Ocean oxygen decline greater than predicted

Ocean oxygen decline greater than predicted

SOURCE: Climate News Network DATE: May 10, 2017 SNIP: US scientists who have been warning that warmer oceans are more likely to be poorer in dissolved oxygen have now sounded the alarm: ocean oxygen levels are indeed falling, and seemingly falling faster than the corresponding rise in water temperature. That colder water can hold more dissolved gas than warmer water is a commonplace of physics: it is one reason why polar seas are teeming with marine life and tropical oceans are blue, clear and often relatively impoverished. In 2013, an international consortium of marine scientists warned that oxygen levels in the oceans could fall by between 1% and 7% by the century’s end. And this could, other scientists predicted, lead to what they politely called “respiratory stress” “The trend of oxygen falling is about two to three times faster than what we predicted from the decrease of solubility associated with ocean warming,” says Takamitsu Ito, of the School of Earth and Atmospheric Sciences at the Georgia Institute of Technology, who led the...
The world’s oceans are storing up staggering amounts of heat — and it’s even more than we thought

The world’s oceans are storing up staggering amounts of heat — and it’s even more than we thought

SOURCE: The Washington Post DATE: March 10, 2017 SNIP: The world is getting warmer every year, thanks to climate change — but where exactly most of that heat is going may be a surprise. As a stunning early spring blooms across the United States, just weeks after scientists declared 2016 the hottest year on record, it’s easy to forget that all the extra warmth in the air accounts for only a fraction of the heat produced by greenhouse gas emissions. In fact, more than 90 percent of it gets stored in the ocean. And now, scientists think they’ve calculated just how much the ocean has warmed in the past few decades. A new study, out Friday in the journal Science Advances, suggests that since 1960, a staggering 337 zetajoules of energy — that’s 337 followed by 21 zeros — has been added to the ocean in the form of heat. And most of it has occurred since 1980. The new value is a number that significantly exceeds previous estimates, Trenberth [Kevin Trenberth, a senior scientist at the National Center for Atmospheric Research] noted. Compared with ocean warming estimates produced by the Intergovernmental Panel on Climate Change, the new values are about 13 percent...
Potential for Collapse of Key Atlantic Current Rises

Potential for Collapse of Key Atlantic Current Rises

SOURCE: Climate Central DATE: January 5, 2017 SNIP: The large, looping Atlantic Ocean current that keeps northwestern Europe fairly warm and influences sea levels along the U.S. coast is a key component of the Earth’s climate system. But because of global warming, it may be more likely to substantially slow down — or even collapse — than previously thought, according to two new studies. If that current, called the Atlantic Meridional Overturning Circulation, were to slow down substantially, it could lead to chillier weather in northern and western Europe, starve economically important fisheries and cause waters to rise along the U.S. coast, leading to more so-called “sunny day” flooding and storm surge when hurricanes come ashore. It could also shift tropical rain belts, causing major disruptions to regional climate in Central and South...
Rising carbon dioxide emissions pose ‘intoxication’ threat to world’s ocean fish

Rising carbon dioxide emissions pose ‘intoxication’ threat to world’s ocean fish

SOURCE: Science Daily DATE: January 20, 2016 SNIP: UNSW Australia researchers have found that carbon dioxide concentrations in seawater could reach levels high enough to make fish “intoxicated” and disoriented many decades earlier than previously thought, with serious implications for the world’s fisheries. The UNSW study, published in the journal Nature, is the first global analysis of the impact of rising carbon dioxide emissions from fossil fuels on natural variations in carbon dioxide concentrations in the world’s oceans. … “High concentrations of carbon dioxide cause fish to become intoxicated — a phenomenon known as hypercapnia. Essentially, the fish become lost at sea. The carbon dioxide affects their brains and they lose their sense of direction and ability to find their way home. They don’t even know where their predators are.” — Dr. Ben...
Changes in Atlantic Sooner Than Expected

Changes in Atlantic Sooner Than Expected

SOURCE: Coastal Review Online DATE: 11/04/2015 AUTHOR: Lisa Sorg SNIP: The disturbance in the North Atlantic could have far-reaching implications for the mid-Atlantic region thousands of miles away. Ocean circulation creates a pressure gradient that causes water to pile up on the highest areas beneath the ocean and away from the coast, explains Mann, who also runs the university’s Earth Sciences Center. If the circulation slows or stops, the pressure decreases and the water relaxes toward the shoreline. Many scientists did not expect the recent shifts to happen so quickly. “I thought the AMOC would change slowly, but the oscillation has been quite dramatic over short periods,” deYoung says. “We like to think of climate as an elephant moving slowly along. But the ocean system is not that simple. We’re open for more surprises.” Mann says climate models didn’t predict such a slowdown until the next century, “but it’s already...