Satellites changed sea-level tracking Study lead author Torbj\u00f6rn T\u00f6rnqvist is a professor in the Department of Earth and Environmental Sciences at Tulane University<\/a>.<\/p>\n \u201cThe ultimate test of climate projections is to compare them with what has played out since they were made, but this requires patience \u2013 it takes decades of observations,\u201d said T\u00f6rnqvist.<\/p>\n He noted that the team was quite amazed at how good those early projections were, especially considering how crude the models were back then, compared to what is available now.<\/p>\n \u201cFor anyone who questions the role of humans in changing our climate, here is some of the best proof that we have understood for decades what is really happening, and that we can make credible projections<\/a>.\u201d<\/p>\n Sea-level rise differs across regions<\/p>\n Professor S\u00f6nke Dangendorf emphasized the importance of translating global patterns into regional forecasts.<\/p>\n \u201cSea level doesn\u2019t rise uniformly \u2013 it varies widely. Our recent study of this regional variability and the processes behind it relies heavily on data from NASA\u2019s satellite missions and NOAA<\/a>\u2019s ocean monitoring programs,\u201d he said. <\/p>\n \u201cContinuing these efforts<\/a> is more important than ever, and essential for informed decision-making to benefit the people living along the coast.\u201d<\/p>\n Satellites confirm acceleration<\/p>\n When satellites first began tracking sea<\/a> levels in the early 1990s, they showed an average increase of about one eighth of an inch per year. It was only later that scientists confirmed this pace was speeding up. <\/p>\n By October 2024, NASA researchers announced that the rate of rise had doubled over three decades. That moment offered the perfect opportunity to compare real-world changes against projections made nearly thirty years earlier.<\/p>\n Close call with predictions<\/p>\n In 1996, the Intergovernmental Panel on Climate Change (IPCC) released its assessment report, just as satellite monitoring began. <\/p>\n The report projected about 8 centimeters of sea-level rise over 30 years. The actual outcome was 9 centimeters, nearly identical.<\/p>\n However, the models underestimated melting ice sheets by over 2 centimeters. Back then, the destabilizing effects of warming ocean waters on Antarctic ice were poorly understood. Greenland\u2019s ice was also flowing into the ocean faster than anticipated.<\/p>\n Components of sea-level rise<\/p>\n The study shows that thermal expansion of seawater and melting of smaller glaciers were predicted fairly well. But contributions from Greenland and Antarctica were treated as negligible. <\/p>\n In reality, these ice sheets accounted for nearly a quarter of observed sea-level rise. Another overlooked factor was groundwater depletion, which transferred more water to oceans than expected.<\/p>\n Ignoring ice-sheets caused errors<\/p>\n Early IPCC reports assumed that the dynamic behavior of ice sheets could be ignored for decades. This assumption proved incorrect. Later assessments that excluded dynamic ice flow produced unrealistically low projections. <\/p>\n Once dynamic ice loss was included, estimates increased significantly. Modern assessments now highlight the \u201cdeep uncertainty\u201d surrounding possible ice-sheet disintegration, which could drive sea levels far higher than expected.<\/p>\n Past models were surprisingly accurate <\/p>\n Thermal expansion was slightly overestimated, which balanced out the underestimated role of ice sheets. <\/p>\n This created projections that, by chance, matched reality more closely than their flawed assumptions should have allowed.<\/p>\n Still, the overall accuracy offers confidence in today\u2019s more advanced models, especially since early reports successfully predicted atmospheric carbon dioxide levels.<\/p>\n Future climate projections<\/p>\n Predictions made in the 1990s have proven largely accurate, but the greatest challenges still lie ahead. <\/p>\n Ongoing uncertainty about ice sheets and human emissions makes continuous monitoring vital for helping coastal societies prepare for what lies ahead.<\/p>\n \u201cGiven the advances in both resolution and process understanding since the 1990s, the early success of the IPCC-SAR projection gives considerable confidence to climate projections for the future,\u201d wrote the researchers.<\/p>\n \u201cMeanwhile, the importance of continued monitoring of all relevant components of the climate system by key agencies cannot be understated.\u201d<\/p>\n The study is published in the journal Earth\u2019s Future<\/a>.<\/p>\n \u2014\u2013<\/p>\n Like what you read? Subscribe to our newsletter<\/a> for engaging articles, exclusive content, and the latest updates.\u00a0<\/p>\n Check us out on EarthSnap<\/a>, a free app brought to you by Eric Ralls<\/a> and Earth.com.<\/p>\n \u2014\u2013<\/p>\n","protected":false},"excerpt":{"rendered":"For centuries, humanity relied on coastal landmarks and tide gauges to understand sea levels. But satellites changed everything.…\n","protected":false},"author":2,"featured_media":369571,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3843],"tags":[728,70,16,15],"class_list":{"0":"post-369570","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-environment","8":"tag-environment","9":"tag-science","10":"tag-uk","11":"tag-united-kingdom"},"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@uk\/115083408117905352","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts\/369570","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=369570"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts\/369570\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/media\/369571"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/media?parent=369570"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/categories?post=369570"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/tags?post=369570"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
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