A broad-based new study of climate change has confirmed earlier evidence of a global rise in average land temperatures of 1 degree Centigrade since the 1950’s. However, it draws no conclusions as to whether this warming is man-made.
The Berkeley Earth Surface Temperature study, released on Thursday, analyzed data from fifteen different sources, some going back more than two centuries, to answer doubts raised by climate change skeptics in response to earlier studies.
Previous studies had been able to rule out certain sources of possible error, including the urban heat island effect and poor station quality, but they had been based on a limited number of data sources, and skeptics had continued to claim that the results might have been skewed as a result. The new study, which includes almost all available data, is intended to counter that claim.
The preliminary results of the study, along with the entire database and other materials, are publicly available at the Berkeley Earth website.
According to the project’s founder, Professor Richard A. Muller, “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. This confirms that these studies were done carefully and that potential biases identified by climate change skeptics did not seriously affect their conclusions.”
Project co-founder Elizabeth Muller added that she hopes the study will “cool the debate over global warming by addressing many of the valid concerns of the skeptics in a clear and rigorous way.”
The authors of the study point out that although 2/3 of the sites examined showed warming, another 1/3 — including much of the United States and northern Europe — had experienced cooling over the past 70 years, and they suggest that this could be responsible for widespread climate skepticism in those regions.
Photo by AgnosticPreachersKid (Own work) [CC-BY-SA-3.0 (www.creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons.