A recent commentary implied that the "precautionary principle" should be a part of American policy in regard to climate change. This isn't without precedent: A similar policy was enacted among earlier civilizations when they began throwing virgins into the pit before the volcano got mad.
The fact is, the science addressing climate change is still in its infancy. Reliable satellite data wasn't available until the mid-to-late-1970s, during the time when scientists were more worried about global cooling. Since then, of course, the climate snapped back before any precautionary principled measures could be enacted, thank heavens.
To date, climate science (as reported in the media) has been fixated on the role of the carbon dioxide added to the atmosphere by humankind's activities. There is indeed a correlation between atmospheric carbon dioxide and the computed average temperature of the earth's atmosphere at the surface, at least when the average temperature is rising. But carbon dioxide by itself cannot account for the claimed increase in global average temperatures; it needs the help of a pollutant different than carbon dioxide, water vapor, the number one greenhouse gas.
The hydrologic cycle is well understood at a conceptual level, but it is poorly understood when studied in the wild. Scientists' computerized general circulation models have a heck of a time getting all the variables lined up. They don't even know if they know all the important variables.
The models are adjusted and tuned just so to replicate historical climates and then they are set loose to project other climates. Unfortunately, those projections often don't gibe well with actual measurements. There are obviously pieces missing.
When told that average annual temperatures at least since the turn of the century have been flat, Rajendra Pachauri, head of the Intergovernmental Panel on Climate Change, told Reuters news service, "One would really have to see on the basis of some analysis what this really represents." He added, "Are there natural factors compensating?"
As I recommended in an earlier letter, let us enact no grand regulatory schemes to counter climate change until we can better separate natural from anthropomorphic influences and better gauge the relative importance of each.
The United States is doing as well as, if not better than, many of the signatories of the Kyoto Protocol by just plodding ahead, without draconian regulations, to devise ever more efficient devices, explore alternative energy sources, advance the science and pump or buy more oil to power the effort.
The precautionary principle in the hands of politicians can, as has been the case in the past, result in a cure worse than the disease.