Airplanes’ contrails appear to be the largest contributors to climate change emissions coming from aviation. Surprisingly, they cause more warming than the CO2 emissions from aircrafts’ fuel. Scientists are now debating on ways how to get rid of them altogether.
Contrails are created when water vapor in the air gathers and condenses on soot particles in aircraft engine exhaust. They usually tend to form only at high altitudes. Also they rarely appear when airplanes fly over tropical and polar regions. That is because of warm temperatures and dry air respectively. The most common ones are over Europe and North America because of the big airplane traffic.
Contrails add to climate change by trapping heat that radiates upward from Earth’s surface. They can have both a warming and a cooling effect. The cooling effect is caused when they reflect the light from the sun back into space before it reaches the surface.
Those at night have just a warming effect, because they trap heat from the Earth without reflecting any incoming sunlight.
Measures Against Climate Change Effect of Airplane Contrails
Scientists agree that politicians should implement policy measures to address the climate impact of contrails. A study published back in 2019 says that their global warming impact will triple by 2050. That is due to the increase in air travel and new technology enabling planes to reach higher altitudes where contrails tend to form.
The ways for reducing the white trails are researched by scientists. The effect of biofuels made from plants, fat, oil and grease has been tested on them. The test were done by having chase planes fly behind a test aircraft that measure the amount of soot being produced by the engines.
Back in 2017, NASA found that biofuel blends can reduce soot by up to 70% and help minimize contrails formation. Another way involves rerouting flights so that they avoid “ice supersaturated” regions where contrails are most likely to form.
However, it could take extra time to fly around those regions which means burning more jet fuel. Since this could raise aircraft CO2 emissions, this way is deemed counterproductive to the goal of reducing aviation’s climate impact.
Regulators could also enforce measures that could reduce contrails emissions. They can add extra fees for night flights to discourage companies from planning them.
Currently, contrails of airplanes pose a threat to the rising climate change emissions globally considering the expected increase of air traffic by 2050. Measures like biofuels combined with stricter regulations could provide the effects needed to reduce the ir carbon impact.