If you live in North America, then no doubt you’re aware of the so-called polar vortex which has come down from the Arctic to freeze the hell out of the continent. And, just as surely as the temperatures started to drop, global warming deniers began to shout about how this supposedly proves that global warming isn’t real.
Okay, so you see here’s the thing… it’s called *global* warming because the whole globe, on average, is getting warmer. Saying that a cold snap disproves global warming is like saying that the IRS no longer exists because you got a tax refund once.
See all that red? Yeah, that’s where the climate is getting warmer. And notice how there’s more red than blue? [image source]
I’ve blogged about this very topic before, namely that “climate” isn’t the same thing as “weather”, but seeing as how the deniers are once again spouting their nonsense, it bears repeating…
Winter is NOT “Proof” of Global Cooling
… The primary flaw in this argument is good ol’ fashioned cherry-picking of data: the “coolers” are choosing to focus only upon data which supports their claims, while ignoring the vast amount of data which points in exactly the opposite direction. By focusing on just the weather reports over the last couple of weeks, or for only a certain part of the planet, they leave out the fact that climate is a phenomenon which is global in nature and that climate science is concerned with long term trends. Essentially, they are confusing weather with climate. Climate experts recently made this point in an Associated Press article which has been widely circulated.
Bottom line: when taking all of the data into account, both concerning the timeline as well as the Earth as a whole, there is a clear warming trend. …
There are some other really good articles about this latest confusion regarding how the polar vortex fits into the broader picture of global warming. For your reference, I’ll suggest two of them:
1. Can global warming be real if it’s cold in the U.S.? Um… yes!
This article is really good because it goes through some of the basics about global warming and climate change in general, and then it emphasizes the importance of temperature trends and statistical analysis of the data. My favorite part is as follows:
… Global warming isn’t expected to abolish winters in the U.S. anytime soon. Right now, climate experts are worried about a 2°C to 4°C rise in global average temperatures by the end of the century. That would create all sorts of disruptive changes. But those few degrees aren’t enough to completely undo the larger swings in temperature we see each year between summer and winter in many parts of the world.
Indeed, many climate models suggest that we’ll still see record cold snaps in the United States as the planet heats up. They’ll just become much less frequent over time — while record heat waves will become increasingly common. See this paper in Geophysical Research Letters from 2009: Over the past decade, it notes, the U.S. has experienced about two daily record high temperatures for every record low. If the planet keeps heating up, that ratio will shift to 20:1 by mid-century. There will still be record lows in many areas. They’ll just be rarer. …
2. Go home, Arctic, You’re Drunk.
This is a humorous and informative post from my skeptical colleague Greg Laden wherein he lays out just how it’s possible for global warming to actually account for the polar vortex phenomenon:
… The apparent contrast between extreme cold and global warming is actually an illusion. If we look at the local weather in many parts of the US we see a giant blob of cold “Arctic air” moving south to engulf our humble hamlets and cities, as though the Arctic Coldness that we know is sitting on the top of our planet, like a giant frosty hat, is growing in size. How can such a thing happen with global warming?
Actually, if you think about it, how can such a thing happen at all? Imagine a somewhat different scenario. Imagine the giant global hulu-hoop of warmth we know of as the tropics suddenly expanding in size to engulf the United States, Europe, Asia, and in the south, southern South America, southern Africa, Australia, etc. for a week or so, then contract back to where it came from. How could that happen? Where would all the heat necessary for that to happen come from? That seems to be a violation of some basic laws of physics. Now, cold is not a thing — it is the absence of heat — but the same problem emerges when we imagine the giant frosty hat of arctic air simply getting many hundreds of percent larger, enough to engulf the temperate regions of the planet. As easy as it might be to imagine such a thing given the images we see on regional weather maps, it is in fact not possible. The physics simply does not work that way.
What is happening instead is the cold air mass that usually sits up on the Arctic during the northern Winter has moved, drooped, shifted, gone off center, to engulf part of the temperate region. Here in the Twin Cities, it is about 8 below zero F as I write this. If I go north towards the famous locality of International Falls (famous for its cold temperature readings often mentioned on the national news) it will in fact be colder. If I go even farther north, at some point it will start to get warm again, as we leave the giant blob of cold air that has engulfed us. In fact, it is relatively warm up on the North Pole right now. Alaska and Europe are relatively warm as well.
The graphic above from the European Centre for Medium-Range Weather Forecasts shows what is happening. The Polar Vortex, a huge system of swirling air that normally contains the polar cold air has shifted so it is not sitting right on the pole as it usually does. We are not seeing an expansion of cold, an ice age, or an anti-global warming phenomenon. We are seeing the usual cold polar air taking an excursion. …
Of course, I don’t expect any of this to phase the hardcore global warming deniers, because they’re off in a fantasy world of their own. No doubt that next time winter strikes the northern hemisphere, they’ll be back spouting this nonsense once again; it’s just plain sad and predictable. I almost feel sorry for them. I mean, how can you not feel sorry for them when this moron is one of their primary spokesmen?
The Skeptical Teacher 