The UN IPCC is facing a new challenge from scientists that doubt its claim that global temperatures are rising because of human pollution. Despite the conclusions of the last IPCC report, that greenhouse gases had already caused an 0.7C increase in the world temperatures and that more warming by the year 2100 would have devastating impacts on humanity and wildlife, new research is casting doubt upon those claims.
The doubts are being raised by John Christy a former IPCC lead author from the University of Alabama plus other scientists. They focus on the thousands of weather stations around the world which have been used to collect temperature data for over 150 years. They believe that these weather stations have been seriously compromised by factors such as urbanisation, changes in land use and being moved from site to site.
The new research that has been conducted involved at least 3 locations and in each case 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.
Professor Ross McKitrick, of the University of Guelph, Canada is another critic who is questioning the methods used by the IPCC. He concluded that the IPCC’s climate data are contaminated with surface effects from industrialisation and data quality problems. These problems add up to a large warming bias.
Anthony Watts, an American meteorologist is also questioning the data of US weather stations. His report shows weather stations where the readings are distorted by heat-generating equipment such as air-conditioning units and waste treatment plants. In other locations weather stations were located near runways at airports. Two examples are at Rome and Manchester airports. Both are affected by various factors that mean the data is unrealiable.
Professor Terry Mills, a professor of applied statistics and econometrics at Loughborough University looked at the same data set as the IPCC. He found that the warming trend over the past 30 years was as likely to be due to random fluctuations as the impact of greenhouse gases.