Back in 2010, Richard Muller, a Berkeley physicist and self-proclaimed climate skeptic, decided to launch the Berkeley Earth Surface Temperature (BEST) project to review the temperature data that underpinned global-warming claims. Remember, this was not long after the Climategate affair had erupted, at a time when skeptics were griping that climatologists had based their claims on faulty temperature data.
Muller’s stated aims were simple. He and his team would scour and re-analyze the climate data, putting all their calculations and methods online. Skeptics cheered the effort. “I’m prepared to accept whatever result they produce, even if it proves my premise wrong,” wrote Anthony Watts, a blogger who has criticized the quality of the weather stations in the United Statse that provide temperature data. The Charles G. Koch Foundation even gave Muller’s project $150,000 — and the Koch brothers, recall, are hardly fans of mainstream climate science.
So what are the end results? Muller’s team appears to have confirmed the basic tenets of climate science. Back in March, Muller told the House Science and Technology Committee that, contrary to what he expected, the existing temperature data was “excellent.” He went on: “We see a global warming trend that is very similar to that previously reported by the other groups.” And, today, the BEST team has released a flurry of new papers that confirm that the planet is getting hotter. As the team’s two-page summary flatly concludes, “Global warming is real.”Here’s a chart comparing their findings with existing data:
The BEST team tried to take a number of skeptic claims seriously, to see if they panned out. Take, for instance, their paper on the “urban heat island effect.” Watts has long argued that many weather stations collecting temperature data could be biased by being located in cities. Since cities are naturally warmer than rural areas (because building materials retain more heat), the uptick in recorded temperatures might be exaggerated, an illusion spawned by increased urbanization. So Muller’s team decided to compare overall temperature trends with only those weather stations based in rural areas. And, as it turns out the trends match up well. “Urban warming does not unduly bias estimates of recent global temperature change,” Muller’s group concluded.
That shouldn’t be so jaw-dropping. Previous analyses — like this one from the National Oceanic and Atmospheric Administration — have responded to Watts’ concerns by showing that a few flawed stations don’t warp the overall trend. But maybe Muller’s team can finally put this controversy to rest, right? Well, not yet. As Watts responds over at his site, the BEST papers still haven’t been peer-reviewed (an important caveat, to be sure). And Watts isn’t pleased with how much pre-publication hype the studies are getting. But so far, what we have is a prominent skeptic casting a critical eye at the data and finding, much to his own surprise, that the data holds up.