Here is an article that puts forward the argument that the biodiversity catastrophe that everyone has been worried about has, in fact, already happened, and that more than half of the world's species are doomed either to extinction or to a shadowy existence in tiny, ecologically irrelevant, artificial niches; that at this point there really is no such thing as the pristine, untouched wild environment; and that at this point the best we can do is try to figure out policies that allow the environment to prevent the failure of human economic development and/or survival. The species that survive will be those that are adapted to live with humans in their human-made environment, either as domesticated species, boutique species like pandas and tigers, or pests and scavengers. "Like it or not," says Stephen Meyer, "nature now works for us."
The idea of the biosphere's being taken over by "weedy" species is one I've heard before. I don't know enough of the science to be able to assess the claim on its merits. But I do have to say that I found the argument about the irrelevance of wildlife preserves convincing.
What it really reminded me of were two things: Chalmers Johnson's argument in The Sorrows of Empire that the battle to prevent the American republic from turning into an empire was actually lost long ago, and what we're seeing now is merely the culmination of that transformation; and a question asked by a researcher on environmental catastrophe and civilization collapse, "What was the going through the mind of the person who cut down the last tree on Easter Island?" (The background here is that the gigantic heads on Easter Island could only be made by cutting down trees to transport the giant rocks, but that each tree cut down made the island less and less habitable, due to soil erosion and other things.)
I've often heard the argument from free-marketeers that the free market will regulate any shortages so that environmental collapse truly threatening to humans will always be forestalled. This may be true in the ideal world where everyone takes their externalities into account, but it surely is not true in the real world, where everyone has every incentive to foist their externalities on other people. The less power you have to complain about what's being foisted on you, the more you suffer other people's externalities. The developing world has been suffering the externalities of the developed world's voracious resource consumption for some time, but I fear the constituency whom no one represents are the people of the future, today's children and the people not even born.
--Melissa O, at 22:07