State Climatologist Offers ‘Hierarchy of Credibility’

Texas’s state climatologist suggests ‘hierarchy of credibility’ could help public sort out competing climate science claims.

SAN FRANCISCO, CA, Dec. 3, 2012 — Texas State Climatologist John Nielsen-Gammon, addressing a climate education session during AGU’s fall meeting, outlined what he calls a “hierarchy of credibility” he hopes the public can use in evaluating climate science claims.

Least credible of all, Nielsen-Gammon told a meeting, are “talking heads” populating television programming. A notch above them are press releases, he advises.

Next comes an individual study, and above that comes a whole series of studies supporting the earlier findings.

The “gold standard” in climate credibility, in Nielsen-Gammon’s book, is a report from the National Academy of Sciences.

Nielsen-Gammon, a Texas A&M faculty member who is the Texas state climatologist, said “the more unexpected the results of a study are, the more likely the study is to be incorrect.” But he noted too a propensity for many in the news media to find those “most unexpected” studies to be the most newsworthy, so they’re often the studies that get the most attention … even though they’re the least likely to stand up under the rigorous scrutiny of further review and testing.

Nielsen-Gammon, who said he generally has found state climatologists to be largely unpoliticized, offers this advice for his climate science and state climatologist colleagues and counterparts: “Be, in practice and reality, a reliable and apolitical source of climate information.”

Bud Ward

Bud Ward is editor of Yale Climate Connections. (E-mail:
Bookmark the permalink.

One Response to State Climatologist Offers ‘Hierarchy of Credibility’

  1. james says:

    I totally agree with the “Hierarchy of Credibility” thing. But how can we evaluate if a particular climate science claim is credible?

    How can we measure the credibility? Only way I can think of is, to wait till the claimed climate change actually happens or not. And then decide if it was true.

    Or look at all the claims made in the past, and evaluate them based on their success rate. It’s more about testing with the real results.

    Computer Technician