Sunday, February 14, 2010
Climategate U-turn as scientist at centre of row admits: There has been no global warming since 1995
...Professor Jones also conceded the possibility that the world was warmer in medieval times than now – suggesting global warming may not be a man-made phenomenon.
And he said that for the past 15 years there has been no ‘statistically significant’ warming.
The admissions will be seized on by sceptics as fresh evidence that there are serious flaws at the heart of the science of climate change and the orthodoxy that recent rises in temperature are largely man-made...
World may not be warming, say scientists
...However, new research, including work by British scientists, is casting doubt on such claims. Some even suggest the world may not be warming much at all.
“The temperature records cannot be relied on as indicators of global change,” said John Christy, professor of atmospheric science at the University of Alabama in Huntsville, a former lead author on the IPCC.
The doubts of Christy and a number of other researchers focus on the thousands of weather stations around the world, which have been used to collect temperature data over the past 150 years.
These stations, they believe, have been seriously compromised by factors such as urbanisation, changes in land use and, in many cases, being moved from site to site.
Christy has published research papers looking at these effects in three different regions: east Africa, and the American states of California and Alabama.
“The story is the same for each one,” he said. “The popular data sets show a lot of warming but the apparent temperature rise was actually caused by local factors affecting the weather stations, such as land development.”
The IPCC faces similar criticisms from Ross McKitrick, professor of economics at the University of Guelph, Canada, who was invited by the panel to review its last report.
The experience turned him into a strong critic and he has since published a research paper questioning its methods.
“We concluded, with overwhelming statistical significance, that the IPCC’s climate data are contaminated with surface effects from industrialisation and data quality problems. These add up to a large warming bias,” he said. ...
...Terry Mills, professor of applied statistics and econometrics at Loughborough University, looked at the same data as the IPCC. He found that the warming trend it reported over the past 30 years or so was just as likely to be due to random fluctuations as to the impacts of greenhouse gases. Mills’s findings are to be published in Climatic Change, an environmental journal.
“The earth has gone through warming spells like these at least twice before in the last 1,000 years,” he said. ...