If you watched our video on The Pentagon’s Cracked Crystal Ball (and if you haven’t, great fun awaits you) you’ll know that one of the recurring elements in the alarmist bag of modeling tricks is shutting down the Gulf Stream and plunging Europe into a new ice age, all courtesy of global warming. While the Gulf Stream, or as the climate insiders prefer to say the Atlantic Meridional Overturning Circulation (AMOC), is certainly real, the idea that global warming will cause it to shut off is mere speculation. Not that there’s anything wrong with guesswork and speculation, since they’re how science progresses. Provided you then test the guesses against the data. And now, with the benefit of the longest AMOC reconstruction yet devised, scientists have determined that there has been no trend in the AMOC for the past 120 years. It sped up from 1900 to 1960, slowed down in the 1970s, sped up again, slowed down again, sped up... you get the idea.
The reconstructed 20th century AMOC index was developed by Neil Fraser and Stuart Cunningham of the Scottish Association for Marine Science, and looks like this:
When the line is going up the AMOC is strengthening, or pulling more warm air across the Atlantic to Europe. When it goes down the opposite trend happens and Europe cools. There’s a theory that says global warming will cause the Greenland ice sheet to melt, flooding the North Atlantic with fresh water, slowing down the overturning process and causing the AMOC to shut off, which will then turn Britain into Siberia. And who would believe such a thing with no supporting evidence? Well, the Pentagon for one, and all the journalists who want the world to be ending by this afternoon’s deadline for filing their stories.
Unfortunately for doom as usual, the data show that while the AMOC rises and falls, it’s no lower now than it was in 1900, it rose during the early 20th century warming, it hit a minimum during the cool early 1970s, and whatever it’s been doing since, it’s not following anyone’s script. Scratch another scare story off the list.