One of the books I read over the holidays was E.O. Wilson's Creation, a bestseller by the two time Pulitzer Prize winner that appeals to two opposing ways of thinking; religion and science to get together to save the biodiversity of the environment. In this very well articulated book, he reminds us that in history (as captured by the fossil record) there has been 6 time periods where biodiversity has been vastly reduced, i.e. a lot of species have gone extinct. The fifth was the end of the dinosaurs 65 million years ago, and in each case it took the world about 10 million years to rebuild, re-evolve that biodiversity.
Sadly, the sixth is happening now. We humans are taking over the planet and creating mainly habitat loss for the other species. Whatever we end up doing in twenty thousand years, it may take nature another 10 million years to recover. It is sad, it is depressing, but it is what it is. The book mentions all the hot spots in the word where species are especially endangered. The rainforests of the Philippines, Madagascar and thr Amazon are among the worst ones. But throughout the book I was waiting for the pragmatic bounding of the problem. How much would it cost to fix it all? If by a magic stroke every country chipped in, what would it take to preserve the forests, or help endangered species recover?
E.O. Wilson answers that question, and frankly the answer is just as depressing as the question. He estimates that $30B annually is needed to preserve all the biodiversity on land. That's it $30 billion dollars. In the grand scheme of things that's tiny.
Compare that to the data on the link here on global defense spending. I don't know if it is true but, is says that the world annually spends $1100B on defense. That's $1.1 trillion dollars. More than half of it is spent by the U.S., less than half is spent by the rest of the world. And all it would take would be 3% of that spending to maintain biodiversity that nature needs 10 million years to recover.
I see now why some of my ecologist, biologist, ornithologist friends of mine are depressed about it.