Unless you’re cursed with the memory of a goldfish, you may remember last winter when the polar vortex swept down and gave a good portion of America a heavy blanket of snow. Remember when Louisiana Congressman John Fleming tweeted that “‘global warming’ isn’t so warm these days?”
Pepperidge Farm remembers, and so does Planet Experts:
“Global warming” isn’t so warm these days. http://t.co/gOqr2RiuNJ
— John Fleming (@RepFleming) January 2, 2014
A lot of Republicans tweeted and sniped that it was super cold that winter, ergo global warming was a lie and scientists were lying liars. Now that winter has struck again, the same sort of tweets are flying around, the same comments are being made. For those of you who like reliving history, Planet Experts’ editor-in-chief Pierce Nahigyan wrote a response to these critics in January 2014, “If Global Warming Is Real, Why Is It So Cold?” It’s not bad (if you can ignore the baffling page design).
But since this is a new winter, let’s reopen this wintry wound.
#1) It Gets Cold in Wintertime
When it’s wintertime in the Northern Hemisphere, it gets cold in America just like everywhere else. When southern Buffalo gets five feet of snow, that’s certainly unusual but it is the time of year for it.
#2) That’s a Lot of Snow
Well that is a lot of snow, and what’s really unusual is that the Midwest and the Great Lakes are likely to experience “one of the longest sub-freezing spells on record for the month of November,” according to the Weather Channel.
In fact, on the 19th, all 50 states (yes, even Hawaii) reported low temperatures of 32 degrees or below. So what’s going on?
What’s going on, at least on the continental side, is an extreme jet stream is channeling Arctic air into the lower 48.
But that’s not the whole story. As the Washington Post’s Chris Mooney points out, the extremely low temperatures are mostly being felt on the eastern side of the U.S. “[T]he eastern United States is experiencing very unusual cold,” he writes, “but that dish is served with a side of baked Alaska.”
The image below comes from the University of Maine’s Climate Change Institute:
As you can see, yes the eastern U.S. is freezing but California’s still stuck in a drought and Alaska is downright crispy.
#3) But Why?
John Holdren, the director of the White House’s Office of Science and Technology Policy, can tell you why:
If you’re still confused (or if bad blue screen makes you cranky and contrary), here’s the deal: Normally, the jet stream (picture a river of air flowing over the planet) flows in a more or less direct path from west to east. However, as the Arctic warms and its ice melts, as it’s been doing for the last few decades, that jet stream is affected, becoming as loopy as an aging river.
Jennifer Francis and Stephen Vavrus, from Rutgers and the University of Wisconsin-Madison respectively, wrote a paper on this phenomenon in 2012. The reason for the effect is simple atmospheric physics. The atmosphere is thicker at the equator because there is more warm air there. Traveling up the northern latitudes, the air becomes thinner and colder. However, if the Arctic atmosphere warms faster than at the mid-latitudes (remember, the Arctic is warming twice as fast as the rest of the planet), this literally throws the jet stream for a loop.
The result? You get five feet of snow in Buffalo.
#4) I’m Still Not Convinced
Here’s a tough truth for you: The United States experiences only two percent of the planet’s weather (it’s two percent of the Earth’s surface). While we’re freezing, both China and Australia got record heat waves. And yes, California’s still baking.
Check that map from the University of Maine again. See those variations listed for the planet’s regions? All of them except for the Antarctic show signs of warming.
Despite the fact that the eastern U.S. is due for a cold, cold winter, 2014 is still on track to be the warmest year in recorded history. May, June, August, September and October have all broken temperature records for their respective months, according to both NASA and the National Oceanic and Atmospheric Administration.
And finally, bear this in mind: Climate is the pattern of weather observed geographically and over the seasons, to paraphrase Dr. Holdren. One season of cold weather does not disprove global warming or climate change. In fact, as the data we’ve reviewed indicates, this cold weather reinforces climate change.
So yes, America, it’s cold outside, and no, it doesn’t disprove global warming. Next week, Planet Experts will cover even more breaking stories: Water Is Wet, Muffins Are Hot.