The oceans of today look different from the oceans of 20 years ago, researchers found in a new global study.
Some Oceans Are Becoming Greener Thanks to Climate Change. A new study found that 60% of the global ocean experienced color change between 2002 and 2023, with tropical oceans near the equator becoming greener.
Around 60% of the world's oceans have changed color, with the blue waters becoming greener over time, according to a study published in the journal Nature. Tropical ocean water near the equator has been especially impacted. Scientists at the Massachusetts Institute of Technology and National Oceanography Center in the U.K. found that the change is likely driven by climate change. "To actually see it happening for real is not surprising, but frightening," said Stephanie Dutkiewicz, the study's co-author and senior research scientist at MIT's department of Earth, atmospheric and planetary sciences and the Center for Global Change Science. "And these changes are consistent with man-made changes to our climate."
The ocean's color is a product of whatever is in the upper layers of the water. It usually appears blue because the ocean acts as a sunlight filter and the water absorbs colors in the red part of the light spectrum, according to the National Oceanic and Atmospheric Administration. A greener color, which the researchers found, happens when light bounces off of materials and life in the water. Greener water is largely driven by the presence of phytoplankton.
The researchers used data from the Moderate Resolution Imaging Spectroradiometer aboard NASA's Aqua satellite — which has been monitoring ocean color for 21 years.Researchers wrote that the change in color "suggest that the effects of climate change are already being felt in surface marine microbial ecosystems."
"It will also change how much the ocean will take up carbon, because different types of plankton have different abilities to do that," she said. "So, we hope people take this seriously. It's not only models that are predicting these changes will happen. We can now see it happening, and the ocean is changing."
"This suggests that the trends we observe are not a random variation in the Earth system. "This is consistent with anthropogenic (Man Made) climate change."Scientists believe in a million years Earth's next ocean could form in the East African Rift Zone, where a rising plume of searing hot rocks is slowly forcing apart a swath of land along the continent's eastern coast but the changes from man made climate change are occurring much faster. Even in our best-case scenarios, oceans are on track to rise 3 to 4 feet (0.6 to 0,10 meters) by 2080. Even a sea-level rise below 3 feet could displace more than 50 million people, 3 million in the US alone. Oceans not only will have less ice at the poles, but they will also continue to acidify in the tropics
.Across the ages, sea levels have risen and fallen with temperatures—but Earth's total surface water was always assumed to be constant. Now, evidence is mounting that some 3 billion to 4 billion years ago, the planet's oceans held nearly twice as much water—enough to submerge today's continents above the peak of Mount Everest. The flood could have primed the engine of plate tectonics and made it more difficult for life to start on land.The ancient water world is also a reminder of how conditional Earth's evolution is.Too much water, or too little, and it wouldn't work.
Over the past 50 years, the volume of the ocean with no oxygen at all has quadrupled, while oxygen-deprived swaths of the open seas have expanded by the size of the European Union. The culprits are familiar: global warming and pollution. Warmer seawater both holds less oxygen and turbocharges the worldwide consumption of oxygen by microorganisms. Meanwhile, agricultural runoff and sewage drive suffocating algae blooms and phyto-planktons which creates the green color.Some seaweed and phytoplankton due to climate change, grow quickly, or bloom. Some blooms can harm people, animals, or the environment. Most harmful blooms that make people and animals sick are caused by phytoplankton. These harmful blooms can be caused by many types of phytoplankton.Copper-based algaecides can effectively kill most phytoplankton groups, and algaecides containing hydrogen peroxide can be equally effective on cyanobacteria, without potential unintended toxic effects on higher trophic levels.This may work in ponds or lakes but has yet to be tested in an ocean!
The analysis builds on a growing body of research pointing to increasingly sick seas pummeled by the effluent of civilization. Earth’s oceans have lost 2 percent of their oxygen since 1960.Two percent might not sound that dramatic, but small changes in the oxygen content of the Earth’s oceans and atmosphere in the ancient past are thought to be responsible for some of the most profound events in the history of life. Some paleontologists have pointed to rising oxygen as the fuse for the supernova of biology at the Cambrian explosion 543 million years ago. Similarly, the fever-dream world of the later Carboniferous period is thought to be the product of an oxygen spike, which subsidized the lifestyles of preposterous animals, like dragonflies the size of seagulls. On the other hand, dramatically declining oxygen in the oceans like we see today is a feature of many of the worst mass extinctions in Earth’s history. So besides adding dissolved oxygen directly to the water, hydrogen peroxide would have an additional effect of accelerating decomposition and disrupting some bacteria that use up all the oxygen thus increasing ocean oxygen .Hello giant dragonfly!.
The Mesozoic era, stretching from 252 to 66 million years ago, is sometimes mistakenly thought of as sort of long and uneventful Pax Dinosauria—a stable, if alien world. But the period was occasionally punctuated by severe climate and ocean changes, and even disaster. Ninety-four million years ago, a gigantic pulse of carbon dioxide rose from the bottom of the ocean. The Earth warmed, the seas rose, and oxygen-deprived waters spread. The smothering seas mercilessly culled through plankton, bizarre bivalves, and squid-like creatures whose tentacles long dangled from stately whorled shells. For the dolphin-like ichthyosaurs, Oceanic Anoxic was the coup de grâce. The ocean reptiles that had been patrolling the ancient seas for more than 150 million years before seemingly took their last gasps suspiciously close to the event.
“Basically there was no oxygen at the bottom of the shelf anywhere in the world.”
Today, as much as 90 percent of commercial fish and shellfish are caught on these shallow shelves—the broad flanks of our continents that slip coyly under the sea, sometimes for hundreds of miles, before remembering to drop off into the abyss. And already, spreading anoxia is beginning to advertise its deadly promise on these fishing grounds: In 2006 a seafloor survey off of Oregon revealed that rockfish, familiar fixtures of the rocky bottom, had completely abandoned their haunts, as anoxic water—water with no dissolved oxygen—spread onto the shallow shelf. But 94 million years ago in the Cretaceous, this problem was not just a seasonal nuisance. It was a global catastrophe.
The source of the great smothering in the Cretaceous seems to have been a molten font burbling deep beneath an ancient sea that separated North from South America. The lava from these eruptions makes up much of what today is known as the Caribbean large igneous province, a vast expanse of frozen lava that stretches from Ecuador in the Pacific to the Antilles bracing against the open Atlantic. Like many scientific sobriquets, “large igneous province” fails utterly to capture the phenomenon it describes—though no description could ever really succeed in evoking its terrible grandeur.
The worst mass extinction of all time, the end-Permian mass extinction 252 million years ago, left behind a large igneous province so sweeping that today it blankets much of Siberia. In fact, eruptions on this scale, though geologically brief and thankfully rare, are associated with at least four of Earth’s five major mass extinctions (and most of the dozen or so less severe, though still transformative, prehistoric crises.
Though the link between these eruptions and the choking seas that accompany them isn’t immediately obvious—that is, how exactly it is that one drives the other—the answer lies in life itself. And strangely, the same mechanisms that pushed the Cretaceous oceans to the edge are also driving the worrying modern expansion of anoxia in today’s oceans. In short, suffocating the oceans is a bad idea for everybody no matter what color it is!
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