How changing the height of the Antarctic ice sheet affects global climate: a mid-Pliocene case study

Warming-induced topographic changes of the East Antarctic ice sheet (EAIS) during the Pliocene warm period could have a significant influence on the climate. However, how large changes in the EAIS height could theoretically affect global climate have yet to be studied. Here, the influence of possible height changes of the EAIS on climate over the East Antarctic ice sheet region versus the rest of the globe is investigated through numerical climate modeling using the Pliocene as a test case. As expected, the investigation reveals that the reduction of ice sheet height leads to a warmer and wetter East Antarctica. However, unintuitively, both the surface air temperature and the sea surface temperature decrease over the rest of the globe. These temperature changes result from the higher air pressure over Antarctica and the corresponding lower air pressure over extra-Antarctic regions with the reduction of EAIS height. This topography effect is further confirmed by energy balance analyses. These findings could provide insights into future climate change caused by warming-induced height reduction of the Antarctic ice sheet.