In short, a Koch-funded study has found that the IPCC “consensus” underestimated both the rate of surface warming and how much could be attributed to human emissions! Here is more of the op-ed: 
 
 How definite is the attribution to humans? The carbon dioxide curve gives a better match than anything else we’ve tried. Its magnitude is consistent with the calculated greenhouse effect — extra warming from trapped heat radiation. These facts don’t prove causality and they shouldn’t end skepticism, but they raise the bar: to be considered seriously, an alternative explanation must match the data at least as well as carbon dioxide does. Our result is based simply on the close agreement between the shape of the observed temperature rise and the known greenhouse gas increase. UPDATE (9 AM, 7/29): The UK Guardian has a good story up, “Climate change study forces sceptical scientists to change minds: Earth’s land shown to have warmed by 1.5C over past 250 years, with humans being almost entirely responsible.” 
 
 And here’s an amusing tweet from a top U.S. climatologist, Michael Mann: 
 
 Below is some background on BEST followed by a longer excerpt of the op-ed. The careful analysis by our team is laid out in five scientific papers now online at BerkeleyEarth.org. That site also shows our chart of temperature from 1753 to the present, with its clear fingerprint of volcanoes and carbon dioxide, but containing no component that matches solar activity. Four of our papers have undergone extensive scrutiny by the scientific community, and the newest, a paper with the analysis of the human component, is now posted, along with the data and computer programs used. Such transparency is the heart of the scientific method; if you find our conclusions implausible, tell us of any errors of data or analysis. What about the future? As carbon dioxide emissions increase, the temperature should continue to rise. It gets better: 
 
 Our results show that the average temperature of the earth’s land has risen by two and a half degrees Fahrenheit over the past 250 years, including an increase of one and a half degrees over the most recent 50 years. But if China continues its rapid economic growth (it has averaged 10 percent per year over the last 20 years) and its vast use of coal (it typically adds one new gigawatt per month), then that same warming could take place in less than 20 years. Science is that narrow realm of knowledge that, in principle, is universally accepted. I embarked on this analysis to answer questions that, to my mind, had not been answered. The Berkeley Earth Surface Temperature Study (BEST) is poised to release its findings next week on the cause of recent global warming.
– Physicist Richard Muller co-founded the Berkeley Earth Surface Temperature project three years ago to debunk global warming fears, even getting a hefty grant from the conservative Koch brothers for his work. Last fall, he backtracked a bit, admitting the evidence for global warming was solid, but denying you could prove humanity was the cause. Today, however, even that last caveat is gone, he writes in the New York Times. "Call me a converted skeptic," Muller writes. "Humans are almost entirely the cause." Muller is still skeptical about alarmists, though, and thinks there is no connection between global warming and Hurricane Katrina or dying polar bears or anything like that. But he is certain that people are causing the world to heat up, a process that will go much faster in the future as China continues to develop. Not everyone is so impressed by Muller's conversion. "I am glad that Muller et al. have taken a look at the data and have come to essentially the same conclusion that nearly everyone else had come to more than a decade ago," one climatologist tells Think Progress. Click for Muller's full column.