New Study: Antarctic Ice Sheet Melt Will Lead To Widespread Cooling, Sea Ice Expansion

Scientists have counter-intuitively determined that a melting Antarctic ice sheet serves to mitigate global warming.

The anticipated accelerated melting of the Antarctic ice sheet (AIS) will mean massive amounts of freshwater will enter the Southern Ocean (SO) over the next one hundred years.

According to a new study‘s panoply of SOFIA (Southern Ocean Freshwater Input from Antarctica) models, a melting AIS will, in turn, cool the SO and Antarctica (the latter by 1°C or more) as well as lead to further expansion of the Southern Hemisphere’s sea ice.

More specifically, as a consequence of future Antarctic ice sheet melt, over the next century the entire 40-70°S region will cool ~0.7°C and sea ice will expand by approximately 2 million km² (per Figure S1 from the study). The lead author already published a 2022 paper documenting “the Southern Ocean (50°S–70°S) sea surface temperature has a significant and robust cooling trend during 1982–2020,” so the cooling trend has been ongoing for over 40 years already.

The authors of the present study maintain the “response to an increased Antarctic sea ice extent and ocean surface cooling results in global atmospheric impacts,” not just local or regional ones. Specifically, the effect of SO cooling includes a (a) reduction in the global warming rate, (b) troposphere-wide cooling, (c) Eastern tropical Pacific cooling, (d) a delay in the anticipated weakening of the AMOC, (e) a northward shift of the ICTZ (Inner-Tropical Convergence Zone), and (f) a “weakening of the jet stream on its equatorward flank in both hemispheres.”

In other words, the key to reducing the global warming “problem” and its presumed side effects may be to cheer on (or hope for) an accelerated AIS melting over the next century.

“Since most of these responses act opposingly to global warming mechanisms diagnosed from model experiments lacking Antarctic freshwater, our results support the notion of a potential delay of anthropogenic climate change through SO [Southern Ocean] processes.”

For those who say a future accelerated Antarctic ice sheet melt will lead to concerning sea level rise, scientists contend this “problem” may be self-correcting as well.

According to the IPCC and climate models, if Antarctica were to ever warm (and it has not warmed in the last 70 years), this warmth would add more precipitation and thus ice mass to the Antarctic ice sheet (IPCC AR4, Krinner et al., 2007, Palerme et al., 2017). The warming-induced ice mass expansion contributes to a reduction in Antarctica’s contribution to sea level rise by 2100. Specifically, a warming Antarctica reduces sea level rise by -1.2 mm/yr.