-carbon alternative fuels, more efficient aircraft, and electric engines to reduce aviation's impact on the environment. A new study suggests, however, that making one simple change could be enough to make a huge difference.

NEW RESEARCH. A recent study suggests that changing aircraft altitude could reduce the environmental impact of aircraft by up to 59%. Photo by Adrian Pingstone.

A team of scientists at Imperial College London has found that by getting just 2% of flights to lower their altitude by 2,000 feet, the damage to the environment caused by aircraft could be reduced by as much as 59%.

"According to our study, changing the altitude of a small number of flights could significantly reduce the climate effects of aviation contrails. This new method could very quickly reduce the overall climate impact of the aviation industry," said lead author Dr. Marc Stettler of the Department of Civil and Environmental Engineering.

Condensation trails, also known as contrails, are white streaks that are produced when hot exhaust gas that comes from airplanes meets the cold, low-pressure air in the atmosphere. These cloud-like formations cause the earth's atmosphere to trap heat, which contributes to global warming.

Another study suggests that contrails could be heating up the planet just as much as carbon dioxide (CO2) emissions produced by aircraft, though contrails are usually short-lived and are easier to tackle.

Contrails only form in thinner areas of the atmosphere with high humidity, so flying an airplane higher or lower to avoid these areas could help prevent a plane from forming contrails.

To come to their conclusion, Stettler and his team analyzed data on aircraft flying in Japanese airspace and used computer simulations to see what would happen if planes flew either 2,000 feet higher or 2,000 feet lower than their current flight paths.

Their research, which was published in the scientific journal Environmental Science & Technology last February, also found that though the change in flight paths leads to an increase in fuel consumption, the reduced contrail formation managed to offset the CO2 emissions produced by the extra fuel.

When paired with the use of cleaner fuel, the altitude adjustments could potentially reduce the harm caused by contrails by up to 90%.

Other experts, however, remain skeptical about how the findings of this study could be used in everyday scenarios.

Andrew Heymsfield of the National Center for Atmospheric Research spoke to CNN and said that all commercial aircraft would need to have instruments that can detect humidity so that pilots and air traffic controllers would know where to direct the planes to avoid forming contrails.

"Those would have to be developed and deployed on an aircraft, so that a 3D depiction of those altitudes could be developed from aircraft which collect those data and then transmit it down to the ground," he said.

He also pointed out that aircraft cannot just fly anywhere since they need to follow a specific flight path. 

Stettler, meanwhile, says that he and his team are discussing with aviation authorities how the findings of their study could be practically applied.

"We are in the process of having discussions with air traffic management service providers, who are responsible for planning with airlines flight trajectories," he said.

Stettler said that he and his team are looking to understand how the whole process works and what strategies could be implemented.

"We think it's something that the aviation industry needs to take seriously," he added.