Summary
As the ice retreats, Antarctic species are struggling to reproduce, feed and compete with invasive species. Credit: Ida Kubiszewski Far from being a remote, isolated continent, Antarctica is integral to Earth's climate and life-support systems. Its vast ice sheet stores more than 90% of the planet's surface fresh water and influences sea levels, circulation of the atmosphere and how much sunlight the planet reflects. Around Antarctica, the Southern Ocean acts as the lungs of the deep sea, accounting for roughly 40% of the global ocean's uptake of carbon dioxide emissions generated by human activities, shaping how seawater mixes and distributes nutrients to support marine life around the globe1. Yet, many of these stabilizing features are showing signs of degradation. The West Antarctic Ice Sheet is retreating, with widespread thinning of glaciers and ice shelves. Changes there are accelerating, as damage in one area exacerbates melting and stresses in others. And now, parts of the more stable East Antarctic Ice Sheet seem to be thinning, too2. Pooling melt water on its surface would eat away at the ice further3, possibly triggering the break-up of more ice shelves4. Meanwhile, Antarctic waters seem to have entered a new regime, with record-low sea ice, greater salinity and less stratification of upper ocean layers5,6 (see 'Antarctica under threat').