London: A US scientific group set up in the wake of the “Climategate” affair has confirmed that the Earth’s surface is really getting warmer.
The Berkeley Earth Project has used new methods and some new data, but finds the same warming trend seen by groups such as the UK Met Office and NASA.
“Climategate”, in 2009, involved claims global warming had been exaggerated.
University of California physics professor Richard Muller, who was concerned by claims that established teams of climate researchers had not been entirely open with their data, established the project.
“We were concerned that the climate scientists were not putting all their data into the public domain, whether using Freedom of Information rules or anything else,” Muller told BBC News.
“Science should be open, and data should be open, as a matter of principle,” he stated.
The group’s work also examined claims from “sceptical” bloggers that temperature data from weather stations did not show a true global warming trend.
The claim was that many stations have registered warming because they are located in or near cities, and those cities have been growing - the urban heat island effect.
The Berkeley group found about 40,000 weather stations around the world whose output has been recorded and stored in digital form. It developed a new way of analysing the data to plot the global temperature trend over land since 1800.
What came out was a graph remarkably similar to those produced by the world’s three most important and established groups, whose work had been decried as unreliable and shoddy in climate sceptic circles.
The National Oceanic and Atmospheric Administration (NOAA) and National Aeronautics and Space Administration (NASA) maintain two of those three records in the US.
The third is a collaboration between the UK Met Office and UEA’s Climatic Research Unit (CRU), from which the e-mails that formed the basis of the “Climategate” furore were hacked two years ago.
“Our biggest surprise was that the new results agreed so closely with the warming values published previously by other teams in the US and the UK,” said Professor Muller.
“This confirms that these studies were done carefully and that potential biases identified by climate change sceptics did not seriously affect their conclusions,” he added.
The Berkeley group said it has also found evidence that changing sea temperatures in the north Atlantic may be a major reason why the Earth’s average temperature varies globally from year to year.