From Today's New York Times
OCTOBER 23, 2008
And Mr. Klinkenborg’s conclusion that an international effort similar to what is happening to address the current global financial crisis will be necessary to protect species prompts a question. What would it cost to stabilize our planet’s biological health by protecting species and their natural habitats? An estimated $13 billion a year would be enough to maintain and expand protected areas in the tropics, where the vast majority of plant and animals species are found.