The researchers behind the curious Berkeley Earth Surface Temperature study have released their latest results, concluding that the globe has warmed around 2.5 degrees Celsius over the past 250 years (see graph at right; PDF available here). Discussing the unpublished work with typical flair in an op-ed for the New York Times, physicist and self-proclaimed skeptic-turned-believer Richard Muller said “essentially all” of the increase is due to humans.