Up until January, most of us hadn’t heard of the Arctic Oscillation, or AO, a pressure system at sea level over the Arctic that has its opposite number at higher latitudes, or about 37-47degrees North. Currently operating in negative phase, the AO is apparently responsible for the extreme cold weather from France to Florida, where manatees and orange trees are dying in equal measure due to freezing weather.
The cold winter isn’t all that surprising. The trend (of colder winters in the U.S., at least) started in the winter of 2006-2007, causing many who had believed the doctrine of climate change to switch their allegiance to the deniers – a situation not improved by the leaked string of e-mails from a climate science group at the University of East Anglia in November of 2009.
The situation is also not improved greatly by the fact that most of the people reading about the newest wave of cold weather haven’t previously heard of the Arctic Oscillation, so its revelation now is the sort of rabbit-out-of-the-hat trick that makes the whole global warming agenda seem suspect. In fact, scientists have recognized its effect on weather for more than a hundred years, and have been measuring it since before the turn of the century, so the lapse may be due more to a journalistic failure to research than any scientific tendency toward obscurantism.
Even so, it’s hard to explain to a man scraping his windshield free of two inches of ice at Orly Airport in Paris, France why temporary cooling can still be part of global warming, because then one has to go into the science of anticyclones, permanent high and low pressure zones, the Arctic as a heat sink, albedo and melting Arctic ice – caused by carbon emissions – leading to a colder Arctic ocean, and all the pressure and temperature variants which transfer heat and cold via global wind patterns.
In fact, the Arctic Oscillation, or AO, is as complex a phenomena as the Pacific Decadal Oscillation (PDO), the Atlantic Multi-decadal Oscillation (AMO), and the El Nino/La Nina Southern Oscillation (ENSO), all oceanic warming and cooling intervals that transfer effects to prevailing global winds (the Polar Easterlies, in the case of the AO). And when the AO went strongly negative around Dec. 14 of 2009, it caused some surprising and extremely chilling weather across the northern hemisphere.
How does the AO work? In two phases, according to the National Oceanographic and Atmospheric Administration, or NOAA, which maps oceans and the atmosphere to assess weather and preserve biospheres. Both phases are, however, natural patterns of variability not integrally related to climate change. In one phase, the pressure is lower over the Arctic and higher over the “middle” latitudes (roughly corresponding to 75 degrees North), and the Arctic Ocean is colder.
In the other, the negative phase, the reverse is true and the Arctic Ocean is warmer, leading to more melting ice or less ice coverage on land. In exchange for a warming Arctic, the middle latitudes become colder than normal, because Nature is nothing if not a balancing act. And those colder temperatures impart their coolness to prevailing global winds.
So how negative is the AO? According to Mark Serreze, University of Colorado’s director of the National Snow and Ice Data Center, it’s as bad as it was in 1950, and has affected weather all across the Northern Hemisphere, from Vermont to China. Historically, the AO was positive from 1899 through 1939, negative from 1940 through 1988, and positive again through from 1989 to the winter of 2009 (graphs here), when the AO went rapidly and surprisingly negative.
In spite of this abrupt alteration, it’s important to note that the AO is a natural pattern, if only to deflect seriously scary rumors that the sudden cooling has been caused by a HAARP beam puncturing the earth’s atmosphere. It’s also important to note that this kind of intermittent cooling, especially in winter, has occurred before, as recently as the late 1970s, and also during the period 1560 to 1850 in Europe (The Little Ice Age), which affected rye growing and caused a spike in prices in what was then a staple food for the poor.
If today’s current AO negativity were to persist for any length of time, we might face similar circumstances, with food crops limited by later springs, earlier winters and overall cooler temperatures. For those of us in the developed world, especially in America, this might mean no more orange juice in winter, or California vegetables in December. For those in third world countries, it might mean actual starvation. In spite of the fact that the AO is as normal pattern, continued melting of Artic ice as a result could lead to a highly negative feedback loop in which more ice melts, perhaps leading to even higher Arctic pressures and more melting.
Then, rather than experiencing warming, as happened up to 2005, the Northern Hemisphere might instead experience another little ice age – a scenario suggested by none other than Woods Hole Oceanographic Institution scientists Terrence Joyce and Lloyd Keigwin, who freely admit that predicting such is limited not only by a lack of historical data but a less-than-perfect understanding of these natural systems.
Others are also suggesting the possibility of another ice age based on a lack of sunspots, and this cause is also poorly understood, poorly documented, and the cause of bitter contention in the scientific, global warming community, with hardline “warmists” sticking to anthropogenic warming or nothing, and others cautiously suggesting nothing is as simple as it appears.
Clearly, the fears of the first group center around a belief that, if an iota of cause is lost, the cause itself is lost and the majority of people will reject the whole notion. I prefer to think most humans are both more flexible and more intelligent. And still others suggest that a warming planet is now being kept cool by a decline in water vapor in the stratosphere. According to NOAA’s Susan Solomon, “stratospheric water vapor represents an important driver of decadal global surface climate change."
Are you starting to get an idea of how complex global warming science really is? Good. The UK’s chief scientific advisor, Professor John Beddington, suggests this inherent complexity is the best reason not to shrug off climate change deniers, whose skepticism reflects the inherent unease of the layman faced with a discipline that takes decades to master. Instead, Beddington suggests, be honest; if all the data isn’t in – if a weather phenomenon’s effects aren’t yet fully known – admit it. There’s nothing wrong with saying, “I don’t know,” or “I was wrong.”
There is everything wrong with continuing to insist on one’s point of view even after it has been is disproven. And, in the long run, the IPCC is likely to be the winner in the anthropogenic climate change war; unfortunately, perhaps not until the ocean has swallowed the doorsteps in Venice.
Currently, according to Serreze, it’s very warm over the Arctic, with local temperatures up to 15 degrees (Fahrenheit; 8.4 degrees Celsius) warmer than normal. However, as Serreze notes, the pattern appears to be weakening. And Arctic sea ice, while below the 1979-2000 average, is still higher than its record low in 2006, so perhaps February (and next winter) will be warmer.
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