Last week, a project called Berkeley Earth released drafts of its findings. The project was started by a physicist, Richard Muller, who had previously expressed doubts about the mathematical rigor of climate science; it received funding from a variety of sources, including the Department of Energy and foundations set up by Bill Gates and the Koch brothers. The Berkeley Earth team set out to analyze records of the Earth's surface temperatures to answer questions about the trajectory of the planet's recent warming that had been raised by skeptics and contrarians. To a very large degree, it discovered that climatologists had been doing a pretty good job after all.
Climatologists have generated a number of reconstructions of global temperature trends based on instruments that have been recording temperatures since the 1800s. However, one of those records was produced by members of the Climatic Research Unit at the University of East Anglia. That record became embroiled in controversy: the CRU was the target of e-mail thefts, was unable to release some of its records due to commercial agreements, and had destroyed some paper copies of original data decades earlier. NASA and NOAA, however, performed independent reconstructions based on publicly available data.
Even those, however, had become the targets of criticism. Recording stations were moved, their surroundings urbanized, and researchers performed adjustments or dropped some stations entirely in order to compensate. Various parties hostile to the findings of climate science have raised questions about this process. Have the scientists really compensated for urbanization? Was the trajectory of the modern warming really as extreme as the temperature records were showing?
And those were the moderate voices. At the more extreme end of the spectrum, some accused researchers of selectively dropping only stations that showed cooling trends, and raised questions about whether the planet had warmed at all. These questions weren't very realistic—melting ice, migrating species, and other factors made it pretty clear the planet was warming—but the climate debate has no shortage of unreasonable voices.
http://arstechnica.com/science/news/2011/10/climate-skeptics-perform-independent-analysis-finally-convinced-earth-is-getting-warmer.ars