IT is terribly unfashionable to admit it, but I’ve just never been able to believe that the late 20th Century was particularly warm. This admission despite ‘the hockey stick’ graph that featured so prominently in the United Nation’s third IPCC assessment report, and despite that amazing looking chart in Al Gore’s movie that also showed a recent spike in global temperatures relative to the last many thousand years.
My key problem with the ‘the hockey stick’ has always been that the upward spike representing runaway global warming in the 20th Century was never of the same stuff as the rest of the chart. That is the spike is largely based on the instrumental temperature record i.e. the thermometer record, while the downward trending line that it was grafted on to, is based on proxies, in particular estimates of temperature derived from studies of tree rings.
It has always, for me, been a case of Michael Mann comparing apples and oranges, or to put it another way sticking an apple on the end of a banana.
The Michael Mann and Shaun Marcott Hockey Sticks
Worst the grafting was necessary because the proxy record, i.e. the tree ring record, shows that global temperatures have declined since about 1960.
Of course we know that global temperature haven’t declined since 1960, or thereabout, so there must be something wrong with the proxy record. This is known as “the divergence problem” and it is a problem, because if tree rings are not a good indicator of global temperature after 1960, how can they be a good indicator of global temperature prior to 1960?
Indeed there doesn’t appear to be a reliable method for reconstructing the last 100 or so years based on the standard techniques used to reconstruct the last 2,000, 4,000 and even 11,000 years of global temperature.
So when someone claims the past 10 years have been hotter than the past 11,300 years, as the Australian Broadcasting Commission did recently [1], there is good reason to cringe.
Of course the ABC didn’t make it up. They were reporting on the work of climate scientists recently published in a reputable journal. In particular a paper by Shaun Marcott and colleagues published in Science [2].
Sceptic, mathematician and blogger, Steve McIntyre, broke the original hockey stick into bits to do a thorough analysis, showing that the entire shaft, not just post 1960, was a fancy construct to create the impression of runaway global warming [3], and he’s done the same with this new Marcott fabrication [2].
While some who read this blog may cringe at my use of the word fabrication, it is more than justified because as Dr Marcott now admits in his own words[4]:
“[T]he 20th century portion of our paleotemperature stack is not statistically robust, cannot be considered representative of global temperature changes, and therefore is not the basis of any of our conclusions. Our primary conclusions are based on a comparison of the longer term paleotemperature changes from our reconstruction with the well-documented temperature changes that have occurred over the last century, as documented by the instrumental record.”
In summary, Dr Marcott created the perception of a spike in temperatures the same way Michael Mann did in that first hockey stick paper that featured so prominently in the third IPCC report, by comparing apples and oranges… or perhaps best described as grafting an apple onto the end of a banana.
***
1. Earth on track to be hottest in human history: study . March 8, 2013
http://www.abc.net.au/news/2013-03-08/climate-study/4561164
2. A reconstruction of regional and global temperature for the past 11,300 years. Marcott et al.. Science, Volume 339, No. 6124, pages 1198-1201.
http://www.sciencemag.org/content/339/6124/1198.abstract
Abstract: Surface temperature reconstructions of the past 1500 years suggest that recent warming is unprecedented in that time. Here we provide a broader perspective by reconstructing regional and global temperature anomalies for the past 11,300 years from 73 globally distributed records. Early Holocene (10,000 to 5000 years ago) warmth is followed by ~0.7°C cooling through the middle to late Holocene (
3. see http://climateaudit.files.wordpress.com/2009/12/mcintyre-ee-2005.pdf and more http://climateaudit.org/multiproxy-pdfs/ and the latest http://climateaudit.org/2013/03/31/the-marcott-filibuster/
4. Response by Marcott et al. http://www.realclimate.org/index.php/archives/2013/03/response-by-marcott-et-al/
A very good updated post at Watts showing "just the facts" about the lack of global warming and SS global warming.
http://wattsupwiththat.com/2013/04/08/are-climate-models-realistic-now-includes-at-least-february-data/#more-83710
So when will the MSM catch up?
Our little mate Lukie linked to that "pedantic buffoonery" in the Bellingham Herald to tell us all that Easterbrook was wrong.
Now that same paper is too piss weak to print a rebuttal:
http://wattsupwiththat.com/2013/04/08/rebuttal-to-the-attack-on-dr-don-easterbrook/#more-83728
'Don’t look now, but maybe a scientific consensus exists concerning global warming after all. Only 36 percent of geoscientists and engineers believe that humans are creating a global warming crisis, according to a survey reported in the peer-reviewed Organization Studies. By contrast, a strong majority of the 1,077 respondents believe that nature is the primary cause of recent global warming and/or that future global warming will not be a very serious problem.'
James Taylor in Forbes Magazine
Could the massive NBN white elephant cost us 90 billion $ and could it blow out the 2014 budget by a further $10 billion?
http://blogs.news.com.au/heraldsun/andrewbolt/index.php/heraldsun/comments/claim_nbn_to_cost_us_90_billion/
Also Gillard's estimate for the take up and roll out was wrong by 98%. Unbelievable.
I was just re-reading Lomborg's book and especially his section on SLR and looking at the Royal Society's graphs again on Antarctica and Greenland.
http://rsta.royalsocietypublishing.org/content/364/1844/1709/F4.large.jpg Of course the Antarctic ice mass ( all models negative for SLR) is about nine times the size of Greenland's ice mass. ( all models positive for SLR )
But the rate of the negative SLR trend from Antarctica is also greater than the positive trend from Greenland, particularly as the graphs extend towards 2300 or another 300 years.
But the Gore Hansen SLR trend until 2100 is about 6 metres or 20 feet, while the IPCC expects Greenland to contribute just 3.5 cm by 2100, or about 1.4 inches.
So how do Gore and Hansen have any credibility at all and why do they have so much influence ,support and promotion in the MSM?
Remember also that the IPCC 4th report states that about 29 cm ( about 1 foot) of SLR would be expected by 2100, but 21cm ( 8.5 inches) of that rise would be due to thermal expansion.
So what does all this really tell you about the claims of impending dangerous SLR and the ongoing CAGW scare as well?
Interesting to read that Briffa, Jones, Vinther et al paper again and look at their table 1.
If we look at the annual temp for Greenland in the decade 1851-60 we have a temp of minus -2.1c. ( annual)
Then if we look at the decade 1981-90 we have an annual temp of minus-2.5c
Then if we look at the decade 1991-2000 we have an annual temp of minus -2.1c.
Luke states that Alley's graph ended in 1855 and we can now show above that the period from 1980 to 2000 was 0.3 C colder than the decade 1851-60. That's a period of twenty years.
So the Alley Greenland graph I linked to finished at a slightly warmer temp in 1855 than the year 2000 and that temp period was cooler than the previous 60 years of the 20th century.
Here is that study. http://www.cru.uea.ac.uk/cru/data/greenland/vintheretal2006.pdf The Table 1 is on page 11.
Interesting how the recent winters and springs ( 1980 - 2000 ) were colder than the 1851- 60 period as well.
Scientists astounded as Baltic sea ice lingers longer.
http://www.thelocal.se/47154/20130405/#.UWFFGBneOHk
Bob Carter is great and if Abbott fails to secure both houses in the election, then Bob maybe needed in any Double Dissolution debate.