Sea ice

The year 2023 shattered the record for the warmest summer in the Arctic, and people and ecosystems across the region felt the impact. Wildfires forced evacuations across Canada. Greenland was so warm that a research station at the ice sheet summit recorded melting in late June, only its fifth melting event on record. Sea surface temperatures in the Barents, Kara, Laptev and Beaufort seas were 9 to 12 degrees Fahrenheit (5 to 7 degrees Celsius) above normal in August. While reliable instrument measurements go back only to around 1900, it’s almost certain this was the Arctic’s hottest summer in centuries. Summer heat extremes in 2023 and over time. NOAA, Arctic Report Card 2023 The year started out unusually wet, and snow accumulation during the winter of 2022-23 was above average across much the Arctic. But by May, high spring temperatures had left the North American snowpack at a recor...

Summer 2024 was officially the Northern Hemisphere’s hottest on record. In the United States, fierce heat waves seemed to hit somewhere almost every day. Phoenix reached 100 degrees for more than 100 days straight. The 2024 Olympic Games started in the midst of a long-running heat wave in Europe that included the three hottest days on record globally, July 21-23. August was Earth’s hottest month in the National Oceanic and Atmospheric Administration’s 175-year record. Overall, the global average temperature was 2.74 degrees Fahrenheit (1.52 degrees Celsius) above the 20th-century average. That might seem small, but temperature increases associated with human-induced climate change do not manifest as small, even increases everywhere on the planet. Rather, they result in more frequent and severe episodes of heat waves, as the world saw in 2024. The most severe and persistent heat waves are often associated with an atmospheric pattern called a heat dome. As a...

Ocean temperatures have been off the charts since mid-March 2023, with the highest average levels in 40 years of satellite monitoring, and the impact is breaking through in disruptive ways around the world. The sea of Japan is more than 7 degrees Fahrenheit (4 degrees Celsius) warmer than average. The Indian monsoon, closely tied to conditions in the warm Indian Ocean, has been well below its expected strength. Spain, France, England and the whole Scandinavian Peninsula are also seeing rainfall far below normal, likely connected to an extraordinary marine heat wave in the eastern North Atlantic. Sea surface temperatures there have been 1.8 to 5 F (1 to 3 C) above average from the coast of Africa all the way to Iceland. So, what’s going on? Sea surface temperatures are running well above the average since satellite monitoring began. The thick black line is 2023. The orange line is 2022. The 1982-2011 average is the middle dashed li...

As winds and waves from Typhoon Merbok devastated communities along the coast of Western Alaska in 2022, Reppi Swan Sr.’s phone began to ring at Kivalina, a barrier island 80 miles above the Arctic Circle. A neighboring family had lost 3 feet of land to the rumbling lagoon, and their home was now sitting just 6 feet from the angry water’s edge. Reppi called his brother Joe Swan Jr. and quickly slid into his insulated rain gear. As a volunteer first responder, Reppi plans for emergencies like this. He and his wife, Dolly, had been patrolling the island for dangerous erosion every few hours during the storm. To prepare, he had already inspected the city’s heavy equipment and located a pile of boulders left over from a recent construction project. Working through the rain, Reppi delivered boulders to the threatened home. With their cousin Carl Swan serving as a spotter, Joe carefully arranged the boulders with a backhoe to stabilize the bank. It would hold at lea...

Atmospheric rivers, those long, powerful streams of moisture in the sky, are becoming more frequent in the Arctic, and they’re helping to drive dramatic shrinking of the Arctic’s sea ice cover. While less ice might have some benefits – it would allow more shipping in winter and access to minerals – sea ice loss also contributes to global warming and to extreme storms that cause economic damage well beyond the Arctic. I’m an atmospheric scientist. In a new study of the Barents-Kara Seas and the neighboring central Arctic, published Feb. 6, 2023, in Nature Climate Change, my colleagues and I found that these storms reached this region more often and were responsible for over a third of the region’s early winter sea ice decline since 1979. More frequent atmospheric rivers By early winter, the temperature in most of the Arctic is well below freezing and the days are mostly dark. Sea ice should be growing and spreading over a wider area. Yet the...