New research from NASA and the National Snow and Ice Data Center (NSIDC) in Colorado measured Arctic sea ice cover on March 22, during what should’ve been its annual peak. In conclusion, the agency reported seeing 5.53 million square miles (14.33 million square kilometers) of sea ice — for context, that’s the lowest Arctic winter sea ice levels have ever been.
To make matters worse, NASA scientists also discovered that, this year, summer ice in the Antarctic retreated to 764,000 square miles (1.98 million square kilometers) as of March 1, tying for “the second lowest minimum extent ever recorded there.” The combined loss of sea ice in both polar regions has led to an all-time low for total sea ice on the planet. In mid-February 2025, ice coverage globally declined by over million square miles (2.5 million square kilometers) from what the average was prior to 2010. Altogether, the missing sea ice is now roughly the same size as the continental United States east of the Mississippi.
“We’re going to come into this next summer season with less ice to begin with,” Linette Boisvert, an ice scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland said in a statement. “It doesn’t bode well for the future.”
“We’re going to come into this next summer season with less ice to begin with,” Linette Boisvert, an ice scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland said in a statement. “It doesn’t bode well for the future.”
Sea ice that covers the Arctic plays a fundamental role in the region’s ecosystem — for instance impacting the way animals breed and find food. And, with less sea ice in winter months, storms can generally become more severe and coastal erosion can increase. Sea ice reduction happens when more sea ice melts during the summer compared to what freezes during the winter. Last year was Earth’s warmest year on record. The Global Carbon Project found that 2024 was also a record high for global carbon emissions from fossil fuels.
Scientists find these measurements by using satellites that track natural radiation in the microwave range — the radiation is different for open water and sea ice. Historical data is also used, like data collected in the 1970s and 1980s with the Nimbus-7 satellite.
“It’s not yet clear whether the Southern Hemisphere has entered a new norm with perennially low ice or if the Antarctic is in a passing phase that will revert to prior levels in the years to come,” Walt Meier, an ice scientist with NSIDC, said in the same statement.
But it’s worth considering that sea ice this year has continued the downward trend scientists have been following for several decades.
