Well, Paul Krugman sure smeared me in his May 29 column (sub. req’d.) where he accused me of “fraud pure and simple” in congressional testimony eight (!) years ago.

Krugman’s screed was just another salvo in the current global warming charm offensive, coinciding with Al Gore’s screeching movie, demonstrations against Max Mayfield, director of the National Hurricane Center, because he had the audacity to NOT blame last year’s Hurricane Katrina on global warming (which would have been “fraud pure and simple”), and multiple smearings of any climate scientist who dares to speak out against the current hysteria.

Krugman was incensed with my July 27, 1998 testimony before the House Committee on Small Business. In it, my purpose was to demonstrate that commonly held assumptions about climate change can be violated in a very few short years.

One of those is that greenhouse gas concentrations, mainly carbon dioxide, would continue on a constant exponential growth curve. NASA scientist James Hansen had a model that did just this, published in 1988, and referred to in his June 23, 1988 Senate testimony as a “Business as Usual” (BAU) scenario.

BAU generally assumes no significant legislation and no major technological changes. It’s pretty safe to say that this was what happened in the succeeding ten years.

He had two other scenarios that were different, one that gradually reduced emissions, and one that stopped the growth of atmospheric carbon dioxide in 2000. But those weren’t germane to my discussion. Somehow, Krugman labelled my not referring to them as “fraud.”

The BAU scenario produced a whopping surface temperature rise of 0.45 degrees Celsius in the short period from 1988 through 1997, the last year for which there was annual data published by the United Nations’ Intergovernmental Panel on Climate Change at the time of my testimony. The observed rise was 0.11 degrees.

I cited the reasons for this. In fact, the rate of carbon dioxide increase in the atmosphere was quite constant–rather than itself increasing like compound interest–during the period. Ten years later, Hansen published a paper in which he hypothesized that “apparently the rate of uptake by carbon dioxide sinks, either the ocean, or more likely the forests and soils, has increased.” This was not assumed in any of his scenarios. In fact, the general hypothesis has been that, as the planet warms, the ocean takes up carbon dioxide at a slower rate.

Then, contrary to everyone’s expectation, the second most-important global warming emission, methane, simply stopped increasing. Some years have shown an actual drop in its atmospheric concentration. To this day, no one knows why.

There’s also the nagging possibility that we haven’t yet figured out the true “sensitivity” of surface temperature to changes in carbon dioxide. Scientifically, that’s a chilling possibility.

On May 30, Roger Pielke, Jr., a highly esteemed researcher at University of Colorado’s Center for Science and Technology Policy Research, examined Hansen’s scenarios. Of the two “lower” ones, he concluded, “Neither is particularly accurate or realistic. Any conclusion that Hansen’s 1988 prediction got things right, necessarily must conclude that it got things right for the wrong reason.” (italics in original)

That’s precisely the keynote of my testimony eight years ago: in climate science, what you think is obviously true can literally change overnight, like the assumption of continued exponential growth of carbon dioxide, or how the earth responds.