Sea ice around the North and South Poles acts as a massive reflector, bouncing a significant amount of the Sun’s energy back into space. However, as global temperatures rise, this reflective layer diminishes, allowing the darker ocean beneath to absorb more heat and further warm the planet. The latest record low in sea ice levels is attributed to a combination of warm air, warm seas, and winds that break apart the ice.
Over the five days to February 13, 2025, the combined extent of Arctic and Antarctic sea ice was 15.76 million square kilometers (6.08 million square miles), surpassing the previous five-day record low of 15.93 million square kilometers (6.15 million square miles) from January-February 2023, according to BBC analysis of data from the US National Snow and Ice Data Center (NSIDC)
Arctic sea ice is currently at its smallest recorded extent for this time of year, while Antarctic sea ice is nearing a new low in satellite records dating back to the late 1970s. The decline of Arctic sea ice in response to climate change is well-documented, with its end-of-summer extent decreasing from an average of 7 million square kilometers in the 1980s to 4.5 million square kilometers in the 2010s. Until the mid-2010s, Antarctic sea ice was surprisingly resilient, but it has since shown a series of very low extents, indicating a shift towards a new regime of lower ice coverage
Antarctic sea ice is particularly vulnerable due to its thinness and mobility, being surrounded by ocean rather than continents like the Arctic. Warmer air and warmer waters have played a significant role in the recent lows, especially during the southern hemisphere summer. The Antarctic ice shelves have experienced extreme surface melting driven by high air temperatures, contributing to the low sea ice levels.
In the Arctic, the late freeze-up around Hudson Bay, due to unusually warm ocean waters, and storms disrupting ice in the Barents and Bering Seas, have contributed to the low ice extent. Thinner ice cover makes it more responsive to weather events, amplifying their impact. Recent weeks have seen Arctic sea ice move even further below average, with temperatures around the North Pole significantly above normal, leading to melting conditions in areas like Svalbard.