{"id":506046,"date":"2026-01-10T11:43:46","date_gmt":"2026-01-10T11:43:46","guid":{"rendered":"https:\/\/www.europesays.com\/us\/506046\/"},"modified":"2026-01-10T11:43:46","modified_gmt":"2026-01-10T11:43:46","slug":"ocean-warming-breaks-record-for-ninth-straight-year","status":"publish","type":"post","link":"https:\/\/www.europesays.com\/us\/506046\/","title":{"rendered":"Ocean Warming Breaks Record for Ninth Straight Year"},"content":{"rendered":"

Every second of last year, the Earth\u2019s oceans absorbed the equivalent in energy to 12 Hiroshima-sized atomic bombs.\u00a0<\/p>\n

Global ocean heat content (OHC) increased for the ninth consecutive year in 2025, according to a report released Friday in Advances in Atmospheric Sciences<\/a>. The study\u2014a collaboration involving more than 50 scientists from 31 international institutions\u2014measured temperature fluctuations in the upper 2,000 meters of the planet\u2019s waters, finding the greatest increases in the Southern Atlantic, the Northern Pacific and the Southern Ocean. Warming waters are linked to increasingly extreme weather patterns, coral reef die-offs and sea level rise.\u00a0<\/p>\n

Earth\u2019s oceans act as the planet\u2019s main thermal energy sink. Absorbing more than 90 percent of the excess heat trapped by greenhouse gases, ocean temperatures serve as a critical indicator of long-term climate change. \u201cGlobal OHC is the single best indicator that the planet is warming,\u201d said Kevin Trenberth, a co-author and scholar at the National Center for Atmospheric Research.\u00a0<\/p>\n

\"\"<\/p>\n

\u201cMeasuring the ocean heat content is probably the best way to measure global heating as a whole,\u201d added Michael Mann, director of the University of Pennsylvania\u2019s Center for Science, Sustainability and the Media. Last year\u2019s total ocean energy increase amounted to 23 Zetta Joules\u2014more than 200 times the electrical energy usage of the entire planet.\u00a0<\/p>\n

The warming was widespread, with 16 percent of the ocean reaching a record high. A further 33 percent of areas ranked among the top three hottest years in recorded history, and 57 percent within the top five years of data. This unabated warming was driven not only by increased greenhouse gas concentrations, but also by a recent reduction in sulfate aerosols that have historically acted as a reflective sunscreen for the planet.<\/p>\n

While warming of the top 500 meters of oceans was visible as early as the late 1970s, man-made heat now penetrates as deep as 2,000 meters below the surface. According to Trenberth, it takes roughly 25 years for heat to travel to such depths, creating a warming effect that will likely persist for centuries. Though the mean sea-surface temperature was lower than in 2023 and 2024, it remained the third warmest year on record.\u00a0<\/p>\n

\"\"<\/p>\n

\u201cA warming ocean leads to warmer, wetter air\u2014which, in turn, leads to stronger storms,\u201d said John Abraham, a professor of thermal sciences at the University of St. Thomas in Minnesota. As ocean temperatures increase, so too does evaporation, leading to more moisture in the atmosphere. \u201cThink of \u2018weather on steroids.\u2019 We can expect our weather to become more extreme and unpredictable.\u201d\u00a0<\/p>\n

Intense monsoon rains that killed more than 1,350 people<\/a> in South and Southeast Asia, catastrophic flash floods along Texas\u2019 Guadalupe River<\/a> that caused 138 fatalities, and over 1,200 wildfires<\/a> that burned more than five million hectares in Canada, can all be linked back to long-term ocean heat accumulation, according to the paper. Meanwhile, the increased frequency and intensity of marine heatwaves has driven record-low mass levels for both the Greenland and Antarctic ice sheets, in turn adding to global sea level rise.\u00a0<\/p>\n

Researchers warn warming oceans also pose a serious threat to coral reefs. \u201cWhen seawater temperature exceeds the thermal tolerance threshold of corals, the symbiotic system collapses,\u201d said Lijing Cheng, an oceanographer from the Chinese Academy of Sciences and co-author of the study.<\/p>\n

Critical to marine ecology, reefs support more than 25 percent of all known marine species despite covering less than 0.1 percent of the seabed. \u201cCorals expel the algae, lose their colorful pigments, and appear \u2018bleached\u2019,\u201d said Cheng, referencing how hotter water is a key stress indicator for reefs.\u00a0<\/p>\n

The forecast remains unchanged: Global ocean heat content is expected to increase year-on-year until net-zero greenhouse gas emissions are achieved. Because of the quantity of thermal energy being stored in the Earth\u2019s oceans, Trenberth warns change is irreversible on a human timescale.\u00a0<\/p>\n

This story is funded by readers like you.<\/p>\n

Our nonprofit newsroom provides award-winning climate coverage free of charge and advertising. We rely on donations from readers like you to keep going. Please donate now to support our work.<\/p>\n

Donate Now<\/a> <\/p>\n

Though a complete reduction in carbon dioxide would not immediately lead to the same pre-1970 ocean temperatures, researchers emphasized the ability to revert course. \u201cWhile these latest data convey the urgency of climate action, we nonetheless still have agency,\u201d said Mann, noting surface warming could stabilize if emissions stopped.<\/p>\n

Abraham agreed, suggesting the fix to ocean heat increases is a matter of will rather than capability. \u201cWe can solve this problem today, with today\u2019s technology,\u201d he said. \u201cThere is real optimism among scientists.\u201d<\/p>\n

\t\t\t\t\tAbout This Story<\/p>\n

Perhaps you noticed: This story, like all the news we publish, is free to read. That\u2019s because Inside Climate News is a 501c3 nonprofit organization. We do not charge a subscription fee, lock our news behind a paywall, or clutter our website with ads. We make our news on climate and the environment freely available to you and anyone who wants it.<\/p>\n

That\u2019s not all. We also share our news for free with scores of other media organizations around the country. Many of them can\u2019t afford to do environmental journalism of their own. We\u2019ve built bureaus from coast to coast to report local stories, collaborate with local newsrooms and co-publish articles so that this vital work is shared as widely as possible.<\/p>\n

Two of us launched ICN in 2007. Six years later we earned a Pulitzer Prize for National Reporting, and now we run the oldest and largest dedicated climate newsroom in the nation. We tell the story in all its complexity. We hold polluters accountable. We expose environmental injustice. We debunk misinformation. We scrutinize solutions and inspire action.<\/p>\n

Donations from readers like you fund every aspect of what we do. If you don\u2019t already, will you support our ongoing work, our reporting on the biggest crisis facing our planet, and help us reach even more readers in more places? <\/p>\n

Please take a moment to make a tax-deductible donation. Every one of them makes a difference.<\/p>\n

Thank you,<\/p>\n

\t\t\t\t\t\"\"<\/p>\n

\t\t\t\t\t
\n\t\t\t\t\t\tJohnny Sturgeon\t\t\t\t\t<\/a><\/p>\n

\t\t\t\t\tFisheries Reporter<\/p>\n

Johnny Sturgeon is a London-based reporter covering fisheries, aquaculture, and maritime crime. He works in partnership with the Outlaw Ocean Project, producing in-depth investigations for both nonprofit newsrooms. A former boatbuilder, he holds a B.A. in History & Politics from the University of Oxford, and an M.S. from Columbia Journalism School.<\/p>\n","protected":false},"excerpt":{"rendered":"Every second of last year, the Earth\u2019s oceans absorbed the equivalent in energy to 12 Hiroshima-sized atomic bombs.\u00a0…\n","protected":false},"author":3,"featured_media":506047,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[23],"tags":[226642,226643,285,82799,142095,746,226644,8298,77541,226645,226646,75932,930,159,226647,67,132,24003,77876,68,226648],"class_list":{"0":"post-506046","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-environment","8":"tag-advances-in-atmospheric-sciences","9":"tag-center-for-science","10":"tag-climate-change","11":"tag-coral-bleaching","12":"tag-coral-reefs","13":"tag-environment","14":"tag-global-ocean-heat-content","15":"tag-greenland","16":"tag-john-abraham","17":"tag-kevin-trenberth","18":"tag-lijing-cheng","19":"tag-michael-mann","20":"tag-oceans","21":"tag-science","22":"tag-sustainability-and-the-media","23":"tag-united-states","24":"tag-unitedstates","25":"tag-university-of-pennsylvania","26":"tag-university-of-st-thomas","27":"tag-us","28":"tag-warming-oceans"},"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@us\/115870630058330467","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts\/506046","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/comments?post=506046"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts\/506046\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/media\/506047"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/media?parent=506046"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/categories?post=506046"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/tags?post=506046"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}