The Gary Null Blog

ScienceDaily (Oct. 21, 2011) — Global warming is real, according to a major study released Oct. 20. Despite issues raised by climate change skeptics, the Berkeley Earth Surface Temperature study finds reliable evidence of a rise in the average world land temperature of approximately 1°C since the mid-1950s.

Analyzing temperature data from 15 sources, in some cases going as far back as 1800, the Berkeley Earth study directly addressed scientific concerns raised by skeptics, including the urban heat island effect, poor station quality, and the risk of data selection bias.

On the basis of its analysis, according to Berkeley Earth's founder and scientific director, Professor Richard A. Muller, the group concluded that earlier studies based on more limited data by teams in the United States and Britain had accurately estimated the extent of land surface warming.

"Our biggest surprise was that the new results agreed so closely with the warming values published previously by other teams in the U.S. and the U.K.," Muller said. "This confirms that these studies were done carefully and that potential biases identified by climate change skeptics did not seriously affect their conclusions."