{"id":558632,"date":"2026-07-20T07:23:11","date_gmt":"2026-07-20T07:23:11","guid":{"rendered":"https:\/\/www.newsbeep.com\/ie\/558632\/"},"modified":"2026-07-20T07:23:11","modified_gmt":"2026-07-20T07:23:11","slug":"a-major-ocean-current-is-on-the-verge-of-collapse-scientists-say-the-effects-may-reach-california-sciencealert","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/ie\/558632\/","title":{"rendered":"A Major Ocean Current Is On The Verge of Collapse. Scientists Say The Effects May Reach California : ScienceAlert"},"content":{"rendered":"<p>Earth&#8217;s climate systems are inexorably and often unexpectedly interconnected.<\/p>\n<p>Dust from North Africa&#8217;s Sahara Desert drifts thousands of miles to <a href=\"https:\/\/www.sciencealert.com\/our-atmosphere-transforms-dust-from-the-sahara-into-minerals-that-fuel-life\" rel=\"nofollow noopener\" target=\"_blank\">fuel food webs<\/a> in the Amazon and the ocean&#8217;s depths, while <a href=\"https:\/\/www.sciencealert.com\/fog-is-teeming-with-life-and-it-may-be-doing-us-a-surprising-favor\" rel=\"nofollow noopener\" target=\"_blank\">pollution-eating microbes<\/a> hitch a ride through the atmosphere on gusts of wind or wisps of fog.<\/p>\n<p>Among the most influential planet-shaping forces is the <a href=\"https:\/\/oceanservice.noaa.gov\/facts\/amoc.html\" rel=\"nofollow noopener\" target=\"_blank\">Atlantic Meridional Overturning Circulation<\/a> (AMOC), an immense Atlantic Ocean current system that acts as a planetary conveyor belt. It brings balmy water northward from the tropics to Europe, then cycles the cooled water back south along the seafloor.<\/p>\n<p>However, human-caused  <a href=\"https:\/\/www.sciencealert.com\/climate-change\" class=\"lar_link lar_link_outgoing\" data-linkid=\"73046\" data-postid=\"209042\" rel=\"nofollow noopener\" target=\"_self\">climate change<\/a> is <a href=\"https:\/\/www.sciencealert.com\/a-strange-cold-blob-in-the-atlantic-signals-were-almost-at-a-tipping-point\" rel=\"nofollow noopener\" target=\"_blank\">slowing this vital system<\/a> and even threatening <a href=\"https:\/\/www.sciencealert.com\/its-confirmed-a-major-atlantic-ocean-current-is-verging-on-collapse\" rel=\"nofollow noopener\" target=\"_blank\">a potentially near-future collapse<\/a>.<\/p>\n<p>Given the gravity of the situation, there has been <a href=\"https:\/\/e360.yale.edu\/features\/amoc-climate-change\" rel=\"nofollow noopener\" target=\"_blank\">much debate<\/a> among scientists about how likely this is to happen \u2013 and when.<\/p>\n<p>The latest effort to iron out our understanding of the AMOC and the consequences of its stalling comes in the form of a study published in <a href=\"https:\/\/doi.org\/10.1038\/s41467-026-72555-w\" rel=\"nofollow noopener\" target=\"_blank\">Nature Communications<\/a>.<\/p>\n<p>A team of scientists used decades of NASA-acquired atmospheric data and climate simulations to project the evolution of the AMOC, forecasting life-changing shifts for communities around the globe.<\/p>\n<p><img decoding=\"async\" width=\"2048\" height=\"1474\" src=\"https:\/\/www.newsbeep.com\/ie\/wp-content\/uploads\/2026\/07\/AMOC-scaled-2-2048x1474-1.jpg\" alt=\"\" class=\"wp-image-209048\"   loading=\"lazy\"\/>An illustration showing part of AMOC&#8217;s effects. <a href=\"https:\/\/www.whoi.edu\/ocean-learning-hub\/ocean-topics\/how-the-ocean-works\/ocean-circulation\/amoc\/\" rel=\"nofollow noopener\" target=\"_blank\">(Eric S. Taylor\/Woods Hole Oceanographic Institution)<\/a><\/p>\n<p>&#8220;It is well known that the AMOC is a big player in the world&#8217;s climate system, and that it is slowing down,&#8221; <a href=\"https:\/\/news.ucr.edu\/articles\/2026\/07\/08\/slowing-atlantic-current-fueling-stronger-california-storms\" rel=\"nofollow noopener\" target=\"_blank\">says<\/a> Mohima Mimi, a climate dynamics researcher at the University of California, Riverside, and the study&#8217;s lead author.<\/p>\n<p>&#8220;What we didn&#8217;t know is exactly how the AMOC might impact atmospheric moisture and storms outside the Atlantic region.&#8221;<\/p>\n<p>The researchers have determined that an amok AMOC could exert significant climatic differences on a worldwide scale, as Mimi <a href=\"https:\/\/news.ucr.edu\/articles\/2026\/07\/08\/slowing-atlantic-current-fueling-stronger-california-storms\" rel=\"nofollow noopener\" target=\"_blank\">explains<\/a>:<\/p>\n<p>&#8220;It turns out a weakening AMOC will strengthen storms across parts of North America by the end of the century, along the California coast in particular, while reducing them over Greenland and the Arctic.&#8221;<\/p>\n<p>This is because weakening of the oceanic conveyor belts affects a similar system in the sky: <a href=\"https:\/\/www.sciencealert.com\/giant-rivers-that-flow-through-the-sky-mapped-for-first-time\" rel=\"nofollow noopener\" target=\"_blank\">atmospheric rivers<\/a>.<\/p>\n<p>Atmospheric rivers (ARs) are long, narrow strips of concentrated water vapor in the atmosphere. Especially strong systems can carry up to <a href=\"https:\/\/www.noaa.gov\/stories\/what-are-atmospheric-rivers\" rel=\"nofollow noopener\" target=\"_blank\">15 times as much water<\/a> as what flows through the mouth of the Mississippi River.<\/p>\n<p>Unsurprisingly, they significantly influence regional climates.<\/p>\n<p>&#8220;In California, atmospheric rivers are a double-edged sword,&#8221; Mimi <a href=\"https:\/\/news.ucr.edu\/articles\/2026\/07\/08\/slowing-atlantic-current-fueling-stronger-california-storms\" rel=\"nofollow noopener\" target=\"_blank\">says<\/a>. They supply <a href=\"https:\/\/science.nasa.gov\/earth\/earth-observatory\/atmospheric-river-lashes-california-150804\/\" rel=\"nofollow noopener\" target=\"_blank\">up to 50 percent<\/a> of annual rainfall in the western US, <a href=\"https:\/\/www.nbclosangeles.com\/weather-news\/california-atmospheric-river-storms\/3566302\/?amp=1\" rel=\"nofollow noopener\" target=\"_blank\">especially California<\/a>, and are the main driver of the state&#8217;s <a href=\"https:\/\/sbds.deltacouncil.ca.gov\/sites\/default\/files\/2025-09-18-atmospheric-rivers-summary-sheet.pdf\" rel=\"nofollow noopener\" target=\"_blank\">volatile water supply<\/a>.<\/p>\n<p><img decoding=\"async\" width=\"2823\" height=\"1779\" src=\"https:\/\/www.newsbeep.com\/ie\/wp-content\/uploads\/2026\/07\/caatmosriver_vir_2023004_lrg.jpg\" alt=\"\" class=\"wp-image-209046\"   loading=\"lazy\"\/>An atmospheric river moving over California, circa January 2023. <a href=\"https:\/\/science.nasa.gov\/earth\/earth-observatory\/atmospheric-river-lashes-california-150804\/\" rel=\"nofollow noopener\" target=\"_blank\">(NASA)<\/a><\/p>\n<p>They also raise flood risk: Atmospheric rivers frequently generate floods, even during droughts, that endanger individuals, destroy homes and infrastructure, and impact water quality statewide.<a href=\"https:\/\/www.nbclosangeles.com\/weather-news\/california-atmospheric-river-storms\/3566302\/?amp=1\" rel=\"nofollow noopener\" target=\"_blank\"><\/p>\n<p>Zooming out to our <a href=\"https:\/\/www.sciencealert.com\/earth-isnt-flat-but-new-theory-suggests-jupiter-might-once-have-been\" rel=\"nofollow noopener\" target=\"_blank\">oblate orb&#8217;s<\/a> coolest regions, atmospheric rivers facilitate surface warming and ice loss at the poles, with crucial consequences.<\/p>\n<p>&#8220;Over Antarctica, ARs account for 40 to 80 percent of summer meltwater in West Antarctic ice shelves, which threatens ice stability and accelerates global sea level rise,&#8221; the researchers <a href=\"https:\/\/doi.org\/10.1038\/s41467-026-72555-w\" rel=\"nofollow noopener\" target=\"_blank\">explain in their paper<\/a>.<\/p>\n<p>Furthermore, the global mean frequency of atmospheric rivers may increase by around 50 percent, the team reports.<\/p>\n<p>ARs may also transport more moisture and last longer, penetrating higher latitudes as the high-altitude westerly <a href=\"https:\/\/www.sciencealert.com\/earths-jet-streams-look-as-chaotic-as-a-van-gogh-right-now-and-thats-a-big-problem\" rel=\"nofollow noopener\" target=\"_blank\">jet stream<\/a> shifts toward the poles in response to anthropogenic warming.<\/p>\n<p><a href=\"https:\/\/www.sciencealert.com\/newsletter?utm_source=promo_stargazing\" rel=\"nofollow noopener\" target=\"_blank\"><img decoding=\"async\" width=\"642\" height=\"336\" src=\"https:\/\/www.newsbeep.com\/ie\/wp-content\/uploads\/2026\/06\/FOMO-1200x628-_Dont-miss-the-next-breakthrough_-cosmic-colourful-642x336.jpg\" alt=\"Subscribe to ScienceAlert's free fact-checked newsletter\" class=\"wp-image-201722\"   loading=\"lazy\"\/><\/a><\/p>\n<p>Overall, as the AMOC slows, it will alter oceanic temperatures and decrease atmospheric moisture in the Northern Hemisphere, while increasing it in the Southern Hemisphere.<\/p>\n<p>In turn, atmospheric rivers are projected to become more frequent and dump more rain in certain parts of the world: South America&#8217;s east coast, southern Asia, western Europe, parts of the Pacific, and around <a href=\"https:\/\/www.sciencealert.com\/the-worlds-largest-ice-desert-surprisingly-lacks-ice-in-one-key-place\" rel=\"nofollow noopener\" target=\"_blank\">Antarctica<\/a>.<\/p>\n<p>The greatest increases are expected to occur along North America&#8217;s west coast, from Baja California to Alaska.<\/p>\n<p>Conversely, atmospheric rivers may become less frequent across the Arctic, Greenland, and northern Asia, as a weakened AMOC leads to cooler surface air temperatures and reduced moisture content.<\/p>\n<p>Other lower-latitude areas, including northern Australia and the South Pacific, may also experience a decrease in AR frequency.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" width=\"642\" height=\"792\" src=\"https:\/\/www.newsbeep.com\/ie\/wp-content\/uploads\/2026\/07\/DynamicAndThermodynamicComponentsOfAtmopshericRiverFrequency-642x792.png\" alt=\"\" class=\"wp-image-209214\"  \/>Changes in AR frequency driven by the dynamic (atmospheric circulation) and thermodynamic (temperature) components of the AMOC (Mimi et al., Nat .Commun., 2026)<\/p>\n<p>This isn&#8217;t necessarily a foregone conclusion. It depends on the world&#8217;s industrial inertia, which is warming our green globe through increased greenhouse gas emissions from <a href=\"https:\/\/www.sciencealert.com\/first-signal-of-climate-change-became-detectable-130-years-ago\" rel=\"nofollow noopener\" target=\"_blank\">burning fossil fuels<\/a> that have lain locked deep inside the Earth for hundreds of millions of years.<\/p>\n<p>Revisiting the double-edged sword, the sometimes-destructive ARs also provide opportunities. Research shows that places like California may be able to <a href=\"https:\/\/hakaimagazine.com\/features\/a-river-runs-above-us\/\" rel=\"nofollow noopener\" target=\"_blank\">capture more water<\/a> by restoring natural landscapes to ameliorate <a href=\"https:\/\/www.sciencealert.com\/persistent-droughts-from-climate-change-could-actually-result-in-less-human-conflict\" rel=\"nofollow noopener\" target=\"_blank\">persistent droughts <\/a>caused by <a href=\"https:\/\/cww.water.ca.gov\/droughtindicator\" rel=\"nofollow noopener\" target=\"_blank\">hotter, drier weather<\/a>.<\/p>\n<p>Related: <a href=\"https:\/\/www.sciencealert.com\/scientists-rule-out-a-worst-case-climate-scenario-but-were-not-off-the-hook\" rel=\"nofollow noopener\" target=\"_blank\">Scientists Rule Out a Worst-Case Climate Scenario, But We&#8217;re Not Off The Hook<\/a><\/p>\n<p>Finally, this work reminds us how our <a href=\"https:\/\/www.sciencealert.com\/earths-seasons-are-strangely-out-of-sync-scientists-discover-from-space\" rel=\"nofollow noopener\" target=\"_blank\">planetary processes<\/a> are <a href=\"https:\/\/www.sciencealert.com\/summer-in-the-northern-hemisphere-might-take-up-half-the-year-by-2100\" rel=\"nofollow noopener\" target=\"_blank\">irreversibly intertwined<\/a>. A change in a single (but major) <a href=\"https:\/\/www.sciencealert.com\/earths-strongest-ocean-current-could-slow-by-20-as-antarctica-melts\" rel=\"nofollow noopener\" target=\"_blank\">ocean current<\/a> can ripple for thousands of miles, driving <a href=\"https:\/\/www.sciencealert.com\/trees-seen-emitting-a-ghostly-light-during-a-thunderstorm-for-the-first-time\" rel=\"nofollow noopener\" target=\"_blank\">storms<\/a> across America, intensifying Amazonian rainfall, and displacing <a href=\"https:\/\/www.sciencealert.com\/incredible-video-a-swarm-of-raging-thunderstorms-as-seen-from-space\" rel=\"nofollow noopener\" target=\"_blank\">tropical rain belts<\/a> southward.<\/p>\n<p>&#8220;This research shows that the effects of the AMOC extend far beyond the Atlantic Ocean,&#8221; Mimi <a href=\"https:\/\/news.ucr.edu\/articles\/2026\/07\/08\/slowing-atlantic-current-fueling-stronger-california-storms\" rel=\"nofollow noopener\" target=\"_blank\">says<\/a>.<\/p>\n<p>&#8220;Understanding these connections will help us better prepare for future changes in water resources and extreme weather.&#8221;<\/p>\n<p>This research was published in <a href=\"https:\/\/doi.org\/10.1038\/s41467-026-72555-w\" rel=\"nofollow noopener\" target=\"_blank\">Nature Communications<\/a>.<\/p>\n<p class=\"has-text-align-left has-sciencealert-light-gray-background-color has-background\">This article was fact-checked by <a href=\"https:\/\/www.sciencealert.com\/michaelirving\" rel=\"nofollow noopener\" target=\"_blank\">Michael Irving<\/a> and edited by <a href=\"https:\/\/www.sciencealert.com\/clare-watson\" rel=\"nofollow noopener\" target=\"_blank\">Clare Watson<\/a>. While we pride ourselves on our process, we are only human. If you spot a mistake, <a href=\"https:\/\/www.sciencealert.com\/contact-us\" rel=\"nofollow noopener\" target=\"_blank\">please let us know<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"Earth&#8217;s climate systems are inexorably and often unexpectedly interconnected. Dust from North Africa&#8217;s Sahara Desert drifts thousands of&hellip;\n","protected":false},"author":2,"featured_media":558633,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[22],"tags":[246,61,60,2209,82],"class_list":["post-558632","post","type-post","status-publish","format-standard","has-post-thumbnail","category-environment","tag-environment","tag-ie","tag-ireland","tag-msft-content","tag-science"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts\/558632","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=558632"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/posts\/558632\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/media\/558633"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/media?parent=558632"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/categories?post=558632"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ie\/wp-json\/wp\/v2\/tags?post=558632"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}