Knute Nadelhoffer, PhD, is one of seven experts who testified earlier this week before a committee of Congress about climate change. In this blog post, I’m going to explain why I found his written presentation irritating and unpersuasive.

This gentleman has 30 years of research experience. His expertise is in “arctic tundra and north temperate forest ecology and biogeochemistry.” He is currently the director of a field station near the Great Lakes Basin “which hosts researchers from around the world.” He is also a professor at the University of Michigan.

All of this is, indeed, worthy of respect. Moreover one of the concerns raised by Nadelhoffer in his presentation does sound disturbing. In his words:

Lake Superior is warming at an alarming rate; Average water temperature increased by 4.5 °F from 1979 to 2006, or approximately 0.2 °F per year during this 28-year interval (Austin & Coleman, 2007)…Given the huge volume of water in this lake, the energy required to raise temperatures this quickly is stunning. [bold added]

But notice his use of theatrical language – alarming and stunning. Notice, also, that he cites only one research paper rather than a number of studies that all found the same thing. I get nervous when people base dramatic claims on a single piece of research.

The abstract of the paper in question is here. The first line of it reads::

Lake Superior summer (July–September) surface water temperatures have increased approximately 2.5°C over the interval 1979–2006, equivalent to a rate of (11 ± 6) × 10⁻²°C yr⁻¹, significantly in excess of regional atmospheric warming. [bold added]

I’m not a scientist, but I think it matters that this paper addresses only summer temperatures rather than year-round ones. I also think it matters that the paper deals with surface temperatures. By mentioning “the huge volume of water” in Lake Superior Nadelhoffer has left the impression that the entire lake has warmed by that amount. But this paper does not make that claim.

I would never have thought to check the above reference had it not been for the fact that Nadelhoffer makes numerous other statements that seem questionable to me. For example, he declares:

We know the climate is changing. It is real, it is happening…

So? Twenty thousand years ago 97% of Canada was covered by ice. That ice melted and shrank all on its own. The Egyptian pharaohs, remember, only came into the picture 5,000 years ago, while the Romans ruled 2,000 years ago. The mere fact that the climate is changing doesn’t mean squat.

Now here’s where the tundra specialist reaches well beyond his expertise and becomes a political advocate:

…the science has become essentially irrefutable on this point – rising concentrations of greenhouse gases…in the atmosphere, resulting from fossil fuel combustion and other human activities, are the primary drivers of these recent changes in the climate system. There are no other viable, science-based explanations for the effects we are seeing…we cannot ignore what the science is telling us about these changes any longer. This sentiment is supported by nearly 149 (as of March 5) scientists from Michigan who have signed a letter appended to my testimony. [bold added]

So in one breath he says the science is irrefutable. In the next he says human-produced greenhouse gases are at fault because we can’t think of any other explanation. And then he announces that we shouldn’t ignore what the science is telling us.

I’m sorry, but the logic here is rather strained. Just because we puny humans – who’ve only been studying this 4.5-billion-year-old planet in a systematic way for a few hundred years – haven’t found another explanation does not mean the answer is obvious or that the case is closed. The notion that 149 other Michigan scientists support this feeble sort of reasoning does not inspire confidence in the intellectual depth of this particular American state.

Nadelhoffer then talks about the Intergovernmental Panel on Climate Change (IPPC). He tells the committee that the IPCC’s 2007 report:

…involved over 500 expert lead authors (including 5 from Michigan) and more than 2000 reviewers (myself included).

As readers of this blog know, it turns out that some IPCC lead authors aren’t experts at all (see here and here). Moreover, it doesn’t matter how many reviewers there were. What’s important is whether or not anyone took their remarks seriously.

As an InterAcademy Council report on the IPCC observed last August, there’s nothing in IPCC procedures that prevents authors from ignoring comments submitted by reviewers. The embarrassing Himalayan glacier error could have been avoided had the IPCC merely paid attention to the reviewers who did, in fact, point it out.

Nadelhoffer continues by declaring that the climate needs to be stabilized. Tell that to the ice sheets that used to blanket Canada. In a presentation 14 double-spaced pages in length this ecologist has a great deal to say about something else that is, frankly, well beyond his purvue (bold added by me):

Congress, likewise, should support efforts to limit human-caused climate change, namely fossil fuel emissions…

…limiting and eventually reducing greenhouse gas emissions…

…if we continue on our current emissions path.

…unless we act to stabilize and reduce GHG emissions.

…we must start now to stabilize atmospheric greenhouse gas emissions…

…if we do not act to mitigate and reduce emissions.

…strong federal policies to reduce fossil fuel emissions.

…regulatory policies to limit harmful greenhouse gas emissions…

It is the proper role of a scientist to observe, record, and interpret data. It is not the role of any scientist in any field to to promote one solution above all others. Scientists worthy of the name do not behave as if there were only one response to a problem.

What are our full range of options? What are the strengths and shortcomings of each? What tradeoffs seem reasonable? How should we prioritize present challenges versus theoretical harm in the theoretical future? All of these questions should be part of a collective conversation in which the entire electorate has a voice. It is not the role of scientists to decide amongst themselves how we should all proceed.

I’m afraid that Nadelhoffer pushed me right over the edge when, toward the end of his presentation, he said:

As a scientist I cannot ignore what solid and rigorous research is telling me every day…Science is not a partisan endeavor.

Actually, sir, the scientific method is not partisan. But human beings frequently are. And those who dress-up their personal worldview as non-partisan science deserve to be scorned.

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hearing main page

Nadelhoffer’s written testimony [backup link]

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