Under all emission scenarios, the Arctic could see summer days with almost no ice more than ten years earlier than previously projected, according to a new study. According to the researchers, earlier forecasts centered on when the region will be free of ice for a month or longer. Greenhouse gas emissions are the primary cause of the occurrence, scientists claim. The study predicts the Arctic’s first ice-free summer day within a decade, highlighting alarming climate change impacts.
Previous research has revealed that by mid-century, the Arctic is expected to have an entire month without floating ice in September, when sea ice extent is at its lowest, while by the end of the century, the ice-free season might stretch several months.
In this study, published in the journal Nature Reviews Earth & Environment, the research team from the University of Colorado Boulder, US, anticipated that the Arctic Ocean would become ice-free for the first time in late August or early September between the 2020s and the 2030s.
Not meaning “zero ice,” the researchers emphasized that the “ice-free” criteria refers to when the ocean has less than 1 million square kilometers of ice, which is less than 20% of the seasonal low ice cover in the 1980s. In previous years, the Arctic Ocean has been estimated to have approximately 3.3 million square kilometers of sea ice at its minimum in September.
“This would transform the Arctic into a completely different environment, from a white summer Arctic to a blue Arctic. So even if ice-free conditions are unavoidable, we still need to keep our emissions as low as possible to avoid prolonged ice-free conditions,” said lead author Alexandra Jahn, associate professor of atmospheric and oceanic sciences at the University of Colorado Boulder.
Researchers analyze sea ice projections and model future changes in the Arctic
The researchers conducted a review of the current literature on sea ice projections. They also analyzed sea ice coverage data from computational climate models to predict how the Arctic will change on a daily basis in the future. They discovered that the first day when the Arctic became ice-free would occur four years earlier than the monthly averages, but might occur up to 18 years sooner.
The findings on sea ice declines have important consequences for Arctic creatures that rely on it for survival, such as seals and polar bears. Furthermore, the researchers warned that as the ocean warms, non-native fish may move in. Also, as sea ice disappears, ocean waves may become larger and cause coastal erosion, endangering the lives of those living near these regions, they said. However, the researchers also said that Arctic sea ice is resilient and can return quickly if the atmosphere cools down.
“Unlike the ice sheet in Greenland that took thousands of years to build, even if we melt all the Arctic sea ice, if we can then figure out how to take CO2 back out of the atmosphere in the future to reverse warming, sea ice will come back within a decade,” said Jahn.