Changing aircraft flight altitudes reduces global warming

Mohamed Ramadan

In a frantic effort to confront global warming and its disastrous consequences, a team of scientists at Imperial College London found that aircraft flying at slightly lower or somewhat higher altitudes would reduce the climate impacts of condensation in their emissions by a noticeable and unexpected rate.

Climate impact of air transport
The study, published in mid-February, in the "Environmental Science and Technology" journal of the American Society of Chemistry periodicals, revealed that when only about 2% of flights fly at 2,000 or higher feet (610 meters), this will To reduce the negative impacts of its condensation on climate change, by a large 59%.

"According to our study, changing the altitude of flight of a small number of flights can significantly reduce the effects of their condensation pathways on climate. This new method can reduce the climate impact," commented Mark Sittler, lead study investigator - via the press release. For fast air transportation. "

The air transport industry is a highly polluting industry, which directly contributes to climate change.

This is mainly due to the huge carbon dioxide emissions from aircraft exhausts. However, there is another reason no less dangerous than those carbon emissions, which is known as condensation pathways.

Condensing paths
When exhaust exhausts loaded with hot gases exit into the cold low-pressure air of the upper atmosphere, these exhausts condense into white clouds-like lines called condensation pathways.

These condensation pathways cause the planet to warm more by trapping the infrared of the planet, while at the same time reflecting short-wave radiation to outer space, which is known as radiative forcing.

Scientists estimate that the effect of both condensate and cloud pathways on climate warming is equivalent to the effect of the overall carbon dioxide emissions from the air transport and aviation industry.

This prompted the research team to find new ways to reduce the climate impacts of the air transport industry, by focusing on confronting the effects of condensation paths, rather than the traditional thinking of reducing carbon emissions for aviation through the use of less polluting fuels or more efficient combustion engines in aircraft.

Change altitude of flight
Scientists have used computer simulations to predict how changing flight altitudes can reduce the formation of condensation paths from them. As the condensate paths are formed only by certain layers of the atmosphere, they are small in thickness and contain a high percentage of moisture. Thus, changing the flight height to avoid these areas will result in condensation paths being reduced to a lesser extent.

In applying this computer simulation using flight traffic data over Japanese airspace - which is very crowded - researchers discovered that 80% of the radiative forcing of aircraft condensation pathways results in only 2% of flight flights. Which means that changing the flight altitude of only those flights will have a major impact.

"Targeting this small number of flights responsible for most condensation paths, by changing their flight altitudes slightly, can significantly reduce the effects of condensate pathways on global warming," explains Roger Teoh, one of the researchers involved in the study - via the press release.

Simple solution and great effect
Computer simulation results confirmed that changing the flight altitude of 2% of flights by two thousand feet (610 meters), whether up or down, will reduce the climate effects of condensation paths by 59%.

At the same time, this change will increase fuel consumption by these planes by only 0.1%, which means that reducing the climate impacts caused by condensation pathways far exceeds the increase in carbon emissions resulting from a slight increase in fuel consumption.

This method, in spite of its simplicity, may contribute greatly to the negative climate consequences of the air transport industry.

The research team explains that adopting other solutions besides changing the flight heights of some flights - such as using clean fuel or more efficient aircraft engines - may reduce the climatic effects of condensation paths by up to 90%.