Archive – Contrails – IMPERIAL COLLEGE – Archive
MADRID, 16 Sep. (EUROPA PRESS) –
A new study dispels fears that diverting flights to avoid the formation of climate-warming condensation trails could inadvertently worsen global warming.
Researchers from Sorbonne University and the University of Reading found that on most flights that form contrails in the North Atlantic, The climate benefit of avoiding them outweighs the additional carbon dioxide emitted by flying a different route.
Contrail avoidance requires comparing the climate impacts of carbon dioxide and contrails, which is called CO2 equivalence. Different methods have been proposed, and the choice of which has been largely political. Scientists feared that some options could be misleading, making avoidance appear beneficial to the climate when it is actually harmful.
The study, published in Atmospheric Chemistry and Physicsconcludes that, for a large majority of North Atlantic flights, avoiding contrails would benefit the climate regardless of the choice of CO2 equivalency.
Condensation trails (the white lines left by airplanes in the sky) They can trap heat in the atmosphere and contribute to global warming.
The new study builds on previous research suggesting that planes could be diverted to avoid the formation of contrails, potentially reducing climate impact. However, the benefits were not clear to avoid condensation trails in the face of the disadvantages of additional CO2 emissions.
Professor Nicolas Bellouin, co-author from the University of Reading, said: “Rerouting flights to avoid contrails could, in theory, reduce the climate impact of aviation and make air travel more sustainable. Our findings remove a major obstacle to implementing contrail prevention, But now we need better predictions and real-world testing to make this work in practice.“.
The new findings show that no matter how the trade-off between contrail prevention and increased CO2 emissions is measured, diversion rarely unintentionally worsens climate effects. The study analyzed almost half a million flights over the North Atlantic in 2019 to estimate how much warming was caused by carbon dioxide emissions from these flights and the condensation trails they formed.
The researchers first examined how current flight paths would warm the world over time. They calculate that CO2 emissions and contrails from these flights will have warmed the climate by about 17 microKelvins in 2039, 20 years later, and 14 in 2119, 100 years later. A microKelvin is a very small unit of temperature change.
The researchers then imagined a situation where planes could avoid all contrails by using just 1% more fuel. In this case, total warming would decrease significantly. By 2039, warming would be reduced by about 5 microKelvins, which is 29% less than without the route change. By 2119, it would be about 2 (14%) less.
The researchers used nine different ways to measure climate impact. In most cases, all of these methods agreed that rerouting flights would be good for the climate.provided that aircraft successfully avoid contrails as predicted.
The researchers stress that there is still a lot of uncertainty in predicting exactly where contrails will form and how much warming they will cause. They suggest focusing initial rerouting efforts on flights that form the warmest contrails, where the climate benefit is clearest.
