{"id":64126,"date":"2026-01-13T18:22:33","date_gmt":"2026-01-13T12:52:33","guid":{"rendered":"https:\/\/www.nextias.com\/ca\/?p=64126"},"modified":"2026-01-14T13:15:44","modified_gmt":"2026-01-14T07:45:44","slug":"warming-of-earth-oceans","status":"publish","type":"post","link":"https:\/\/www.nextias.com\/ca\/current-affairs\/13-01-2026\/warming-of-earth-oceans","title":{"rendered":"Warming of Earth\u2019s Oceans"},"content":{"rendered":"\n<p><strong>Syllabus: GS3\/Environment &amp; Climate Change<\/strong><\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>Context<\/strong><\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>According to a study titled<strong> <\/strong><strong><em>\u2018Ocean Heat Content Sets Another Record in 2025\u2019<\/em><\/strong><strong>,<\/strong> found that the oceans absorbed more heat in 2025 than in any year since modern measurements began in the 1960s.\n<ul class=\"wp-block-list\">\n<li>It focused on the <strong>top 2,000 meters of the ocean<\/strong>, where <strong>most heat is stored<\/strong>.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>Key Findings of Study<\/strong><\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Record-Breaking Ocean Heat Content (OHC): <\/strong>The <strong>Earth\u2019s oceans absorbed 23 Zettajoules (ZJ)<\/strong> of additional heat in <strong>2025<\/strong>, surpassing all previous records since the 1960s.\n<ul class=\"wp-block-list\">\n<li>It marks a <strong>44% increase<\/strong> compared to <strong>2024<\/strong>, when oceans absorbed <strong>16 ZJ<\/strong>.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Rising Global Sea-Surface Temperatures (SSTs): <\/strong>Global average SSTs in 2025 were the <strong>third highest on record<\/strong>, roughly <strong>0.5\u00b0C above the 1981\u20132010 baseline<\/strong>.\n<ul class=\"wp-block-list\">\n<li>The South Atlantic, North Pacific, and Southern Ocean were identified as the fastest-warming regions.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Oceans Absorb 90% of Anthropogenic Heat: <\/strong>Nearly <strong>90% of the excess heat<\/strong> trapped by <strong>greenhouse gases (GHGs)<\/strong> since the industrial era has been absorbed by the oceans.\n<ul class=\"wp-block-list\">\n<li>This has led to <strong>steady, long-term warming<\/strong> even during years when atmospheric temperature rise slows temporarily.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Increased Ocean Stratification: <\/strong>Rising heat content has intensified <strong>ocean stratification<\/strong> like separating warm, light, nutrient-poor surface waters from cooler, denser, nutrient-rich deep waters.\n<ul class=\"wp-block-list\">\n<li>It <strong>reduces vertical mixing<\/strong>, meaning:\n<ul class=\"wp-block-list\">\n<li>Less <strong>CO\u2082<\/strong> absorbed by oceans.<\/li>\n\n\n\n<li><strong>Oxygen depletion<\/strong> in deeper waters.<\/li>\n\n\n\n<li><strong>Nutrient scarcity<\/strong> for marine life near the surface.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Threats to Marine Ecosystems: <\/strong>Stratification and warming together threaten <strong>phytoplankton populations<\/strong>, which form the <strong>base of marine food webs<\/strong>.\n<ul class=\"wp-block-list\">\n<li>Decline in phytoplankton affects <strong>zooplankton<\/strong>, <strong>fish<\/strong>, <strong>crustaceans<\/strong>, and <strong>corals<\/strong>, increasing the risk of <strong>ecosystem collapse<\/strong>.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Marine Heat Waves (MHWs) Intensifying: <\/strong>Marine heat waves (defined as <strong>ocean regions 3\u20134\u00b0C above average for \u22655 days)<\/strong> are becoming <strong>more frequent, longer, and more intense<\/strong>.\n<ul class=\"wp-block-list\">\n<li>According to the <strong>IPCC (2021)<\/strong>, MHW frequency has <strong>doubled between 1982 and 2016<\/strong>.<\/li>\n\n\n\n<li>MHWs drive <strong>coral bleaching<\/strong>, reduce coral reproduction, and alter fish migration patterns.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Stronger and More Destructive Storms: <\/strong>Warmer oceans are fueling <strong>more powerful tropical storms<\/strong>, <strong>cyclones<\/strong>, and <strong>hurricanes<\/strong>.\n<ul class=\"wp-block-list\">\n<li>Increased evaporation and heat transfer intensify storms, leading to <strong>stronger winds<\/strong>, <strong>heavier rainfall<\/strong>, and <strong>worse flooding<\/strong> upon landfall.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-background has-fixed-layout\" style=\"background-color:#fff2cc\"><tbody><tr><td><strong>Oceans Warming<\/strong><br><br>&#8211; Ocean warming is <strong>primarily driven by human-induced climate change<\/strong>, with greenhouse gas emissions, thermal expansion, and <strong>altered ocean-atmosphere interactions<\/strong>.<br>&#8211; According to the <strong>World Meteorological Organization (WMO)<\/strong> and the <strong>IPCC<\/strong>, over <strong>90% of excess heat trapped by greenhouse gases<\/strong> since the 1970s has been absorbed by the oceans.It affects global weather patterns, marine ecosystems, and coastal communities.<br><br><strong>Causes of Ocean Warming<\/strong><br><br>&#8211; <strong>Increased GHGs concentrations<\/strong>, especially <strong>carbon dioxide (CO\u2082), methane (CH\u2084), and nitrous oxide (N\u2082O)<\/strong>, trapping heat in the Earth\u2019s atmosphere.<br>&#8211; <strong>Deforestation and industrial emissions<\/strong> reduce natural carbon sinks.<br>&#8211; <strong>Changes in ocean circulation<\/strong>, influenced by atmospheric warming.<br><br><strong>Impact on Marine Life and Ecosystems<\/strong><br><br>&#8211; <strong>Coral bleaching<\/strong> is increasing, with up to <strong>70\u201390% of coral reefs<\/strong> expected to be lost if global warming exceeds 1.5\u00b0C.<br>&#8211; <strong>Fish migration patterns<\/strong> are shifting toward cooler waters, impacting global fisheries.<br>&#8211; <strong>Deoxygenation<\/strong> and acidification further stress marine ecosystems.<br><br><strong>Ocean Warming and Climate Feedback Loops<\/strong><br><br>&#8211; As water warms, it expands <strong>(thermal expansion)<\/strong>, contributing to sea level rise, <strong>alters the density<\/strong> and <strong>circulation of ocean currents.<\/strong><br>&#8211; Warming oceans amplify climate change through <strong>feedback mechanisms<\/strong>:<br><strong>Reduced CO\u2082 absorption capacity<\/strong> of warmer waters.<br><strong>Melting polar ice<\/strong> leads to further heat absorption (albedo effect).<br><strong>Altered weather systems<\/strong> such as stronger El Ni\u00f1o events.<br>-The <strong>UN Environment Programme (UNEP)<\/strong> notes that these feedbacks could accelerate warming beyond current projections.<br><br><strong>Regional Focus: Indian Ocean<\/strong><br><br>-Data from the <strong>Ministry of Earth Sciences (MoES)<\/strong> and <strong>INCOIS <\/strong>show that:<br>The <strong>Indian Ocean has warmed by 1.2\u00b0C since 1950<\/strong>, faster than the global average.<br>&#8211; It contributes to <strong>intense monsoons<\/strong>, <strong>cyclone variability<\/strong>, and <strong>coastal flooding<\/strong>.<br>&#8211; The <strong>Arabian Sea<\/strong> is particularly affected, witnessing a rise in severe cyclonic storms.<br>&#8211; The <strong>India Meteorological Department (IMD)<\/strong> warns that increasing ocean heat content is linked to <strong>sea-level rise<\/strong> along India\u2019s coastline, affecting coastal ecosystems and communities.<br><br><strong>Mitigation and Global Action<\/strong><br><br>&#8211; The <strong>UN Decade of Ocean Science for Sustainable Development (2021\u20132030)<\/strong> emphasizes:<br>&#8211; Enhanced <strong>marine observation networks<\/strong>.<br>&#8211; <strong>Reducing emissions<\/strong> through renewable energy transition.<br>&#8211; <strong>Blue carbon initiatives<\/strong> like mangrove and seagrass restoration.<br><br>India\u2019s <strong>National Centre for Coastal Research (NCCR)<\/strong> and MoES have initiated <strong>long-term ocean observation programs<\/strong> under the <strong>Deep Ocean Mission<\/strong>, aimed at understanding and mitigating ocean warming effects.<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full is-resized\"><img data-dominant-color=\"90b5d0\" data-has-transparency=\"false\" loading=\"lazy\" decoding=\"async\" width=\"962\" height=\"632\" src=\"https:\/\/wp-images.nextias.com\/cdn-cgi\/image\/format=auto\/ca\/uploads\/2026\/01\/deoxygenation.png\" alt=\"\" class=\"not-transparent wp-image-64127\" style=\"--dominant-color: #90b5d0; aspect-ratio:1.5221699983011496;width:353px;height:auto\" srcset=\"https:\/\/wp-images.nextias.com\/cdn-cgi\/image\/format=auto\/ca\/uploads\/2026\/01\/deoxygenation.png 962w, https:\/\/wp-images.nextias.com\/cdn-cgi\/image\/format=auto\/ca\/uploads\/2026\/01\/deoxygenation-300x197.png 300w, https:\/\/wp-images.nextias.com\/cdn-cgi\/image\/format=auto\/ca\/uploads\/2026\/01\/deoxygenation-768x505.png 768w\" sizes=\"auto, (max-width: 962px) 100vw, 962px\" \/><\/figure>\n<\/div>\n\n\n<p><a href=\"https:\/\/indianexpress.com\/article\/explained\/explained-climate\/2025-earth-oceans-warmer-10465821\/\" target=\"_blank\" rel=\"noopener\">Source: IE<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p><strong>Context<\/strong><\/p>\n<li class=\"ms-5\">According to a study titled \u2018Ocean Heat Content Sets Another Record in 2025\u2019, found that the oceans absorbed more heat in 2025 than in any year since modern measurements began in the 1960s.<\/li>\n<p><\/p>\n<p><strong>Key Findings of Study\u00a0<\/strong><\/p>\n<li class=\"ms-5\">Record-Breaking Ocean Heat Content (OHC): The Earth\u2019s oceans absorbed 23 Zettajoules (ZJ) of additional heat in 2025, surpassing all previous records since the 1960s.<\/li>\n<li class=\"ms-5\">It marks a 44% increase compared to 2024, when oceans absorbed 16 ZJ.<\/li>\n<p><a href=\"https:\/\/www.nextias.com\/ca\/current-affairs\/13-01-2026\/warming-of-earth-oceans\" class=\"btn btn-primary btn-sm float-end\">Read More<\/a><\/p>\n","protected":false},"author":4,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[21],"tags":[],"class_list":["post-64126","post","type-post","status-publish","format-standard","hentry","category-current-affairs"],"acf":[],"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/posts\/64126","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/comments?post=64126"}],"version-history":[{"count":4,"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/posts\/64126\/revisions"}],"predecessor-version":[{"id":64206,"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/posts\/64126\/revisions\/64206"}],"wp:attachment":[{"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/media?parent=64126"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/categories?post=64126"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/tags?post=64126"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}