Several readers have sent me articles in the last two weeks reporting that NASA scientists are finding that the Earth is trapping a lot less heat than global warming models have predicted we would retain, given our carbon dioxiode levels and current emissions. I don’t run around looking for stories to confirm a skepticism I might have about global warming. I truly think that we all ought to be more humble when it comes to modeling complex system. And that humility could be the possibility that we might actually destroy ourselves, but also the possibility that we will do very little damage or in fact improve things. So, rather than comment on the problems with global warming modeling, or the similarities between global warming modeling and econometric modeling of macroeconomic phenomenon, and rather than picking apart the science, I’ll just share another story that comes from Alston Chase’s excellent book, Playing God in Yellowstone (so much for pleasure reading while on vacation):
No one knew in fact what role predators had among Yellowstone fauna. In the park, wolves and mountain lions had disappeared before any studies had been done. And to sort out the relative effects of food and predation in controlling and influencing prey populations would have required ambitious studies of what biologists called three interacting “trophic levels”: vegetation, herbivores, and carnivores. Yet, James M. Peek, Professor of Wildlife Biology at the University of Idaho, told me recently that, “we have yet to see a good integrated study in North America where the three trophic levels have been adequately addressed. These are interlocking systems that must be studied together. (wintercow emphasis added, reminding readers that this issue is multiplied by a factor of more than 10 when it comes to climate issues)
Certainly in Yellowstone such a study was impossible. Without carnivores, a crucial element for understanding was missing. Their probably role in the park, therefore, had to be inferred from studies done elsewhere, in places, as we have seen, that were quite different. Yet such extrapolation, like metaphor, tended to be inexact. Truth about wildlife did not travel well. No two game ranges were alike, and none remained the same. Just as the philosopher Heraclitus had observed, “you cannot step twice into the same river,” so too we could never be sure whether one place told us the truth about another, or that our learning about he past told us what we needed to know about the present. What scientists called a “controlled experiment” could never be done in wildlife ecology. Just when we might think we had found the truth, the truth would change, flying away from us, as Plato would say, like a statue of Daedalus. Mother Nature would always remain one step ahead.
So wildlife biologists relied on models, the similes of science, and as with any analogy, the model chosen had much to do with the conclusions reached. “If you have no predators in Yellowstone,” explained Peek, “it is easy to minimize their influence; but if you go north where wolves are plentiful and see a lot of carnage on the calving grounds it is easy to overlook the habitat.”
In fact the majority of studies, elsewhere in North America, did suggest that Aldo Leopold had been correct: ungulates could destroy a range and predators could protect it.
Aldo Leopold is of course the famous conservationist who wrote the Sand County Almanac (recommended) and he also first believed that predators, like wolves and coyotes, were pests and should be eliminated.