World May Not Be Warming After All

Imagine that:

The United Nations climate panel faces a new challenge with scientists casting doubt on its claim that global temperatures are rising inexorably because of human pollution.

In its last assessment the Intergovernmental Panel on Climate Change (IPCC) said the evidence that the world was warming was “unequivocal”.

It warned that greenhouse gases had already heated the world by 0.7C and that there could be 5C-6C more warming by 2100, with devastating impacts on humanity and wildlife. 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.”

You can't compare two data points for a particular weather station and come to any sort of conclusion if that weather station has been moved or the environment around it significantly changed. Those who have tried to do that, whether by fraud or by accident, have caused skewed results that simply can't be counted on.