The co-author of a widely-cited global warming study has owned up to a major math error uncovered six days after its Oct. 31 publication by an independent scientist.
The study used a new method of measuring the ocean's absorption of heat, and concluded - through incorrect math - that 60% more heat had been absorbed than previously thought.
The report was covered or referenced by MSM outlets worldwide, including the Washington Post, New York Times, BBC, Reuters and others.
Shortly after the article was published, however, independent UK-based researcher Nicholas Lewis published a comprehensive blog post, claiming he had found a "major problem" with the research.
“So far as I can see, their method vastly underestimates the uncertainty,” Lewis said in an interview Tuesday, “as well as biasing up significantly, nearly 30 percent, the central estimate.”
Lewis added that he tends “to read a large number of papers, and, having a mathematics as well as a physics background, I tend to look at them quite carefully, and see if they make sense. And where they don’t make sense — with this one, it’s fairly obvious it didn’t make sense — I look into them more deeply.”
Lewis has argued in past studies and commentaries that climate scientists are predicting too much warming because of their reliance on computer simulations, and that current data from the planet itself suggests global warming will be less severe than feared. -Washington Post
"When we were confronted with his insight it became immediately clear there was an issue there," said Ralph Keeling, a scientist with the Scripps Institute of Oceanography who co-authored the paper with Princeton University scientist and lead author, Laure Resplandy. "We’re grateful to have it be pointed out quickly so that we could correct it quickly."
Keeling said they have since redone the calculations, finding the ocean is still likely warmer than the estimate used by the IPCC. However, that increase in heat has a larger range of probability than initially thought — between 10 percent and 70 percent, as other studies have already found.
“Our error margins are too big now to really weigh in on the precise amount of warming that’s going on in the ocean,” Keeling said. “We really muffed the error margins.” -San Diego Union-Tribune
"I accept responsibility for what happened because it’s my role to make sure that those kind of details got conveyed," Keeling told the Washington Post on Tuesday.
Keeling addressed the math error in a Friday note:
Note from co-author Ralph Keeling Nov. 9, 2018: I am working with my co-authors to address two problems that came to our attention since publication. These problems, related to incorrectly treating systematic errors in the O2 measurements and the use of a constant land O2:C exchange ratio of 1.1, do not invalidate the study’s methodology or the new insights into ocean biogeochemistry on which it is based. We expect the combined effect of these two corrections to have a small impact on our calculations of overall heat uptake, but with larger margins of error. We are redoing the calculations and preparing author corrections for submission to Nature. -Scripps.ucsd.edu
The scientists have submitted a correction to the journal Nature, which published the study.