Over the weekend, UC-Berkeley professor Richard Muller outed himself as a “converted” climate “sceptic” in the New York Times after his Berkeley Earth Surface Temperature project concluded the earth’s surface temperature had increased 2.5 degrees Fahrenheit in the past 250 years and one and a half degrees in the past 50 years, likely entirely because of human industrial activity.
What makes this newsworthy, according to The Guardian, is that BEST had received $150,000 from the Charles G. Koch Charitable Foundation, whose namesake also runs the climate sceptic research program The Heartland Institute.
From Muller’s op-ed:
“…our record is long enough that we could search for the fingerprint of solar variability, based on the historical record of sunspots. That fingerprint is absent. Although the I.P.C.C. allowed for the possibility that variations in sunlight could have ended the “Little Ice Age,” a period of cooling from the 14th century to about 1850, our data argues strongly that the temperature rise of the past 250 years cannot be attributed to solar changes. This conclusion is, in retrospect, not too surprising; we’ve learned from satellite measurements that solar activity changes the brightness of the sun very little.”
“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 scepticism, but they raise the bar: to be considered seriously, an alternative explanation must match the data at least as well as carbon dioxide does. Adding methane, a second greenhouse gas, to our analysis doesn’t change the results.
What now? As a scientist, Muller can only cross his fingers.
“I hope that the Berkeley Earth analysis will help settle the scientific debate regarding global warming and its human causes. Then comes the difficult part: agreeing across the political and diplomatic spectrum about what can and should be done.”