The Arctic ice cap is melting faster than ever before, threatening to push so much fresh water into the North Atlantic that it could disrupt how the ocean regulates global temperatures, a prominent oceanographer has warned.
As the head of a 40-member climate mission to the Arctic aboard the Canadian Coast Guard ice breaker Amundsen, Belgian researcher Roger Francois is concerned about how the pace of climate change may affect the future of deep water pools and currents, and how this imbalance may worsen the effects of global warming.
Over the course of the past two million years, temperatures have risen and fallen in 100,000-year cycles, with a sheet of ice forming over the Arctic cap each time followed by a rapid melt, he told AFP.
The last warming occurred between 20,000 and 15,000 years ago, and led at that time to a rise in sea level of 130 metres.
"This really is the trend with the thaws in Greenland and Antarctica," said Francois, who is a professor at the University of British Columbia in Vancouver.
"The biggest difference with today is the time scale. It has never been faster."
Each cycle is marked by an increase in carbon in the atmosphere. At the last change, the rate of carbon dioxide in the air increased from 180 parts per million (ppm) to 280 ppm over 5000 years. Until the Industrial Revolution, the level remained at 280 ppm, and since then it has skyrocketed to more than 400 ppm in 2015, he explained.
"If we continue this way, and that's what seems to be happening, we'll end up by the end of the century with rates we have not had since the days of the dinosaurs, the Mesozoic Age," with 1000 ppm, Francois warned.