As for the Gulf Stream, it is “very unlikely” to undergo “a large abrupt transition during the 21st century,” according to the new report. The current is expected to slow slightly, meaning a little less heat from the tropics would reach the North Atlantic, which could be good news for Europe and North America, since that would temper some of the impact of global warming in the north.
Whatever happens, you can stop fretting about the Gulf Stream scenario in Mr. Gore’s movie and that full-fledged Hollywood disaster film “The Day After Tomorrow.” Mr. Gore’s companion book has a fold-out diagram of the Gulf Stream and warns that “some scientists are now seriously worried” about it shutting down and sending Europe into an ice age, but he must have been talking to the wrong scientists.
There wouldn’t be glaciers in the English shires even if the Gulf Stream did shut down. To understand why, you need to disregard not only the horror movies but also what you learned in grade school: that the Gulf Stream is responsible for keeping London so much warmer than New York even though England is farther north than Newfoundland.
This theory, originated by a 19th-century oceanographer, is “the earth-science equivalent of an urban legend,” in the words of Richard Seager, a climate modeler at the Lamont-Doherty Earth Observatory of Columbia University. He and other researchers have calculated that the Gulf Stream’s influence typically raises land temperatures in the north by only five degrees Fahrenheit, hardly enough to explain England’s mild winters, much less its lack of glaciers.
Moreover, as the Gulf Stream meanders northward, it delivers just about as much heat to the eastern United States and Canada as to Europe, so it can’t account for the difference between New York and London. Dr. Seager gives the credit to the prevailing westerly winds — and the Rocky Mountains.
When these winds out of the west hit the Rockies, they’re diverted south, bringing air from the Arctic down on New York (as in last week’s cold spell). After their southern detour, the westerlies swing back north, carrying subtropical heat toward London. This Rocky Mountain detour accounts for about half the difference between New York and London weather, according to Dr. Seager.
The other half is caused by to the simple fact that London sits on the east side of an ocean — just like Seattle, which has a much milder climate than Siberia, the parallel land across the Pacific. Since ocean water doesn’t cool as quickly as land in winter, or heat up as much in summer, the westerly winds blowing over the ocean moderate the winter and summer temperatures in both Seattle and London.
So unless the westerlies reverse direction or the Rockies crumble, London and the rest of Western Europe will remain relatively mild. The danger London faces isn’t an ice age but a long, inexorable warming that will keep the temperatures and sea levels gradually rising for centuries — not an action flick but a super-slow-motion documentary.
Buy on AliExpress.com
