Modeling shows that stratospheric aerosol injection has the potential to cut back ice sheet loss resulting from climate change.
One in all the various effects of world warming is sea-level rise resulting from the melting and retreat of the Earth’s ice sheets and glaciers in addition to other sources. Because the sea level rises, large areas of densely populated coastal land could ultimately develop into uninhabitable without extensive coastal modification. So as to stave off this possibility, carbon emissions need to succeed in net negative, a state that is difficult to attain under current circumstances.
There are numerous proposals to drastically mitigate the consequences of climate change, and essentially the most expansive of those involve interventions that may alter facets of your entire globe — the geoengineering techniques. While they’ve some promise, we don’t understand enough about natural cycles to completely assess how helpful such interventions will likely be.
A global team of researchers led by Professor John C. Moore, on the University of Lapland, Rovaniemi, Finland, and Professor Ralf Greve, on the Institute of Low Temperature Sciences, Hokkaido University, has used simulations to look at the potential effects of a geoengineering technique called stratospheric aerosol injection on ice sheet melting. Their findings were published within the Journal of Geophysical Research: Earth Surface.
“Stratospheric aerosol injection, or SAI, would artificially introduce aerosols into the stratosphere by aircraft or high-altitude balloons to create a cooling effect via global dimming and increased albedo — the degree to which Earth reflects sunlight,” Moore explains.
Moore, Greve and colleagues used the SICOPOLIS model to simulate the changes within the Greenland Ice Sheet for the period 1990-2090 under three different scenarios: RCP8.5 (worst-case scenario, unabated warming); RCP4.5 (intermediate scenario, possibly achievable under current conditions); and GeoMIP G4 (RCP4.5 plus the injection of 5 million metric tons of sulfur dioxide per 12 months into the stratosphere during 2020-2070).
The simulations showed that SAI of sulfur dioxide would have a transparent protective effect on the Greenland Ice Sheet. Under RCP8.5, there can be ice loss comparable to roughly 90 mm sea-level rise; under RCP4.5, ice loss can be roughly 60.6 mm sea-level rise; but under GeoMIP G4, ice loss can be limited to roughly just 37.6 mm sea-level rise. When these scenarios were tested with a distinct model, Elmer/Ice, the outcomes were similar. The margins of the ice sheet would profit essentially the most under GeoMIP G4.
“While this study shows that SAI could contribute to the protection of the Greenland Ice Sheet, and hence, potentially, all other ice cover on Earth, geoengineering is a highly contentious topic,” Greve concludes. “The most important issue is that it addresses only the symptoms of world warming, not the basis causes — and will even delay the changes required to deal with the causes. Moreover, resulting from the immense complexity of the natural systems on Earth, it’s not possible to predict exactly what positive and negative outcomes could result.”
