Changes to the Antarctic ice sheet at the bottom of the southern hemisphere have been triggered by sea level changes in the northern hemisphere over the past 40,000 years, a new study discovered. .
Researchers from McGill University found that ice sheets at opposite ends of the Earth can influence one another by tweaking sea levels in surrounding waters.
New models found that as the climate cooled in the northern hemisphere and more water turned to ice, sea levels in Antarctica dropped, making its ice sheet grow. .
Likewise, as temperatures rose again, the ice sheets in the Northern Hemisphere retreated, causing levels to rise around Antarctica and its ice sheet to retreat.
Polar ice sheets evolve on various different time scales and are in constant flux, with the ice growing and retreating depending on the climate and the surrounding water levels.
'They evolve on various different time scales and are in constant flux, with the ice growing and retreating depending on the climate and the surrounding water levels.
To investigate the mechanisms involved in driving changes in the Antarctic ice sheet the researchers looked at a wide range of geological records, from cores of sediment from the ocean bottom near Antarctica to records of land exposure and past shorelines.
The only possible explanation, the scientists say, were changes in sea level caused by the growth or retreat of ice sheets in the Northern Hemisphere.
Researchers were able, for the first time, to simulate, simultaneously, changes in both sea levels and ice dynamics in both hemispheres over the past 40,000 years.
Global sea levels could rise as much as 1.2 metres (4 feet) by 2300 even if we meet the 2015 Paris climate goals, scientists have warned