A wise tutor once told me that if something is written down in a scientific textbook it is probably true, but if it is published in a journal then put it on probation. It was good advice, especially when it comes to climate science. Many is the time that a particular paper, or indeed a suite of them from the same stable, is latched onto by one side or another as proving a point or winning an argument, sometimes paraded in the media as such, for subsequent papers published perhaps sometime later, to show that the original findings were not that clear cut. Science has run its self-correcting course though often advocates don’t keep up and remain quoting the original paper as though it was gospel. The moral is that, especially in climate science, look hard enough at almost any research paper and you will raise more questions than answers. It’s inevitable.
It’s with this attitude that I approach a recent paper in Nature by Shakun et al.
Updated below with MUST READ comments from Piers Corbyn and YouTube
Article continues below this advert:
It’s a fascinating study that overturns what was though to be the role of CO2 after the last glaciation. It claims that rising temperatures were preceded by rising CO2. This, of course, throws an interesting light on the rise in CO2 since the Industrial Revolution that the IPCC says is affecting out climate, dominating the warming, since 1960-80. The paper says, “Global temperature reconstructions and transient model simulations spanning the past century and millennium have been essential to the attribution of recent climate change, and a similar strategy would probably improve our understanding of glacial cycle dynamics.”
The curious thing is that if you look at the rise of CO2 in the atmosphere in the past 20,000 years or so and compare it to the rise in temperature, if you use data from Antarctic ice cores you find that the temperature leads the CO2 rise, as it seems to do in previous glaciations. But Shakun et al extend their analysis of global temperature to include 80 proxy stations scattered more evenly across the globe, though almost all of them very close to the oceans. The temperature proxies include ice cores, isotopic ratios, pollen, microfossils and a few others.
When those proxies are included the relationship between the CO2 increase and the temperature increase is reversed. This time the CO2 predates the temperature increase. The paper’s figure 2 (above) shows the results
The paper has attracted some comment centered around two issues. One is the method of area-weighting to produce a global mean temperature of the 80 proxy sites. The other has been about what the proxies themselves show and it has been suggested that, whilst they all show a rise in temperature since the last glaciation, they do not all have the same timings, and some are not useful at all. Producing an average temperature curve from this sample worries me.
The paper's figure 2 shows that the temperature increased by about 3.5 deg C between about 18,000 BC and 10,000 BC. During the same period CO2 increased by 70 ppm, from 190 to 260 ppm. Pre-industrial values for C02 are 280 ppm and today they are 390, a rise of 110 ppm. During this time the global temperature has increased by about 0.8 deg C. There are clearly other things going on.
Calibration Curses
Lean and DeLand in the Journal of the American Meteorological Society is another fascinating paper relating to the question of the variability of the Sun’s spectrum. #It was suggested recently by researchers that variations in the Sun’s spectrum, in particular the out of step changes in optical and Ultra-Violet radiation may mean that during solar minimum, when total solar irradiation (TSI) is at its minimum, more energy might be deposited in the earths atmosphere because UV radiation was in antiphase with the TSI.
This remarkable conclusion was based on observations made by the Spectral Irradiance Monitor (SIM) on the Solar Radiation and Climate Experiment (SORCE) spacecraft. It suggested that between 2004 and 2008 the Sun’s visible and Infra-Red irradiance increased as the TSI decreased as the Sun headed towards minimum. At the same time UV decreased 3-10 time more than expected.
Clearly, as the Sun is the primary driver of the terrestrial weather system understanding how its radiant energy is deposited in the atmosphere and on land is of vital importance. It’s well known that over the solar cycle the TSI varies by about 0.1 % and recently it was discovered that over a solar cycle the UV radiation varies by a greater proportion. Only the SIM however scrutinized these changes simultaneously showing that as the sun ended cycle 23 it displayed a 0.3 W per sq m decrease in UV at the same time as a 0.3 W per sq m increase in visible energy.
This changed many looked at the Sun-Earth interaction suggesting it was the often-discussed amplifying factor whereby small changed in TSI (0.1 %) which were seemingly negligible in climatic terms could be influencing the Earth’s climate to a greater extent than that variation suggested. It would have mean a reappraisal of solar-terrestrial climatic interactions.
Lean and DeLand examine the calibration of the SIM during 2008 when the Sun was in a minimum level of activity and didn’t change much. They say they found trends in solar irradiance and solar activity that are unlikely to be solar in origin and that the effects previously noted are calibration effects are not real.
They say: “rather than revising current understanding of solar physics and solar variability effects on climate, what is needed is improved characterization of the SORCE SIM observations….To prevent future research following a path of unrealistic solar-terrestrial behavior, the SORCE SIM observations should be used with extreme caution in studies of climate and atmospheric change until additional validation and uncertainty estimates are available.”
I think that goes for the Shakun et al paper as well. My old tutor was right!
Feedback: david.whitehouse@thegwpf.org
# Click source for link
Also see the following YouTube from CO2Science.com
Posted by David Appell (Twitter) on Apr 11th 2012, 1:05 PM EDT
A recent paper claims that the apparent solar spectrum changes are an artifact of sensor drift:
Lean, Judith L., Matthew T. DeLand, 2012: How Does the Sun’s Spectrum Vary?. J. Climate, 25, 2555–2560.
http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-11-00571.1
Posted by Piers Corbyn (Twitter) on Apr 11th 2012, 8:56 PM EDT
David (Whitehouse, author of article rather than comment above); Your first comment on Shakun et al should surely be amended in red to read: It’s a fascinating study that CLAIMS TO overturn(s) what was thought to be the role of CO2 after the last glaciation.
SURELY The issue is Not the two you mention as being discussed, ie,
(i)The area weighting of data used to produce the world mean temperature and
(ii) questions as to what these Northern hemisphere proxies actually mean.
Don't be trapped into debates on Shokun's anti-scientific terms. I make the point in:
that the whole idea of constructing a world mean and using that to deduce it is being 'driven' by CO2 IS DISHONEST DELUDED NONSENSE.
The area weightings and meaning of proxies they use might be OK but the whole physical basis of Shokun at al is anti-physics, twaddle and trickery to hide the rise of the main sea temperature of the planet (southern ocean) prior to CO2 rise.
The world mean temperature is NOT a physical quantity responding to CO2 it is an average of different time varying quantities (SH and NH temperatures). We need to be clear the Southern Ocean did not warm up BECAUSE of the rise in CO2 which came 800 years later! (That rise in CO2 incidentally being the CO2 driven off the warming Southern Ocean!!!)
What happened is simple, the world warmed starting with the Southern ocean and the NH followed about 1600 years later (with Greenland warming abruptly) and somewhere during the midst of all this CO2 levels rose as Oceans warmed.
What some construct of bits of NH and bits of SH whether 'honestly' balanced or of fair or unfair proxies is of no relevance to the physics and as meaningless and designed to mislead as other noise coming from the thieves kitchen from whence this concept emanated.
The question WHY warming after ice-ages starts with the southern hemisphere is interesting and indeed we started discussing that on facebook http://www.facebook.com/profile.php?id=100001281948141
but I've no idea how to link anyone to a facebook discussion (with KK)
Scientists who analyse Shakun on his own deceitful terms are missing the point. Argument around PHYSICS must rule.
Posted by Piers Corbyn (Twitter) on Apr 13th 2012, 11:01 PM EDT
Further to my note above I want to re-stress that Combating this latest warmist "Temps follow CO2" Lie is very important.
The Nature-BBC article by Shakun et al is the last stand of the warmist CO2 sect. It took them years to cook up this hideous lie. Destroy this and they are finished.
We must be clear: It's not the detail of Shakun et al's Nature-BBC con that matters but the con itself. Put physics first!
Criticizing the detail of their con rather than the con itself is like criticizing a thief for not having a full inventory of what he stole rather than banging him up for robbery.
I would urge all to:
(i) Examine the Shakun at al article especially the pics in detail to see how brazenly deceitful and politically driven their 'Global mean temperature' concept is: http://sciences.blogs.liberation.fr/files/shakun-et-al.pdf
It is as dishonest as it is cleverly presented and well illustrated.
Posted by David Appell (Twitter) on Apr 14th 2012, 1:29 PM EDT
Piers: claiming every piece of science you disagree with is "politically driven" is a sure way not to be taken seriously by the nondenialist community.
Will you be submitting a letter to Nature with your concerns?
Posted by Piers Corbyn (Twitter) on Apr 14th 2012, 10:12 PM EDT
David Appel, you are lieing.
I do not claim that "every piece of science I disagree with is politically driven".
I demand you either withdraw this defamatory infantile pathetic remark or produce a list of every piece of science (published or unpublished) I disagree with combined with statements from me that each is politically driven.
Tell me in this specific case; if Shakun et al's deceit is not politically driven then what is it driven by?
I understand you have no scientific qualifications.
Posted by David Appell (Twitter) on Apr 19th 2012, 6:50 PM EDT
> if Shakun et al's deceit is not politically driven
> then what is it driven by?
Insofar as I don't know the man, let alone his psychology, I can't possibly ascertain his motivations behind his scientific work. The question is, how can you?
Posted by David Appell (Twitter) on Apr 21st 2012, 9:29 PM EDT
Piers, after watching an interview of you, my original comment (which was no more than a euphemism) has more support than I expected:
RT interview with Piers Corbyn
Dec 13, 2011
http://www.youtube.com/watch?v=bXNFl6Ft5Hk
Corbyn: "[The Kyoto Protocol] is a gravy train for so-called scientists, looking into things which don't exist, and, of course, for governments to impose taxations, and oil companies to increase oil prices on the back of increasing energy prices, which is the thing demanded by the global warmists nonsense lobby."
Corbyn: "This is just an example of another trick played by the global warmists who pull your heart strings to make you support delusional nonsense and help them on their way on the gravy train."
10 comments found showing page 1 of 1 « previous 1 next »
» News articles may contain quotes, these are copyright to the respective publication which will be stated, along with a link to the source article where available.
» If you feel your copyright has been violated please contact us and the article will be removed or amended at your request.
Articles Recently Viewed
3,719
Donations
» Please support the site by making a donation. No matter how big or small, your contribution helps to support the cause.
Tweet Article
Post to Facebook
Print Article
Lean, Judith L., Matthew T. DeLand, 2012: How Does the Sun’s Spectrum Vary?. J. Climate, 25, 2555–2560.
http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-11-00571.1