I recently encountered a post which made the following argument against the reality of global warming:
Once again I have the pleasure of poking the myth of Global Warming in the eye with a literary pointy stick. According to the “science” behind the theory, the more CO2 in the air, the higher the temperature should climb. Fair enough. However, according to this, 2006 was Earth’s 5th warmest year, it would appear that CO2 levels have dropped, else, 2006 would have been the warmest year.
The post goes on to critique the news report of 2006 being the 5th-warmest year on record, arguing at each turn that anthropogenic global warming is folly, in fact, that it’s a hoax.
Of course it’s the post which is folly. The idea that global temperature must rise and fall with each little rise and fall in CO2 level ignores the fact that in addition to a trend due to global warming, there is also natural variation in the climate system. This is especially ironic, since denialists so often point to natural variation in the climate system to claim that modern warming isn’t unusual.
Let’s take a look at the time series of global annual average temperature during the modern global warming era (1975 to present), to get an idea of what the trend is, and what the natural variation is like. Here’s the annual average global temperature from 1975 through 2006, according to HadCRU:
The red line is the trend determined by fitting a straight line to the data. The trend so determined is unquestionably statistically significant, i.e., it’s not just due to random variation. The rate indicated by this trend is 
The trend is due to the increased greenhouse gases in the atmosphere, which is due to human activity. This is anthropogenic global warming. We can subtract this trend from the original data, leaving residuals:
Clearly the residuals are not constant! This is the natural variation in global average temperature.
There are many reasons for this natural variation. Heat is energy, and energy can be exchanged between earth’s various systems; it’s the energy in the surface layer of the atmosphere that determines surface temperature. For example, at times the pool of warm water in the Pacific ocean is more exposed to the atmosphere; this leads to an exchange of energy, heating the atmosphere at the expense of ocean heat. This phenomenon is called el Nino. The last really big el Nino was in 1998, and that’s why 1998 was so warm (the hottest year on record, according to HadCRU). Note that the residual for 1998 is the highest in the modern global warming era; el Nino caused a large positive (warm) natural variation.
Sometimes a large volcano explodes, injecting massive amounts of stuff, including sulfates, into the atmosphere. If the explosion is big enough, and blows material high in the air, that material can disperse worldwide. Sulfates tend to form aerosols, tiny particles that are reflective, blocking some of the incoming sunlight from reaching earth’s surface; this tends to cool the surface. It takes a few years for the sulfates to settle out of the atmosphere, so large volcanic eruptions tend to cool the surface for a few years. The last big volcanic eruption was the explosion of Mt. Pinatubo. That’s why 1992 and 1993 were cooler; Mt. Pinatubo caused a negative (cool) natural variation.
These are just two of the factors that can lead to natural variation in global temperature. But the thing about these natural variations is that they’re only temporary. Mt. Pinatubo didn’t get rid of global warming, solving our climate crisis; it only cooled the planet for a few years. El Nino didn’t send global warming into a tailspin, hurtling us toward fiery death; it only warmed the planet for a year or so.
We can get an idea of the typical size of natural variation by computing the r.m.s. value of the residuals (the standard deviation). The standard deviation of the residual variation from 1975 to 2006 is 0.09oC. This is the typical deviation of global average temperature from its global-warming trend, but individual deviations can be larger or smaller. Normally, most residuals will be within 
The present global warming trend is for global average annual temperature to increase by 0.019oC every year. In addition, we expect up to 0.18oC of natural variation, which can be up or down, but is generally unpredictable. Given that the natural variation in one year is nearly ten times as large as the trend in one year, the idea that global temperature must rise and fall on an annual basis with each little rise and fall in CO2 level is — to put it politely — folly.
The dangerous thing about global warming is that it is persistent. The natural variations are sometimes positive, sometimes negative, but on average the ups cancel the downs and the net effect is zero. The trend, on the other hand, continues inexorably. A small trend of 0.019oC per year, becomes 0.19oC per decade, becomes 1.9oC per century. So when we look at the average temperature over many years, we’ll notice a steady upward trend. In fact, here’s the temperature plot with annual averages (as before), and I’ve added 5-year averages as well:
It’s worth noting that during the modern global warming era, each and every 5-year period shows a higher global average temperature than its predecessor.
The current trend rate is a “mere” 0.019oC per year. Unfortunately, over the next century, as greenhouse gases continue to increase and feedback mechanisms in the climate system kick in, that rate is likely to increase.
55 responses so far ↓
Tim // February 20, 2007 at 5:30 pm
How dare you bring real science to this discussion! :D - Tim
inel // February 20, 2007 at 5:50 pm
This is such a clear visual explanation of the difference between the red line trend in your first diagram and the residual black dots in your second diagram. Thanks. I do hope Brit and Grit look at your graphs and understand them.
A 10-second video separating the small-but-persistent temperature increases caused by human activity from the unpredictable natural variations in global average temperature would be great to show students, especially with annotations for the one-off impacts of el Niño and Mt. Pinatubo. YouTube, anyone?
I really do hope that Brit and Grit will read your post and try to understand the reality of global warming instead of deliberately spreading confusion.
Kevin Jaeger // February 20, 2007 at 6:01 pm
Nice graphs, and obviously the point about natural variation is a valid one, but starting a graph at 1976 is exactly the kind of data cherry picking that undermines confidence.
Try rewriting your post using data from 1940-1975. Is the trend there anthropogenic too?
[Response: The trend from 1945 to 1975 is indeed antrhopogenic, but of a different kind. The (very slight) cooling was the result of man-made aerosols from industrial activity; these were severely curtailed in the 1970s by law because they're responsible for acid rain.
I'm not cherry-picking, I'm making the presentation more comprehensible by restricting myself to a period during which the trend is approximately linear. Over the 20th century greenhouse gas forcing has become ever stronger, aerosol forcing both waxed and waned, and solar forcing appears to have increased slightly in the early part of the century but shows no trend since about 1950. This has led to a pattern of changes, but it's during the last 30 years or so that greenhouse gases have overwhelmed other factors, leading to the period from 1975 to the present being the "modern global warming era." This post gives some of the details.]
britandgrit // February 20, 2007 at 7:53 pm
Hi Inel,
The Brit and I read tamino’s blog on a regular basis. He makes a very good case for his point of view, and has always been calm and polite in our discussions. However, I still have my doubts as to the validity of the data, and would point out that this whole post is based on the assumption that greenhouse gases are causing the assumed temperature trend. You have to keep in mind that the base data which is averaged to get the “global average,” are “corrected” to account for local conditions, and “weighted” to account for areas where insufficient information is available. Considering the tiny variations we are talking about, until tamino gets around to presenting the raw data, explaining how it is corrected, and finding a way to reassure me as to why the areas of the world showing the highest warming are those that have the scantiest data, everything else is moot.
[Response: You can get the raw data from GHCN. They make available both the adjusted, and the unadjusted data, and by the way, the adjustments that have been made are for U.S. stations only, and the procedure is well documented in Hansen et al. and references therein.]
the Grit
jre // February 20, 2007 at 8:24 pm
I read the post to which you refer.
Wow.
I was stunned by how bad, on how many levels, it succeeded in being. The britandgrit post is completely free of information — no; scratch that. It is rich with negative information, to the point where I had to ask if it is possible that the author knows less than nothing about his chosen subject. Couple that with an abrasive, supremely arrogant style of argument (if that’s the word), and you have … well, a real steamer.
Then a happy thought occurred to me. If that p0st had never been written, then neither would the present one have been. From this rich fertilizer, you seem to have grown a rose.
Steve Bloom // February 20, 2007 at 8:38 pm
Actually, Grit, I suspect you might be happier with the global trend in melting glaciers, since they’re not subject to fakery. Of course they don’t watch every single glacier all the time, and it is known that some glaciers are expanding slightly (since precipitation and temperature are not coupled), so I’m sure you can find some way of wriggling out of that one too.
britandgrit // February 20, 2007 at 9:57 pm
Hi tamino,
Thanks. I’ve been looking for that for awhile now.
jre, basically I have given up discussing the science, since that has been conscripted for political purposes. However, if you wish to make the discussion personal, kindly take it to our blog so we don’t upset tamino.
Steve Bloom, I recently found some interesting information on that, http://britandgrit.wordpress.com/2007/02/14/al-gore-wrong-again/
Excuse me for not adding the text-link html, it’s been a hectic day with no signs of slowing down :) However, the articles I link to cast much doubt on the “globalness” of glacier melting, and suggests that instances where glaciers are retreating have been cherry picked for presentation for propaganda purposes. As I see it, the wriggling out is on the side of Global Warming proponents, who go to great lengths to silence their critics. I’ve also written about that. Why they should be so afraid to face scrutiny of the science behind global warming, I would think, should make everyone take another look at it.
Once again, thanks tamino. You are always welcome on our blog, and we value your contributions on this topic. Oh, and I believe I may have slipped up somewhere and assigned you the male gender. Since I don’t recall you stating this, my apologies.
the Grit
[Response: I am indeed male, as is the character from whom I took my pseudonym (the hero of Mozart's opera "The Magic Flute")]
inel // February 20, 2007 at 11:32 pm
Hello the Grit,
Nice to hear from you at tamino’s place.
Yes, tamino is a real gentleman. In fact, I respect his words and those of all other scientists and engineers who have a good sense of humour and are calm, polite, knowledgeable, tolerant, collaborative, supportive of their peers, eager to explain their points in detail, keen to answer questions no matter how ordinary, and able to refine their own conclusions in response to more appropriate data.
All the most competent and personable engineers and scientists I have been taught, hired and mentored by, as well as those engineers I have hired, taught and mentored myself in a number of countries have exhibited similar traits.
Of course, scientists and engineers are naturally sceptical, i.e. we question everything that matters to us until we are comfortable with our own judgment based on sources we trust. At some point, though, each of us has to decide who and what he or she trusts.
There is no point in being unnaturally sceptical, except as a game intended to provoke people to respond, thus distracting them from more useful endeavours and possibly earning yourself greater kudos or cash at the same time. If you trust no-one, then it’s up to you to simply go to the source data and verify it for yourself if you are so keen to disprove the minutiae.
When you cannot see the wood for the trees you need to be careful if you choose to sharpen a few more sticks to poke in someone’s eye. (I am about to don protective goggles … hold on … 8-) … ahhh, that’s better.)
What you fail to see in your games is that what you choose to declare as moot—i.e. a hypothetical case that exists only in our heads as a concept for playful or antagonistic discussion in our ivory blog towers—is actually a real and valid concern for members of the public who want to act now to combat climate change and ensure as healthy a future as possible for our children and grandchildren.
John L. McCormick // February 21, 2007 at 1:28 am
Britandgrit,
You are both??? wasting your time on this Open Mind blog.
Get yourself an agent and book contract. Write up your certain knowledge that greenhouse gases are not causing the assumed temperature trend.
That would make the NYT best seller list for months. The press would be all over you guys?? proving several thousand international scientists wrong.
Then, go for broke. Make a movie…call it “An Indefensible Lie”. Do world speaking tours and get awards…even an Academy Award and Nobel prize.
Then, you could be satisfied the world is listening to you(s).
John McCormick
[Response: I understand your frustration. But I prefer a more genial dialogue. Remember that Brit and Grit represent many of the fears, doubts, and frustrations of a lot of people. The more we learn to address their doubts with reason, the better we'll be able to motivate the public to act on the issue of global warming.]
Kevin Jaeger // February 21, 2007 at 2:04 am
“The trend from 1945 to 1975 is indeed anthropogenic, but of a different kind. The (very slight) cooling was the result of man-made aerosols from industrial activity; these were severely curtailed in the 1970s by law because they’re responsible for acid rain.”
This is truly an astounding statement by any measure. If you wonder why people treat global warming prognostications with some skepticism, you might want to ponder just how much scientific uncertainty got assumed away in those two sentences.
To accept that, one has to accept:
1) We have somehow measured global atmospheric aerosols
2) We are able to discern the anthropogenic component.
3) Reasonably reliable measurements existed from the 1940s to present
4) The acid rain laws of the 70s reduced anthropenic aerosols not just in North America and Western Europe, but also in the communist countries and Asia - resulting in a global reduction.
5) The effect of aerosols on the climate are sufficiently well understood that we can say the mid-century cooling was anthropogenic, and that the cooling period was brought to end by acid rain initiatives.
All this, while even the IPCC categorizes the scientific understanding of aerosols as “Very low”.
Do you think there’s any chance you’re making assertions unsupported by our current scientific understanding, Tamino?
[Response: My statement represents the concensus view of climate scientists working in the field; of course there's a chance it's not correct. But the rise in anthropogenic sulfate aerosols due to industrialization during and after WWII is just about undeniable, especially given the fact that acid rain (certainly a result of sulfates) became a big enough problem to motivate environmental legislation. And sulfate aerosols are definitely reflective; the cooling effect of volcanic eruptions testifies to that. The industrial activity of Asia in the post-war era simply can't compare to that of the U.S. and Europe; only now are the CO2 emissions of China becoming comparable to those of the U.S., despite the fact that their population is well over a billion people.
The implication that because we don't have precise measurements of aerosol concentrations in the post-war era, we can't possibly draw valid conclusions about their existence, increase, origin, or effects, is classic denialist sophistry. My assertions may be in error, but they are certainly supported by current scientific understanding.]
CraigM // February 21, 2007 at 2:06 am
That was a good piece Tamino. I’ve read a few of your blogs recently. You have a real talent for communication. I’ve learnt to keep an eye out for your comments over at realclimate. Keep up the good work.
Kevin Jaeger // February 21, 2007 at 3:30 am
Denialist sophistry??????
By acknowledging the limits of what we know versus what are plausible theories consistent with climate models - this is denialist sophistry???
I am constantly taken aback at how climate scientists oversell theories as scientific fact.
Just to put in perspective what the IPCC calls “very low” understanding this notorious site specializing in denialist sophistry describes the effect of aerosols like this:
“Scientists have much to learn about the way aerosols affect regional and global climate. We have yet to accurately quantify the relative impacts on climate of natural aerosols and those of human origin. Moreover, we do not know in what regions of the planet the amount of atmospheric aerosol is increasing, is diminishing, and is remaining roughly constant. Overall, we are even unsure whether aerosols are warming or cooling our planet.”
Though clearly the “direct” effect is cooling. Which denialist site is that?
This one:
http://earthobservatory.nasa.gov/Library/Aerosols/aerosol.html
tamino // February 21, 2007 at 3:45 am
No it isn’t. But you’re not fooling anybody, pretending that’s what you meant. Your implication was clear: that because we don’t have precise measurements of aerosol concentrations in the post-war era, we can’t possibly draw valid conclusions about their existence, increase, origin, or effects. And that is not only denialist sophistry, it’s classic.
Dano // February 21, 2007 at 4:53 am
Another classic:
I am constantly taken aback at how climate scientists oversell theories as scientific fact.
Do share, Kev, which scientists do so.
Please provide an example, explain the theory, and show where the theory is substituted as fact.
I’ll patiently await your reply.
Best,
D
Steve Bloom // February 21, 2007 at 10:08 am
Grit, here’s some actual glacier data for you. BTW, since local climatic conditions vary so much, there certainly are some of glaciers that aren’t losing much mass and/or are static, and even a very few that are advancing. Most are in retreat.
Regarding Greenland, I notice that in the article you linked the main author of the study said, “Future warming may lead to rapid pulses of retreat and increased discharge rather than a long, steady drawdown.” I have to say that sounds like a prediction of continued loss, which is unsurprising given the more detailed description of what’s going on here.
Alan Woods // February 21, 2007 at 11:03 am
So tamino, you are saying that you might be wrong, but for the right reasons. And Kevin might be right, but for the wrong reasons?
And for that you roll at the intellectually barren ‘denialist’ tag. As I’ve said before - you’ve chosen the wrong name for this blog.
[Response: I admit I could be wrong. But the accusation that I'm "making assertions unsupported by our current scientific understanding" is as patently false as the original accusation that I was cherry-picking. It's part of a very thinly veiled attempt to throw some dirt on global warming science in general. Then, after denying what is the *standard* scientific concensus regarding the mid-century cooling as though it were some sort of crackpot invention of my own, and in very snide fashion, Kevin attempts to claim the highest motives. That's insulting.
His motive is crystal clear: he came here to pick a fight. He can take it elsewhere; bickering is pointless. As for the title of this blog, it's also an entrance requirement.]
reasic // February 21, 2007 at 4:09 pm
Kevin,
I think your latest quotes misrepresents the message of the website you linked. Your quote ended with this sentence:
When I went to the site, the first thing I saw was this sentence, which was to the right a bit, and in very large, bold print:
Then, in a later paragraph, I found this:
Clearly, the intent was not to say that scientists have no idea what effect aerosols have on the climate.
I’ve also looked at the newest IPCC report summary for the doubts about the effects of aerosols that you’ve mentioned, and I couldn’t find anything. I did, however find this:
While it is admitted that aerosols are “the dominant uncertainty”, it is also stated that aerosols are much better understood than they were at the time of the Third Assessment Report. The science of climate change is continually improving as more data becomes available. Are you quoting a previous report by the IPCC? If so, that might no longer accurately represent the IPCC’s views.
Andrew Dodds // February 21, 2007 at 4:16 pm
The Grit -
Saying ‘basically I have given up discussing the science, since that has been conscripted for political purposes. ‘
By this statement, do you mean that every scientist in the field is deliberately skewing his or her results to favour AGW? That’s a pretty sweeping statement to make.
To take an example - around 5 years ago, there was a widespread fear that increased meltwater in the North Atlantic could shut down the Gulf Stream. Now, further research has shown this to be very unlikely, and this result largely accepted by the scientific community. Yet according to your logic, any research suggesting that a disaster was not going to happen should have been suppressed - so what gives?
Surely these scientists should be cast out for failure to be sufficiently doomerish!
Or is it simply that you dismiss as ‘politicised’ and science that comes to conclusions that you don’t like?
inel // February 21, 2007 at 7:13 pm
Hello Andrew Dodds,
The reason I responded as I did to the Grit after he said:
basically I have given up discussing the science, since that has been conscripted for political purposes
is that he is not going to be persuaded by science, and I am not going to discuss politics.
So the only things left for me to highlight are:
* the traits of rigour, reasonableness, contribution and collaborative independent thinking that garner respect from me for the world’s climate scientists
* the fact that any decision to remain obstinately sceptical in the face of an overwhelming case for GW—i.e. being a doubter on an unequivocal matter—really depends on how an individual makes an informed judgement
* denial of the connection between A and GW in AGW (!) makes me wonder whether that individual has the courage to revise their own judgement when new data arises to reinforce the modelled, predicted, observed, reported and widely accepted situation.
I rediscovered a good quote this afternoon from Colin Prentice, Professor of Earth System Science, Bristol University (one of the scientists who took part in the NERC debate earlier this year) that summed up my thoughts when I wrote to the Grit yesterday.
inel // February 21, 2007 at 7:16 pm
Whoops! I nearly burnt the sausages just then, but the quote I referred to is here.
britandgrit // February 21, 2007 at 7:53 pm
Hi all,
Andrew, let’s start with the last first since I can see it while I type. If you followed the political side of this, you’d find that the IPCC reports are edited by political representatives of many governments before publication. In one of my posts I linked to an article with quotes from some of the scientists saying they were harassed and badgered by IPCC officials to come to the expected conclusions. I’ve found other reports of similar activity occurring at many universities. There was at least one case where a researcher was forced to modify the language in his paper to have a more forceful verification of Global Warming before it would be published. You may have noticed that for the latest IPCC report the summary was written before the report was completed. While anyone should find this suspicious, an IPCC official explained that anything in the report which did not match the summary would be changed. You should also note that not every scientist is supporting AGW. There are a great many who flat out deny many things about it. However, their voices are shouted down by politicians, the press, and others who stand to profit if AGW is accepted. Really, if the facts are so clear, why silence the critics? As to the example you quote, then why are predictions of great sea level rises still included not only in the latest IPCC Summary for Policy Makers, but also being cited by the politicians using AGW (that’s a lot easier to type, thanks) to further their own goals? Why aren’t scientists rising up to point fingers of shame at this convenient lack of publicity?
OK, who else called my name?
Ah, Steve. There is a post on our blog that shows glaciers in India are not melting. That’s 700+ over a fairly large area. Considering that the reports of glacier melt are only based on the very small sample being studied, at best, it calls for more study, not a major change in the lives of everyone on Earth. As to the quote you point out, the key word is “may.” Hardly the basis for the drastic changes the politicians are calling for.
Next is John. That would be “the Grit.” I share a blog with my partner from England, the Brit. We find the cultural differences and similarities we discover while conversing through the blog medium keep us interested in the process.
While I would love to have the opportunity to follow your suggestion, I don’t have the connections the Champion of Global Warming does. Perhaps if I had inherited a fortune from growing tobacco and flunked out of graduate school, things would be different. (sorry tamino, but I can’t resist) John, if you would like to continue this without a moderator, come visit. I post on GW frequently and all views are welcome.
Which brings me to inel. We agree on tamino. However, having been at various times an engineer and a computer scientist, which must be why I am so skeptical, I don’t see why my concerns bring such a fanatical response. Surely, if the science is so clear, settled, and universally accepted, rather than calling people who ask questions or point out apparent inconsistencies names, it should be a simple matter to demonstrate where they are incorrect? This is an excellent reason to sharpen another stick.
As to who we should trust, I can easily reply that it should not be the United Nations, politicians, or scientists who are either under peer pressure to conform or stand to gain financially from reaching a certain conclusion.
As to being unnaturally skeptical,as you pointed out, it’s my nature. Besides, considering the stakes we are playing for, it would seem prudent to question every tiny detail, examine and reexamine every tiny bit of evidence, question and test every assumption, until it is all as well understood as humanly possible. I would think that the millions, possibly billions, who will live or die based on the world making the correct decision, deserve at least that. Oh, and don’t forget, assuming that AGW is real and making the changes our politicians are putting us on the path of, will kill millions of people.
tamino, thank you for the chance to orate. You are a scholar and a gentleman.
the Grit
John // February 21, 2007 at 11:56 pm
May i raise another question?
What comparative advantage would adaptation have vis a vis mediation? If we can all accept for the moment that AGW is real, then why shouldn’t we wait, from financial (future vs. present cost), scientific (assumption of further increases in human knowledge, computer power and human cultural awareness) and mathematical (discount rates, wealth creation and enhancement of life and knoweldge contribution from currently poor societies) points of view?
inel // February 22, 2007 at 1:16 am
Hi John,
The Stern Review on the Economics of Climate Change gives a comprehensive independent assessment of the economic impacts of climate change, and how we deal with it through adaptation and mitigation, from an international perspective.
On this British government Treasury page you can find PDFs of the Full Report and Executive Summary from October 2006 as well as three documents from February 2007 on more recent Reflections and Responses
A: The case for action to reduce the risks of climate change;
B: Value judgements, welfare weights and discounting: issues and evidence;
C: Building an effective international response to climate change
If you are not interested in the full PDFs but just want to read the first two pages of the 27-page Executive Summary, I have posted the content here.
Steve Bloom // February 22, 2007 at 2:27 am
Well, Grit, I did a bit more checking. I couldn’t find any specific reference to 700+ Indian glaciers on your blog, but the Hindustan Times article you seemed to base your opinion on did have some specific claims I could follow up on. I checked one of them:
“Maintaining that the glaciers are undergoing natural changes, witnessed periodically, he said recent studies in the Gangotri and Zanskar areas (Drung- Drung, Kagriz glaciers) have not shown any evidence of major retreat.”
Hmm. A quick google of Gangotri found this article in today’s Times of India (quoting):
“scientist from garhwal university recently published their findings in current science that the 260 sq km gangotri glacier was shrinking at a faster rate than before. they stated that from 1936 to 1996, the glacier had receded by 1,147 metres, and it had retreated more than 850 metres between 1971 and 1996, against a total of 2,000 metres in the last 200 years. this phenomenon has set alarm bells ringing among geologists, who have warned that urgent steps be taken to tap the increasing amounts of water going wasted into the sea.”
This seems somehow more specific than the one you quoted in that it refers to an actual study with actual data. I traced the reference back to Current Science, which seems to be the major Indian scientific publication, and unsurprisingly it’s loaded with research on Himalayan glaciers. See e.g. this paper from last month (quoting the entire abstract):
“The Himalayas possess one of the largest resources of snow and ice, which act as a huge freshwater reservoir. Monitoring the glaciers is important to assess the overall reservoir health. In this investigation, glacial retreat was estimated for 466 glaciers in Chenab, Parbati and Baspa basins from 1962. Expeditions to Chhota Shigri, Patsio and Samudra Tapu glaciers in Chenab basin, Parbati glacier in Parbati basin and Shaune Garang glacier in Baspa basin were organized to identify and map the glacial terminus. The investigation has shown an overall reduction in glacier area from
2077 sq. km in 1962 to 1628 sq. km at present, an overall deglaciation of 21%. However, the number of glaciers has increased due to fragmentation. Mean area of glacial extent has reduced from 1.4 to 0.32 sq. km between the 1962 and 2001. In addition, the number of glaciers with higher areal extent has reduced
and lower areal extent has increased during the period. Small glaciarates and ice fields have shown extensive deglaciation. For example, 127 glaciarates and ice fields less than 1 sq. km have shown retreat of 38% from 1962, possibly due to small response time. This indicates that a combination of glacial fragmentation, higher retreat of small glaciers and climate change are influencing the sustainability of Himalayan glaciers.”
The lesson here would seem to be that basic fact-checking before accepting unsubstantiated claims is a good thing. Unfortunately, a quick google would seem to indicate that the Hindustan Times article has been taken on faith all over the wingnut blogosphere. Imagine that.
Kevin Jaeger // February 22, 2007 at 2:58 am
Dano - you want examples of overselling climate change theories? The examples are too many to mention and I won’t test our host’s patience, but I’ll give you one example funded by my tax dollars:
http://adaptation.nrcan.gc.ca/pdf/1d1c33dfe37544f8be8ab1434d8da736_e.pdf
“Response strategy to maintain shipping and port activities in the face of climate change: reduced water levels in the Great Lakes / St. Lawrence Seaway ”
Suffice to say climate models do not have the skill to predict reduced water levels in the St. Lawrence Seaway due to greenhouse gas emissions. No one can demonstrate such precise predictive powers on a regional level - yet they are carrying on as if they could.
Poking around the government of Canada web site you can find, if you’re interested, province-by-province projections of temperature and precipitation for each of the four seasons in the year 2080. They can’t predict that either.
John // February 22, 2007 at 4:49 pm
I have read the Stern report. I would refer you to Indur Golkany’s The Improving State of the World, recently published. His is an original IPCC contributor, so his thoughts are appreciated. Mediation vs. adaptation are subjects of which he is knowledgable, so look beyond his tie to Julian Simon, Cato, etc., if you find those ties objectionable.
Thus my question remains.
John // February 22, 2007 at 7:00 pm
Dano; I have to agree with kevin. GCMs, their interplay and IPCC’s, et al, over reliance upon them stirs one to disbelieve and therefore attempt to discredit them. We and our computing power are simply no match for the real world, aka the climate.
John Cross // February 22, 2007 at 8:49 pm
John: two comments.
First, in regards to adaptation vs mitigation. While we may be able to adapt, there is no clear case that all the necessary parts of the ecosystem will adapt with us. For example, 1/3 of human nutrition is due to pollinator bees and there is nothing to say that bees (which seem already on the decline) will increase or decrease under global warming scenarios. Thus it would seem that some mitigation would be in order.
In regards to your comment about computing power and the real world, that is something I am somewhat familiar with. In fluid dynamics there is no way for us to predict the motion of an atom through a turbulent flow - even for a couple of centimeters. Yet with limited computing power we can produce very useful results. To test your confidence in computer models that approximate the real world, think about that the next time you are boarding a flight.
inel // February 22, 2007 at 9:56 pm
Hello John,
I have written my answer to your question:
and tried to explain why I suggested you refer to the Stern Review for at least some of the answers to your many questions in my post here.
It is obvious that you already knew a lot more than I when you posted your rhetorical question. I was just trying to be helpful by offering you the best place to start looking for answers.
I am not an economist, but I am aware that it is possible to make numbers on a spreadsheet behave in various ways depending on one’s viewpoint and priorities which determine the approach taken with respect to costs (including opportunity costs), investments, timescales, ROI, and so on.
The bottom line for me is that the longer we wait to tackle climate change, the worse the potential impact and the more expensive the resulting damage and recovery operation … and if we wait so long that we wake up one morning and realise we have missed the window of opportunity to tackle climate change due to our own selfishness and greed, we will have adaptation costs (and probably psychological issues) to deal with that make today’s grumbles about lifestyle changes pale into insignificance by comparison.
nanny_govt_sucks // February 22, 2007 at 11:57 pm
I wonder if, instead of just saying “consensus” you could actually point to the scientific study or studies supported by a majority of climatologists that show that mid-century was caused or shows compelling evidence that it was caused by anthropogenic sulfate aerosols. Thanks.
Dano // February 23, 2007 at 12:19 am
Kevin:
Poking around the government of Canada web site you can find, if you’re interested, province-by-province projections of temperature and precipitation for each of the four seasons in the year 2080. They can’t predict that either.
Can you explain to us how you know what the temperature will be in 2080 and how you know that model output has those temps wrong?
Besides, drawing on my limited and long-unused French, this is not an example of overselling a climate theory. This is a paper outlining what to do in case x happens. I hope this is not the best you can do.
Best,
D
Hank Roberts // February 23, 2007 at 12:43 am
Let’s try your words in that search tubes thingy
http://scholar.google.com/scholar?q=mid-century+cooling+anthropogenic+sulfate&hl=en&lr=&scoring=r&as_ylo=2002
tamino // February 23, 2007 at 1:07 am
For those who are genuinely interested in the history of anthropogenic aerosols, some papers that deal with the topic are:
Johns et al. 2003, Climate Dynamics, 20, 583.
Myhre et al. 2000, Atmospheric Environment, 35, 2361.
On another topic:
Lately the discussion has devolved into argument, mainly driven by closed-minded skeptics who would not be persuaded if God Himself came down from heaven to show them the light. This is not the place for that. If that’s what you want to do, fine; take it elsewhere, there are tons of sites that will accomodate those wishing to beat the dead horse. Further contentious comments will simply not appear here.
stewart // February 23, 2007 at 1:43 pm
Tamino: a 3-part post.
1 (the suck-up).
I enjoy this blog, it’s nice to have a decent presentation of the science that complements other sites such as RealClimate.
2 (the quote).
If we claim to approach this in a scientific and not polemic/ideological fashion (there’s other places for that), then evidence is paramount. T.H. Huxley, when asked what evidence would change his mind about evolution, famously replied ‘A rabbit fossil in the Cretaceous’.
3 (the proposal/swerve).
Following Tamino’s last comment, a question that might help separate science-based from other commentors (Tamino, would you consider this as a thread?). For those who don’t accept the evidence as convincing for the anthropogenic effect, what would change your mind?
Similarly, for those who do accept the scientific consensus, what evidence would make you an agnostic?
Preposterous answers (’an ice-free north pole year round’) can give an idea how seriously someone’s opinions should be regarded. Me? I’d say a decline in atmospheric CO2 levels for 3 years, high northern cooling in the absence of an ozone hole, or a decline in night-time temperatures would all be strong evidence against AGW. However, as even the tobacco scientists are getting on board, I don’t expect any of these things to happen.
Cheers,
Tim // February 23, 2007 at 2:57 pm
Stewart,
For me, that exercise is pretty straightforward. I really don’t have a dog in this fight. However, if we’re talking anthropogenic effects, then it behooves me to act accordingly.
I see lots of data that suggests that we should be doing something. The question remains how immediately we must act.
At the same time, I will say that when I see some of the same people lining up against AGW that I see taking extreme positions in other areas, I start to get suspicious. For example, if Rush Limbaugh thinks it’s bogus, then I’m inclined to think that it’s true–regardless of the subject. He has simply lost too much credibility with me to be considered a reliable source of information.
I strongly suspect that the “anyone but Al Gore” crowd is probably responding against AGW because of Gore, as much as they are responding to anything about the science. - Tim
tamino // February 23, 2007 at 3:58 pm
I don’t think I want a general “what would change your mind” discussion, because that would bring out the obstinate skeptics, who would be sure to pepper their comments with the same-old-same-old folly and insults. I want this to be a friendly place where those who want to know more can feel safe to ask questions or express (honest) doubts, without fear of being “jumped on” either by skeptics or believers.
But there’s certainly merit in the question. It spurs us to examine what part of our belief is rooted in objective information, and how belief might change if information changes. So, I’ll think about how the question might be framed in a way which avoids the almost inevitable flood of invective that unfortunately characterizes discussion on this topic. Ideas?
Neil Craig // February 23, 2007 at 4:13 pm
You told Kevin regarding starting your graph with 1975 “I’m not cherry-picking, I’m making the presentation more comprehensible by restricting myself to a period during which the trend is approximately linear”
Sorry but you are. You can only get a straight line by restricting your data. Had you restricted your data up to 1998 (as the IPCC in 1998 obviously had to) you would have had a steeper straight line which fitted rather closer to the predicted 3 C rise by 2100. Your flatter line showing a 0.5C over 32 years implies, if continued, about a 1.5 C rise by then - neither catastrophic nor even unprecidented.
Good statisticians would, to check the validity of their predictions, instead remove the data of statistical anomaly which the theory was first based on since that is already selected data. This means they would use only the data from 1998 to present & the only straight line which can reasonably be drawn there is downwards. This does not prove cooling, since I would be putting more weight on limited data than reasonable, but that is what you have done & picked the data purely because to “make the presentation” you want.
[Response: your entire argument is so full of holes, it's impossible to take you seriously. For example: if you'd bothered to run the numbers you'd have found that even if we start in 1998, the trend is still upwards, not downwards. But it's not statistically significant, which is no surprise with only 9 years of data, a 2-sigma error range nearly ten times as large as the annual trend, and the first year (1998) showing the strong effect of a strong el Nino. Also, restricting to the time period 1975 to 1998 gives a LESS steep slope, not "a steeper straight line which fitted rather closer to the predicted 3 C rise by 2100."
The trend from 1975 to the present IS statistically significant -- absolutely no doubt. And I chose that time interval, not only because the trend during that time period is approximately linear, but because this is the time during which greenhouse-gas forcing has dominated other forcings, making it the "modern global warming era."
Yours is precisely the kind of not-even-poorly thought out argument that is nothing but a waste of time.]
John L. McCormick // February 23, 2007 at 4:51 pm
Tamino, you have a real challenge on your hands if you expect the next or any future questions to bring out the best among all commentors.
An open blog to some is an invite to the keg party. Without merciless moderating it can become a mob-scene of uninhibited strangers. And one can only imagine the bile you and RC moderators have to delete on an hourly basis.
Perhaps a few topics that are less prone to confrontation (and I do not imply you are offering up discussions bound to start a food-fight) might raise the bar of civility and intellect.
For instance, sea level rise is a now-measured consequece of AGW; it will impact vital infrastructures like petrochemical storage and refinery capacity and power stations around the globe where those sites are at sea level. Ask the question: how would engineers respond to the challenge of defending the sites against storm surges and innundation or relocating them to higher ground.
Or, what is the industrial nations’ capability to meet the future global energy demand in a warming world.
And, the plight of downslope countries and municipalities dependant upon glacial melt runoff and reliable snow pack is becoming a recognized concern in many highly populated areas. How should the international foreign relations interests be engaged in that looming dilemma of lost water resources?…adaptation or MIGRATION.
Finally, how about a discussion on :
“the response to AGW is not only an environmental matter; it is an engineering and sociological challenge”.
I appreciate your interests are closely bound to the science of AGW but that is the minefield being cleared. What to do about AGW is the minefield being loaded.
John // February 23, 2007 at 5:52 pm
I am not a scientist, so I may be underweight in this class; nor am I a polemicist - I’d like to separate the science from the politics. However, I do have unbridled enthusiam for the human race and our ability to solve problems. Julian Simon’s point of view is preferred to the Erlichs’. So, with these admonitions in mind, I would be glad to stand down if my questioning of the process is offensive. I
f it is not, then: adaptation would imply that the sytem adapts as well as the constituent components. For example, wealth endows responsibility and concern. We in the industrialized, globalized, world are concerned about global warming; those living on less than $1 a day are not. It would seem therefore that our encouragement of their economic growth (and hopepful leapfrogging over our past errors) would bring them to similar levels of realization. It may also bring a few million more scientists into the foray, from the next generation, who may continue to find answers. Second, the system itself adapts. 1,200 ppm is an ideal growing medium for most C3 plants (& maybe bees…!). Plant productivity may continue to increase significantly. Increased efficiencies of drip, hydro, et al, water usage will allow better irriagation, tillage and so forth. Third, our knowledge factories continue to increase both in ability and in productivity - AGW questions of 1995 (IPCC 2) are more easily answered with today’s capabilities. Finally, the ‘unknown unknown’ always lurks beyond tomorrow. Yes, the earth may wipe us out with Gaian revenge, but I doubt it. You folks who know far more than I about the science of global warming will continue to arrive at solutions to questions we are only just now beginning to grasp.
So, mitigation vs. adaptation remains the question. Inel, the Stern report is a political answer. I am curious about scientific answers. I do not question GW or AGW. I question wheter we have even some of the answers. I question whether waiting may be preferable to jumping.
P.S. The fluid dynamics computational powers brought to bear in dealing with the challenges of subsonic commercial flight are orders of magnitude less than those required for global climate concerns; yet, I feel certain that each of you will grow to the challenge…
tamino // February 23, 2007 at 5:54 pm
On the subject of “what would change your mind,” Inel has posted on that topic. I look forward to seeing the discussion that ensues.
inel // February 23, 2007 at 5:55 pm
This is for stewart :-)
I would change my mind to think global warming were a topic best left to the realms of scientific research—not yet proven, not newsworthy, and certainly not worth worrying about—if … this were to happen.
inel // February 23, 2007 at 8:25 pm
My reply to John in response to his comment:
John // February 23, 2007 at 10:35 pm
To Tamino:
Did I read one of your comments to the effect that the 95% life eradication event of 250M years ago was a result of global warming? Surely you jest! There just may have been a rather large meteor in the neighborhood…
To Inel: lovely castle. My apologies for poor typing and grammatical miscontructs. I meant mitigation when I wrote mediation. I wrote vs. when I should have written ‘in conjunction with’. If we can emerge from the semantic clouds for just a moment, I am curious about the values of mitigation and adaptation scientifically, economically, and humanely. I am niether a heretic against nor a believer in AGW’s dire consequences for humanity and for the Earth. I am simply curious, intellectually curious. So, if we can get there, let’s go. If this blog is simply a soap box for chicken little, then let us know and we shall continue the search for intelligent life on this planet.
[Response: No, I'm not jesting. At one time most major extinctions were attributed to impact events, but it is now believed that only the K-T boundary (end of dinosaurs) extinction can be confidently fit into that category. The most likely reason for the end-Permian extinction is the collapse of methane clathrates, flooding the atmosphere with greenhouse gases and causing catastrophic climate change. Scientific American had a nice article on the topic a few months ago.]
Slioch // February 24, 2007 at 1:01 am
Thanks, Tamino, for your efforts. I was directed to your site by a similar thread in today’s Scotsman newspaper (http://thescotsman.scotsman.com/scitech.cfm?id=289422007#new
I made the following (edited) point in response to the claim that there has been no warming for the last five years:
“If this was the year 1990, no doubt we would have climate change sceptics telling us that global warming had stopped since 1983, since the temperatures are as follows (temperatures in degrees Celsius compared with 1961-1990 mean, from: http://www.cru.uea.ac.uk/cru/info/warming/ – click on “Comma-Separated Values”):
1983 0.177
1984 -0.021
1985 -0.037
1986 0.03
1987 0.179
1988 0.18
1989 0.104
Here again a period of little or no increase for several years follows the abnormally warm year of 1983, just as the abnormally warm year of 1998 has yet to be exceeded. In fact, both 1983 and 1998 were El Nino years, when large amounts of heat are released from the Pacific, causing a global increase in temperature of up to c.0.2C. See also CRU sheet 2 and look under “El Niño and La Niña” to see a graph of these effects in more detail.”
Steve Bloom // February 24, 2007 at 3:01 am
Um, John, I don’t know if there’s a soapbox involved, but the sky is definitely falling. This article also demonstrates nicely one of the ways that important conclusions can be drawn fron observed climate behavior, in this case confirmation that the pattern of warming is consistent with GHGs rather than increased irradiance.
inel // February 24, 2007 at 12:57 pm
Here’s another chance for you to see the castle, John ;-)
inel // February 24, 2007 at 12:58 pm
tamino, sorry I omitted my blockquote closure on my last comment after the word humanely
[Response: I changed it for you.]
John // February 24, 2007 at 6:10 pm
Inel
Nordhaus has done a much better job than I could of reviewing the economics of Stern. While Moncton may be a laugh, (be sure not to attend his non-event! ha!) Global Economics is less so.
Tamino; Thanks for the reference to falling clathrates. I am familiar with the ScAm article, too. It addresses the theory of ~26Myr ‘dieoffs’. I did not note a perspective on the Permian extinction. Irridium measurements globally are the basis for the theory, which of course is just that. Speaking of clathrate theory, a rather distinguished gentleman wrote ‘The Deep Hotbiosphere’ a short time ago. If the AGW alarmists really want to go off the deep end, have a read.
Steve Bloom: I read many of your comments and appreciate them, along with this entire blog. However, if you will notice just below your soles, you will note an ever so small box with the word soap worn away with the passage of time. No offense - just awareness.
John // February 24, 2007 at 8:22 pm
Inel: the WGII & WGIII are available currently and I have read them (if you dare to venture into the dragon’s lair, they are available at the junkscience.com site…). The Stern report was a Policy and Politics event, so comparing Golkany, a policy wonk, to Stern may not warrant as stern a hmmm as proffered. We here in the States (our group is one of financial analysts and economists) do not have the fervor of the European attitude; we are nevertheless, interested in the issue. You mom (& mine) may have been correct in suggested hillside realty. That however remains an economic and social issue (& an interesting anecdotal tie between us).
We remain uncowed by either theologians or heretics. Frankly, our interest lies in creating and protecting wealth for clients, cultures and humanity. Simon vis a vis Erlich (& Stern) will always be our origination point for discussion, with a firm commitment to the former. As an educator, you attempt to bring to fruition the possibilities of young minds. Therein lies the answer to each AGW question - with each new generation and within your own profession. Thank you for your efforts!!!
inel // February 24, 2007 at 11:00 pm
Hi John,
Thanks for reading my notes, and thank you very much for explaining your position. Does hmmm … come across as stern—wow! I use it as “I need to think about this …” Do you want to see what I think of Nordhaus’ article? (I wrote earlier today, but have not posted yet.) It might make you smile :-)
We may have more in common than you think: I remain uncowed by theologians and heretics and my interests are not that different from yours, though I am an engineer by profession, not an economist, as you can tell ;-)
I have visited junkscience.com and will do so again, but not to get copies of reports published by the IPCC, as I prefer to get a report directly from its source when possible.
FYI, the WG II and WG III reports that are currently available are the AR3 ones that were published in 2001; I wrote that I would prefer to wait until AR4 WG II and WG III SPMs and Technical Summaries are released by the IPCC in April and May 2007, because they will provide the latest assessment on mitigation and adaptation options, and those will better answer your questions. I realise the areas you ask about were described in the 2001 WG III SPM as Gaps in Knowledge and Section 24 included this cautionary remark:
guthrie // February 24, 2007 at 11:09 pm
Ahhh, so Slioch and Neil have turned up!
A friendly wave to Slioch and a thatrical boooo! to Neil.
John // February 25, 2007 at 5:55 pm
Good Afternoon, Inel,
Looking forward to your Nordhaus review, please share. I was under the impression that the junkscience WG 2 & 3 was for the press only, that Malloy released in a moment of weakness…
As an engineer, perhaps you can respond to the following. Current science, technology and business have no solution to AGW (short of such economic absurdities as reductions in output or lifestyles, increases in taxation and regulation, etc.). So, rather than bogging to the choir, as so many websites do, why not try to: a) find common ground with business, skeptics, etc.; b) pursue a thousand avenues of applied science which would continue economic growth for all (particularly those in the third world) while answering the AGW problems over the next century. Science has effectively defined the problem. There is no current, viable, solution. Science finds solutions. Let’s get on with it, rather than blather on about who knows what, who is apostate and why. There are no conspiracies in business or in the environmental movement (at least none that can matter). There are no bad guys. Its not about degrees of guilt, or shouldn’t be. We are all responsible for the problems. We can all contribute to a myriad of solutions. (If these queries are inappropriate for a blog such as this, I shall stand down, Tamino). In short, how can we continue to grow and be less messy in the process?
inel // February 27, 2007 at 12:36 pm
Good morning, John.
inel on Nordhaus on Stern is here ;-)
inel on GROCC, the Global Roundtable on Climate Change, is here.
Enjoy!
P.S. Where is your blog, John? You are welcome to carry on these business/engineering discussions elsewhere, and I am happy to visit your blog, and encourage others to do so, if mine doesn’t suit you.
Kelly O'Day // February 28, 2007 at 7:11 pm
Tamino:
Great post, thanks.
As a climate science absolute beginner, I have reproduced your charts in a Excel workbook link to help me understand your points.
I have very similar results, however, my original annual data is slightly different from your’s. My regression slope is 0.0175 versus your value of 0.019.
The residuals look similar as does the 5 year average plot. I can’t figure out the relatively minor discrepancies between my Hadley Centere data and yours. Could you take a look at my Excel workbook or send me your source data.
Thanks
Kelly O’Day
http://processtrends.com
Kelly O'Day // March 13, 2007 at 2:51 pm
Tamino
I have been fascinated with the 1975 Newsweek article on global cooling. Your post on Natural Variation got me to looking at the northern hemisphere trendlines.
link
My chart shows 4 subsets of the GISS’s 1880 - 2006 data. Newsweek had the misfortune of writing their article in 1975, just after the 1939 - 1972 downward trend ended.
I notice that the 1973-2006 trend is 0.054 F per year, compared to the 1880 - 1921 rate of 0.007 F per year. If we assume the 1880 - 1921 increase rate was early industrial revolution related, the 1973 - 2006 increase rate is 7.7 times as great!
I used Dr. Taylor’s change point analysis to caculate the change point years. Ar you familiar with CPA? As a mathamatician, do you think CPA is a valid way to analyze time series data?
Kelly O’Day
http://processtrends.com
[Response: I'm not familiar with "change point analysis," but the pages to which you link indicate that it's based on a number of methods including CUSUM analysis -- which I'm very familiar with, and which is a tried-and-true method. I haven't looked at change point analysis it in detail, but a preliminary view indicates that it's a sound approach to identify the "turning points" of trend. I general find the turning points by doing what I call a "multilinear fit," and the points I get are very similar to the ones you find -- easily within the expected errors. It's generally true in statistical analysis, that there are many different "roads" but they all lead to "Rome" (the same overall conclusion).
At first I thought your numbers were wrong! For one thing, you're using deg.F rather than deg.C, which is definitely not the scientific norm. Even at that, the trend you get is higher than I expected. But looking at all the data, it's clear you were using GISS data for *northern hemisphere meteorological stations*, which includes land but not sea. I generally use the global rather than hemispheric data, and use the GISS "land+SST" data to include the oceans, in which case the "modern global warming era" (from multilinear fit) comes out as 1975-present, and the rate as 0.0185 deg.C/yr (0.033 deg.F/yr). It well illustrates that the northern hemisphere has been warming faster than the southern, and that land has been warming faster than sea.
As for the 1880-1921 trend, using the same data I get 0.0038 deg.C/yr (0.0069 deg.F/yr), but computing the probable error range (including the effects of autocorrelation) this is plus or minus 0.0048 deg.C/yr (0.0087 deg.F/yr), so the error range is larger than the estimated value. So, we can't really be sure that it's a trend at all -- it may just be an expression of that natural variation.]
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