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This is a self-reinforcing cycle that existing climate models largely ignore.<\/p>\n
That feedback loop, the researchers found, could contribute just as much to rising seas as the direct effects of a warming atmosphere.<\/p>\n
The missing Antarctic feedback loop<\/p>\n
The Intergovernmental Panel on Climate Change (IPCC<\/a>) currently treats Antarctic ice shelf<\/a> melt as a fixed input. Melt happens, water enters the ocean, and sea levels rise.\u00a0<\/p>\n What the models don\u2019t account for is what that meltwater does to the ocean itself, and how the ocean then responds.<\/p>\n \u201cMost current climate models that inform international policy don\u2019t consider this feedback loop at all,\u201d said the study\u2019s lead author, Madeleine Youngs, an assistant professor at the University of Maryland<\/a>.\u00a0<\/p>\n The researchers said the IPCC currently treats ice shelf melting as a fixed process instead of one that interacts with other climate systems. <\/p>\n They argue that future sea level rise<\/a> estimates will be more accurate if climate models include feedback loops linked to ice shelf meltwater.<\/p>\n Melting speeds up more melting<\/p>\n The mechanism comes down to the physics of water temperature and density. Under normal conditions, cold, dense water sinks and settles near the ocean floor, forming a barrier layer that keeps warmer deep-ocean currents from reaching the underside of ice shelves.<\/p>\n When ice melts, the freshwater<\/a> it releases dilutes and weakens that barrier. Warmer water from the deep ocean pushes through and reaches the base of the ice, accelerating melting.\u00a0<\/p>\n More melt produces more freshwater, which weakens the barrier further, allowing in still more warm water. The cycle feeds on itself.<\/p>\n \u201cIt\u2019s a positive feedback loop where more melt leads to warmer water reaching the ice, which causes even more melt,\u201d Youngs said.<\/p>\n \u201cIf we [humans] continue to do business as usual, it\u2019s distinctly possible that we reach the climate tipping point sooner rather than later, especially as we consider this positive feedback loop.\u201d<\/p>\n One of the more nuanced findings is that this dynamic plays out differently depending on where in Antarctica the melting is occurring.<\/p>\n In regions like the Weddell Sea<\/a>, the feedback is straightforwardly dangerous. As upstream ice melts and freshwater pours in, the cold-water barrier erodes, warm water floods through, and melting accelerates further.<\/p>\n In other regions, including the West Antarctic Peninsula and the Amundsen Sea, the picture is more complicated.\u00a0<\/p>\n There, meltwater flowing in from upstream actually forms a cold freshwater barrier that temporarily shields the ice from warmer ocean currents, creating a negative rather than positive feedback.<\/p>\n \u201cOur study suggests that these regions \u2013 usually regarded as the most at-risk \u2013 are actually more protected than we thought, at least in the short term, because of this negative feedback loop,\u201d Youngs said.\u00a0<\/p>\n \u201cBut this protection depends on massive upstream melting happening first, and that upstream melt has its own severe consequences on sea levels.\u201d<\/p>\n What rising seas could mean<\/p>\n More than 680 million people worldwide live in low-lying coastal zones<\/a> that are vulnerable to sea level rise.<\/p>\n The IPCC currently estimates that Antarctic meltwater could contribute up to 28 to 34 centimeters (11 to 13 inches) of additional sea level rise by 2100 under high-emissions scenarios.<\/p>\n Even a modest increase beyond that range would meaningfully expand the reach of storm surges and permanent flooding from Miami to Mumbai and hundreds of cities in between.<\/p>\n If the feedback loops identified in this study are as significant as the research suggests, those estimates may need to be revised upward.<\/p>\n \u201cThis is really just a first investigation into this topic,\u201d Youngs said.<\/p>\n \u201cWhat we\u2019re showing is that the feedbacks in the Antarctic<\/a> region are real, extremely impactful, and vary depending on where they take place on the continent. We can\u2019t just consider the direct impact of a warming atmosphere.\u201d<\/p>\n Tracking Antarctica\u2019s tipping points<\/p>\n The research team is already working on the next phase.<\/p>\n Youngs and her colleagues are developing higher-resolution simulations that incorporate meltwater feedback processes and trace projected trajectories from today through 2100.<\/p>\n The focus will be on identifying which ice shelves are closest to the point of no return.<\/p>\n \u201cThe next step is understanding exactly when and where things tip \u2013 and what that means for all of us,\u201d Youngs concluded.<\/p>\n The study is published in the journal Nature Geoscience<\/a>.<\/p>\n \u2014\u2013<\/p>\n Like what you read? Subscribe to our newsletter<\/a> for engaging articles, exclusive content, and the latest updates.<\/p>\n Check us out on EarthSnap<\/a>, a free app brought to you by Eric Ralls<\/a> and Earth.com<\/a>.<\/p>\n \u2014\u2013<\/p>\n","protected":false},"excerpt":{"rendered":"Current projections of sea level rise from Antarctic ice melt may be significantly underestimating the threat. A new…\n","protected":false},"author":2,"featured_media":458748,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[61,60,82],"class_list":["post-458747","post","type-post","status-publish","format-standard","has-post-thumbnail","category-science","tag-ie","tag-ireland","tag-science"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts\/458747","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/comments?post=458747"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts\/458747\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/media\/458748"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/media?parent=458747"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/categories?post=458747"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/tags?post=458747"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}![\"Top:](\"https:\/\/www.newsbeep.com\/ie\/wp-content\/uploads\/2026\/05\/meltwater_antarctic-ice-shelves_speeds-melting_Madeleine-Youngs_1s.webp\")
<\/a>Top: A diagram illustrating the Antarctic ice shelf meltwater interactions between a floating glacier and warm water. Bottom: A heat map depicting the temperatures of the Antarctic ice shelf. Credit: Madeleine Youngs. Click image to enlarge. Antarctic melting is not uniform<\/p>\n