Hollywood blockbuster ‘The Day After Tomorrow’ was an apocalyptic tale about the Gulf Stream — the ocean current which circulates warm water from the tropics to the Northern Hemisphere — being disrupted by global warming. In the following guest blog post, Rog summarises the latest research findings from Richard Seager on the Gulf Stream. This research suggests even if the Gulf Stream slows, New York won’t freeze over.
Oh well, I enjoyed the movie.
Rog writes:
There has been considerable speculation that changes to the body of water known as the “Gulf Stream” can alter climates on a local and global scale. Tim Flannery in his book ‘The Weather Makers’ speculates that the sudden drop of five degrees centigrade in Greenland ice cores was due to changes in the flow of the Gulf Stream.
Tim Flannery then goes on to state that changes to the Gulf Stream constitute a “tipping point” in global climate change.
The Pentagon shares Flannery’s views, in a study published in 2003 they warned that changes to the direction of the flow of the Gulf Stream could result in northern latitudes becoming suddenly colder and tropics much warmer leading to floods of desperate immigrants. The study notes that: “The dramatic slowing of the thermohaline circulation is anticipated by some ocean researchers, but the United States is not sufficiently prepared for its effects, timing, or intensity”.
However, in a recent article in the American Scientist, Richard Seager from Columbia University’s Lamont-Doherty Earth Observatory disputes all these scenarios. He claims:
“..temperatures will not drop to ice-age levels, not even to the levels of the Little Ice Age, the relatively cold period that Europe suffered a few centuries ago. The North Atlantic will not freeze over, and English Channel ferries will not have to plow their way through sea ice. A slowdown in thermohaline circulation should bring on a cooling tendency of at most a few degrees across the North Atlantic—one that would most likely be overwhelmed by the warming caused by rising concentrations of greenhouse gases. This moderating influence is indeed what the climate models show for the 21st century and what has been stated in reports of the Intergovernmental Panel on Climate Change. Instead of creating catastrophe in the North Atlantic region, a slowdown in thermohaline circulation would serve to mitigate the expected anthropogenic warming!”
Note that Richard Seager’s revelation was not founded on any new evidence.
“..All Battisti and I did was put these pieces of evidence together and add in a few more illustrative numerical experiments. Why hadn’t anyone done that before? Why had these collective studies not already led to the demise of claims in the media and scientific papers alike that the Gulf Stream keeps Europe’s climate just this side of glaciation? It seems this particular myth has grown to such a massive size that it exerts a great deal of pull on the minds of otherwise discerning people.
This is not just an academic issue. The play that the doomsday scenario has gotten in the media—even from seemingly reputable outlets such as the British Broadcasting Corporation—could be dismissed as attention-grabbing sensationalism. But at root, it is the ignorance of how regional climates are determined that allows this misinformation to gain such traction.”
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Comment/guest posts welcomed from others readers of this blog, email jennifermarohasy@jennifermarohasy.com .
Jennifer Marohasy BSc PhD has worked in industry and government. She is currently researching a novel technique for long-range weather forecasting funded by the B. Macfie Family Foundation.