Lots of shenanigans going on with the graphs used in the movie, apparently, most of all involving a key data set about temperatures over the last 120 years that was inaccurately sourced, allegedly outdated, and then manipulated to make it seem as though it was current. “There was a fluff there,” said the producer when questioned about it.
And that ain’t all:
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 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.
Really? I seem to recall reading recently that current temperatures don’t exceed those of the past 1,000 years, no matter how much Al Gore wishes it were true. Which right-wing rag did that come from again?
Ah yes. Yesterday’s New York Times:
[A] report last June by the National Academies seemed to contradict Mr. Gore’s portrayal of recent temperatures as the highest in the past millennium. Instead, the report said, current highs appeared unrivaled since only 1600, the tail end of a temperature rise known as the medieval warm period…
“Nowhere does Mr. Gore tell his audience that all of the phenomena that he describes fall within the natural range of environmental change on our planet,” Robert M. Carter, a marine geologist at James Cook University in Australia, said in a September blog. “Nor does he present any evidence that climate during the 20th century departed discernibly from its historical pattern of constant change.”
In October, Dr. Easterbrook made similar points at the geological society meeting in Philadelphia. He hotly disputed Mr. Gore’s claim that “our civilization has never experienced any environmental shift remotely similar to this” threatened change.
Nonsense, Dr. Easterbrook told the crowded session. He flashed a slide that showed temperature trends for the past 15,000 years. It highlighted 10 large swings, including the medieval warm period. These shifts, he said, were up to “20 times greater than the warming in the past century.”
Exit question: Does it matter anymore?