Today’s edition of Nature included an alarming paper, indicating record ozone loss in the Arctic due to an unusually long period of cold temperatures in the lower stratosphere.
On the same day, coverage of the story by the Canadian Press included a fundamental error that is already contributing to public confusion about the reality of climate change.
Counter-intuitively, while global warming causes temperatures in the troposphere (the lowest layer of the atmosphere) to rise, it causes temperatures in the stratosphere (the next layer up), as well as every layer above that, to fall. The exact mechanics are complex, but the pattern of a warming troposphere and a cooling stratosphere has been both predicted and observed.
This pattern was observed in the Arctic this year. As the Nature paper mentions, the stratosphere was unusually cold in early 2011. The surface temperatures, however, were unusually warm, as data from NASA shows:
While we can’t know for sure whether or not the unusual stratospheric conditions were caused by climate change, this chain of cause and effect is entirely consistent with what we can expect in a warming world.
However, if all you read was an article by the Canadian Press, you could be forgiven for thinking differently.
The article states that the ozone loss was “caused by an unusually prolonged period of extremely low temperatures.” I’m going to assume that means surface temperatures, because nothing else is specified – and virtually every member of the public would assume that too. As we saw from the NASA maps, though, cold surface temperatures couldn’t be further from the truth.
The headline, which was probably written by the Winnipeg Free Press, rather than the Canadian Press, tops off the glaring misconception nicely:
Record Ozone loss over the Arctic caused by extremely cold weather: scientists
No, no, no. Weather happens in the troposphere, not the stratosphere. While the stratosphere was extremely cold, the troposphere certainly was not. It appears that the reporters assumed the word “stratosphere” in the paper’s abstract was completely unimportant. In fact, it changes the meaning of the story entirely.
The reaction to this article, as seen in the comments section, is predictable:
So with global warming our winters are colder?
First it’s global warming that is destroying Earth, now it’s being too cold?! I’m starting to think these guys know as much about this as weather guys know about forecasting the weather!
Al gore the biggest con man since the beginning of mankind!! This guys holdings leave a bigger carbon footprint than most small countries!!
I’m confused. I thought the north was getting warmer and that’s why the polar bears are roaming around Churchill looking for food. There isn’t ice for them to go fishing.
People are already confused, and deniers are already using this journalistic error as evidence that global warming is fake. All because a major science story was written by a general reporter who didn’t understand the study they were covering.
In Manitoba, high school students learn about the different layers of the atmosphere in the mandatory grade 10 science course. Now, reporters who can’t recall this information are writing science stories for the Canadian Press.
“… because a major science story was written by a general reporter who didn’t understand the study they were covering”
While your interpretation may be correct, there’s another way of reading this: the editors (who must be given credit for being expert wordsmiths) may know exactly what they are doing: sowing FUD, in the certain knowledge that anyone who suggests such a thing (in this case, me) comes across as a paranoid conspiracy theorist.
Kate, since that’s your neck of the woods (prairie?) maybe a letter to the paper would help. They should issue a correction at the very least. Maybe even a guest column. I know a good Canadian scientist and writer…
This is a brilliant post and brilliant-looking blog (that I will have to investigate), which defies your very modest years. Thank you for explaining this paper so clearly and without being in-any-way patronising (something I find hard to avoid). Can you do the same for me and explain why it is that bodies such as NASA and the NOAA ssem to issue so much conflicting information? Or may be they don’t? Either way, their stuff, almost certanly mis-reported, seems to feature regularly on denialist websites such as WUWT. Why is this?
P.S. Keep up the good work; and I will try not to regret all the years I have “wasted” not fighting for a sensible response to climate change.
“This pattern of a warming surface and a cooling upper atmosphere is due to an enhanced greenhouse effect: since more heat is trapped near the surface, less is radiated back up through the stratosphere.”
Is it really that simple? It now sounds very unlikely to me as the change in outgoing long-wave radiation is very small (0.9 W/m²?). I’ve read a few explanations which are quite a bit more complicated and none of which I’ve both fully understood and fully believed. Here’s my attempt at explaining it from what I have understood:
I’d be interested to hear other explanations.
(And my attempted humorous/sarcastic response to a confusion about the toposphere/stratosphere resulting from similarly vague reporting in the UK press in the same thread:
> Is it really that simple?
It’s complicated enough for Gavin Schmidt to lose his way while explaining it :-)
Your bringing up of UV/ozone heating is part of the explanation. It’s not the whole story though.
My take: if we forget about ozone and assume the atmosphere is “grey” over the thermal infrared, there would not be a stratospheric cooling effect. When CO2 concentrations increase, the radiating surface (the Earth’s “photosphere”) will move up by one scale height per doubling, its temperature will be the same as before (as dictated by Stefan-Boltzmann; the same total amount of energy has to be gotten rid of), and the whole temperature profile below it will move up, all the way down to the ground.
Now the atmosphere is not grey. What we see therefore is that, when CO2 increases, a redistribution of outgoing radiation takes place: more is radiated and escapes on wavelengths where the atmosphere is still transparent, less where it is opaque. But the latter wavelengths are precisely the ones CO2 in the stratosphere likes to absorb — the Kirchhoff-Bunsen principle. The net result of the CO2 concentration increase is that both stratospheric absorption and emission go up, but the former less than the latter. So temp has to come down to restore the balance.
This austral winter the temperatures on Antarctica have been higher than usual: http://www.esrl.noaa.gov/psd/map/images/rnl/sfctmpmer_90b.rnl.html , so this would make the ozone hole down under abnormally large and intense following austral spring? I don’t remember that large an anomaly from Antarctica previously, so there might have been a breach in the southern polar vortex last summer`?
Martin, thank you for your clear explanation.
The Gavin Schmidt post you link to is one of the ones which originally confused me on this subject. Doing a bit of link following from there gets to this article. That makes the point that hadn’t occurred to me before that simple loss of ozone will, more or less directly, cause cooling of the stratosphere as well. Is there not a small positive feedback there.
Bummer that it was in Canada, not the U.S., so it doesn’t fit the requirements for submitting to MediaBugs.org (they keep a DB documenting the bug, the media outlet’s response, whether the bug was corrected, etc.) – but I’ll look around & see if a U.S. paper or blog made the same error.
My favorite recollection involving a reporter botching the science has to do with something I read a long time ago. I wish I could be more specific, but in the article, the reporter mentioned Antarctic icebergs that were 328 feet thick and that the Antarctic peninsula had warmed about 35 degrees F. I was stunned that icebergs were measured that accurately, and that the peninsula had warmed so much.
Then it occurred to me that the reporter had converted metric units to English units without thinking. 100 meters is about 328 feet, and assuming a few degrees C change is the same as a few degrees C absolute temperature leads one to an incorrect Fahrenheit value.
Journalists are rarely well-trained in the sciences, and incorrect reporting is the result.
jyyh: large ozone hole this year
The weasel and Eli have taken a few whacks at this.
BTW, if the winter strat T was higher, than there will be less ozone loss down under.
The average person was already confused about global warming and the ozone hole. Most of the public I talk to think these two phenomena are one in the same. How many weather forecaters warn us to put on sunblock because it is “hot outside”? How many people understand that you can get sunburned while skiing? People incorrectly believe that heat causes sunburn People also incorrectly think that global warming is because of the ozone hole. I try to explain the difference to people, usually with little success.
It’s strange how many people still doubt whether climate change really exists when there is so much evidence for it. Journalists like the one you mention from the Canadian Press should be disappointed with themselves with not doing their job properly of informing the public of the issues.
I think that certain companies try to encourage the line of global warming doesn’t exist. That way they are able to pollute the environment without public pressure making them more responsible for their actions. It’s clear that major corporations stand to make more money from people not understanding climate change and thinking that it is a normal process and is not the cause of record levels of pollution.
Journalism is an important profession and those tasked with bringing the truth to the public should spend more time researching their articles before making such statements.
You and your readers might be interested to read a recent article in the Global Environmental Change journal by Neil Gavin and Tom Marshall, entitled ‘Mediated climate change in Britain: Scepticism on the web and on television around Copenhagen’. However, for the benefit of those that cannot access the full text (or do not wish to pay to do so), I summarised their findings in my blog on 30 September 2011, in a suitably-titled post: ‘Why I’m so hacked off with journalists’!
P.S. I can’t believe I did not mention this when I first commented on this 7 weeks ago!