The ocean keeps gulping up a colossal amount of CO2 from the air, but will it last?
By Editor - Thu Mar 14, 12:07 pm
The ocean has proved to be an exceptionally selfless and dependable planetary companion. With no benefit to itself, Earth's vast sea has gulped up around 30 percent of the carbon dioxide humans emitted into Earth's atmosphere over the last century. Critically, scientists have now confirmed that the ocean in recent decades has continued its steadfast rate of CO2 absorption, rather than letting the potent greenhouse gas further saturate the skies. Their research, published Thursday in the journal Science, found that between 1994 and 2007, the oceans reliably sucked up about 31 percent of the carbon dioxide produced by humans, even as CO2 concentrations skyrocketed to their highest levels in at least 800,000 years. This means the ocean is now absorbing a significantly larger bulk of carbon, amounting to well over 2 trillion tons each year. “We can regard what the ocean is doing for us as providing a service, by mitigating CO2 in the atmosphere,” said Matthew Long, an oceanographer at the National Center for Atmospheric Research who had no role in the study. But a weighty question still looms: How much longer can we rely on the ocean to so effectively store away carbon dioxide, and stave off considerably more global warming?”At some point the ability of the ocean to absorb carbon will start to diminish,” said Jeremy Mathis, a National Oceanic and Atmospheric Administration (NOAA) climate scientist who coauthored the study. “It means atmospheric CO2 levels could go up faster than they already are.””That's a big deal,” Mathis emphasized.In stormy waters, scientists prepare to drop an ocean-collecting device into the water.Image: noaaIt's a big deal because carbon dioxide levels aren't just abnormally high, but today's accelerated pace of heat and carbon dioxide rise is nearly unparalleled on Earth. “What's important to recognize is the changes humanity is driving at present are commensurate with the most significant events in the history of life on this planet,” said Long. That means — as long as we continue emitting profound amounts of heat-trapping gases — we'll need the ocean to keep absorbing massive quantities of CO2, so the planet doesn't grow absurdly hot.Fortunately, there's still time. For the next 50 years or so, the oceans will continue to gulp up about the same amount of carbon dioxide. “[The ocean's] going to continue to help suck up CO2,” said Josh Willis, an oceanographer at NASA's Jet Propulsion Laboratory who had no role in the research. “It's like it's eating at a really big buffet, really slowly,” he explained.
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