Retired science teacher Peter Foster, of Waikouaiti, believes the case for global warming is anything but settled. Here he explains his views (links are in italics).
The 1990 IPCC report showed that in the last 1000 years the medieval warm period (MWP) 900-1300 AD was slightly warmer than the present time, but its 2001 and subsequent reports contained the Michael Mann based graphs showing unprecedented warming in late 20th century with no MWP and no little ice age.
In a peer reviewed 2005 paper, McIntyre and McKitrick took Mann's graph to task. Basically Mann was funded by US Congress and through them was forced to make available his data and algorithms. McIntyre showed that you can take a set of random numbers in Excel, apply Mann's methodology and you will get a hockey stick graph.
As a result of the McIntyre & McKitrick paper the US Congress ordered two reviews into the matter, both of which condemned the hockey stick graph, as did the Penn State University investigation by Wegmen et al, which in polite speak said Mann's paper was rubbish. A readable analysis of the appalling construction of this graph by McKitrick can be found here.
Mann's graph was followed by similar ones in the Amman and Wahl papers which all suffered from the same problems and were rejected by several science journals but somehow made it into the IPCC 4th Assessment Report. You can read this sorry saga at this web site.
Next came the Briffa graph based on 12 selected tree cores from the Yamal peninsular in Russia. They were selected from 46 cores of still growing trees because they "fitted the hockey stick" - what sort of science do you call that? When the other 34 equivalent cores were added in the medieval warm period reappeared and the modern warm period ceased to show any unprecedented modern warming, see here for full analysis. (tree rings are affected by many things, CO2 and water strongly affect rings as well as temperature).
There is plenty of evidence from pollen distribution and other proxies, and from historical accounts of where plants grew then but cannot grow now, that the medieval warm period was warmer than the present warm period. Therefore, when one sees graphs showing the opposite it should cause any scientist to question either the construct of that graph or the data that suggests otherwise and the latter is pretty robust.
The hockey stick and its re-incarnations are products of poor science and/or faulty statistical analysis and it is time that that was recognised. The 2006 NAS report, relied on by many people, is out of date.
What is left after all of this, is the original research that was published in the 1990 IPCC report based on proxies as shown in the accompanying graph. e.g. Loehle These proxies show no unprecedented warming in the late 20th century.
Now to the last 100 years or so.
Recently the Hadley Climate Research Unit (HadCRU) at the University of East Anglia was hacked into and the emails and computer programs used there were released onto the Internet. For a brief outline of poor science, manipulation of science journals and the thinking of these high priests of global warming refer to the Telegraph and various articles here
HadCRU hold the largest database of world temperatures and is the most influential source of information on global warming for the IPCC, consequently errors from HadCRU have huge political implications.
HadCRU (Jones) and GISS (Hansen) both show the present as being warmer. However record recorded temperatures from the 1930's indicate it was not so. The GISS graph shows warming but there are errors that are not accounted for. The largest error error arises from the changes in the surroundings of the met stations used. A project by Anthony Watts to survey all the met stations is 82% complete and shows that 69% of North American met stations have a 2 to 5°C error due to changes around the met stations. see here In addition, the way the database deals with urban heat island effect (most met stations are in cities and cities generate heat) is very questionable.
(see here for NZ) The NIWA response was to refer only to the Wellington site and say that they adjusted 0.8°C upward due to moving the met station to a new higher location. But as any year 10 student should be able to tell you, adding a constant to an equation does not alter slope.
One could understand decreasing later data to compensate for urban heat island effect from increasing city size, but what NIWA have done is the exact opposite - to increase later data and decrease early data, thus giving the appearance of increasing temperatures consistent with global warming - where no increase exists. There is an urgent need for NIWA to release all data and the reasons for each and every change in the raw data, only then will independent analysis be able to confirm or refute the present NIWA graph.
In Sweden Emeritus Professor Wibjorn Karlen has used the NORDKLIM database (combined recordings from all Nordic countries), to graph changes over the last 150 years. His graphs show the 1940 peak as being at least at warm if not warmer than the present 2000 peak. In the emails Karlen takes HadRU to task as to how they can show Nordic countries with temperatures rising when they use the same data base. The correspondence and graphs are on this web site
Similar results are now appearing from the UK, Australia, Africa and North America.
Clearly there is an urgent need for HadCRU, NASA-GISS and NOAA to release all data used and their manipulations of it. Without this there can be no independent verification of climate change.
However, with the hockey stick in tatters and serious questions raised regarding current warming versus 1940 peak the case for catastrophic global warming is in serious doubt.
Postscript. Fallout from HadCRU emails
Professor Phil Jones, head of HadCRU, was stood down pending an investigation and Penn State University has announced an investigation into the work of Dr Michael Mann. HadCRU has agreed to release data but it appears that a lot of the raw data has been destroyed. Jones threatened to destroy the data if he was forced to release it but whether he has or whether this was destroyed earlier is not known.
• Retired science teacher Peter Foster is now a deer farmer at Merton. He was the recipient of FoRST teaching fellowship (OU Geology dept 1995)
