Overview

The assertion that the climate is changing as a result of human activities due to emissions of CO ₂ and other greenhouse gases which magnify the natural greenhouse effect seems to have been elevated into a dogma with the passage of time. And this is supposed to have a whole range of disastrous consequences. This dogma is in sharp contrast with the views of a prominent Netherlands scientist, Frits B ttcher, who believes that this assertion may well turn out to be one of the greatest scientific errors of the twentieth century. Is that assessment correct? In our view, the answer to that question is overwhelmingly negative, but also affirmative to a small extent. Negative because the International Panel on Climate Change (IPCC), which plays a central role in the scientific underpinning of the measures which are currently being considered to counter the greenhouse effect, expressly refuses to commit itself and repeatedly points to the great uncertainties in its analysis. Chapter 14 of IPCC s Third Assessment Report provides a clear example of this. In it, IPCC admits albeit in scientific jargon which somewhat obscures the picture for the lay reader that the models used at the present time cannot deliver reliable projections for the future (see box). But, even in the highly simplified Summary for Policymakers (17 pages of text), the word uncertainty or an equivalent occurs no fewer than forty times. This is probably unprecedented for such a short document. The most striking illustration of this...