Sunday, September 23, 2012

Weather or Not We Want It

Take a good look at the photo above. It is the greatest contraction in sea ice since we began measuring this phenomenon over three decades ago. “On August 26, Arctic sea ice extent broke the record low set in 2007, and it has continued to decline since, dropping below 1.5 million square miles. That represents a 45 percent reduction in the area covered by sea ice compared to the 1980s and 1990s, according to the National Snow and Ice Data Center (NSIDC), and may be unprecedented in human history. The extent of sea ice that melted so far this year is equivalent to the size of Canada and Alaska combined.
“The loss of sea ice initiates a feedback loop known as Arctic amplification. As sea ice melts, it exposes darker ocean waters to incoming solar radiation. The ocean then absorbs far more energy than had been the case when the brightly colored sea ice was present, and this increases water and air temperatures, thereby melting even more sea ice… Peter Wadhams, the head of the polar ocean physics group at the University of Cambridge in the U.K., told BBC News on September 6 that the added heat from sea ice loss is equivalent to the warming from 20 years of carbon dioxide emissions. Carbon dioxide is the main greenhouse gas that is causing manmade global warming.” Huffington Post, September 12th.
So the world should be warming really fast… and bitter winters should be a distant memory for hundreds of millions of people right? Well, not exactly… there’s one additional factor: the Gulf Stream… that air flow that sweeps from west to east, moving north or south and changing direction all the time. When it pushes up through colder northern air and then flows down to where temperatures might normally be warmer, that southern climate clearly feels the brunt of the colder air carried in by the Gulf Stream. And vice versa.
Jennifer Francis, an atmospheric scientist at Rutgers University in New Jersey, “published a study last year in which she showed that Arctic warming might already be causing the jet stream to become more amplified in a north-south direction. In other words, the fall and winter jet stream may be getting wavier. A more topsy-turvy jet stream can yield more extreme weather events, Francis said, because weather and climate extremes are often associated with large undulations in the jet stream that can take a long time to dissipate.
“‘We know that certain types of extreme weather events are related to weather that takes a long time to change,’ Francis said… While there are indications that the jet stream is slowing and may be more prone to making huge dips, or ‘troughs,’ scientists have a limited ability to pinpoint how this will play out in the coming winter season… ‘The locations of those waves really depends on other factors,’ Francis said, such as El Niño and a natural climate pattern known as the Arctic Oscillation. ‘I can only say that it’s probably going to be a very interesting winter,’ she said… Francis’ work has linked Arctic warming to the unusually cold and snowy winters of 2009-10 and 2010-11, during which the U.S. East Coast and parts of Europe were pummeled by fierce winter storms and experienced cooler-than-average conditions. The winter of 2011-12 was much milder, by comparison, but Francis said it, too, was consistent with her research.” Huffington Post.
Huh? You mean we could freeze our butts off this winter… and this is a product of global warming? Yep! Or not. The one thing that seems to be happening is the potential for extreme and unpredictable swings in temperatures and weather patterns. If that old cold north wind begins to blow, and the Gulf Stream happens to be “up there” at the time, it will carry that frigid air wherever it goes, but it could equally be picking up warmer air from the south, if the Gulf Stream slips lower, and carrying that to those in northern reaches.
Instability is not particularly good for agriculture, because plants tend to operate within fixed ranges of temperature tolerances… and at specific times in the growing process. Food shortages, new insect migration patterns, etc. could deeply impact the human condition by spreading disease and famine at unprecedented levels. Further, the general increase in overall temperature could have a profound effect on water supplies and drought conditions, making what the West and the Mid-West are experiencing now a more permanent feature.
I’m Peter Dekom, and I suspect that trying not to reduce our food or water supplies or amplify disease patterns might be legitimate individual concerns for each and every one of our elected officials, assuming they care about us at all.

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