The weirdest millennium
Much research effort over the past years has gone into reconstructing the temperature history of the last millennium and beyond. The new IPCC report compiles a dozen reconstructions for the temperature of the Northern Hemisphere (including of course the original "hockey stick" reconstruction, despite opposite claims by the Wall Street Journal). Lack of data does not permit robust reconstructions for the Southern Hemisphere. Without exception, the reconstructions show that Northern Hemisphere temperatures are now higher than at any time during the past 1,000 years (Figure 1), confirming and strengthening the conclusions drawn in the previous IPCC report of 2001.
Fig. 1: Figure 6.10 (panel b) from the paleoclimate chapter of the current IPCC report (see there for details).
“Climate sceptics” do not like this and keep coming up with their own temperature histories. One of the weirdest has been circulated for years by German high-school teacher E.G. Beck (notorious for his equally weird CO2 curve). This history shows a medieval warm phase that is warmer than current climate by more than 1 ºC (see Figure 2). So how did Beck get this curve?
Fig. 2, modified from E.G. Beck (we added the green parts).
The curve is a fake in several respects. It originally is taken from the first IPCC report of 1990: a scan of the original is shown in Figure 3. At that time, no large-scale temperature reconstructions were available yet. To give an indication of past climate variability, the report showed Lamb’s Central England estimate. (Unfortunately this was not stated in the report – an oversight which shows that IPCC review procedures in the early days were not what they are now. We will post in more detail on the history of this curve another time.)
Fig. 3. The past millennium as shown in the first IPCC report of 1990, before quantitative large-scale reconstructions were available. This curve was based on Lamb's estimated climate history for central England.
But Beck did not stop at simply using this outdated curve, he modified it as highlighted in green in Figure 2. First, he added a wrong temperature scale – the tick marks in the old IPCC report represent 1 ºC, so Beck’s claimed range of 5 ºC exaggerates the past temperature variations by more than a factor of three. Second, the original curve only goes up to the 1970’s. Since then, Northern Hemisphere temperatures have increased by about 0.6 ºC and those in central England even more – so whatever you take this curve for, if it were continued to present, the current temperature would be above the Medieval level, as in the proper reconstructions available today. As this would destroy his message, Beck applied another fakery: he extended the curve flat up to the year 2000, thereby denying the measured warming since the 1970s. With this trick, his curve looks as if it was warmer in Medieval times than now.
When approached directly about these issues, Beck published a modified curve on a website. He changed the temperature range from 5 ºC to 4.5 ºC – but he shortened the arrow as well, so this was just cosmetics. He also added instrumental temperatures for the 20th Century at the end – but with his wrong temperature scale, they are completely out of proportion. (In fact his version suggests temperatures have warmed by 2 ºC since 1900, more than twice of what is actually observed!)
Beck goes even further: in a recent article (in German), he has the audacity to claim that his manipulated curve is right and the more recent scientific results shown by IPCC are wrong. And for years, he has offered his curve on an internet site (biokurs.de) that distributes teaching materials for schools, with support from German school authorities. It is quite likely that his fake curve has been shown (and will continue to be shown) to many school children.
29 May 2007 at 5:33 AM
the Chicken Little story has many variants. the one read to me as a child ends with Chicken Little, Henny Penny, and the rest going gaily into the den of Foxy Loxy never to emerge again - an unequivocal moral here: be silly and get eaten!
it is the climate change deniers who most use this kind of imagery these days, but it seems to me that they are the silly ones, and possibly more likely to get eaten by the fox in the end, time will tell
in the meantime, thanks again for your balanced and good natured reports
29 May 2007 at 5:50 AM
Thanks Stefan,
Congratulations on your recent Science article, which I read only a few days ago.
http://www.pik-potsdam.de/~stefan/Publications/Nature/rahmstorf_etal_science_2007.pdf
It worries me that we (i.e. our politicians) are not going to address the issue of climate change in time to avoid serious consequences. Institutions like the Wall Street Journal and people like Beck are not helping the issue.
What do you know about Beck’s backgraound and motivation? You mention that he is a school teacher. Does he have any qualifications in climatology or even scientific research? To me Beck’s diagram is a schematic, which although misleading as you suggest, is not a scientific graph.
It stikes me as odd that German school authorities accept Beck’s material. I assume you mean state (government) school authorities, rather than private school authorities. Have the school authorities been alerted to the questionable science behind his website?
29 May 2007 at 6:01 AM
Oh my, Beck also presents Gavin Menzies fantasies about the Chinese navy sailing around the North coast of Greenland in 1421.
29 May 2007 at 6:42 AM
I don’t really have as much knowledge about these things as you guys, but I would like to know more.
If there is insufficient data from the southern hemisphere to permit robust reconstructions of the earths temperature over the last 1000 years, is it possible that the southern temperature was a lot hotter than today and the global temperature has actually been reasonably consistent, just shifted from southern hemisphere to northern, possibly caused by the weakening of the magnetic field since Roman times or something that somebody like me wouldn’t know about?
[Response:This is very unlikely. As discussed in the paleoclimate chapter (chapter 6) of the latest IPCC scientific assessment report, model simulations reproduce the gross behavior of the Northern Hemisphere temperature reconstructions, including the anomalous recent warmth, as a result of a combination of natural and anthropogenic radiative forcing. The anomalous recent warmth is associated with the latter. These same simulations predict similar overall behavior for the southern hemisphere. The ‘null hypothesis’ would be that the southern hemisphere mean temperature would have a similar history. Some minor are likely to be observed, due for example to the greater thermal inertia of the southern hemisphere (more ocean surface) which damps the response to high-frequency forcing, and possible differential hemispheric surface temperature changes associated with variations in cross-equatorial heat transport (e.g. changes in the thermohaline circulation). -mike]
If the temperature at the southern pole is well below freezing, even with a rise in temperature of 5C, why would the ice melt or does water not freeze below 0C anymore? (Sorry if that sounds a little patronising, but I’ve asked this question of other people, several times and they tend to change the subject, probably because they don’t know the answer)
[Response:If I understand your question, you are wondering about why people worry about Antarctic melting? The answer is, this isn’t the worry, when we are talking about the vast majority of the continent, which as you correctly point out is well below freezing and will remain so for a long time. But the edges of the continent — in particular the Antarctic Peninsula in summer — can and do melt, but from above (warm summer and sunlight), and below (warm ocean).–eric]
29 May 2007 at 6:46 AM
Thanks, guys, for bringing this stuff to lay readers such as myself. I’m sure I’ve seen that 1990 IPCC graph used elsewhere, but can’t remember where. (I hope your future post on that graph will go into this in some detail.)
A question: in my neck of the woods, there’s a guy who talks about the Climate Audit all the time, and often sends me links to their latest posts. I’m no scientist, so a lot of their stuff is over my head.
How serious are their allegations about researchers not being transparent with data? Their latest crusade is to try to dent the IPCC’s review of the urban heat island literature by saying it’s just one guy [edited]. How valid is this criticism? Note that I’ve read the relevant bits in the IPCC WG1 report, but they’re trying to make an end-run around the IPCC by charging that its review of the UHI literature was biased. This sounds suspiciously like a conspiracy theory to me… Would you agree?
Sorry if this was off topic. Have you thought about compiling a FAQ of “best hits”?
29 May 2007 at 7:05 AM
Some questions.
Did the little ice age exist? Y/N
Did the Medival warm period exist? Y/N
[Response:See our glossary entries on the LIA and MWP. -mike]
Volatility. It looks from the graph that volatility of temperature has gone down. Is this an artifact because we have better measurements, or is another process going on?
Nick
29 May 2007 at 7:47 AM
#5
Urban heat island effects. I heard somewhere they compared temperatures with and without wind and found the same temperature (thus no UHI). My little quibble is whether there’s heat than can emanate from towns that is unaffected by air movements (eg radiation?) and whether that might affect the measurements.
Keep up the good work chaps.
29 May 2007 at 7:49 AM
Leading officials of the German Mining Chemical & Energy Union (IGBCE) have adopted the arguments propagated by E. G. Beck to justify the continued use of domestic lignite despite CO2 emissions that are nearly triple the amount per kWh of gas generation. Lignite surface mining is destroying natural landscape, fertile farmland, and human settlements such as our village of Heuersdorf. With the German economy now recovering from record postwar unemployment, CO2 emissions are again rising, making Kyoto fulfillment increasingly unlikely.
Anyone interested in the German lignite industry may want to consult my study on the topic: http://www.acidrain.org/pages/publications/reports/APC18.pdf
[Response: The IGBCE is really using Beck’s faked materials? Can you point me to sources for this info? If true, it’s incredible. But even the German daily “Die Welt” ran an editorial which stated that “biologist” E.G. Beck has proven that the CO2 concentrations were already above 420 ppm in the 1940s - this is his CO2 nonsense we posted about earlier. (And note how a school teacher is promoted to a scientist to make this sound credible.) -stefan]
29 May 2007 at 7:52 AM
It strikes me as yet another example of past variability being used to undermine the evident validity of GHG increase experiments.
I don’t read German so I’ve no idea whether he draws a direct connection between the cool period and the 30-year war. Could you possibly elucidate on this?
29 May 2007 at 8:14 AM
The millennium past is far, far, less weird than what we are seeing popularized in this one:
http://adamant.typepad.com/seitz/2007/05/dogs_cats_moonb.html
29 May 2007 at 8:30 AM
Where are the error bars on the opening graph?
29 May 2007 at 8:31 AM
Uh, that’s actually figure 6.10 (or actually actually, part of the figure)
29 May 2007 at 8:33 AM
Re #4 and Bobby’s question “If the temperature at the southern pole is well below freezing, even with a rise in temperature of 5C, why would the ice melt or does water not freeze below 0C anymore?”
The problem with Earth Science is that it is not simple as that. First the temperature in the Antarctic Peninsula, where melting is already happening, is not the same as that at the South Pole. Since the South Pole is at a greater altitude and latitude that the Antarctic coast it is much colder, and it is not the ice there that causes concern. The main worry is the Antarctic ice shelves which not only are on the coast but are floating in the sea. This means that, not only are they warmed from above by a stronger greenhouse effect, they are also warmed from below by an ocean which is being heated.
Another complication is that since they are floating, if the shelves do melt then they will not cause a sea level rise. However, it is thought that they are holding back the ice sheets which feed them, and if the shelves do collapse then the ice sheets will slide off the land into the sea and raise sea level. When this happens then the remaining sheets will be converted to ice shelves since the sea level rise will cause the grounding lines to retreat.
The main threat is from the West Antarctic ice sheet, which feeds the Ross Sea ice shelf, and is close to sea level. The rest of Antarctica is fairly mountainous and so, as you suggested, would require higher temperature to melt.
If the West Antarctic ice shelf melted then sea level would rise by about 7 m (20 feet), the same as would happen if the Greenland ice sheet melted completely. However, if the Greenland ice started melting and raised sea level by only 1 m say, that might destabilize the West Antarctic ice sheet. The consequent rise in sea level around the Greenland coast could accelerate the melting there!
If both the Greenland and West Antarctica ice sheets melted, then the subsequent 40 foot rise in sea level would have a devastating effect on most of the great cities of the world.
HTH, Cheers, Alastair.
29 May 2007 at 8:33 AM
And so why not post that one instead?
29 May 2007 at 8:43 AM
Nice work Stefan,
chaps like Beck do not make life easier.
@JBloom
No, as far as I understand Beck does not link climate change to the 30-year war. But in general, he argues that climate change is a natural proces and as such a positive issue. He is just a high school teacher, but it is important to understand that high school teachers in Germany are very smart; many of them are even smart enough to become part of our political establishment (a wee bit of sarcasmn). Any news from Stefans debate with Mangini in “Die Zeit”. IMHO it would be of interest for the English language readers.
29 May 2007 at 8:43 AM
Hi,
What does the large PS 2004 line represent, and how is it most commonly interpreted?
29 May 2007 at 8:47 AM
Hello. I was very surprised to learn that the southern hemisphere data is not included in global climate change models? i understand we can extrapolate to include it but that is not as robust as including it directly. I have always wondered why the southern hemisphere is not experiencing the same global warming that the northern hemisphere is. first of all, is this true? isn’t this a very big problem for modelling global warming? Please help me understand southern hemisphere climate change.
[Response:Of course the Southern Hemisphere is in the models - we’re talking here not about models but about reconstructions of past changes from data such as tree rings, ice cores etc. -stefan]
29 May 2007 at 9:02 AM
In addition to Alistair:
Sea water does not freeze at 0C. Pressure of the ice sheets should also have a signicant influence, or am I wrong?
29 May 2007 at 9:12 AM
If sea water gets diluted by fresh water freezing temperature in general should rise and to a certain extent produce a natural counter effect (more sea ice). Is this reflected in the models for seal level rise? Many thanks.
29 May 2007 at 9:14 AM
Beck may be smart but he’s no scientist. He’s lost in his own ideas & preconceptions (&unfortunately influencing others) while the ice melts. According to the June 07 National Geographic, the Greenland ice sheet is melting twice as fast as it was just 10 years ago.
29 May 2007 at 9:59 AM
Re 17
Hi Peter, I am not sure if I understand your question, but even if I did I doubt that I could answer it
However, I know a man that might.
If you go to Bob Grumbine’s FAQ “ he calculates that the Arctic sea ice will raise sea level by 0.4 mmm. I don’t think he calculates the effect of the Antarctic ice shelves but presumably they would be similar.
I don’t trust ice sheet modelers because I suspect that they ignore terrestrial heat flow, and the reduction in ice sheet friction when sea water floats ice sheets so reducing the normal force from the ice that remains grounded.
Re 18 In most cases the fresh water (in the form of ice/bergs) is removed by wind to warmer climes where it cannot refreeze. That remaining is soon mixed with the much deeper salty water so its freshness is lost.
29 May 2007 at 10:13 AM
Has anyone gone to Kentucky and seen the museum that puts the dinosaurs in with the people chronologically? School aged children in both Kentucky and Germany are being taught this stuff even in this “advanced” age in 2007. Beck is representative of what people do despite the best science.
29 May 2007 at 10:16 AM
“We are unknown, we knowers, to ourselves…of necessity we remain strangers to ourselves, we understand ourselves not, in ourselves we are bound to be mistaken, for each of us holds good to all eternity the motto, ‘Each is farthest away from himself”-as far as ourselves are concerned we are not knowers. –NIETZSCHE
29 May 2007 at 10:29 AM
Could somebody explain the scale on the verticle axis? It s not clear to this non-scientist what “anomoly” means. It appears that for an extended period, until 1950, the “T anomoly” fluctuated between 0 and -1 with a range of fluctuation of about 1/2 to 3/4.
The recent upward spike to +.5 appears to be the start of a trend. However, my misfortunes in the investment arena have taught me to delay drawing conclusions from patterns that are within the range of normal fluctuations. i.e. beware reggression to the mean.
[Response: The axis says “temperature anomaly with respect to 1961-1990″; this means that the temperature values are given as deviation from the average temperature of the period 1961-1990. The graph shows that before this time interval, temperatures were generally colder, while right now we’re about 0.5 ºC warmer than the 1961-1990 average. -stefan]
29 May 2007 at 10:38 AM
The 11th and 12th Century warming is interesting. Does anyone have a good theory for why this occurred?
An aside for Tim Lambert: there is no way you could know that the Chinese DID NOT sail around the north end of Greenland in the 15th Century, unless maybe you can prove that there was ice there at the time. Characterizing it as a “fantasy” lacks proper scientific objectivity. Gavin Menzies engages in speculation based on scant evidence - yes. However, the evidence is not nonexistent. I recall that at one time, the speculations of Alfred Wegener were characterized as “preposterous” by the geologists of his day. Too bad the scientists of his era didn’t live long enough to eat crow.
29 May 2007 at 11:12 AM
11, 14: The issue is the gross misleading statements and figures by Beck, not the “error bars” which are actually indicated in the figure at the link if one was really interested in checking. Why not use the same skepticsm about Beck’s distortion of science?
29 May 2007 at 11:21 AM
Thanks Alistair!
26: I agree with you, the whole article of Beck linked by Stefan is a compilation of false assumptions and crude theories.
29 May 2007 at 11:33 AM
>error bars
The error bars are the gray band in the upper third of the full three-part, full page image. They won’t be easy to see at screen resolution, they’re so close to the temperature graph that the just look like a blur around the main line. See the full chapter for that and much mnore.
You can get the chapter — it’s a PDF file — from the link provided at the top. There are _many_ graphs and figures there, read them together.
This — for about 24 hours after I post it — will open a temporary file with all three parts of that figure: http://pdfdownload.bofd.net/070529/tmp-IVjavr/6626817035.png
29 May 2007 at 11:33 AM
Off topic - but I don’t know where else to ask a question on this site:
This old post: http://www.realclimate.org/index.php/archives/2005/10/global-warming-on-mars/
contains the statement
” the evidence is for significant cooling from the 1970’s, when Viking made measurements, compared to current temperatures”
but without a reference. Nor was I able to find it on the internet. Can someone provide a reference for this statement?
Thanks,
29 May 2007 at 11:39 AM
29. Also off but we have two Peters on board. I change my nick to PeterK to reflect this, however it would be nice to avoid off topic questions.
29 May 2007 at 12:03 PM
#17: Southern Hemisphere not warming:
Where the heck did you get that idea? Check out the online ABC (Australian Broadcasting Commission) news for a hefty dose of grim reality about what climate change is doing to the south. It’s quite interesting to watch the recriminations fly between the political parties as they fight over what can be done about dwindling water supplies and what we should do about our emissions. Looking at it right now I note that by coincidence there is an artical covering new research that shows that the Indian Ocean has increased in temperature by 2 degree over the course of the last 40 years.
(On a brighter note; it looks like we are starting to get some respite via the La Nina pattern that appears to be kicking in - phew!)
29 May 2007 at 12:20 PM
re 25:
One very good piece of evidence that the Chinese were not sailing around Greenland in the 15th century is that there are no known records of such expeditions. We do know that Zheng He led a fleet through Asia and as far as the coast of Africa. So the Chinese were keeping records, and the records have survived.
29 May 2007 at 12:37 PM
A quick question: why do most of the reconstructions considerably underestimate the actual temperature record in the latter part of the millennium (e.g. 1970-2000). Do temperature proxies not respond well to (relatively) rapidly increasing temperatures?
29 May 2007 at 12:59 PM
Kroganchor (#24) An anomoly is the difference between some average value and current values. Temperature anomolies are calculated using the average in a stated interval. For instrumental measurements this is usually a thirty year period, e.g. 1950 to 1979.
Anomolies are usful when you want to compare changes over time or distance for example the change in yearly average temperature in New York and Cairo. Clearly, on average NY is colder in absolute terms, but by looking at the difference between the average temperature in NY over 30 years and the yearly average we get a yearly anomaly and can directly compare the anomolies.
Similarly, if we find the 30 year average temperatures at some place for January and June we can compare trends in monthly temperatures over long periods of time and see whether there is more of a trend in the winter or summer.
29 May 2007 at 1:30 PM
Speaking of what shoolchildren are getting exposed to, the National Science Teachers Association in the US is still recommending Kenneth Greens “Climate Change: Understanding the Debate”. The NSTA was featured on RC some time ago. http://www.realclimate.org/index.php/archives/2007/01/calling-all-science-teachers/
Kenneth Green was the one who was offering $10,000 payments for scientists who would be willing to publicly attack the IPCC report a few months ago, and is associated with the American Enterprise Institute and the Fraser Institute.
Even with all the negative attention the NSTA recieved after refusing to distribute “An Inconvenient Truth” to science teachers, they’re still playing the same game.
29 May 2007 at 1:33 PM
#24 Kroganchor
Global surveys of instrumentally measured temperature are shown as anomlies because it is easier to compare the change of a temperature measurement station compared to itself than to attempt to put all stations on a single absolute scale.
The data shown above are reconstructions from proxy measurements of temperature (such as tree ring widths) and so are inherently more noisy than an instrumental measurement. I guess they are shown as anomlies because they are calibrated using instrumental anomaly data.
If you want to see why the current rises in temperature are more than just an “uptick”, see here:
http://www.globalwarmingart.com/wiki/Image:Instrumental_Temperature_Record_png
This is an instrumental record and is much less noisy than the proxy reconstruction shown above.
29 May 2007 at 1:40 PM
One positive point to make. Do not understate children’s intelligence. School kids in German high schools (Gymnasium) usually have a good sense of humour regarding weird teachers and their theories. I think that logic applies everywhere around the globe.
29 May 2007 at 2:01 PM
>Mars, Viking
This may help:
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19910013700_1991013700.pdf
(Various possibilities considered — changes in dust storms seems most likely reason for change in albedo and thus temp.)
The above is — I’d guess — likely the background for the recent story in Science.
I found what’s said to be a copy of that, reposted on this site by someone. Since that’s probably a copyright violation I’ll make a brief excerpt from it instead of copying the copy.
http://www2b.abc.net.au/science/k2/stn/newposts/2889/topic2889064.shtm
— can’t vouch for it — text below excerpted from the copy I found on the abc.net.au page:
A Darker, Hotter Mars
By John Simpson
ScienceNOW Daily News
4 April 2007
“Slight variations in the hue of the Red Planet appear to drive the martian climate. … and could be responsible for a curious increase in the planet’s temperature in recent years, a team of planetary scientists reports.
“Martian temperatures depend in part on how much sunlight is absorbed or reflected. … Spacecraft images show that more than one-third of its surface area has shown seasonal variations that brighten or darken by at least 10%.
“… The researchers mapped albedo changes on the martian surface over 20 years, comparing images from the late-1970s Viking mission to the Mars Global Surveyor mission from 1999. … The overall reduction in albedo, in part, corresponds to the planet’s warming of 0.65°C over 20 years…”
Original behind the subscription barrier at: http://sciencenow.sciencemag.org/cgi/content/full/2007/404/4
29 May 2007 at 2:06 PM
:32
Correct, there is no evidence that Chinese ships ever made it to Greenland. The Chinese expeditions are well known. Many people also believe that the word Greenland (in English) or Groenland in German derives from the medieval warm phase and the meaning stands for nowadays “green”. This is highly disputed by linguists.
Also the viking sagas mention “Vinland”, thougt to stand for “wine”. This is also disputed. By archeological evidence it seems to be true that the early medieval centuries in the Northern hemisphere were a warm climatic period. But one should not draw conclusions like Beck that all shipping routes in the Northern hemisphere were free of ice and Greenland was a place like Florida.
29 May 2007 at 2:13 PM
#36 SomeBeans - Thank you for info. I am still confused. Why do not the fluctuations occur symmetrically around the zero value, if we are measuring anomolies?
29 May 2007 at 2:19 PM
What constantly amazes me is how wingnuts like Beck with their pet theories manage to engage the state apparatus of policy, thanks to those who are gullible and/or have an agenda.
29 May 2007 at 2:30 PM
#40 Kroganchor
The zero for the anomalies is set to the average of some 30 year period (I believe 1961-1990 is traditional in this instance), therefore any anomalies are only distributed uniformly in this reference period - outside this period you will see the effect of long term trends.
29 May 2007 at 3:08 PM
Re #39: [Many people also believe that the word Greenland (in English) or Groenland in German derives from the medieval warm phase and the meaning stands for nowadays “green”.]
The claim that Greenland is green is not entirely inaccurate. At some places on the coast, and in summer, it can appear quite verdant. (Like any arctic or alpine meadow.) This site has some pictures, including reconstructions of some of the original Norse settlements:
http://www.greenland-guide.gl/leif2000/project.htm
Add to the natural greenness some enthusiastic marketing by Eric the Red, and consider that he and the settlers were used to the climate of Iceland and Norway, and “green” seems a perfectly reasonable name.
29 May 2007 at 3:14 PM
re 25
“…there is no way you could know that the Chinese DID NOT sail around the north end of Greenland in the 15th Century, unless maybe you can prove that there was ice there at the time.”
The Chinese kept excellent records, particularly regarding expeditions that were as large and expensive, as a venture such as you suggest would be.
In addition, the one Chinese expedition that came closest stopped short of Europe and (presumably) returned to China after a change in leadership that curtailed further exploration outside of Chine. John S. Lewis describes this voyage in the first chapter of his book “Mining the Sky”. Had they continued on, long before approaching Greenland they would have first visited Europe (because shipping of that time period tended to keep land in sight for a number of reasons for which there is no need to go into here).
Suffice to say there is no record of such an encounter in either European or Chinese history.
29 May 2007 at 3:37 PM
re #25: I recall that at one time, the speculations of Alfred Wegener were characterized as “preposterous” by the geologists of his day.
This is not an accurate account of what happened with Wegener. I’ve dealt with this as part of a different fringe science theory (pseudo and fringe science people are always using a false history of Wegener’s ideas and the reaction to them). I’ll cut and paste from my site regarding Wegener:
According to the typical way of putting it, Wegener put forward a simple theory which said the continents had once been one, had split apart long ago, and slowly moved to their present locations. For this he was shunned and summarily dismissed by all science, only to be vindicated several decades after his death by scientists who realized that Wegener’s theory was exactly what had actually happened.
Good story… too bad it didn’t happen that way.
It seems that comparing themselves to Wegener is a popular pursuit with many people. One problem with their comparison is that the commonly expressed sentiment — “no one supported Wegener” — is wrong. It is also a fact that Wegener’s proposed mechanisms were obviously inadequate, as evidenced by the fact that he himself admitted this was so in the 4th edition of his book. This part about the mechanism has special significance for supporters of the AAT/H who look to Wegener’s theory as a icon, and I’ll get to that in a moment.
Contrary to these comparisons, many people who disagreed with Wegener about his idea took it quite seriously: they disagreed in scientific journals and conferences. Wegener’s idea wasn’t widely accepted because there was no reasonable candidate for a mechanism capable of producing the effect. This is a perfectly reasonable objection to a theory. When finally such a candidate was found, Wegener’s underlying idea — but not his inadequate mechanism — was accepted.
Although some reaction was probably based on being hide-bound, a major reason for Wegener’s idea not being accepted was that he had no reasonable mechanism, apparently no way for it to actually happen. Until a reasonable hypothesis regarding a mechanism was brought forward, it is reasonable to reject a theory. In Wegener’s case, this took quite a few years, decades, actually, and this helped opposition harden against the idea.
Wegener was correct only in the initial part of his claim — the part about what happened. He was dead wrong, almost laughably so, about the mechanism. His mechanism, a combination of pole-fleeing force and the tidal attraction of the sun and moon, was far far less powerful than would be necessary (several 1000’s of times so), and Wegener admitted this himself in the 4th edition of his book.
List and comments from Continental Drift: The Evolution of a Concept by Ursula B. Marvin, Ph.D., Smithsonian Institution Press: Washington, D.C. (1973):
Prominent Wegener supporters included:
Arthur Holmes of Durham and Edinburgh universities, “he was among the earliest and greatest pioneers in developing the radiometric methods for determining the ages of rocks and minerals and the age of the earth itself”; Emile Argand, founder of the Geological Institute of Neuchatel, Switzerland; S. William Carey, professor of geology at the University of Tasmania; C.S. Wright; Lester King, professor of geology at the University of Natal; Professor Reginald A. Daly of Harvard University, who Marvin calls a scientist “of unchallenged prestige”; Alexander Du Toit, Johannesburg, South Africa, author of Our Wandering Continents; Armadeus W. Grabau, “an American paleontologist and author of several textbooks on stratigraphy and index fossils”; Leonce Joleaud, French geologist; R.D. Oldham, “discoverer of the seismic evidence for the earth’s core”; and Dr. W.A.J.M. Waterschoot van der Gracht, “a Dutch geologist and vice president of the Marland Oil Company”.
29 May 2007 at 4:52 PM
Another off-subject comment: Take a look at:
http://www.ns.umich.edu/htdocs/releases/story.php?id=5864
climate monitoring station: Moon-based observatories proposed
29 May 2007 at 5:19 PM
Thanks to #28 for posting the link to the complete charts. I presume that the grey bars on the Hadley reconstruction are some kind of error estimate made by varying the model inputs? What we are interested in in this thread, however, are the error bars on the temperature reconstructions from proxies. What is striking from the IPCC chart is that the “instrumental record” starts diverging seriously upwards from the “proxies” around 1950, and is in the “10%” overlap range by about 1980.
[Response: Actually, you have mis-interpreted the information provided because you have not considered the implications of the smoothing constraints that have been applied at the boundaries of the time series. I believe that the authors of the chapter used a smoothing constraint that forces the curves to approach the boundary with zero slope (the so-called ‘minimum slope’ constraint). At least, this is the what it is explicitly stated was done for the smoothing of all time series in the instrumental observations chapter (chapter 3) of the report. Quoting page 336 therein, This chapter uses the ‘minimum slope’ constraint at the beginning and end of all time series, which effectively reflects the time series about the boundary. If there is a trend, it will be conservative in the sense that this method will underestimate the anomalies at the end. So the problem is that you are comparing two series, one which has an overly conservative boundary constraint applied at 1980 (where the proxy series terminate) tending to suppress the trend as the series approaches 1980, and another which has this same constraint applied far later (at 2005, where the instrumental series terminates). In the latter case, the bounday constraint is applied far enough after 1980 that is does not artificially suppress the trend near 1980. A better approach would have been to impose the constraint which minimizes the misfit of the smooth with respect to the raw series, which most likely would in this case have involved minimizing the 2nd derivative of the smooth as it approaches the terminal boundary, i.e. the so-called ‘minimum roughness’ constraint (see the discussion in this article). However, the IPCC chose to play things conservatively here, with the risk of course that the results would be mis-interpreted by some, as you have above. -mike]
The simple read on this, surely, is that the proxies are not reflecting current temperatures (calibration period) and so cannot be relied upon as telling what past temperatures were either?
[Response: Well, no, actually the proper read on this is that you should make sure to understand what boundary constraints have been used any time you are comparing two smoothed series near their terminal boundaries, especially when the terminal boundaries are not the same for the two different series being compared. -mike]
[Response: I’ve removed a comment which in retrospect was probably inappropriate. -mike]
29 May 2007 at 5:49 PM
re: #45
Wegener’s is certainly one claimed by classic fringers, but the history is actually even more complicated, i.e., for example, Americans were mostly against it from the beginning, whereas there was more acceptance in Europe.
QrazyQat (and anyone else who likes history of science): I recommend:
The Rejection of Continental Drift: Theory and Method in American Earth Science (Paperback) , by Naomi Oreskes.
http://www.amazon.com/Rejection-Continental-Drift-American-Science/dp/0195117336/ref=pd_bbs_sr_2/103-4988737-0613408?ie=UTF8&s=books&qid=1180477984&sr=8-2
Some people at RC may know Prof. Oreskes from a famous Science article:
http://en.wikipedia.org/wiki/Naomi_Oreskes
If you ever get a chance to hear her speak, GO! She gave a fine, lively historical talk last Fall at Stanford on the history of Fred Singer, Frederick Seitz, the George C. Marshall Institute, and related characters, well-known (if not beloved) by RC readers.
29 May 2007 at 7:10 PM
stefan - I was wondering if you had seen this:
http://ff.org/centers/csspp/pdf/20070522_isdo.pdf
“A Science–Based Rebuttal to the Testimony of Al Gore before the United States Senate
Environment & Public Works Committee
National Headquarters: ! Capitol Hill Office:
11781 Lee Jackson Mem. Hwy., Third Floor! 209 Pennsylvania Ave, S.E., Suite 2100
Ph: 703-246-0110 � Fax: 703-246-0129! Washington, D.C. 20003
FF.org � ScienceAndPolicy.org! Ph. 202-454-5249 � Fax: 202-454-5223
CENTER FOR SCIENCE AND PUBLIC POLICY a project of Frontiers of Freedom
Craig Idso
Center for the Study of Carbon Dioxide and Global Change
May 2007″
It written by Craig Idso and is chock full of single proxy studies that ‘prove’ the MWP was warmer than today. I actually do not get why skeptics think that it is SO important what the temperature of the MWP was. Both events, recent anthropogenic warming and the MWP, to me are independent. Even if the MWP was proved in peer reviewed studies to be warmer than today that does not mean that it will not get warmer still from our greenhouse emissions.
It also shows the double speak of the skeptics. On the one had decrying the unreliability and so-called dodgy stats (M&M) in the hockey stick they then use similar proxy data with the same now strangely not dodgy stats to claim that the MWP was warmer than today.
29 May 2007 at 7:17 PM
Beck is not the only person to misuse the IPCC 1990 graph. Christopher Monckton, Viscount of Brenchley, published this graph in his “Apocalypse Cancelled” global warming denial piece in the UK Daily Telegraph, here:
http://www.telegraph.co.uk/news/graphics/2006/11/05/warm-refs.pdf
Monckton claimed that the graph was included in the 1996 IPCC Report, wrongly implying that it originated there, and also falsely claimed that “According to â�¦ Soon and Balliunas (2003)*, the medieval warm period was warmer than the current warm period by up to 3C,” thus implying that the current warming is of little concern. (Apocalypse Cancelled, p.5, References, Sunday Telegraph, 5 November 2006).
In fact, the Soon and Balliunas (2003) paper makes no reference to the current warm period or to 3C. It merely claimed “the twentieth century is probably not the warmest” … “of the last millennium”.
*SOON, W. and Baliunas, Sallie. 2003. Proxy Climate and Environmental Changes of the Past 1000 Years, Climate Res. 23: 89�110.
29 May 2007 at 8:05 PM
I wouldn’t attempt to defend Beck’s rigged graphs; nevertheless, there is significant variation (~1 degree) temperature variation in the last thousand years even when we eliminate the last hundred years.
What accounts for that?
[Response:There is a large literature on this. In my view one of the clearest papers is that by Crowley and Lowry in Science a few years ago. Here’s a link to the abstract.
The temperature variations are probably much less than 1 degree C by the way. One of the points of his paper is that we understand the response of the climate to forcing (e.g. sun, CO2, aerosols) rather well, and looking at the past variations gives us about the same for the climate sensitivity (how much temperature will change for a given forcing) as we already had calculated from first principles. –eric]
29 May 2007 at 10:58 PM
re 47:
*chuckle*
re 49
“I actually do not get why skeptics think that it is SO important what the temperature of the MWP was. Both events, recent anthropogenic warming and the MWP, to me are independent.”
This is much like similar arguments we see from Creationists when they say the fossil record is incomplete and thus fossils cannot be seen as evidence for evolution. (Of course, the argument ignores the fact we do have nearly complete records, as in the case of Whales, but I digress).
The point is, this is not about trying to convince you, any more than creationists are trying to convince me of the veracity of their claims; what is really happening is the denialist industry is putting up smoke screen, creating straw man arguments that are used to appeal to an underinformed public.
The sad part is it works.
Here’s another (rhetorical) question regarding the U.S. and its position on global warming: Many of us expend quite a bit of energy planning for the future of our children; where they will go to school, figuring out what appeals to them, encouraging them to grow, to branch out and learn. We put money away to insure they can afford a good education, dedicate huge blocks of our time to them, are there for them when they need us and generally demonstrate the nuturing tendencies for successful child rearing. It goes even further: when they have children, we are often there for them, helping them when they hit difficult times, providing moral support and the benefit of our own experience to help them through. In short, we evidence the behavior of people who look far into the future with a concern for our offspring and descendants. Also, let’s not forget that as a nation we make a lot of noise about being concerned for our children and their future.
Yet when perhaps the gravest crisis to face civilization rears its ugly head, is shown to be a threat to the future we are trying to prepare for our children, and that we are part of the problem, what do a large segment of us do?
Exactly.
29 May 2007 at 11:35 PM
Beck’s graph of historical “chemical” CO2 measurements (all over the map, often over 400 ppm) gets picked up as “unpublished” source material in Tim Ball’s slide show for the Frontier Centre for Public Policy:
http://www.fcpp.org/pdf/TimBallJan2607handouts.pdf
It’s on page 17 of this PDF (top slide - it’s handout format with two slides per page.)
I note as well the sketchy temperature graph at the top of p. 11 of this PDF. It’s somewhat similar to the 1990 one above but not identical. It lists IPCC 1995 as the source. Is it in fact picked up from the 1995 report, and if so it is a fair reflection of the original? (Sorry I haven’t dug back myself tonight - I’m already up way too late.)
29 May 2007 at 11:44 PM
Stefan, great post and thanks. have you ever considered the need for teaching people about polar cities….?
30 May 2007 at 12:28 AM
Mr. Jones (or Shell?) #47 — the link (as I said in #28) was in the main article — in the line that says: “… from the paleoclimate chapter of the current IPCC report (see there for details).” The link gets you that chapter — it’s a large PDF, and you should really read the whole thing.
In #28, the link was to a temporary copy of the one image ( now expired) for anyone who couldn’t get the PDF.
That’s via the Firefox extension PDFDownload, by the way; they provide the 24-hour temporary copies.
Mike again, thanks for the explanation of the smoothing — worth saving that one as a good explanation of what the picture means. (And, the figure as Spencer notes in #12 could be described a bit more clearly in the main post)
Aside to Robert Rohde — can you include Mike’s explanation in his response to #47 above, if you use the image on globalwarmingart? It really helps understand what the ‘error bars’ mean in the original — clearly it takes reading the whole IPCC report to understand that stuff. I”m as always in y’all’s debt for making it clearer.
30 May 2007 at 2:00 AM
Re: Ender and Mc Intyre. What is for sure as evidenced in core ice samples over the past 650,000 years is that NOW is easily and dramatically the highest the level of CO2 has ever been. Also there is always a slight time lag between when a CO2 spike occurs and the air/sea temp heating up. And the two graphs practically mirror each other. CO2 has a spike and sure enough (every time) temp follows. Look at An Inconvenient truth..Gore has been meticulous to keep the science accurate and transparent. However this current rise in CO2 is not a anomaly or transient spike it is instead an UNPRECEDENTED and disturbing rapid trend. Temp will very very soon follow the CO2 graph up-up and away. Can we hold on the the tigers tail long enough to shoot a tranquilizing dart into her?? Logic says nope..I’m praying to all gods and sundry that I’m wrong.
30 May 2007 at 2:21 AM
Lawrence Coleman (#56) wrote:
27 Apr 2007
The lag between temperature and CO2. (Goreâ??s got it right.)
Filed under: Climate Science Paleoclimate Greenhouse gases Arctic and Antarcticâ?? eric @ 2:45 pm
http://www.realclimate.org/index.php/archives/2007/04/the-lag-between-temp-and-co2/
Actually the paleoclimatoligcal record at least appears to show temperature lagging behind carbon dioxide. There has been some recent debate - and it may possibly have even lead, but it appears to lag by approximately 99 yrs. Feedback. Warming ocens and plants lead to higher levels of carbon dioxide by putting more of the co2 sequetered t0 the atmpospher - for exmple, they reduce the capaicty of the ocean to to but carbon dioxide leads to the buldup of thermalradiation and thus temperatio.
30 May 2007 at 3:31 AM
Re: Greenland and MWP. I have an interesting paper that,although very qualitative, disagrees with the notion of an medieval warm period on Greenland, and for that matter also over the northern hemisphere in general. Nansen F. (1926) Klima-vekslinger in historisk and post-glacial time (”Klimate shifts in historical and post-glcacial times”)
His argument include that the graves dug in the medieval period coincides, with the present day (1920 in this case) depth of the permafrost. The graves were typically 2-3 feet deep, not 6. Also description of the ice-conditions from Norwegian 13. century sources said that the the drift-ice even in august usually extended slightly to the west of the southernmost cape. BTW as seen even from Beck’s curve any Chinese expedition in 1421 is already within the “little ice-age” so I do not see why this should support a theory on medieval warm periods.
On a larger scale Nansen cites from papers on water-level in the Caspian sea that the 12. century likely experienced dry (warm?) conditions, while written sources from Hangchow in China indicate colder temperatures in China than around 1900. The Chinese source described the date of latest snowfall in the spring.
30 May 2007 at 3:33 AM
Thanks Tim, I think the ocean temps have a 100yr lag? Air temp is mainly a result of greenhouse effect. Good point about the warmer it gets the more CO2 released by plants..although..some countries get drier and some wetter..australia for one is getting much drier..so is many countires of europe..so I’m not sure about the net effect of botanical CO2 release. CO2 release is dependant on the concentration of nitrogen in the soil…again drier country’s plants generally have little nitrogen in the soil so as the weather warms the plants will not produce much more CO2. But in wetter area that are getting wetter..plants have an almost unlimited potential to pump out CO2 due to the humous of the soil. In those arid countries or the ones getting nmore arid…vegetation will probably die off with say a doubling of atmospheric CO2 as has been proven to occur.
30 May 2007 at 4:47 AM
Re 47
There might be some problems with the tree ring-temperature relationship. It is known that the tree ring-temperature relationship has changed in the last about 20 years compared to the time between 1850-1980. This also partly explains the differences at the end of the period. It shows that climate change might also influence this relationsip (there are several possible reasons). However, the reconstructions use the time period before 1980 for calibration, and secondly, proxies other than tree rings show a similar temperature evolution. It is very unlikely that a possible change of the proxy-temperature relationship is just similar for a broad variety of different proxies and thus would introduce a considerable bias in the overall picture.
30 May 2007 at 6:17 AM
The most conspicious human activity of the 20th century was continuous hot and cold warfare which has continued unabated to this date. World War II saw the formation of the military-industrial complex (MIC),now immense world-wide enterprise which consumes enormous of amounts energy and resources which also requires even energy for their aquisition and manufacture into weapons. In Fig 1 there is a distinct peak in the temperature curve in the WW II years. Has any consideration been given to assigning a forcing factor for warfare and the MIC’s? The extensive use of jet planes for transport of men and materials to the front (and for removal of injured and dead soldiers from the war theater) must be consuming colossal amounts of fuel, which is probably the real reasons for the increase in prices of gasoline, diesel and commercial jet fuel and of copper and zinc which are used for the production brass for ammuntion. Or put another way, how much carbon dioxide is produced by these activities and other government activities such as intelligence. If world peace were to break out and the MIC’s reduced to near nil, how much cabon dioxide would not be produced?
Will swords ever be beaten into plowshares? We can only hope.
30 May 2007 at 7:09 AM
Becks graph stops in 1970, the IPCC graph in about 1985. Why are the last 20 years of data missing from the IPCC graph?
30 May 2007 at 7:19 AM
Re #57
Good grief - I should know better than to post when I am falling asleep at the keyboard. Typos. Missing lettes. 99 yrs instead of 900 yrs. Oy!
30 May 2007 at 7:28 AM
Lawrence Coleman (#59) wrote:
No - its 900 yrs. Or at least that is what it would appear to be. And not a problem: I just didn’t want to leave an opening for some denialist to come along and give you trouble. Still, I wish I had been a little more awake. No alcohol - it interferes with my meds - just sleep deprivation, which isn’t really a good idea, either. And now my wife woke me up early and the kitten insisted that I come out.
Oh well - maybe I will get more sleep tonight.
30 May 2007 at 9:07 AM
#62
Because it was drawn in 1990?
30 May 2007 at 1:03 PM
Re #52 - most global warming deniers are just cultural misfits looking for attention.
30 May 2007 at 2:20 PM
> I actually do not get why skeptics think that it is SO important what the temperature of the MWP was.
For myself (not a skeptic of AGW), it is very important in understanding what the effect of AGW will be. If the MWP was warmer that currently, that is evidence that current warming is not as harmful as some claim.
30 May 2007 at 2:32 PM
“Re #52 - most global warming deniers are just cultural misfits looking for attention.”
Or, perhaps they are paid shills for wealthy corporations and individuals who are profiting from maintaining the status quo in energy and consumerism. This is certainly true of right wing talk radio in the US.
30 May 2007 at 4:05 PM
>62,
It’s explained in the original chapter from which it’s taken (the link is in the main article, before the comments). Look at the chapter text for the table (6.1) identifying the records charted.
The figure shown here at RC is 6.10(b) from the chapter:
———
Reconstructions using multiple climate proxy records, identified in Table 6.1, including three records (JBB..1998, MBH..1999 and BOS..2001) shown in the TAR, and the HadCRUT2v instrumental temperature record in black.
———
>65, RichardT: No, it wasn’t drawn in 1990. You can look this stuff up.
30 May 2007 at 5:37 PM
The inline response to #47 is, in fact, incorrect - please read the caption of this graphic, which clearly explains the smoothing process used.
[Response:No, actually the inline response is probably correct. The caption doesn’t indicate how many adjacent values were used in calculating the mean used to pad the series. If the number of adjacent values used was one half filter width, then the boundary constraint is essentially identical to that achieved by reflecting the series about the terminal boundary, i.e. the ‘minimum slope’ constraint. Even if few adjacent values were used, the method still supresses any trend near the boundary. –mike]
30 May 2007 at 6:53 PM
Re #67: [ If the MWP was warmer that currently, that is evidence that current warming is not as harmful as some claim.]
Except that the current warming (by which I mean the warming that has happened so far) is not a big problem, and would be even less of a problem if we had reason to believe that it was just another wiggle in the curve, which would soon reverse itself. The problems come from the warming that is predicted to happen; warming that is either “in the pipeline” from existing CO2, or which will be caused by future increases in CO2.
30 May 2007 at 8:54 PM
That’s what I like to see, healthy discourse about the accuracy of postings. With accurate science, the truth will show itself with a wink and a smile, though the topic may be bleak.
30 May 2007 at 9:48 PM
re: #67 Steve Reynolds
Suppose you know that:
a) Today’s temperature (Tnow) is going up very fast, for pretty-well-understood physics, which will make the temperature keep going up (with the usual jiggles) for decades. I.e., the first derivative is certainly positive.
b) There are 6.5B people on the planet, with more to come, compared to ~300M people around 1000AD (http://www.census.gov/ipc/www/worldhis.html), with more people living on the coasts that existed in 1000AD, and stress on water supplies, etc.
c) Now, let us just suppose that you could magically transport today’s instruments back to 1000AD and measure the temperature (T1000AD), so that you got much tighter error bars than one can get with reconstructions.
What exactly would you do different if today:
T1000AD > Tnow ( a little cooler today) OR
T1000AD == Tnow (same) OR
T1000AD < Tnow ( a little warmer already)
Put a different way, if the temperature keeps heading up, does it matter whether the date at which T1000AD == Tnow happens is 5 years from now, or 5 years ago? I.e., does one say: "It won't happen for 5 years, so we're OK ... but in 5 years, I'll decide there's trouble"?
====
For what it's worth, suppose you didn't believe the usual reconstructions. How about glacier records (as discussed in another thread), but more specifically:
a) See Figure 5 in
http://www.unige.ch/forel/PapersQG06/Holzhauser2005.pdf,
which shows the Great Aletsch Glacier’s advances & retreats [a long glacier, which tends to smooth out short-term fluctuations, and is only now responding to 1980s temperatures.]
b) It is worth looking at the chart of Great Aletsch:
http://glaciology.ethz.ch/messnetz/glaciers/aletsch.html
c) and read the actual data, especially the last column, which shows the total length change, which is ~-700m since 1986.
http://glaciology.ethz.ch/messnetz/data/aletsch.html
d) The scale is inverted between a) and d), but if you draw the line from (2000AD, 3300m) to (2027AD, 3300+700=4000m), you get a gross approximation to what you’d expect if the glacier keeps retreating at the same rate. [It may be looks almost vertical, and the point (2027AD, 4000m) is slightly below the bottom edge of the chart.
e) Anyway, read the article (with the caveats & speculations), and assess whether or not the charts make sense, and whether or not something unusual is happening right now.
30 May 2007 at 10:26 PM
Very well, I will accept your explaination as the math is beyond my competence (alas!). I would be pleased if you could explain why a number of proxy records, despite being available up until 1980 or so, have been truncated at earlier times - some end in 1960, some as early as 1930 (eg, Briffa et al) Would any doubts about the reliability of the proxies in this period cast doubt on the same proxies for earlier periods? If not, why not?
31 May 2007 at 12:14 AM
Beck and the rest of his deluded ilk don’t seem to be convincing anyone with their nutty ideas:
275 Australian economists today issued a joint statement, calling on the Australian Government to stop undermining international efforts to tackle climate change and to ratify the Kyoto Protocol without delay.
The statement draws attention to the likely economic damage to Australia that will come from failing to reduce greenhouse gas emissions. They acknowledge that the latest Intergovernmental Panel on Climate Change report presents of new and stronger evidence that global warming is attributable to human activities. They also acknowledge warnings from the CSIRO (Australia’s peak science organisation) that climate change has the potential to seriously disrupt agricultural output, water flows and natural systems in Australia.
Some quotes from the statement:
â��Policy measures are available that would greatly reduce emissions of carbon dioxide and other greenhouse gases at modest economic cost.”
�Australia has shown over the last two decades that it can manage significant change without major negative consequences for incomes or employment and, in fact, with change being a stimulus to improving innovation in the longer term.�
�The Kyoto Protocol represents the first step towards a major international effort to deal with climate change in the long term. The refusal by Australia and the United States to ratify the Kyoto Protocol is undermining global efforts to tackle climate change.�
The statement can be found here. (The first page is the media release. Skip to page two to read the statement.)
31 May 2007 at 12:33 AM
56: “What is for sure as evidenced in core ice samples over the past 650,000 years is that NOW is easily and dramatically the highest the level of CO2 has ever been.”
I hope you’re referring to the last 650,00 years as “ever”. There’s been many times, millions of years back, when CO2 concentration was much greater than today — and much greater than current projections for 2100+.
31 May 2007 at 12:45 AM
66, 68: Who wake you guys up? Can you be a little more creative with your ad hominems? And check your non sequiturs at the door, please.
31 May 2007 at 3:27 AM
This is a bit OT, but I just read THE RISING, a novel about global warming. The premise seems plausible to me (tho perhaps not likely), but what do I know. The Rone & Ross ice sheet distintegrate (like the Larsen B), and this causes the land glaciers to slip into the sea, which causes a 1 foot sea rise. The loss of the weight of so much land ice then causes local Antarctic earthquakes (as noted to happen in Iceland & Greenland), and this causes more ice to break up & fall into the sea….and volcanoes under the antarctic (3 known, one unknown heretofore by scientists) erupt, and that really causes more ice to melt into the sea, and a part of a mountain & lots of big ice chunks to plunge in, causing a tsunami up the Atlantic ocean, wiping out inhabitants on both littorals. And there’s a 3 foot sea rise, which overflows the California aquaducts, making agri there impossible (who knew a 3 ft rise could do that??).
Now the worst is not what global warming does, but how the government and people react. That’s the really scary part. It’s a good, near-future sci fi read, and I thought somewhat more plausible than DAY AFTER TOMORROW.
31 May 2007 at 4:23 AM
Their latest crusade is to try to dent the IPCC’s review of the urban heat island literature by saying it’s just one guy [edited]. How valid is this criticism? Note that I’ve read the relevant bits in the IPCC WG1 report, but they’re trying to make an end-run around the IPCC by charging that its review of the UHI literature was biased.
I don’t trust ice sheet modelers because I suspect that they ignore terrestrial heat flow, and the reduction in ice sheet friction when sea water floats ice sheets so reducing the normal force from the ice that remains grounded.
31 May 2007 at 5:02 AM
I hope you’re referring to the last 650,00 years as “ever”. There’s been many times, millions of years back, when CO2 concentration was much greater than today
True. Of course multicelled life didn’t appear on earth until around 600 million years ago, so as long as we aren’t concerned about having multicelled life anywhere on earth we could use those higher CO2 levels to feel fairly safe about the earth’s future.
Personally I have an interest in the continued existence of multicelled life, so I feel it safe to ignore conditions that existed more than 600 million years ago as irrelevant to what conditions may or may not be acceptable in the modern era.
31 May 2007 at 5:44 AM
[[For myself (not a skeptic of AGW), it is very important in understanding what the effect of AGW will be. If the MWP was warmer that currently, that is evidence that current warming is not as harmful as some claim. ]]
And evidence that heavier-than-air flight was impractical would show there’s no threat to the railroads from an air travel industry.
31 May 2007 at 7:07 AM
Re 81:
I think we need to keep in mind that 4.6Bya there was not only no any celled life on this planet, but there was no planet on this planet. Prior to the Cambrian Explosion, there were no advanced civilizations, much less not-so-advanced one, or even cockroaches, rats, used car salesmen, or any of the other scourge of society.
We should also keep in mind that there are parts of this planet where multi-celled intelligent life live that are a heck of a lot warmer than other places, and particularly, a heck of a lot warmer than what the more northern and southern extremes are ever going to be under any global warming scenario. Some of y’all might think 40C/104F is a hot day. But some of us are grateful for days that are only that hot. If things start getting over 45C/113F, then I might think it’s really hot.
There are plenty of reasons to be concerned about the things that are believed to lead to global warming. Suggesting all higher life forms are going to go extinct any time soon is the sort of doom and gloom that people use to discredit the underlying science.
31 May 2007 at 7:16 AM
#67 #81
[[For myself (not a skeptic of AGW), it is very important in understanding what the effect of AGW will be. If the MWP was warmer that currently, that is evidence that current warming is not as harmful as some claim. ]]
If the MWP was warmer than today it means the earth’s more susceptible to feedbacks, forcings, influences etc. The exact opposite of what you’ve said.
[Response: In my opinion, the magnitude of the MWP would have to be (globally) much greater than today’s level to have any implication at all. That is, given the current uncertainties in the forcings (principally solar and volcanic) and the continued uncertainty in the climate sensitivity only a dramatically warmer MWP will be any kind of constraint. Thus the couple of tenths of deg C that are in dispute here are simply just not that relevant for the questions of future climate. They are very interesting in terms of climate history and spatial patterns of change of course, but the MWP question is just not that important. - gavin]
31 May 2007 at 7:57 AM
Re:76 Rob B. But I bet you’re glad you weren’t around thouse millions of years back. Think you’re missing a little piece of the puzzle..this time it’s us who have changed the biochemistry..not comets, not dinousaurs breaking wind…this time Rob..it’s US!
31 May 2007 at 9:10 AM
“66, 68: Who wake you guys up?” -Rod B
It was this guy that awakened me:
The Greenhouse Effect: Science and Policy
Stephen H. Schneider
Science 10 February 1989 243: 771-781 [DOI: 10.1126/science.243.4892.771] (in Articles)
……of Science Article Article The Greenhouse Effect: Science and Policy Stephen…Global warming from the increase in greenhouse gases has become a major scientific…That infrared radiation is trapped by greenhouse gases and particles in a planetary atmosphere……
(Perhaps someone can produce the abstract.)
Even back then it was apparent that the unpredictability of climate (and therefore local weather) was going to have major detrimental effects on our global civilization and the planetary biosphere.
The science is mostly in, local climates almost everywhere are changing in unpredictable ways, worldwide agriculture is starting to feel these changes, species die-offs are an almost daily occurrence, global average temperatures are up, but the denialists continue to spew their scientific sounding nonsense. Maintenance of the social and economic status quo seems to be a principal explanation. Got a better one?
31 May 2007 at 9:56 AM
I have a question about temperature. There is plenty of talk about the global rise in mean temperature. What I am curious about is the projections for temperature variability. It’s well documented that the diurnal temperature range is declining, and thus that the rise in mean temperature is due to disproportionate rise in daily minimum temperature. If we look at a time series of daily temperature (min, max, or average), how is the variance and correlation structure expected to change, if at all? Can someone give a brief answer and perhaps point to references on this?
31 May 2007 at 10:50 AM
Earth Nears Tipping Point
http://www.csmonitor.com/2007/0530/p02s01-wogi.html
Looks like we have 10 years once again to mitigate climate change and here is the reason why I doubt it will happen even with all of the noises coming from the climate science community.
http://gristmill.grist.org/story/2007/5/29/14713/4957
Looks like those with the money (ie the fossil fuels industry) will gets its way with the present US administration anyway and with the present administrations policy comes no hope for the rest of the emerging world economies as well.
So it looks like no matter what exerts say politicians and fossil fuel lobbyists are going to screw us in a manner of speaking.
[edit]
31 May 2007 at 10:56 AM
> a little more creative with your ad hominems? And check your non sequiturs
The Contributors here are quite good at pruning that sort of thing. Trust me on this. If they’d let every draft I tried to post appear in public, I’d be recognized as a far more caustic and intemperate writer. “Are you sure you’re not from [a lobby, a thinktank, the flying saucer] isn’t an ad hominem, tho’ it’s not snugglebunny-grade writing. An ad hominem would be “look at what this person wrote elsewhere, he makes clear he’s from (or soon going to) [a lobby, a thinktank, Antares] his argument’s not worth considering” —- the point is to try to get the source and documentation, to understand what’s real, on the facts.
Always the facts, the cites, the careful reading of the text and the explanation by those who understand the particular area of the science.
31 May 2007 at 11:23 AM
Thank you for doing everything here at realclimate. It is definitely clearing a lt of things. However, i’ve heard of some new papers in geophysical research letters that seem to suggest warming on neptune and mars or something, and that the warming correlates well with the solar output and earth’s temperature trend. Now even though correlation is not causation, they were very convincing…any chance you could cover those articles? I’m being bombarded by so much criticism and it would be great to have an argument back at them. Thanks!
31 May 2007 at 11:38 AM
The Russians are coming…to save the day!
http://en.rian.ru/russia/20070530/66362712.html
31 May 2007 at 11:59 AM
Re #85
You might want to have a look at these two posts. The first is specifically about Mars - but touches on Pluto’s presumed “global warming.” (Didn’t know it got that much sunlight.)
5 Oct 2005
Global warming on Mars?
Guest contribution by Steinn Sigurdsson
http://www.realclimate.org/index.php/archives/2005/10/global-warming-on-mars/
3 Aug 2005
Did the Sun hit record highs over the last few decades?
Guest commentary by Raimund Muscheler
http://www.realclimate.org/index.php?p=180
Anyway, some others might have more information for you - and I might be able to get back later today.
31 May 2007 at 12:00 PM
I have read this article with interest, and read the paleoclimate section of the IPCC report, and there are two things that still bother me:
1. In the graph shown above from the IPCC report, what makes the “hockey stick” shape is the temperature record appended to the end of the proxy record. Without the temperature record the time period from 1800-2000 looks very much like the time period from 800-1000. The proxy records are truncated earlier than the temperature record, but to be consistent with the temperature record, they would need to show a dramatic change between the end of the time series and now. Has anyone looked for this?
2. I haven’t seen an explanation of what caused the Medieval Warm Period and the Little Ice Age. The IPCC report shows some correlation with solar output, but the difference does not seem to be large enough (<0.5 W/m^2). Is there a generally accepted explanation for what caused these climate changes?
31 May 2007 at 12:19 PM
re: #73: sorry, I messed up an edit: should have said:
T1000AD < Tnow (already warmer)
If one says "(T1000AD > Tnow) = OK, but thinks in terms of time instead, with (smoothed) rising temperatures, all this means is that on some date in recent past or near future), the world suddenly goes from OK to not-OK, which makes no sense at all. The first derivative of the temperature is positive, and I don’t see any evidence of a negative second derivative to change that.
Anyway, if you don’t like the usual proxy reconstructions, how about glaciers?
a) Look at Figure 5 in
http://www.unige.ch/forel/PapersQG06/Holzhauser2005.pdf,
31 May 2007 at 12:48 PM
There is this article on Mars:
http://www.realclimate.org/index.php/archives/2005/10/global-warming-on-mars/#more-192
I thought I remembered something around here about Neptune but I can’t find it at the moment…
31 May 2007 at 1:00 PM
Rod B (#76) wrote:
I don’t know specifically how many times they have been above today’s level of 378 ppm (is that the current?), but with the strong feedbacks for the carbon cycle (not included in the IPCC WG1 AR4 estimations), models are projecting between 730 and 1020 ppm by 2100. Levels of 1000 ppm or more have been associated with ocean anoxia and mass extinctions, both on land and in the ocean. Of course, the anoxia due to temperature would take a while to work its way through the ocean. Centuries, most likely. Algae blooms and the anoxic deadzones they leave behind are of more immediate relevance as far as the ocean is concerned.
31 May 2007 at 1:12 PM
Kenny, keep in mind that each planet has different drivers. Solar radiation on Mars is only 36% what is on Earth. And for Neptune, the energy from the Sun is tiny (about 0.1% what Earth receives). The Mars climate models explain the effect on Mars quite well, and we have yet to see a full “year” for Neptune. Anybody who makes this argument is either ignorant or deliberately trying to obfuscate the issue.
31 May 2007 at 1:39 PM
Here’s a link to the “Neptune’s warming” paper:
http://www.agu.org/pubs/crossref/2007/2006GL028764.shtml
Ray Ladbury paraphrased the abstract:
“Just because there’s no statistically significant correlation and we have no mechansim how this would occur doesn’t mean we’re wrong.”
31 May 2007 at 2:01 PM
Re #83 (comment)
Gavin, the height of the MWP is less important than the variation of temperature between MWP-LIA-current. Depending of the temperature reconstruction, the variation is 0.1 to 0.7 °C and additional some 0.1 °C at maximum average induced by volcanic explosions in all reconstructions. The range is pretty wide, as that represents natural (mainly solar) variability in the past.
I know that some (like Briffa) assume that a larger natural variability in the past is a sign of a larger sensitivity for any forcing (assuming, as in most climate models, that the different forcings have similar sensitivities). Others like Esper, Luterbacher, Moberg, ea. have the opposite opinion:
“So, what would it mean, if the reconstructions indicate a larger (Esper et al., 2002; Pollack and Smerdon, 2004; Moberg et al., 2005) or smaller (Jones et al., 1998; Mann et al., 1999) temperature amplitude?
We suggest that the former situation, i.e. enhanced variability during pre-industrial times, would result in a redistribution of weight towards the role of natural factors in forcing temperature changes, thereby relatively devaluing the impact of anthropogenic emissions and affecting future predicted scenarios.”
I agree with the latter (but you know, that I am convinced that the role of solar is underestimated in current models)…
31 May 2007 at 2:42 PM
#43, You must also talk to an Icelander, as I did, and the story of Greenland was a practical joke by Icelanders who were perfectly happy to keep away unwanted visitors by diverting them to greener pastures.
31 May 2007 at 2:48 PM
Re SomeBeans (#87):
Some more info on Neptune…
The following post analyzes the paper on the statistically insignificant correlations (by the authors’ own admission) between Neptune’s brightness and Earth’s temperature, then in an update includes a link to a tech paper which concludes that the evidence regarding Neptune is most easily explained by seasonal variability (seasons last longer out there). Given the problems Connelly cites, it seems odd that the orginal paper ever made it through peer review.
Suggestive correlations between the brightness of Neptune, solar variability, and Earth’s temperature?
Posted on: May 10, 2007 4:02 PM, by William M. Connolley
http://scienceblogs.com/stoat/2007/05/suggestive_correlations_betwee.php
31 May 2007 at 3:16 PM
Re #73,
John,
The glaciers in the Alps show several retreats and advances in the Holocene. Wood from trees growing far higher than today (and human bodies) are now released by retreating glaciers. That points to higher temperatures and/or less precipitation in the past. One investigation on that subject points to the possibility that Hannibal could get over the Alps without problems, because there were no ice barriers…
Some references:
http://adsabs.harvard.edu/abs/2004AGUFM.U43A0743J
http://tinyurl.com/24y999
31 May 2007 at 4:01 PM
Ref comment #2:
“It worries me that we (i.e. our politicians) are not going to address the issue of climate change in time to avoid serious consequences. Institutions like the Wall Street Journal and people like Beck are not helping the issue.”
Seems to me there’s an even more insidious level of abrogation of responsibility at play here. To wit:
CLIMATE: NASA chief questions need for action on warming
http://www.eenews.net/Greenwire/2007/05/31/#10
Lauren Morello, Greenwire reporter
“NASA Administrator Michael Griffin questioned the need today for action against global warming in a taped radio interview that aired just ahead of President Bush’s announced effort to help forge a new international agreement for curbing greenhouse-gas emissions.
Griffin told National Public Radio he has “no doubt that a trend of global warming exists” but said he is unsure that it is “a problem we must wrestle with.”
The majority of scientific evidence supports observations that the Earth’s average global temperature has warmed by about 1 degree Celsius over the last century, Griffin said.
“Whether that is a long-term concern or not, I can’t say,” he said. “I don’t think it’s within the power of human beings to assume that the climate does not change, as millions of years of history have shown.”
Griffin further addressed climate change in a statement released by NASA today in response to the NPR interview.
“NASA is the world’s pre-eminent organization in the study of Earth and the conditions that contribute to climate change and global warming,” Griffin said in the statement. “It is not NASA’s mission to make policy regarding possible climate change mitigation strategies.”
In response to Griffin’s interview, House Science and Technology Committee Chairman Bart Gordon (D-Tenn.) issued a statement questioning whether NASA is adequately carrying out its scientific duties related to climate change.
“Based on NASA’s own five-year budget plan, the agency will be unable to start any of the new Earth observations initiatives recommended by the National Academies for the foreseeable future,” Gordon said. “That’s not going to get us where we need to be in our understanding of climate change. NASA needs to do more.”"
31 May 2007 at 4:24 PM
I hate to break a thread, but the new millennium just got weirder.
Where is RealClimate with the Michael Griffin - James Hansen thing?
31 May 2007 at 4:54 PM
I’m wondering if anyone here has a reaction to Michael Griffin’s comment on NPR today that
“I would ask which human beings â�� where and when â�� are to be accorded the privilege of deciding that this particular climate that we have right here today, right now is the best climate for all other human beings. I think that’s a rather arrogant position for people to take.”
I heard this on the radio this morning and was astonished. My take is here (and I gave realclimate.org a plug):
http://www.ourtask.org/2007/05/nasa-administrator-not-sure-global.html
31 May 2007 at 4:57 PM
I don’t think I can edit my comment, but the a?? characters are supposed to be em dashes…. looked OK in preview…
31 May 2007 at 5:22 PM
I know I seem to be nit-picking on various comments, but I feel you need to be careful and precise in what you say, lest these comments come back and bite you on the nether regions! In that context…
Gavin, in response to #83 says “Thus the couple of tenths of deg C that are in dispute here are simply just not that relevant for the questions of future climate.” This is a rather dangerous position to take because sceptics would suggest that “If a couple of tenths of a degree C is not relevent to future climate, then why the fuss about the couple of tenths of a degree C rise that happened over the 20th C?”. Please be more careful.
[Response: The warming over the last hundred years is significantly more than ‘a couple of tenths of a degree C’ - i.e. 0.8 deg C (and counting), but the issue with climate change is not that the last hundred years have been disastrous, but that the future continuation of this process may be. And there, we are taking about mutliple degrees. -gavin]
31 May 2007 at 6:45 PM
Can you provide us with the most useful action can individuals take to counter the comments by NASA Administrator Michael Griffin? Is there someone (significant) at NASA we can email to register our displeasure? Should we contact our congressional representaitves? Which ones are most significant with respect to this issue?
Thanks.
31 May 2007 at 7:46 PM
Yet deciding that a significantly warmer earth is best for all other human beings (which is what doing nothing amounts to) is not an arrogant position to take, apparently.
31 May 2007 at 7:57 PM
Since the topic of “global warming on other planets” has emerged again, I would like to mention a point I noticed.
If GW is happening on another planet, the effect could be related to the issue of proximity: being closer or farther away, as a function of phase in the orbit. In effect, a “seasonal” issue (although I guess planetologists like to use that term for effects due to axial tilt with respect to the ecliptic plane; I’m using it here to refer to expected changes over the course of a planetary year). But if the effect is happening within a seasonal timeframe, then you can’t prove that it’s anything other than a seasonal effect, so it’s not evidence of extra-terrestrial GW.
On the other hand, if it happening on a timescale that exceeds the planetary year; and if it dominates the seasonal changes, then whatever is causing it must have a greater effect that the seasonal changes. In particular, if it is laid at the door of increase in solar luminosity, then that increase has got to be a bigger effect than the natural change in solar intensity due to the changing radius: If the effect of the “GW” is bigger than the effect of the seasons, the cause of the “GW” must be bigger than the cause of the seasons. This puts a lower limit to the required change in luminosity required to explain the “GW” on other planets.
But the seasonal variation is well-knowns: Since
TSI is proportional to luminosity/(orbital_radius)**2,
the fractional variation of TSI is (2*delta_r)/(average_r), which is
4*(aphelion - perihelion)/(aphelion + perihelion).
The two candidates of interest (because of observed time frames of the putative “GW” events) are Mars and Jupiter. When you do these calculations, you find a required change in solar luminosity of 37.4% and 19.7% respectively. However, since TSI as measured on Earth has only varied in the range of about 0.1% since 1988, you can’t possibly seek an explanation of these non-seasonal behaviors in the Sun.
So, in summary, GW on Mars and Jupiter certainly cannot be blamed on the Sun; and events on the other planets can credibly be attributed to merely seasonal variation.
31 May 2007 at 8:28 PM
re: #100 (re #73, and check #93 for edit fix)
Ferdinand: yes, what they say is completely consistent with the Holzhauser paper which goes back to 1500BC. The Hormes Unteraar Glacier paper covers earlier periods, although the latest one meshes with the earliest period on the Holzhauser paper.
Is your argument that it was warmer than currently during some periods before 1500BC?
If so, we agree 100% … of course, there should have been warmer periods back then. See: Brian Fagan, “The Long Summer” for example.
I haven’t found a handy chart of typical solar insolation In Switzerland (~47 degrees N), but:
a) Based on normal orbital cycles, and eyeballing a few charts, I see that the typical July solar insolation at 30 degrees N should have fallen from a peak ~550 W/m^2 10,000 years ago to ~ 475 W/m^2 now. These would be less in Switzerland.
b) Of course, there would be imposed the usual 11-year jiggles, plus any Maunder Minimum equivalents to drop the temperatures, plus any other of the usual effects.
c) But still, one would expect that even with the usual jiggles, overall natural temperatures should have shown a slow cooling trend last 10,000 years, i.e., especially more than 3500 years ago, there should have been warmer periods, simply because the typical insolation should have been higher.
c) But, the Unteraar is heading up the hill just like the Great Aletsch, see:
http://glaciology.ethz.ch/messnetz/glaciers/unteraar.html.
d) Hannibal crossed the Alps Fall 218BCE, in middle of a long Aletsch retreat period centered on 1AD in Holzhauser Fig 5, and people still debate his exact route:
http://www.livius.org/ha-hd/hannibal/alps.html,
http://news-service.stanford.edu/news/2007/may16/hannibal-051607.html: maybe thsi research will produce results.
But for now, if they went via the route occupied by Montgenevre … via Googlemaps, the village is along one side of the pass, and the ski resort is across the street, so I doubt there are “ice barriers” these days, although they certainly get snow.
Anyway, all of this perfectly consistent with natural cooling (with jiggles) over millennia, shorter earlier glaciers, longer recent ones … except recently, when the glaciers turn and retreat, heading soon (decades, at current rate, for Aletsch, anyway) further up than any time in last 3500 years…
31 May 2007 at 8:52 PM
It’s mind boggling that the NASA Administrator would make a statement that he’s unsure that climate change is a problem that must be dealt with. What is he thinking? That if we don’t worry about it will go away? I can’t understand how someone in his position, wouldn’t know about the problems that are being confronted today from the effects of climate change, such as native residents of northern Canada and Alaska,dealing with the adverse effects of melting permafrost. The residents of low lying islands in the Pacific Ocean are seeing the results of rising sea levels at this very time. There are many other detrimental effects that have been documented on this site, before, such as dying coral reefs,and the loss of reflecting ice and snow, both at high altitudes and in the polar regions, reducing the Earth’s albedo, which leads to more heating.
I suppose we shouldn’t be too surprised. The foot dragging by this administration’s political appointees, as opposed to career professionals, in the scientific area, has been evident from day one.
31 May 2007 at 9:16 PM
Some misinformation about Antarctic ice appears in this thread, so far uncorrected, I think. Specifically I believe Eric’s reply to #4 is incorrect.
The West Antarctic ice sheet is not particularly melting; it is warming up a bit, it is softening a bit, the ice shelves holding it back are retreating, all of which causes the ice to flow faster. If we get the several meters of West Antarctic driven sea level rise it will predominantly be because of what amounts to a mechanical failure of the ice sheet.
Glaciers flow downhill and warmer glaciers flow downhill faster. Above a certain flow rate there is no equilibrium with precipitation and the glacier vanishes. The West Antarctic can be considered a few huge glaciers, and this idea holds for them as well.
31 May 2007 at 9:49 PM
RE 89: I ran into someone like that Kenny. All you have to do is conduct your own quick research. Space.com and NASA are the good, readily available sources for the layman.
Any assertion that outer solar system planets could be warmed by the sun in a significant way appears unfounded. The kind of solar output variation necessary to warm up Pluto or Neptune would be very noticeable to us. Keep in mind that no variation in solar output was ever actually observed until the age of satellites. The gas giants are mostly driven by their internal heat. In the case of Jupiter, the internal heat effect is far beyond any other input (see space.com). Most outer planets’ climates are a matter of educated guesses since there has not been enough observation to cover even 5 “years” of it. In other words, we don’t exactly know what the “climate” of Saturn or Neptune is really like and we are not in a position to say affirmatively that it is changing. As an example, Pluto takes 248 years to revolve around the sun. Any latest observation on those planets is likely to be the best to date, making comparison inappropriate, and will be a punctual observation, i.e. not a long term trend. In any case, these planets’ and their atmosphere are so dfferent from ours that any comparison beyond a specific point is very hypothetical.
There is a lot of noise about Mars, it is quite undeserved. Mars’ seasonal cycle naturally exposes it to more intense southern hemisphere summers, which are not entirely compensated by its northern hemisphere winters, hence a natural deficit in southern carbonic ice (see NASA, good discussion on that). How much of an anomaly the recent southern hemisphere CO2 ice deficit constitutes is debatable. Furthermore, dust storms appear to be a major driver of Mars weather and short term climate. Lastly, the correlation between Mars and Earth is actually weak to non existent; what the Mars-global-warming proponents ignore or leave in the dark is that the recent warming trend (if there is such a thing) is quite recent. Mars went through a signficant cooling period after the V