A team of scientists at the British Antarctic Survey has solved a long-standing mystery of what drove rapid climate warming during the Last Interglacial period 130,000 years ago, and the research suggests that the same processes are accelerating sea ice retreat across the Arctic today. As a result, the Arctic may be completely free of sea ice by 2035.
“High temperatures in the Arctic have puzzled scientists for decades. Unravelling this mystery was technically and scientifically challenging,” said study co-lead author Dr. Maria Vittoria Guarino. “For the first time, we can begin to see how the Arctic became sea ice-free during the last interglacial. The advances made in climate modeling means that we can create a more accurate simulation of the Earth’s past climate, which, in turn gives us greater confidence in model predictions for the future.”
For the investigation, the experts used the latest version of the UK Hadley Center climate model to compare Arctic sea ice conditions during the last interglacial with present day. This model is the UK’s most advanced physical representation of the Earth’s climate and provides a critical tool for climate research.
The current study is unique in that it accounted for the effects of melt ponds, which have a strong influence on sea ice retreat.
Melt ponds are shallow pools of water that form on the surface of Arctic sea ice during the spring and summer. These ponds affect how much sunlight is absorbed by the ice and how much is reflected back into space.
The model simulations revealed that during the last interglacial, the impact of intense springtime sunshine created many melt ponds, which played a crucial role in the retreat of Arctic sea ice.
A simulation of the future using the same model indicates that the Arctic may become sea ice-free by 2035.
“We know the Arctic is undergoing significant changes as our planet warms. By understanding what happened during Earth’s last warm period we are in a better position to understand what will happen in the future,” said Dr. Louise Sime. “The prospect of loss of sea-ice by 2035 should really be focusing all our minds on achieving a low-carbon world as soon as humanly feasible.”
The melt pond scheme that was incorporated into the climate model was developed by Dr. David Schroeder and Professor Danny Feltham from the University of Reading. They said the research shows just how important sea ice processes like melt ponds are in the Arctic, and why it is crucial that they are accounted for in climate models.
The study is published in the Nature Climate Change.