Cold? Blame Global Warming

[Buster's Uncle]

Cold? Blame Global Warming
BY Carlton Wilkinson |  01/07/14 - 05:08 PM EST



NEW YORK (TheStreet) -- While the deep freeze we're experiencing may seem like proof that global warming is a myth, the truth is exactly the opposite, according to scientists who predicted this type of extreme weather in a study published in September.

Three scientists from Atmosphere and Environmental Research, Lexington, Mass., and one from Harvard co-authored an article in Oceanography that directly correlates melting Arctic Sea ice with extreme winter weather conditions on continents south.

"Arctic sea ice plays an important role in modulating surface conditions at high latitudes, and even small changes in sea ice extent can cause Arctic climate to change dramatically, with ensuing feedbacks on the entire Earth climate system," the study says.

The "ensuing feedbacks" result in part from distorted a jet stream pattern, the so-called "polar vortex." Normally it's a circular pattern around the pole that helps contain the region's chill. Distort the pattern and the chill spills south and can turn into a vicious cold snap anywhere in the northern hemisphere.

A seesaw effect of warm Arctic Ocean weather translating into colder weather on the northern continents has long been observed. However this Arctic Oscillation, as it is termed, has been notoriously difficult to predict. What the study found is that diminishing sea ice in the fall is a clear indicator of mild Arctic winters and, therefore, a warning of severe winter weather elsewhere.

Basically, the loss of sea ice exposes darker ocean water, which absorbs more heat, multiplying the effects of the warming that cause the melt in the first place. The warmer ocean is simultaneously more exposed to the atmosphere, where the sea ice would normally keep the ocean waters bottled up. The added moisture can create more abundant snowfalls elsewhere, and the increased heat creates new convection patterns that help disturb the polar vortex.

While the study sought to identify a mechanism for predicting severe winter weather, it also linked that weather to a pattern of global warming that has seen the world's average temperature rise significantly over the past several decades. Heat trapped in part by human-emitted gasses initiates the melting of sea ice, setting off a chain reaction that results in severe winter weather for us.

The temperature in New Jersey right now is 5 degrees Fahrenheit, with wind chills below zero. Southern New Jersey is a humid sub-tropical region with relatively mild winters, particularly the Shore area where I am. Temperatures in the single digits aren't completely unheard of here, but they are extremely rare.

By contrast, winter temperatures more typical of New Jersey can be found right now in Nome, Alaska, where it is a practically balmy 31 degrees F. Still, we can take some comfort: Barrow, Alaska, north of the Arctic Circle, is -11 degrees. Sisimiut, Greenland is 16 degrees. Both are right in line with the average temperatures for this time of year.

If you think of the Arctic Circle as a freezer, global warming has propped open the freezer door, making our climate, however temporarily, more like the climate at the top of the world.


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