When Did Global Warming Stop?
Has Global Warming Stopped?
As I write, the temperature outside my door reads 34 degrees Fahrenheit, belying the brilliant sunshine. But our forecast calls for up to an inch of snow tonight, and further West, they are already getting pounded with another in a seemingly endless series of winter storms. And I live in Atlanta, where the average maximum temperature for this time of year is 56 degrees!
So does this mean that global warming has stopped, and everything is OK, if only we remember to lay in a sufficient supply of wool sweaters, blankets and long underwear?
Well, some folks seem to think so. For example, a person styling him- or herself as “NorthernOnt” commented on a news forum:
Poor AGW advocates. They are now in full damage control, trying to change the narrative they have controlled for the last 20 years. For years we have been bombarded with Global Warming causes mass droughts, melting ice and glaciers, sea level rise etc etc. Someone forgot to tell Mother Nature to co-operate. Now warming has ceased, there is flooding where none should be, places where snow and extreme cold are rare are now experiencing their 3rd year of such weather, etc etc. Only a fool or a paid lackey with vested interests in keeping the AGW charade going still believe in catastrophic Global Warming. All evidence points to a coming Ice Age, which is due anytime soon, and that is backed up by solid 100% real world historical data, not some BS computer models with programmers in the pay of the environmental movement.
“All evidence points to a coming Ice Age, which is due anytime soon..."
I guess he thinks warming has stopped, all right.
You may be wondering what evidence supports the prediction of an Ice Age “soon.”
In one sense, so am I—at least, I am if “soon” means anything less than several thousand years. One notable scientific estimate—Berger and Loutre, 2002, in Science --puts the next glaciation 50,000 years in the future.
In another sense, we can be considered to be in an Ice Age now—an intermittent Ice Age, characterized by periodic ‘interglacials.’ In this view, the current interglacial just happens to frame the development of human civilization as we know it. You can’t get much sooner than ‘now!’
But is “Mother Nature” in fact ‘refusing to cooperate’?
Let’s take “NorthernOnt”—I’ll call him “Mr. NO,” for brevity—point by point. He cites AGW predictions of “mass drought, melting ice and glaciers, sea level rise.” What did we see in 2010—looking, of course, at “solid 100% real world historical data?”
Serious droughts occurred in China (first half of the year) and in Brazil; the latter drought is ongoing and extremely severe. Drought in northern China continues, with significant impact on the global price of wheat. New Zealand experienced drought in 2010. Eastern Australia emerged from multi-year drought, although Southwestern Australia’s ongoing drought continued with their driest year on record. Multiyear drought also ended for Israel and Jordan late in 2010.It was, overall, a wetter-than-average year, but “mass drought” was not in short supply.
Drought Images, 2001-2010Click thumbnail to view full-size
Melting Ice and Glaciers
Arctic sea ice experienced the third-lowest minimum extent ever in 2010, and several times set new records for lowest extent for those points in the year. Antarctic sea ice temporarily reversed a modest growth trend and is below average at present.
As to glaciers, I’m not aware of anyplace where 2010 summary data is available; it takes quite a while to compile glacier data, perhaps because the predominant methods of measuring mass loss involve actually going to the glacier, and it takes time to make and compile all the information. But the World Glacier Monitoring Service has a graph of glacier mass balance to 2009 now available. Since a picture is proverbially worth a thousand words, here’s the latest ‘picture’:
Sea Level Rise
Here’s the latest satellite data from the University of Colorado, which (rather oddly for a university in a landlocked state) is the primary institution monitoring Sea Level Rise:
Well, what about the other three points, made a couple of sentences further on? Mr. NO said:
“. . . warming has ceased, there is flooding where none should be, places where snow and extreme cold are rare are now experiencing their 3rd year of such weather. . .”
As my lead paragraph indicates, I’ve got to give him something on point 3—where I live it is indeed unusually cool this winter, and the same was true last winter—though not the winter before. So there are clearly some places experiencing cool winter weather over the last two or three years. The question is, what does that mean, if anything?
Let’s come back to that later, and address the other two points first.
World View of Global Warming
- Global warming photography, climate change science, weather, arctic, antarctica, climate zones, glac
Global warming photography - photographs of global climate change in the Arctic, Antarctica, glaciers, temperate climate zones, rising seas.
Flooding Where None Should Be
What, then, about the “flooding were none should be?” Well, that’s a tough one—because there isn’t anyplace flooding shouldn’t be. Search as you will, you will not find a climate scientist forbidding flooding anywhere. Period.
Poor Mr. NO may assume that predictions of drought in certain areas—Eastern Australia, perhaps?—mean no flooding. But that would only be true for droughts that were literally endless. By contrast, real world droughts, however bad, do break eventually.
And it may very well be terrible floods that break those droughts--as we saw in Queensland and Victoria in January of 2011.
Warming Ceased. . .
All of which brings us back to the allegation that ‘warming has ceased.’ Before we look at whether or not we have evidence to support Mr. NO, let me note that he’s not the first to make the claim.
. . . in the mid-1990s?
For example, the scientist Dr. Henrik Svensmark wrote in 2009 that “In fact global warming has stopped and a cooling is beginning.” He did not say just when the warming had stopped, but his reason for believing that Earth is cooling was decreasing Solar magnetic activity, which he noted he and his colleagues had been watching “with increasing concern, since it began to wane in the mid-1990s.” So perhaps warming stopped in the mid-1990s?
. . . in 1998?
Well, that would be in accord with Dr. Bob Carter, who the UK Daily Telegraph describes as “a geologist at James Cook University, Queensland, engaged in paleoclimate research.” In his 2006 op-ed for the Telegraph, Dr. Carter said that warming “stopped in 1998,” describing the temperature graph from that year forward to 2006 as being in “stasis.”
So warming must have stopped in 1998.
. . . in 2001?
Or you could take the opinion of David Whitehouse, who created a tempest in a teacup in 2007 by stating (you guessed it) that “global warming has ceased.” His grounds for saying so were that “The fact is that the global temperature of 2007 is statistically the same as 2006 as well as every year since 2001.”
So global warming stopped in 2001.
. . . in 2002?
Then again, you could go by the word of renowned climate contrarian Viscount Christopher Monckton of Brenchley. He’s responsible for this graph showing that warming stopped in 2002:
. . . in 2008?
There was another outbreak of ‘global warming cessation’ in 2008. 2007 had been an extremely warm year in terms of global temperature, inconveniently following on the heels of Drs. Carter and Whitehouse’s articles, and it was followed by a relatively cooler year in 2008.
In February, blogger Michael Asher rather breathlessly wrote in a dailytech.com post that “over the past year, anecdotal evidence for a cooling planet has exploded.” (I’m tempted to quip here about the advisability of trusting exploding evidence, but let’s move quickly on.) His headline? “Twelve-month long drop in world temperatures wipes out a century of warming.”
So we saw global warming not just stop, but actually ‘reverse’ itself in 2008.
(In essence, this is also the lode being mined by Viscount Monckton.)
Wow! What a shocking decline!
. . . in 2010?
Alas, the respite proved to be short-lived; 2009 was warmer than 2008, and 2010, as we have now learned, set numerous records for warmth.
All the global warming ‘wiped out’ in 2008 had returned, like a particularly nasty stain upon the carpet.
Not to worry. 2010 was warm, but that can only mean one thing:
An Ice Age is due anytime soon!
Ice Age Due?
There's a name for this!
OK, I'm getting a little facetious. What we've been looking at in detail here is the fallacy called "cherry-picking"--basically, taking information out of context.
In statistics, this fallacy is often manifested by using too small a number of samples--in the case of global temperatures, too short a timeline. There are well-known tests that should be used to ensure that one doesn't use too small a sample size--tests you'd really think Drs. Carter and Whitehouse would be familiar with, and even the good Viscount of Brenchley.
What do temperature trends look like if you use a longer timeline, say the generally-accepted 30 year baseline?
You can see two things in this graph.
First, the trend is consistently upward over the longer term. You can't tell just by looking at the graph, but standard criteria show that this trend is statistically significant, meaning that there is a very low probability that it could be due to chance.
Second, there are lots of upward and downward 'squiggles' along the way. By picking them out, you can make it look as if it's cooling--or warming!--at just about any point in time. But these 'cherry picks' have no value, if you are looking for the truth. They are only valuable if you want to support 'your' point in debate.
Case in point would be the downward squiggle at the end of graph. That's the 'cooling' we're experiencing right now. It's real--but almost certainly not meaningful. You'll find no shortage of folks claiming otherwise.
But just remember, their claims are only the latest in a series--and you now know why they are nearly sure to be wrong.
Or maybe it just stopped in my back yard?
Oh, yes, I promised earlier to consider one more thing: does the cold weather I personally experienced in December (and continue to experience into early February) mean anything in terms of how hot or cold the planet as a whole was?
"We are the world"--but how about my back yard?
As you can see in the photos below, there was enormous warming in my yard. (OK, this is the front, not the back!) Consider the rosemary shrub at 8 AM, and the sloppy street behind it. Then compare the appearance not two hours later:
Or take a wider view across the street. At 9, my neighbor's house and lawn are covered in snow. Before noon, both have melted dramatically.
Would I be justified in claiming that this somehow 'proves' the planet is warming?
Surely, such a claim would be met with derisive laughter. But it's little more foolish than many of the claims examined above. Really, it's just more obviously foolish.
No, looking at the graph below, my little patch of heaven--or at least, suburbia--doesn't say much about world temps. (Perhaps I should have said, “Mr. NO, not much?”)
My back yard was cold this morning. It was cold in December, too, like a lot of back yards in the eastern US--and in Northern Eurasia.
But that wasn't the case in the Canadian Arctic, or Africa, or Southeast Asia, or the Middle East. To get a sense of the whole, you need to look at the whole--or at least at a sufficiently representative sample.
Specific times and places can be examples. My yard this morning exemplifies a cold snap in a warming world.
Toowoomba on January 10--tragically!--exemplified the sort of intense flooding we may expect to see more frequently in a warming world.
But arguments from an overly-restricted context are examples, too: examples of misleading argumentation. I'm very much afraid we can also expect to see a great deal more of that in a warming world.
And disproportionately, it will be intended to mislead us into thinking that nothing is wrong.
Update--July 18, 2011
Well, sure enough, the 'cooling' noted above petered out, with May and June 2011 returning to temperatures more or less typical for the decade of the 00s--June, for instance, was the 10th-warmest June on record, .58 C above the baseline (NOAA data.)
We also had a couple more claims of global warming cessation:
1) Pat Michaels, a well-known denialist, wrote an online article for Forbes.com entitled "Why Hasn't The Earth Warmed In Nearly 15 Years?"--so, for him, warming seems to have stopped in 1996. Of course, the uncharitable might wish to point out that the headline conflates 'no warming' with 'warming that is not quite statistically significant,' which is really not the same thing. Or that every year since 1996 has been warmer than any year prior to 1996.
2) Steve Goddard, formerly associated with denialist blog Watt's Up With That, cast a blogvote for global warming having stopped in 2002, since there is a flat linear trend from that date to present. Ho hum.
His claim is examined by statistician 'Tamino' at this site--though you already know the basic answer, from having read this article:
Update--January 30, 2012
David Rose, allegedly a journalist, wrote in the UK newspaper The Daily Mail that: "Based on readings from more than 30,000 measuring stations, the data was issued last week without fanfare by the Met Office and the University of East Anglia Climatic Research Unit. It confirms that the rising trend in world temperatures ended in 1997."
I think we can conclude that this qualifies as an assertion that "Global warming ended in 1997."
It's unclear just what 'data' he is referring to, but the Met Office described his characterization as "entirely misleading." Given that of the 14 years in the HACRUT dataset since 1997, 11 were warmer than 1997, that does seem to be the case. (The exceptions were 1999, 2000, and 2008.)
It is true that, figuring from 1997 to the present, the warming trend is very small--.013 degrees C per decade, according to the woodfortrees website, which provides tools for anyone to perform a variety of climate-related analyses for themselves. This warming is not statistically significant.
Update--October 22, 2012
David Rose once again tries to misrepresent warming, based upon the new HadCRUt4 version. It's more of the same, and is ably deconstructed by Tamino (once again!):
Strange how Mr. Rose fails to report the demise of the idea that 'there's no statistically significant warming since 1995,' isn't it?
While I'm updating, perhaps it is worth mentioning the NCDC result for 2011:
This year tied 1997 as the 11th warmest year since records began in 1880. The annual global combined land and ocean surface temperature was 0.51°C (0.92°F) above the 20th century average of 13.9°C (57.0°F). This marks the 35th consecutive year, since 1976, that the yearly global temperature was above average. The warmest years on record were 2010 and 2005, which were 0.64°C (1.15°F) above average.
Climate nerds breathlessly await the numbers for 2012, which began on the cool side with the same La Nina that ended 2011, but has been warming pretty rapidly since toward the level of the warmest years in the record. With a weak El Nino forecast for the end of the year, will it make it?
Regardless, the long-term warming trend remains robust, and the elevated temperatures of the last decade remain the 'new normal.'
Update--August 29, 2015
Warming denialism has had little new to offer for some time; more effort seems to have been focussed on the supposed 'recovery' of Arctic sea ice in 2013 and 2014, following the stunning new record low minimum of 2012. (2015 is shaping up to be lower once again, though probably not a new record low.)
That does not mean that this form of denial has gone away, however; Viscount Monckton continues to insist that warming has stalled since January of 1997. He manages this by considering only one of five major temperature datasets; the others show quite considerable warming, particularly during the last two years or so.
For after a slightly cooler 2013, 2014 proved to be the warmest year in the thermometric record, and 2015 is virtually certain to smash that record handily. 12-month means ending this year have consistently been in the top 10 warmest such periods, and several have been warmest ever. And there is a strong El Nino at work, an influence which raises global temperatures somewhat. (It was an extremely strong El Nino in 1997-1998 which made that such a popular candidate period for the 'death of global warming.' 2010, too, was an El Nino year, albeit not quite as strong.) Its influence is expected to peak in the coming winter.
After that, we may expect some temporary cooling. Will denialist claims then heat up once again? They don't call them 'contrarians' for nothing.
"Grow old along with me/The best is yet to be," wrote Romantic poet Robert Browning to his wife, Elizabeth Barrett Browning. And as global warming denialism ages, it, too, gets better and better--if, that is, one is speaking of comic value.
For the venerable Global Warming Policy Foundation (GWPF), a UK-based denialist outfit, has just published a new statistical analysis. Its utterly amazing conclusion is that warming stopped in either 2002 (based on the HADCRUT instrumental data) or 1999 (based on the RSS satellite data). It's probably just a coincidence that the GWPF picked the instrumental data and satellite data that give the lowest rates of warming… right?
Segmented line analysis of HADRUT data, per GWPF
Segmented line analysis of RSS data, per GWPF
GWPF forecasts for HADCRUT
It's pretty funny that the GWPF is predicting no warming based on statistical analyses that can't agree whether warming stopped in 1998 or 2002, and pretty funny that the two modeling techniques used deliver quite different forecasts, making not one, not two, but four different forecasts--all of which we are apparently supposed to take more seriously than anything that is based on, you know, physics.
However, funnier yet is the fact that the HADCRUT temperature had already exceeded the margins of error in the relevant analyses by the time the report was published!
So, to sum up, this report is the first instance of a 'warming cessation' claim which:
- can't actually decide when warming stopped
- gives a margin of error as large (line segment) as the total observed warming to date, or larger (ARIMA model) on a five year forecast (!)
- is pretty clearly contradicted by observations by the time it is published
No wonder some folks have given the GWPF the nickname "Gentlemen Who Prefer Fantasy."
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