blackfoot-valley

A point should be emphasized: from the Pleistocene ice ages to the pres- ent interglacial warming, and including the recent “Little Ice Age”, all these dy- namic changes occurred before there could be any realistic possibility of human activities being a causitive factor. No one really knows what causes ice ages, though there are detailed hypotheses and conjectures aplenty (not theories - to scientists, a theory is a system rigorously tested and firmly accepted by virtually all in the field for a very long time (the theory of gravity). At any rate, it is clear that a mere two- decade warming trend is a flimsy base on which to make predictions of future trends, much less to assert that they are human-caused. Nor can computer models possibly be input with the infinite number of variables that would be needed to produce reliable predictions, as studies in the dynamic and develop- ing field of chaos have made abundantly clear. To cap it off, analysis of the Greenland ice cores also make it clear that 15,000 years ago, the beginning of the end of the recent ice age was accompanied by a great and sudden increase of atmospheric carbon dioxide in amounts far exceeding anything mankind has ever produced by burning fuels. Whatever produced all that CO 2 - and its at- tendant “greenhouse effect” - is under investigation, but it was not man who did it. Climate will undoubtedly continue to change in the future as it has in the past. However uncertain the future will always be - a study of those patterns of past events that really happened is a better guide to future climate trends than hypothetical projections based on necessarily inadequate data and pushed in some degree by political hopes. It would indeed be ironic that, after all re- cent worry over global warming, we should instead be confronted by another ice age. And - perhaps - some new versions of Glacial Lake Missoula! 26