In the December 9th New York Times, columnist Tom Friedman tells his readers that the precautionary principle demands that the world take aggressive action to curb the risks of damaging climate change, even if the likelihood of it is only one percent. To support his claim, he writes: “The evidence that our planet, since the Industrial Revolution, has been on a broad warming trend outside the normal variation patterns — with periodic micro-cooling phases — has been documented by a variety of independent research centers.”
Friedman has just about all of this wrong.
For starters, very few, if any, scientists contend that the beginning of the Industrial Revolution sparked a nearly instantaneous rise in temperatures. The rise in temperatures that most of the CRU scientists and most mainstream scientists consider to be non-normal is the one that began in 1975 and ended in 1998.
This is an important point, because although we did in fact start warming in approximately the year 1800, meaningful rises in co2 would not occur for nearly a century and a half. Why did we begin warming in 1800? One answer is that it was time for the pendulum to swing back toward warm after the 550-year period known as the Little Ice Age. Internal dynamics and possibly solar variability likely brought our ocean-atmosphere system both into and out of the LIA.
The arguments about what falls within “normal,” temperature-wise and climate-wise, will continue for some time, largely because of reasonable disputes concerning tree-ring analysis. The tree-ring analysis that Michael Mann, Keith Briffa, the Goddard Institute for Space Studies, and the Climatic Research Unit at the University of East Anglia all depend on to show the Modern Warm Period as troublingly pronounced is fraught with issues. Tree rings simply cannot be read with the omniscience they would require to provide a true record of temperature. Why not? Because individual trees growth is affected by too many variables: changing soil composition, changing numbers of competitor trees in a stand, changing precipitation, changing levels of cloud, nearby volcanic eruptions (especially pertinent in Siberia from which many of the most significant tree-ring studies are drawn). This is only a partial list!
Tree-ring data, as a proxy for temperatures, will be laughed at within a generation. Some are laughing now.
In the meantime, there is abundant evidence that the Medieval Warm Period lasted from roughly the year 1000 to the year 1300 and was warmer than today. Hundreds of articles produced by non-Big Oil funded scientists have confirmed the existence of, the worldwide character of, and the strength of the Medieval Warm Period.
As Mr. Friedman insists that primarily (or only!) oil-funded science disputes the findings of global warming alarmism, perhaps he would like to name names? Or is this a conspiracy theory that cannot survive the light of day? In point of fact, the heroic scientists who look at climate with eyes that can see anything other than a disaster movie in the making generally do so at their career and financial peril. In the climate wars, Goliath is the scientists funded by governments (cashing checks worth billions). David is the important minority of scientists who have publication blocked by the antics described in the CRU e-mail release, who lose offices and tenure-track positions because of their heresy.
A final point. Not one climatologist suggests that the decade just ended, touted as the warmest on record, is anywhere near as warm as the Holocene Optimum. (The Holocene interglacial, our quite gentle climatic nest, started 11,000 years ago.) The Holocene Optimum lasted from 8,000 to 5,000 years before present. The world ocean was higher; forests extended to the Arctic Ocean; sea level was at least a meter higher than today.
Why is a situation like the Holocene Optimum considered dangerous and out of control? Yet, we are not as warm as that now. And we may not get that warm again before the next Ice Age begins. If we do, why will intelligent men and women, many of them scientifically trained, believe that THIS TIME forests straining to move north toward the Arctic Ocean are part of a disaster movie, and last time they were a beautiful and Edenic part of nature?
As for the precautionary principle, it is wrongly applied here. As Bjorn Lomborg correctly points out, every dollar spent researching and “fighting” climate change is one less dollar that can be spent on something else. I, for one, would rather see clean-water systems installed in the Third World (and my own country, for that matter), before another 100 billion dollars are spent on computer modeling the effect of a trace atmospheric gas that has yet to generate a warming that exceeds the Holocene Optimum (and, likely, the Medieval Warm Period).