{"679709":{"#nid":"679709","#data":{"type":"news","title":" 2024\u2019s Extreme Ocean Heat Breaks Records Again, Leaving 2 Mysteries to Solve","body":[{"value":"\u003Cdiv class=\u0022theconversation-article-body\u0022\u003E\u003Cp\u003EThe oceans are heating up as the planet warms.\u003C\/p\u003E\u003Cp\u003EThis past year, 2024, was the warmest ever measured for the global ocean, following a record-breaking 2023. In fact, every decade since 1984, when satellite recordkeeping of ocean temperatures started, has been \u003Ca href=\u0022https:\/\/climatereanalyzer.org\/clim\/sst_daily\/?dm_id=world2\u0022\u003Ewarmer than the previous one\u003C\/a\u003E.\u003C\/p\u003E\u003Cp\u003EA warmer ocean means increased evaporation, which in turn results in heavier rains in some areas and droughts in others. It can power hurricanes and downpours. It can also harm the health of coastal marine areas and sea life \u2013 coral reefs suffered their \u003Ca href=\u0022https:\/\/www.reuters.com\/business\/environment\/global-coral-bleaching-event-expands-now-largest-record-2024-10-17\/\u0022\u003Emost extensive bleaching event on record in 2024\u003C\/a\u003E, with damage in many parts of the world.\u003C\/p\u003E\u003Cp\u003EWarming ocean water also affects temperatures on land by changing weather patterns. The EU\u2019s Copernicus Climate Change Service announced on Jan. 10 that data showed 2024 had also broken the record for the \u003Ca href=\u0022https:\/\/climate.copernicus.eu\/global-climate-highlights-2024\u0022\u003Ewarmest year globally\u003C\/a\u003E, with global temperatures about 2.9 degrees Fahrenheit (1.6 Celsius) above pre-industrial times. That would mark the first full calendar year with average \u003Ca href=\u0022https:\/\/www.un.org\/en\/climatechange\/science\/climate-issues\/degrees-matter\u0022\u003Ewarming above 1.5 C\u003C\/a\u003E, a level countries had \u003Ca href=\u0022https:\/\/theconversation.com\/after-cop27-all-signs-point-to-world-blowing-past-the-1-5-degrees-global-warming-limit-heres-what-we-can-still-do-about-it-195080\u0022\u003Eagreed to try to avoid\u003C\/a\u003E passing long-term.\u003C\/p\u003E\u003Cp\u003EClimate change, by and large, takes the blame. Greenhouse gases released into the atmosphere trap heat, and about \u003Ca href=\u0022https:\/\/www.climate.gov\/news-features\/understanding-climate\/climate-change-ocean-heat-content\u0022\u003E90% of the excess heat caused by emissions\u003C\/a\u003E from burning fossil fuels and other human activities is absorbed by the ocean.\u003C\/p\u003E\u003Cp\u003EBut while it\u2019s clear that the ocean has been warming for quite some time, its temperatures over the past two years have been far above the previous decades. That leaves two mysteries for scientists.\u003C\/p\u003E\u003Ch2\u003EIt\u2019s Not Just El Ni\u00f1o\u003C\/h2\u003E\u003Cp\u003EThe cyclic climate pattern of the \u003Ca href=\u0022https:\/\/www.climate.gov\/news-features\/blogs\/enso\/what-el-ni%C3%B1o%E2%80%93southern-oscillation-enso-nutshell\u0022\u003EEl Ni\u00f1o Southern Oscillation\u003C\/a\u003E can explain part of the warmth over the past two years.\u003C\/p\u003E\u003Cp\u003EDuring \u003Ca href=\u0022https:\/\/theconversation.com\/el-nino-is-starting-to-lose-strength-after-fueling-a-hot-stormy-year-but-its-still-powerful-an-atmospheric-scientist-explains-whats-ahead-for-2024-223013\u0022\u003EEl Ni\u00f1o periods\u003C\/a\u003E, warm waters that usually accumulate in the western equatorial Pacific Ocean move eastward toward the coastlines of Peru and Chile, leaving the Earth slightly warmer overall. The \u003Ca href=\u0022https:\/\/theconversation.com\/el-nino-is-back-thats-good-news-or-bad-news-depending-on-where-you-live-205974\u0022\u003Elatest El Ni\u00f1o began in 2023\u003C\/a\u003E and caused global average temperatures to rise well \u003Ca href=\u0022https:\/\/www.climate.gov\/news-features\/blogs\/enso\/july-2024-enso-update-summer-vacation\u0022\u003Einto early 2024\u003C\/a\u003E.\u003C\/p\u003E\u003Cp\u003EBut the oceans have been even warmer than scientists expected. For example, global temperatures in 2023-2024 followed a \u003Ca href=\u0022https:\/\/climatereanalyzer.org\/clim\/sst_daily\/?dm_id=world2\u0022\u003Esimilar growth and decline pattern\u003C\/a\u003E across the seasons as the previous El Ni\u00f1o event, in 2015-2016, but they were about 0.36 degrees Fahrenheit (0.2 Celsius) higher at all times in 2023-2024.\u003C\/p\u003E\u003Cp\u003EScientists are puzzled and left with two problems to solve. They must figure out whether something else contributed to the unexpected warming and whether the past two years have been a sign of a sudden acceleration in global warming.\u003C\/p\u003E\u003Ch2\u003EThe Role of Aerosols\u003C\/h2\u003E\u003Cp\u003EAn intriguing idea, tested using climate models, is that a swift \u003Ca href=\u0022https:\/\/www.nature.com\/articles\/s41467-023-42891-2\u0022\u003Ereduction in aerosols\u003C\/a\u003E over the past decade may be one of the culprits.\u003C\/p\u003E\u003Cp\u003EAerosols are solid and liquid particles emitted by human and natural sources into the atmosphere. Some of them have been shown to partially counteract the impact of greenhouse gases by reflecting solar radiation back into space. However, they also are responsible for poor air quality and air pollution.\u003C\/p\u003E\u003Cp\u003EMany of these particles with cooling properties are generated in the process of burning fossil fuels. For example, sulfur aerosols are emitted by ship engines and power plants. In 2020, the \u003Ca href=\u0022https:\/\/www.imo.org\/en\/MediaCentre\/PressBriefings\/pages\/34-IMO-2020-sulphur-limit-.aspx\u0022\u003Eshipping industry implemented\u003C\/a\u003E a nearly \u003Ca href=\u0022https:\/\/doi.org\/10.1029\/2024GL109077\u0022\u003E80% cut in sulfur emissions\u003C\/a\u003E, and many companies shifted to low-sulfur fuels. But the larger impact has come from power plants reducing their emissions, including a big shift in this direction in China. So, while technologies have cut these harmful emissions, that means a brake slowing the pace of warming is weakened.\u003C\/p\u003E\u003Ch2\u003EIs This a Warming Surge?\u003C\/h2\u003E\u003Cp\u003EThe second puzzle is whether the planet is seeing a warming surge or not.\u003C\/p\u003E\u003Cp\u003ETemperatures are clearly rising, but the past two years have not been warm enough to support the notion that we may be seeing an acceleration in the rate of global warming.\u003C\/p\u003E\u003Cp\u003EAnalysis of four temperature datasets covering the 1850-2023 period has shown that the \u003Ca href=\u0022https:\/\/www.nature.com\/articles\/s43247-024-01711-1\u0022\u003Erate of warming has not shown a significant change\u003C\/a\u003E since around the 1970s. The same authors, however, noted that only a rate increase of at least 55% \u2013 about half a degree Celsius and nearly a full degree Fahrenheit over one year \u2013 would make the warming acceleration detectable in a statistical sense.\u003C\/p\u003E\u003Cp\u003EFrom a statistical standpoint, then, scientists cannot exclude the possibility that the 2023-2024 record ocean warming resulted simply from the \u201cusual\u201d warming trend that humans have set the planet on for the past 50 years. A very strong El Ni\u00f1o contributed some natural variability.\u003C\/p\u003E\u003Cp\u003EFrom a practical standpoint, however, the extraordinary impacts the planet has witnessed \u2013 including extreme weather, heat waves, wildfires, coral bleaching and ecosystem destruction \u2013 point to a need to swiftly reduce carbon dioxide emissions to limit ocean warming, regardless of whether this is a continuation of an ongoing trend or an acceleration.\u003C\/p\u003E\u003Cp\u003E\u003Cem\u003EThis article has been updated with Copernicus Climate Change Service\u2019s global 2024 temperature data.\u003C\/em\u003E\u003C!-- Below is The Conversation\u0027s page counter tag. Please DO NOT REMOVE. --\u003E\u003Cimg style=\u0022border-color:!important;border-style:none;box-shadow:none !important;margin:0 !important;max-height:1px !important;max-width:1px !important;min-height:1px !important;min-width:1px !important;opacity:0 !important;outline:none !important;padding:0 !important;\u0022 src=\u0022https:\/\/counter.theconversation.com\/content\/246843\/count.gif?distributor=republish-lightbox-basic\u0022 alt=\u0022The Conversation\u0022 width=\u00221\u0022 height=\u00221\u0022 referrerpolicy=\u0022no-referrer-when-downgrade\u0022\u003E\u003C!-- End of code. If you don\u0027t see any code above, please get new code from the Advanced tab after you click the republish button. The page counter does not collect any personal data. More info: https:\/\/theconversation.com\/republishing-guidelines --\u003E\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003E\u003Cem\u003EThis article is republished from \u003C\/em\u003E\u003Ca href=\u0022https:\/\/theconversation.com\u0022\u003E\u003Cem\u003EThe Conversation\u003C\/em\u003E\u003C\/a\u003E\u003Cem\u003E under a Creative Commons license. Read the \u003C\/em\u003E\u003Ca href=\u0022https:\/\/theconversation.com\/2024s-extreme-ocean-heat-breaks-records-again-leaving-2-mysteries-to-solve-246843\u0022\u003E\u003Cem\u003Eoriginal article\u003C\/em\u003E\u003C\/a\u003E\u003Cem\u003E.\u003C\/em\u003E\u003C\/p\u003E\u003C\/div\u003E","summary":"","format":"full_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003EIn fact, every decade since 1984, when satellite recordkeeping of ocean temperatures started, has been warmer than the previous one.\u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"In fact, every decade since 1984, when satellite recordkeeping of ocean temperatures started, has been warmer than the previous one."}],"uid":"27469","created_gmt":"2025-01-17 16:27:48","changed_gmt":"2026-01-01 18:35:52","author":"Kristen Bailey","boilerplate_text":"","field_publication":"","field_article_url":"","location":"Atlanta, GA","dateline":{"date":"2025-01-09T00:00:00-05:00","iso_date":"2025-01-09T00:00:00-05:00","tz":"America\/New_York"},"extras":[],"hg_media":{"676055":{"id":"676055","type":"image","title":" The global ocean\u2019s surface temperature was still well above average going into 2025. Meaghan Skinner Photography\/Moment via Getty Images","body":"\u003Cp\u003E\u0026nbsp;The global ocean\u2019s surface temperature was still well above average going into 2025. Meaghan Skinner Photography\/Moment via Getty Images\u003C\/p\u003E","created":"1737131416","gmt_created":"2025-01-17 16:30:16","changed":"1737131416","gmt_changed":"2025-01-17 16:30:16","alt":" The global ocean\u2019s surface temperature was still well above average going into 2025. Meaghan Skinner Photography\/Moment via Getty Images","file":{"fid":"259762","name":"file-20250109-19-4cps5m.jpg","image_path":"\/sites\/default\/files\/2025\/01\/17\/file-20250109-19-4cps5m_0.jpg","image_full_path":"http:\/\/hg.gatech.edu\/\/sites\/default\/files\/2025\/01\/17\/file-20250109-19-4cps5m_0.jpg","mime":"image\/jpeg","size":240626,"path_740":"http:\/\/hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/2025\/01\/17\/file-20250109-19-4cps5m_0.jpg?itok=tEB_EbXq"}}},"media_ids":["676055"],"related_links":[{"url":"https:\/\/theconversation.com\/2024s-extreme-ocean-heat-breaks-records-again-leaving-2-mysteries-to-solve-246843","title":"Read This Story on The Conversation"}],"groups":[{"id":"1188","name":"Research Horizons"},{"id":"367481","name":"SEI Energy"},{"id":"1280","name":"Strategic Energy Institute"}],"categories":[{"id":"144","name":"Energy"}],"keywords":[{"id":"479","name":"Green Buzz"},{"id":"187915","name":"go-researchnews"},{"id":"186858","name":"go-sei"}],"core_research_areas":[{"id":"39531","name":"Energy and Sustainable Infrastructure"}],"news_room_topics":[{"id":"71911","name":"Earth and Environment"}],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Ch5\u003EAuthor:\u003C\/h5\u003E\u003Cp\u003E\u003Ca href=\u0022https:\/\/theconversation.com\/profiles\/annalisa-bracco-1447820\u0022\u003EAnnalisa Bracco\u003C\/a\u003E, Professor of Ocean and Climate Dynamics, \u003Ca href=\u0022https:\/\/theconversation.com\/institutions\/georgia-institute-of-technology-1310\u0022\u003E\u003Cem\u003EGeorgia Institute of Technology\u003C\/em\u003E\u003C\/a\u003E\u003C\/p\u003E\u003Ch5\u003EMedia Contact:\u003C\/h5\u003E\u003Cp\u003EShelley Wunder-Smith\u003Cbr\u003E\u003Ca href=\u0022mailto:shelley.wunder-smith@research.gatech.edu\u0022\u003Eshelley.wunder-smith@research.gatech.edu\u003C\/a\u003E\u003C\/p\u003E","format":"limited_html"}],"email":[],"slides":[],"orientation":[],"userdata":""}}}