The North Atlantic ocean current, which warms northern Europe, may be slowing

The North Atlantic ocean current, which warms northern Europe, may be slowing

SOURCE: Yale Climate Connections DATE: August 15, 2019 SNIP: A stubborn blue spot of cool ocean temperatures stands out like the proverbial sore thumb in a recent NASA image of the warming world – a circle of cool blue on a planet increasingly shaded in hot red. A region of the North Atlantic south of Greenland has experienced some of its coldest temperatures on record in recent years, a cooling unprecedented in the past thousand years. What explains that anomaly? Climatologist Michael Mann of Penn State University, in this month’s “This is Not Cool” video, explains that this phenomenon may be an indication that the North Atlantic current, part of a larger global ocean circulation, is slowing down. Stefan Rahmstorf of the University of Potsdam, Germany, says this circulation – called the thermohaline circulation, but popularly known to many in the U.S. as “the Gulf Stream” – keeps northern Europe several degrees warmer than it would otherwise be at that latitude. [T]he consequences of a shutdown would be serious for agriculture – and for temperate weather – in northern Europe. “We are 50 to a hundred years ahead of schedule with the slowdown of this ocean circulation pattern, relative to the models,” according to Mann. “The more observations we get, the more sophisticated our models become, the more we’re learning that things can happen faster, and with a greater magnitude, than we predicted just years...
Gulf Stream current at its weakest in 1,600 years, studies show

Gulf Stream current at its weakest in 1,600 years, studies show

SOURCE: The Guardian and Real Climate DATE: April 11, 2018 SNIP: The warm Atlantic current linked to severe and abrupt changes in the climate in the past is now at its weakest in at least 1,600 years, new research shows. The findings, based on multiple lines of scientific evidence, throw into question previous predictions that a catastrophic collapse of the Gulf Stream would take centuries to occur. Such a collapse would see western Europe suffer far more extreme winters, sea levels rise fast on the eastern seaboard of the US and would disrupt vital tropical rains. The new research shows the current is now 15% weaker than around 400AD, an exceptionally large deviation, and that human-caused global warming is responsible for at least a significant part of the weakening. Scientists know that the Atlantic Meridional Overturning Circulation (AMOC) has slowed since 2004, when instruments were deployed at sea to measure it. But now two new studies have provided comprehensive ocean-based evidence that the weakening is unprecedented in at least 1,600 years, which is as far back as the new research stretches. “AMOC is a really important part of the Earth’s climate system and it has played an important part in abrupt climate change in the past,” said Dr David Thornalley, from University College London who led one of the new studies. He said current climate models do not replicate the observed slowdown, suggesting that AMOC is less stable that...
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...