Scattering sunlight-reflecting particles in the atmosphere has the potential to slow down the rapid melting in West Antarctica and decrease the risk of disastrous sea-level rise, according to a study led by researchers from Indiana University. This study is among the first to explore the impact of climate engineering on Antarctica, as scientists emphasize the increasing probability of accelerated ice loss in the region within this century. The research findings were published in the Journal of Geophysical Research: Atmospheres.
Current global warming trends may still lead to significant sea-level rise, even if the goal of keeping global warming within 1.5 degrees Celsius above pre-industrial levels is achieved. Examining methods to reflect sunlight back into space prior to its absorption into the Earth’s climate system might provide more time for addressing climate change and avert or delay climate tipping points, including the collapse of the West Antarctic Ice Sheet.
The researchers investigated a type of climate engineering called stratospheric aerosol injection, which involves releasing vast amounts of small sulfur droplets into the stratosphere through airplanes to control global temperatures. The concept is inspired by the cooling effect that occurs after large volcanic eruptions disperse particles into the upper atmosphere, lasting from months to years. This approach was also mentioned in a White House report outlining potential research programs on stratospheric aerosol injection and marine cloud brightening—another proposed strategy for cooling the planet.
To study the potential of stratospheric aerosol injection for slowing down Antarctic ice loss, the researchers used high-performance computers and global climate models to simulate various scenarios. They discovered that the most effective strategy for preserving Antarctica’s land ice involves releasing aerosols at multiple latitudes within the tropics and sub-tropics, with a greater proportion in the Southern Hemisphere. This approach helps to keep warm ocean waters away from the ice shelves.
While the simulated scenarios at multiple latitudes showed promising results in terms of Antarctic ice loss reduction, more research is needed to quantify the change in melt rates. On the other hand, some single-latitude injection scenarios actually accelerated ice loss due to shifts in prevailing winds drawing warm ocean waters toward the ice shelves.
Stratospheric aerosol injection also presents risks, such as changes in regional precipitation patterns and the possibility of “termination shock“—a rapid rebound of global temperatures if the treatment is interrupted. This study contributes to the growing understanding of the advantages and drawbacks of deliberately cooling the planet, which is becoming a more widely-discussed topic as the effects of climate change become increasingly apparent.
Further research is necessary before determining whether moving forward with climate engineering efforts, including stratospheric aerosol injection, is a suitable decision. This holds true for both Antarctica and the rest of the planet.