found this article related to this movie:
http://news.independent.co.uk/environment/climate_change/article2355956.ece
The real global warming swindle
A Channel 4 documentary claimed that climate change was a conspiratorial lie. But an analysis of the evidence it used shows the film was riddled with distortions and errors
By Steve Connor
Published: 14 March 2007
A Channel 4 documentary that claimed global warming is a swindle was itself flawed with major errors which seriously undermine the programme’s credibility, according to an investigation by The Independent.
The Great Global Warming Swindle, was based on graphs that were distorted, mislabelled or just plain wrong. The graphs were nevertheless used to attack the credibility and honesty of climate scientists.
A graph central to the programme’s thesis, purporting to show variations in global temperatures over the past century, claimed to show that global warming was not linked with industrial emissions of carbon dioxide. Yet the graph was not what it seemed.
Other graphs used out-of-date information or data that was shown some years ago to be wrong. Yet the programme makers claimed the graphs demonstrated that orthodox climate science was a conspiratorial “lie” foisted on the public.
Channel 4 yesterday distanced itself from the programme, referring this newspaper’s inquiries to a public relations consultant working on behalf of Wag TV, the production company behind the documentary.
Martin Durkin, who wrote and directed the film, admitted yesterday that one of the graphs contained serious errors but he said they were corrected in time for the second transmission of the programme following inquiries by The Independent.
Mr Durkin has already been criticised by one scientist who took part in the programme over alleged misrepresentation of his views on the climate.
The main arguments made in Mr Durkin’s film were that climate change had little if anything to do with man-made carbon dioxide and that global warming can instead be linked directly with solar activity - sun spots.
One of the principal supports for his thesis came in the form of a graph labelled “World Temp - 120 years”, which claimed to show rises and falls in average global temperatures between 1880 and 2000.
Mr Durkin’s film argued that most global warming over the past century occurred between 1900 and 1940 and that there was a period of cooling between 1940 and 1975 when the post-war economic boom was under way. This showed, he said, that global warming had little to do with industrial emissions of carbon dioxide.
The programme-makers labelled the source of the world temperature data as “Nasa” but when we inquired about where we could find this information, we received an email through Wag TV’s PR consultant saying that the graph was drawn from a 1998 diagram published in an obscure journal called Medical Sentinel. The authors of the paper are well-known climate sceptics who were funded by the Oregon Institute of Science and Medicine and the George C Marshall Institute, a right-wing Washington think-tank.
However, there are no diagrams in the paper that accurately compare with the C4 graph. The nearest comparison is a diagram of “terrestrial northern hemisphere” temperatures - which refers only to data gathered by weather stations in the top one third of the globe.
However, further inquiries revealed that the C4 graph was based on a diagram in another paper produced as part of a “petition project” by the same group of climate sceptics. This diagram was itself based on long out-of-date information on terrestrial temperatures compiled by Nasa scientists.
However, crucially, the axis along the bottom of the graph has been distorted in the C4 version of the graph, which made it look like the information was up-to-date when in fact the data ended in the early 1980s.
Mr Durkin admitted that his graphics team had extended the time axis along the bottom of the graph to the year 2000. “There was a fluff there,” he said.
If Mr Durkin had gone directly to the Nasa website he could have got the most up-to-date data. This would have demonstrated that the amount of global warming since 1975, as monitored by terrestrial weather stations around the world, has been greater than that between 1900 and 1940 - although that would have undermined his argument.
“The original Nasa data was very wiggly-lined and we wanted the simplest line we could find,” Mr Durkin said.
The programme failed to point out that scientists had now explained the period of “global cooling” between 1940 and 1970. It was caused by industrial emissions of sulphate pollutants, which tend to reflect sunlight. Subsequent clean-air laws have cleared up some of this pollution, revealing the true scale of global warming - a point that the film failed to mention.
Other graphs used in the film contained known errors, notably the graph of sunspot activity. Mr Durkin used data on solar cycle lengths which were first published in 1991 despite a corrected version being available - but again the corrected version would not have supported his argument. Mr Durkin also used a schematic graph of temperatures over the past 1,000 years that was at least 16 years old, which gave the impression that today’s temperatures are cooler than during the medieval warm period. If he had used a more recent, and widely available, composite graph it would have shown average temperatures far exceed the past 1,000 years.