Via Atrios we “learn” what scientists have been worrying about since the 1990s: that climate change is slowing the Gulf Stream that keeps the Northern Hemisphere temperate:
Scientists believe that the huge volumes of freshwater flowing into the North Atlantic from the rapidly melting ice cap of Greenland have slowed down the ocean “engine” that drives the Gulf Stream from the Caribbean towards north-west Europe, bringing heat equivalent to the output of a million power stations…
“There is more than a 99 per cent probability that this slowdown is unique over the period we looked at since 900 AD. We conclude that the slowdown many have described is in fact already underway and it is outside of any natural variation,” Professor Rahmstorf said.
The scientists calculated that some 8,000 cubic kilometres of freshwater has flowed from Greenland into the Atlantic between 1900 and 1970, and this rose significantly to 13,000 cubic kilometres between 1970 and 2000.
A shut down of the Meridional overturning circulation would suddenly decrease the amount of heat in the North Atlantic, leading to much colder temperatures in Europe and North America. A 2003 report prepared for the Department of Defense outlines what would happen if an abrupt climatic change similar to the 8200 years before present event were to recur today:
* Annual average temperatures would drop up to 5° F in North America, and up to 6° F in northern Europe. This is not sufficient to trigger an ice age, which requires about a 10° F drop in temperature world-wide, but could bring about conditions like experienced in 1816–the famed “year without a summer”. In that year, volcanic ash from the mighty Tambora volcanic eruption in Indonesia blocked the sun’s rays, significantly cooling the globe. Snow fell in New England in June, and killing frosts in July and August caused widespread crop failures and famine in New England and northern Europe.
* Annual average temperatures would warm up to 4° F in many areas of the Southern Hemisphere.
* Multi-year droughts in regions unaccustomed to drought would affect critical agricultural and water resource regions world-wide, greatly straining food and water supplies.
* Winter storms and winds would strengthen over North America and Europe.
You’ll notice use put the word “learn” in quotes up there. And that’s because this possibility has been part of the discussion for years, and instead of anyone doing anything about it, we’ll just wave our hands at the next round of Hurricane Sandies, ask who coulda predicted that Miami would go the way of Atlantis, and blame the Great Dust Bowl of 2017 the fault of immigrants, while wondering abjectly how this could have happened. You know, just like we do with Keurig pollution.
I really get annoyed with people -and with myself, for that matter- when easily predictable negative consequences come to pass as a result of behavior everyone knows is stupid or deleterious. Sex columnist Dan Savage has a whole archive of “How’d THAT Happen?” questions, which all have the same response: “You did it to yourself.” And ya know, color me unsympathetic or uncharitable, but in the 1990s I was going door-to-door for Greenpeace and telling people a weakened gulf stream was a likely consequence of all the carbon we were dumping into the atmosphere.
Glad to see people are noticing, but it’s a little late. Sorry to be a grump. Better get a coat, it’s gonna be chilly.