New research provides strong evidence that one of the long-predicted worst-case impacts of climate change — a severe slow-down of the Gulf Stream system — has already started.
The system, also known as the Atlantic Meridional Overturning Circulation (AMOC), brings warmer water northward while pumping cooler water southward.
“I think we’re close to a tipping point,” climatologist Michael Mann told ThinkProgress in an email. The AMOC slow down “is without precedent” in more than a millennium he said, adding, “It’s happening about a century ahead of schedule relative to what the models predict.”
The impacts of such a slowdown include much faster sea level rise — and much warmer sea surface temperatures — for much of the U.S. East Coast. Both of those effects are already being observed and together they make devastating storm surges of the kind we saw with Superstorm Sandy far more likely.
The findings come in two new studies published this week. One study published in the journal Nature, titled “Observed fingerprint of a weakening Atlantic Ocean overturning circulation,” was led by the Potsdam Institute for Climate Impact Research. It finds that the AMOC has weakened “around 15 per cent” since the mid-twentieth century, bringing it to “a new record low.”