More than half of the world\u2019s oceans have changed significantly in color over the past 20 years, with climate change as the likely cause, new research suggests. Oceans around the equator have shifted to a greener hue, a trend that cannot be explained by natural, year-to-year variability alone. \u201cWe are affecting the ecosystem in a way that we haven\u2019t seen before,\u201d B. B. Cael, an ocean and climate scientist at the National Oceanography Center in England, tells an international news channel. The ocean\u2019s color changes based on what\u2019s found in its upper layers, according to a statement from MIT. Bluer oceans tend to have little life, while greener oceans have more phytoplankton\u2014marine algae that photosynthesize. Phytoplankton are the base of the marine food web, serving as fuel for zooplankton and fish, which in turn are eaten by larger fish, seabirds and marine mammals. But phytoplankton are also critical for combating the climate crisis. Researchers estimate the oceans absorb about 30 percent of the carbon dioxide produced by humans, largely thanks to the photosynthesis of these algae. Different kinds of plankton reflect and absorb light in different ways, meaning that a shifting ocean color equates to a changing ecosystem, Cael tells Vice\u2019s Becky Ferreira. Such changes could have a ripple effect on the entire food web and potentially even affect the ocean\u2019s ability to store carbon. Cael and his colleagues examined data from the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA\u2019s Aqua satellite, which has been monitoring ocean color for 21 years. The team looked at measurements from seven visible wavelengths and found that color shifts had occurred between 2002 to 2022 in 56 percent of the oceans, primarily around the tropics and subtropics. They published their findings Wednesday in the journal Nature. To determine whether the trend was related to climate change, the team turned to a model created by study co-author Stephanie Dutkiewicz in 2019, which simulated how the Earth\u2019s oceans would respond under two scenarios: one with added greenhouse gases and one without. The results predicted in the greenhouse gas model aligned almost exactly with what the researchers found from real-world data\u2014within 20 years, about half of the oceans significantly shifted in color, per the MIT statement. \u201cI\u2019ve been running simulations that have been telling me for years that these changes in ocean color are going to happen,\u201d Dutkiewicz tells MIT. \u201cTo actually see it happening for real is not surprising, but frightening. And these changes are consistent with man-induced changes to our climate.\u201d Though the team says climate change is to blame for the greener waters, the process within the oceans that\u2019s causing this shift is still a mystery. Sea surface temperatures have increased, but the ocean areas that changed color were not the same as the specific regions that warmed at the surface, Cael tells an international news channel. Instead, scientists suggest the trend comes from nutrient distribution\u2014rising temperatures reduce the mixing between different layers of water and limit upwelling of nutrients. This, in turn, might alter which types of plankton can survive best. The new findings \u201cconfirm suspicions\u201d about how oceans are responding to climate change, Tammi Richardson, a phytoplankton researcher at the University of South Carolina who wasn\u2019t involved in the study, tells New Scientist\u2019s Madeleine Cuff. \u201cIt\u2019s giving us much more solid evidence that the ocean is becoming greener, beyond the few data points that we\u2019ve had historically.\u201d While the MODIS satellite could pick up on the oceans\u2019 shifting hue, scientists still aren\u2019t sure whether these changes will ever be visible to the human eye. \u201cIf a big tipping point was reached in some places: maybe,\u201d Dutkiewicz tells an international media. \u201cThough you\u2019d have to study the colors for a while to be able to pick up on the changes.\u201d<\/p>\n","protected":false},"excerpt":{"rendered":"
More than half of the world\u2019s oceans have changed significantly in color over the past 20 years, with climate change as the likely cause, new…<\/p>\n","protected":false},"author":1,"featured_media":8144,"comment_status":"registered_only","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[14],"tags":[],"class_list":["post-8143","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-technology"],"aioseo_notices":[],"jetpack_publicize_connections":[],"_links":{"self":[{"href":"https:\/\/www.diplomacypakistan.com\/index.php?rest_route=\/wp\/v2\/posts\/8143","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.diplomacypakistan.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.diplomacypakistan.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.diplomacypakistan.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.diplomacypakistan.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=8143"}],"version-history":[{"count":0,"href":"https:\/\/www.diplomacypakistan.com\/index.php?rest_route=\/wp\/v2\/posts\/8143\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.diplomacypakistan.com\/index.php?rest_route=\/wp\/v2\/media\/8144"}],"wp:attachment":[{"href":"https:\/\/www.diplomacypakistan.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=8143"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.diplomacypakistan.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=8143"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.diplomacypakistan.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=8143"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}