Atmospheric Scientist here at Weather Underground, with serious nerd love for tropical cyclones and climate change. Twitter: @WunderAngela
By: Angela Fritz , 7:35 PM GMT on July 30, 2012
I originally posted this in Jeff Masters' blog, which you can see here.
The Berkeley Earth Surface Temperature (BEST) group is in the news again, surprising climate change skeptics with results from a new study that shows the earth has warmed 2.5 °F over the past 250 years, and 1.5 °F over the past fifty years, and that "essentially all of this increase results from the human emission of greenhouse gases." Dr. Richard Muller, who heads the BEST team, now considers himself a "converted skeptic," which he wrote about in a New York Times op-ed on Saturday:
"Call me a converted skeptic. Three years ago I identified problems in previous climate studies that, in my mind, threw doubt on the very existence of global warming. Last year, following an intensive research effort involving a dozen scientists, I concluded that global warming was real and that the prior estimates of the rate of warming were correct. I'm now going a step further: Humans are almost entirely the cause."
Not only is the lead scientist of the project a former climate change skeptic, BEST itself is funded by the Charles G. Koch Charitable Foundation, an organization that is rooted deep in the oil industry and the manufactured doubt industry. Two years ago a report found that the Koch brothers outspent Exxon Mobile in science disinformation at a whopping $48.5 million since 1997. Despite the special interest of their funders, BEST has made it clear, both on their website and in the results they've come to, that funding sources will not play a role in the results of their research, and that they "will be presented with full transparency."
Figure 1. The BEST surface temperature reconstruction (black) with a 95% confidence interval (grey). The overlying curve (red) is a curve fit to the temperature reconstruction based on atmospheric carbon dioxide concentration and volcanic activity.
Muller's research comes to essentially the same conclusion as similar well-known studies on the topic of global temperature rise. It attempts to address the question of attribution—how much has the globe warmed, and what is to blame? They found that solar activity relates very little to the fluctuations in temperature over the past 250 years, and that the warming is "almost entirely" due to greenhouse gas emissions, combined with some variability from volcanic eruptions. It's important to note that while Muller and his team found warming of 2.5 °F over the past 250 years, and 1.5 °F over the past fifty years, the IPCC did not find quite that much warming in their AR4 assessment.
BEST was in the news in October when they released results from their first independent study of surface temperature, which set out to address some common skeptic concerns about previous temperature reconstructions (e.g. NASA, NOAA, and HadCRU), including the urban heat island effect and the potential "cherry picking" of data. Both of these concerns were found to be non-issues. BEST concluded that the urban heat island effect does not contribute significantly to the land temperature rise. In fact, in their new study, they were able to reproduce the warming trend using nothing but rural stations.
BEST Part II doesn't necessarily bring anything new to the science as it currently exists; we've known for decades that the planet is warming and the cause is manmade. But in this case the scientific process played out the way it should: a skeptic of a certain scientific result took on the project, and was open and willing to accept whatever result the science gave him. We now have another batch of results in the group of well-known temperature reconstructions, funded by big-oil-interests, that tells us the planet is warming and that the cause is fossil fuel emissions.
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