The rapid melting of sections of West Antarctica could be slowed down by scattering sunlight-reflecting particles in the atmosphere, researchers find.
A team of researchers at Indiana University have looked at how climate engineering could be leveraged to protect Antarctica from melting and reduce the risk of catastrophic sea-level rise.
The study focused on stratospheric aerosol injection, a form of engineering in which large amounts of tiny sulfur droplets are released into the stratosphere by a fleet of aeroplanes. The method has been proposed as a potential strategy to keep global warming at bay.
“Even if the world meets the ambitious target of limiting global warming to 1.5°C above pre-industrial levels – which we are not on track to do – we are going to see significant sea-level rise,” said Paul Goddard, an assistant research scientist and co-author of the study.
“Exploring ways to reflect sunlight into space before it is absorbed into the Earth’s climate system could help buy us more time to address climate change and avoid or delay climate tipping points, such as the West Antarctic Ice Sheet collapse.”
The approach mimics what happens when a large volcano spews vast amounts of particles into the upper atmosphere and precipitates a cooling effect that can last months or years.
In the study, the researchers used high-performance computers and global climate models to simulate different stratospheric aerosol injection scenarios, identifying the cooling strategy with the most potential to slow Antarctic ice loss.
“Where you release the aerosols matters a lot and can affect the climate differently,” Goddard said. “In this case, we found that releasing stratospheric aerosols at multiple latitudes within the tropics and sub-tropics, with a greater proportion in the Southern Hemisphere, is the best strategy for preserving land ice in Antarctica because it helps keep warm ocean waters away from the ice shelves.”
Researchers simulated 11 different stratospheric aerosol injection scenarios. Three cases spanned multiple latitudes with temperature targets of 1.5, 1 and 0.5°C above pre-industrial levels.
The simulations ran between 2035 and 2070. They included a moderate emissions scenario with no stratospheric aerosol injection that served as a key point of comparison.
The results showed that stratospheric aerosol injection at multiple latitudes helped to reduce Antarctic ice loss. However, this was not the case in all scenarios when the geoengineering methods were used.
Notably, several single-latitude injection scenarios actually accelerated Antarctic ice loss due to a southward shift of prevailing winds drawing warm ocean waters towards the ice shelves.
“If we’re ever going to engineer the climate, how we do it really matters,” Goddard said.
The researchers’ work was published in the Journal of Geophysical Research: Atmospheres.
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