The underlying reason that we are having trouble dealing with global warming is that we are not used to dealing with environmental change. This is true both in the history of beliefs and ideas in Western Civilization and in modern environmental sciences, which are formulated primarily in terms of steady-state conditions and theory. In Western Civilization the idea is known as the Great Balance of Nature that nature undisturbed by people achieves a permancy of form and structure which is best of itself, for us, and for all life. (I discuss this in my book, Discordant Harmonies, and pursue its many implications in another book, No Man's Garden.)
Case in point: In 1991, I and several colleagues published a forecast about how global warming would effect the Kirtland's warbler, an endangered species that nests only in Michigan. The state of Michigan had set aside 38,000 acres of jack pine forest, the only kind of forest in which this bird nested, and managed these for the warbler.
The warbler nests only in young jack pine woodlands, and jack pine only comes in after a fire. It can't grow in the shade of taller trees, so if there are no fires, jack pine disappears. Periodic fires set intentionally in the Kirtland's warbler's forest were benefiting the bird. This raised the question: if the climate warms and jack pine can no longer grow in the part of Michigan where the warbler nests, what will happen to the bird's habitat? (For reasons not completely understood, the warbler only nests in a specific kind of sandy soil found only in southern Michigan, so the bird is unlikely to migrate north.)
The computer model of forest growth that I developed with colleagues at IBM Thomas J. Watson Laboratory (available to download at www.naturestudy.org) forecast that by 2015 jack pine would decline significantly and the warbler would begin to get into trouble.
Oddly, although there is so much written and said about global warming, and although this 1991 prediction got the attention of newspapers around the world, no one has tried to see if the forecast is turning out ot be valid. Here's an opportunity to test at least one global warming forecast. Why is nobody taking advantage of this test? (Stay tuned.)
Forecast Jack pine forest under present climate and 40 years in the future
These forecasts are based on the use of the JABOWA forest model (see www.naturestudy.org) and a standard climate model.
Copyright © 2007 Daniel B. Botkin
Theo Richel says
Dear dr Botkin,
I read your comment in the NYT where you referred to the Kirtland Warbler. I felt inspired and started to search the internet and found this page (http://www.nature.org/magazine/spring2006/features/art17199.html ) where the following quote comes from:
‘In 1974 and again in 1987, trained observers in Michigan counted only 167 singing males. State and federal agencies poured millions of dollars into creating and maintaining the conditions the bird requires for successful nesting. Decades later, their efforts appear to be succeeding: The June 2005 census yielded 1,415 singing males, the most ever’. I do not know whether this matured in a peer reviewed study, but it looks serious enough. I look out to your reaction and thank you beforehand.
Theo Richel makes a good point. I noted in the original article that the Audubon Society and government agencies (the State of Michigan, and the U. S. Fish and Wildlife Service to be specific) took actions to provide a sustainable habitat for the warbler. Michigan set aside 38,000 acres within which stands of jack pine are burned and managed for this species. What has not been done is to check whether there is a slowing in the growth of jack pine, which was the primary direct measure of the forecasting methods I used. If jack pine has started to decline at all, this still might cause trouble for the warbler in the future. But the good news about the Kirtland’s warbler suggests that focus on habitat conservation and improvement —-on mitigating the effects of global warming in general —- can more than correct the expected negative effects of global warming.