{"id":401439,"date":"2025-09-06T01:42:10","date_gmt":"2025-09-06T01:42:10","guid":{"rendered":"https:\/\/www.europesays.com\/uk\/401439\/"},"modified":"2025-09-06T01:42:10","modified_gmt":"2025-09-06T01:42:10","slug":"atlantic-ocean-currents-are-collapsing-and-the-consequences-could-be-disastrous","status":"publish","type":"post","link":"https:\/\/www.europesays.com\/uk\/401439\/","title":{"rendered":"Atlantic Ocean Currents Are Collapsing, and the Consequences Could Be Disastrous"},"content":{"rendered":"

A newly published peer-reviewed study in the Journal of Geophysical Research: Oceans<\/a> suggests that the Atlantic Meridional Overturning Circulation (AMOC)<\/strong> \u2014 a major system of ocean currents that regulates heat and weather patterns across the globe \u2014 could begin collapsing as early as 2055<\/strong>. <\/p>\n

A Giant Ocean Engine Under Threat<\/p>\n

The AMOC<\/strong> functions like a vast conveyor belt, pulling warm water northward on the ocean\u2019s surface and sending cold, dense water southward along the seafloor. It plays a vital role in regulating the climate<\/strong> of the Northern Hemisphere, including warming Western Europe<\/strong>, influencing African and Asian monsoons<\/strong>, and controlling sea level patterns<\/strong> on the U.S. East Coast. But new simulations suggest that this stability may be more fragile than once believed.<\/p>\n

The latest models show that even under a \u201cmiddle of the road\u201d emissions scenario \u2014 where global temperatures rise by about 4.8\u00b0F (2.7\u00b0C)<\/strong> above pre-industrial levels \u2014 the AMOC could collapse by 2063<\/strong>. Under higher emission paths, the breakdown could begin as early as 2055<\/strong>. \u201cThe chance of tipping is much larger than previously thought,\u201d said Sybren Drijfhout, a professor of physical oceanography at the University of Southampton and Utrecht University. This is a striking departure from earlier estimates, which suggested such an event might not occur until late in the 22nd century.<\/p>\n

The risk isn\u2019t just theoretical. Recent trends already show deep water formation \u2014 the engine of the AMOC \u2014 is weakening<\/strong>, largely due to melting Arctic ice<\/a> and rising air temperatures. As cold, salty water at the surface becomes lighter due to warming and freshwater dilution, it loses its ability to sink. Once this process halts, the current system begins to unravel.<\/p>\n

\"Image\"(a): The AMOC strength at 1,000\u00a0m and 26 N for the quasi-equilibrium hysteresis simulation, including the statistical equilibria at\u00a0\u00a0=\u00a00.18, 0.45, and 0.48\u00a0Sv (last 50\u00a0years are displayed). The yellow shading is the observed AMOC strength (Smeed et\u00a0al.,\u00a02018<\/a>). (b): The time-mean AMOC in depth coordinates\u00a0for the first 50 model years of the quasi-equilibrium. (c): The time-mean AMOC in density coordinates ( , first 50 model years), where the three curves represent the (section-averaged) depth level. The 20-m depth contour is smoothed to reduce its meridional variability. (d): Similar to panel c, but now for the surface-forced AMOC. The presented results are from the quasi-equilibrium hosing simulation.<\/p>\n

Detecting the Collapse: A New Indicator Emerges<\/p>\n

Historically, scientists have struggled to track the AMOC\u2019s strength in real time. Conventional metrics like sea surface temperature<\/strong> were often unreliable under fast-changing climate conditions. That challenge led researchers to develop a new and more precise marker: surface buoyancy flux<\/strong>.<\/p>\n

This parameter combines heat and salinity changes<\/strong> at the ocean\u2019s surface to estimate shifts in water density<\/strong> \u2014 the key driver behind deep water formation<\/strong>. \u201cThe advantage of [the surface buoyancy flux] is that it can be calculated in many climate models,<\/strong>\u201d explained Ren\u00e9 van Westen, postdoctoral researcher in climate physics at Utrecht University and lead author of the new study. \u201cTherefore, we were aiming to develop a new indicator that also works under climate change.<\/strong>\u201d<\/p>\n

The results were sobering. According to van Westen, the surface buoyancy flux was stable until 2020<\/strong>, indicating little recent change in the AMOC. But since 2020, the signal has been rising<\/strong>, implying that the current is weakening more rapidly than previously understood<\/strong>. The team found that when this indicator falls to zero, it means no dense water is sinking<\/strong>, signaling the beginning of a functional collapse<\/strong>. \u201cWhen this quantity reduces to zero, it means that the surface has become too light and no sinking takes place,<\/strong>\u201d van Westen added.<\/p>\n

Global Impacts of an AMOC Shutdown<\/p>\n

Should the AMOC collapse<\/strong>, the ramifications would be globally disruptive and regionally catastrophic<\/strong>. Europe would face colder, stormier winters<\/strong> and reduced rainfall<\/strong>, potentially cutting agricultural output by up to 30%<\/strong>. Meanwhile, U.S. East Coast cities<\/strong> could see a sharp increase in sea levels<\/strong> due to water redistribution. The Amazon rainforest<\/strong>, African Sahel<\/strong>, and South and East Asian monsoon systems<\/strong> could all experience major instability, with knock-on effects for food security<\/strong>, migration<\/strong>, and economic resilience<\/strong>.<\/p>\n

Unlike a sudden weather event, an AMOC collapse would unfold over decades, but its long-term impact<\/strong> would be profound. While the study estimates it would take over 100 years for full disruption<\/strong>, others like Drijfhout argue it could happen in just 50 years<\/strong> \u2014 a blink in geologic time. \u201cThe AMOC is like a campfire with a dwindling amount of fuel,<\/strong>\u201d he said. \u201cIf we stop throwing new wooden blocks on the fire, the fire does not immediately die, but it keeps smouldering for some time.\u201d<\/p>\n

Can It Still Be Prevented?<\/p>\n

Despite the alarming projections, there is still a narrow window of opportunity<\/strong>. The researchers emphasize that reducing carbon emissions sharply<\/strong> could still make a meaningful difference. \u201cAn AMOC collapse scenario can possibly be prevented when following a low emission scenario,<\/strong>\u201d van Westen said, \u201cbut this would require reaching net-zero carbon emissions around 2050.<\/strong>\u201d<\/p>\n

This timeline aligns with international goals like the Paris Agreement<\/strong>, which aims to limit warming to below 1.5\u00b0C (2.7\u00b0F)<\/strong>. Yet even in those low-emission scenarios, the study found that collapse still occurred in two of the 25 models<\/strong> tested. That suggests the AMOC may already be in a state of slow degradation<\/strong>, and stabilizing it could demand more than emissions cuts alone \u2014 possibly including carbon removal technologies<\/strong> and geoengineering interventions<\/strong>.<\/p>\n","protected":false},"excerpt":{"rendered":"A newly published peer-reviewed study in the Journal of Geophysical Research: Oceans suggests that the Atlantic Meridional Overturning…\n","protected":false},"author":2,"featured_media":401440,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[8],"tags":[70,16,15],"class_list":{"0":"post-401439","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-science","8":"tag-science","9":"tag-uk","10":"tag-united-kingdom"},"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@uk\/115154816410049067","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts\/401439","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/comments?post=401439"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts\/401439\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/media\/401440"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/media?parent=401439"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/categories?post=401439"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/tags?post=401439"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}