29 July 2012

The Conversion of a Climate-Change Skeptic

By Joe Romm, a Climate Progress cross-post
ten year data analysis comparison graph
The decadal land-surface average temperature using a 10-year moving average of surface temperatures over land. Anomalies are relative to the Jan 1950 – December 1979 mean. The grey band indicates 95% statistical and spatial uncertainty interval.A Koch-funded reanalysis of 1.6 billion temperature reports finds that “essentially all of this increase is due to the human emission of greenhouse gases.”
The Berkeley Earth Surface Temperature Study (BEST) is poised to release its findings next week on the cause of recent global warming.


UPDATE (9 pm): A NY Times op-ed by Richard Muller, BEST’s Founder and Scientific Director, has been published, “The Conversion of a Climate-Change Skeptic.” Here is the money graf:
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.
Yes, yes, I know, the finding itself is “dog bites man.” What makes this “man bites dog” is that Muller has been a skeptic of climate science, and the single biggest funder of this study is the “Charles G. Koch Charitable Foundation ($150,000).” The Kochs are the leading funder of climate disinformation in the world! 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. Moreover, it appears likely that essentially all of this increase results from the human emission of greenhouse gases.
These findings are stronger than those of the Intergovernmental Panel on Climate Change, the United Nations group that defines the scientific and diplomatic consensus on global warming.
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 some background on BEST followed by a longer excerpt of the op-ed.

     A group of scientists led by one well-known skeptic, Muller — and whose only climatologist listed is Judith Curry, a well-known confusionist [see Schmidt and Annan and Steig andVerheggen, and CP] — decided to reexamine all of the temperature data they could get their hands on. I broke the story of their initial findings in March 2011 (with the help of climatologist Ken Caldeira) – see Exclusive: Berkeley temperature study results “confirm the reality of global warming and support in all essential respects the historical temperature analyses of the NOAA, NASA, and HadCRU.”
     The top figure is an updated chart of their findings from March of this year. They found a lot of warming. Indeed, their key paper from 2011 found:
… our analysis suggests a degree of global land-surface warming during the anthropogenic era that is consistent with prior work (e.g. NOAA) but on the high end of the existing range of reconstructions.
So the only remaining question for BEST was: What is the cause of that warming? Of course, those who read ClimateProgress or the scientific literature already knew the answer to that question (see the 12/11 post, It’s “Extremely Likely That at Least 74% of Observed Warming Since 1950″ Was Manmade; It’s Highly Likely All of It Was).
     BEST is set to release those findings this week. The excellent UK Guardian reporter, Leo Hickman, tweeted earlier today that “Significant climate-related news will be breaking on Guardian website in next 24-36 hours” and then he tweeted an hour ago the link to the excerpt of Muller’s op-ed. 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.
Well, in fact, to be seriously considered, an alternative explanation must match the data at least as well as does CO2 — and it must offer some mechanism that counteracts the well-known warming effect of CO2. Not bloody likely.
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. I expect the rate of warming to proceed at a steady pace, about one and a half degrees over land in the next 50 years, less if the oceans are included. 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. I hope that the Berkeley Earth analysis will help settle the scientific debate regarding global warming and its human causes.
Ouch.
     I asked Caldeira for a comment on Muller’s op-ed. He writes:
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.
     The basic scientific results have been established for a long time now, so I do not see the results of Muller et al as being scientifically important.  However, their result may be politically important.  It shows that even people who suspect climate scientists of being charlatans, when they take a hard look at the data, see that the climate scientists have been right all along.
Who’d have thunk it? Not the Kochs….