Polar Vortex and Climate Change: Why Rush Limbaugh and Others Are Wrong
By Terrell Johnson Published: Jan 9, 2014, 10:44 AM EST weather.com
Here’s some news for people on all sides of the climate change debate: Winters still get cold, often unbearably cold, especially if you live in a place like Crane Lake, Minn., which hit 38 below zero this week.
But no matter how low the temperature dropped in your area today, that doesn’t mean global warming isn’t happening.
So as Americans debate whether a warming planet can still have punishing winters and try to figure out what a “polar vortex” is – with everyone from Rush Limbaugh to the Drudge Report and a few other commentators talking about it – we’d like to add a dose of science to the conversation.
Let’s look at the claims skeptics are making one by one:
1) “Polar vortex” is a concept “created to make you think winter is caused by global warming.”
Yesterday on his radio program and website, Rush Limbaugh called a “hoax” the claim that global warming was causing the cold weather snap, and that the media had invented the term “polar vortex” to explain it all away.
Actually, the term “polar vortex” is not a new one. It’s used by meteorologists to describe a pattern of winds that swirl around the North Pole, as Weather Underground’s Dr. Jeff Masters describes it in a blog post today:
“In the winter, the 24-hour darkness over the snow and ice-covered polar regions allows a huge dome of cold air to form. This cold air increases the difference in temperature between the pole and the Equator, and leads to an intensification of the strong upper-level winds of the jet stream. The strong jet stream winds act to isolate the polar regions from intrusions of warmer air, creating a ‘polar vortex’of frigid counter-clockwise swirling air over the Arctic.”
For a historical perspective, here’s an article from the August 1950 issue of the scientific journal Tellus, describing a lab experiment that replicated the effects of the polar vortex.
2) Winters as cold as this one prove that global warming isn’t real.
On Monday, U.S. Sen. James Inhofe (R-Okla.) appeared on the floor of the U.S. Senate and said this:
(Please click the link below this article to see this video on the Weather Channel site)
We include this example not to pick on Inhofe, but to share one of the latest and highest-profile examples of claims about global warming and climate change that have spread around the mainstream national media in recent years.
In the video, Inhofe cites several examples of frigid cold and winter snowstorms from recent years, including one that he says “snowed out” a planned rally on global warming that was to be led by U.S. Rep. Nancy Pelosi (D-Calif.) in March 2009.
No scientist argues that long-term global warming means that we won’t still experience winter, even bitterly cold winters like this year’s has become. The changes to the climate that scientists who are concerned about global warming point out are exactly that: long-term. Individual weather events don’t mean that the trend isn’t taking place.
(It’s also important to point out that the United States makes up less than 2 percent of the Earth’s surface. So even when we see heavy snow events and blasts of Arctic air like this week’s, there are many parts of the world experiencing record heat, such as Australia.)
3) The ship that got stuck in Antarctica proves polar ice isn’t melting.
Since Christmas, nearly every day has brought reports of the Russian ship carrying researchers and adventure tourists that got stuck in sea ice on its way to Antarctica.
After a few aborted attempts, the passengers on board were finally rescued, but a pair of icebreaker ships remained stuck in ice-clogged Commonwealth Bay off the coast of Antarctica.
ANDREW PEACOCK/AFP/GETTY IMAGES
This photo, taken by passenger Andrew Peacock on Dec. 29, 2013 shows a thin fresh coat of snow on the trapped ship MV Akademik Shokalskiy as it waits to be rescued. Passengers on the Russian research ship, then trapped in thick Antarctic ice, were facing an uncertain wait for one last icebreaking attempt.
To climate change skeptics, the episode has made for entertaining talk-show fodder. On his radio show Monday, Rush Limbaugh said this:
“Well, obviously there is no melting of ice going on at the North Pole. If they’re gonna tell us the polar vortex is responsible for this cold, that means record cold is also happening in the North Pole, which means there isn’t any ice melting, and we know about the global warming expedition that went down to the South Pole, Antarctica, to prove that the ice is melting, and they got stuck, and then the rescuers got stuck, and then the people rescuing the rescuers got stuck, but never mind that.
“They were just exploring the Antarctic, the news said. No; what they were doing was going down to prove the ice was melting, and they got stuck in it because they ran into ice where they didn’t expect to find any. So no matter how they go at this, they’re losing.”
When it comes to Antarctic sea ice, Limbaugh isn’t off the mark. Last September, the amount of sea ice that surrounds Antarctica reached the largest extent on record since measurements began in the late 1970s. It’s a development that has puzzled climate scientists, because it’s occurred even as the world’s air and oceans have warmed significantly during the same time period.
But Limbaugh spoke in the show section quoted above about the North Pole – the Arctic. There, the trend since the 1970s has been unequivocally downward:
Average Monthly Arctic Sea Ice Extent in November, 1978-2013
Including 2013, the linear trend in November ice extent is –4.9 percent per decade relative to the 1981 to 2010 mean, or a loss of about 20,700 square miles per year. (Courtesy National Snow and Ice Data Center)
Though the Arctic’s sea ice extent did rebound this year from 2012, when it shrank to an all-time record low for summer, the long-term trend of declining sea ice in summer continues.
This year was still the sixth smallest sea ice extent on record, and older, thicker Arctic sea ice continues to rapidly melt away. You can see more at the Arctic Report Card released by the National Oceanic and Atmospheric Administration in December.
4) The planet hasn’t warmed for the past 15 years, so climate change isn’t real.
Technically, this isn’t really true. Though surface temperatures haven’t gone up by as much as climate models predicted they would by now, they’ve still been rising slightly throughout the decade.
Starting with its first report in 1990, the Intergovernmental Panel on Climate Change projected that the planet would warm by about 0.15 to 0.3°C per decade, if greenhouse gas emissions into the atmosphere continued at their current pace.
That projection held true for years until about 1998, one of the planet’s hottest years on record. Since then, despite ever-increasing emissions, global temperatures have risen by only about 0.05°C per decade.
Why this is happening is something climate scientists still are trying to figure out. Many point to the world’s oceans, which are absorbing most of the increase in both heat and carbon dioxide, while others note that our most-cited historical temperature observation recordsleave out large parts of the planet, including the poles.
Still, it’s undeniable that a long-term warming trend remains in place, as this temperature trend map from 1960 to 2013 shows:
Trends in mean surface air temperature from 1960 to 2013. Notice that the Arctic is red, indicating that the trend over this 50-year period is for an increase in air temperature of more than 2°C (3.6°F) across much of the Arctic, a larger increase than in other parts of the globe.
As the map above shows, warming doesn’t occur at the same rate worldwide. Some places, like the tropics, have warmed at a much slower pace than the higher latitudes, where warming has been most pronounced.
And the world hasn’t stopped experiencing dramatic warming: the past decade has been one of “unprecedented” climate extremesaccording to the World Meteorological Organization, while 2013 brought the world’s hottest November in more than 130 years of record-keeping, and 2012 was the hottest year on record for the U.S.
If global warming is indeed on “pause,” we can only hope it doesn’t resume.