Monday, March 16, 2015

Will The Same Mucked Up Jet Stream That Froze New England Spawn Deadly Heat Waves?

This schematic shows very big ridges and dips
in the jet stream. New research backs up
claims that global warming might
be contributing to weather patterns that
make the jet stream get stuck in weird positions
like this, causing extreme weather and disasters.  
As we warm the planet by belching extra CO2 into the atmosphere, are we also making our weather patterns get stuck in weird positions, like a contortionist who suddenly develops back spasms?

The evidence seems to be growing that the answer is yes.

I've mentioned the idea that climate change might be getting the jet stream "stuck" in weird positions in this here blog thingy before, but new research strengthens the idea this jet stream theory is right.

While scientists agree that global warming is occuring, there's often not total consensus on what oddball things might come out of climate change or how these things will play out.

As the Washington Post notes, Rutgers University's Jennifer Francis has for a few years now postulated that the rapidly melting Arctic has been screwing around with the jet stream. The Arctic is warming faster than the mid-latitudes and tropics, reducing the contrast in temperature between, say, Cuba and the North Pole.

Francis says this helps make the jet stream dip and bulge and swerve much more than it used to, and get stuck in these weird positions more often.

The upshot of this is that areas of the globe then get trapped in extended periods of extreme weather, perhaps like the drought in California and the New England cold and snow blitz this winter.

A number of climate scientists, though, didn't buy Francis' theory.

However, the Washington Post says several papers have come out in the past couple of years that back Francis' assertions, and a new report in the journal Science expands on this.

Says the Washington Post:

"The new paper, by Dom Coumou and two colleagues at the Potsdam Institute for Climate Impact Research and the University of Potsdam in Germany, finds that the melting Arctic is indeed messing with the jet stream (as well as the broader atmospheric circulation) and our weather.

But it also goes goes further by asserting that there's a strong effect in the summer in particular. The progress of weather is slowing during the summer, the authors assert, and the result could be a very deadly one - including 'more persistent heat waves in recent summers.'"

An unprecedented, long heat wave contributed to the deaths of up to 35,000 people in Europe in the summer of 2003, says New Scientist.  An incredible heat wave in Russia during 2010 killed an estimated 55,000 people was one of the worst weather disasters of its kind, says Nature.

If the new research is right, any spot in the northern hemisphere, and perhaps the southern one as well, is now much more at risk of these destructive, deadly heat waves.

The theory goes like this: When the temperature contrast between the Arctic and the tropics is as strong as it used to be, the jet stream is also stronger, so storms zip along its path. Also, the jet stream's northward bulges and southward plunges aren't usually extreme, and change positions fairly often.

This means bad or extreme weather tends not to linger in any one place for too long.

With the climate now changing, the temperature contrast between the Arctic and the tropics is decreasing.  As that temperature gradient grows fainter, the jet stream slows, weather systems don't move fast, and once the jet stream doesn't change positions as often.

That would mean people stuck under a big northward bulge in the jet stream get trapped in a heat wave that seemingly never ends. Those at the bottom of a big get stream dip stay cold for a long period of time and the people on the east side of a big dip, where the storms congregate, get extended periods of flooding rain or deep, deep snow.

Any kind of stuck weather pattern like this is a recipe for a deadly disaster.  They'll keep studying this threat more, I'm sure, but it might be another reason for climate change deniers to stop throwing snowballs on the U.S. Senate floor and actually enact some economic growth policies that reduce our dependence on carbon.

Just a suggestion, guys.


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