The planet is heating up, but here in the South we’re freezing over.
The Atlantic is getting warmer, but there’s a “bomb cyclone” detonating up the sea coast, flinging ice and snow like shrapnel.
Not at all.
“This is an important situation when we have to think about the difference between weather and climate,” said Christopher “Chuck” Bailey, who teaches on weather, climate and climate change at the College of William and Mary in Williamsburg.
“We are having some ridiculously cold weather right now, but that doesn’t necessarily mean our climate is in a different state than we think it’s been.”
Simply put, studies indicate that global warming increases the chances for a whole host of weather extremes — droughts and heat waves, rain and flood events — all over the planet.
And Hampton Roads — which is no stranger to a brutal winter cold snap now and again — could be prone to Arctic freezes more frequently and for longer periods in the future.
The current deep freeze has been hanging around since before Christmas, said Bailey, and will stretch through the weekend as frigid air is sucked into the Eastern U.S. from the North Pole, Greenland and even Siberia.
“I don’t know if I’d say it’s a new normal,” said Bailey. “But the idea that they will happen — and happen with some regularity — is one of the things that is likely.”
A big reason for that likelihood has to do with the polar jet stream — a powerful, fast wave of wind moving west to east, circling the upper Northern Hemisphere.
It’s always present, caused by the temperature difference between the equator and the pole, explained Kunio Sayanagi, an expert on jet stream dynamics at Hampton University.
Jet streams fluctuate naturally. But greenhouse gases are rapidly melting polar ice — in the last few decades, the Arctic has warmed at about twice the rate of the entire Northern Hemisphere, a phenomenon known as Arctic Amplification.
As the temperature difference between the pole and equator eases, the undulating winds of the jet stream weaken. They dip and swell in greater waves. And they slow down, hovering for longer periods.
This gives weather patterns a better chance to dig in over a particular region, churning up into heat waves, floods and blizzards.
“Each weather system is going to stay overhead each location for a longer period of time,” said Sayanagi of a stalling jet stream. “So, even if the intensity of a storm does not change, if it hovers over us for a longer time, it will have a more extreme consequence.”
In a report published in 2012 by the American Geophysical Union, atmospheric scientists Jennifer A. Francis of Rutgers University and Stephen J. Vavrus of the University of Wisconsin-Madison offered evidence that the jet stream’s weaker winds and bigger wave amplitudes “may lead to an increased probability of extreme weather events that result from prolonged conditions.”
“Gradual warming of the globe may not be noticed by most,” the authors write, “but everyone — either directly or indirectly — will be affected to some degree by changes in the frequency and intensity of extreme weather events.”
Warming water temperatures attributed to global warming can also intensify weather events, said Bailey. Recent examples? The 60 inches of rain that drenched Texas last August during Hurricane Harvey, stoked by a warmer Gulf of Mexico, and the 60 inches of snow that pounded Erie, Pa., around Christmas, fueled by a warmer Lake Erie.
While experts are loath to blame any single weather event on climate change, said Bailey, “increased variability is one of the things that is the new normal.”
Last week, as frigid temperatures turned the East Coast into an ice box and shattered some records, President Donald Trump tweeted that “Perhaps we could use a little bit of that good old Global Warming.”
“He either doesn’t understand it, or doesn’t want to understand it,” said Bailey. “Or is playing to a certain audience.”
Francis and Vavrus urged more research “to provide valuable guidance to decision-makers in vulnerable regions.”
Sayanagi urged more people to join the conversation, examining both the economic and environmental costs of climate change, and pushing action sooner rather than later.
“I like to present the (cautious) scientific side,” said Sayanagi. “But how politicians should be acting is different. Should they wait for clear evidence that we completely messed up the climate?”
Contact Dietrich at 757-247-7892 or email@example.com. Follow on Twitter at DP_Dietrich