?Eleven percent of all bird species are on the verge of extinction as a consequence of what we?ve done. A report of the world?s plants suggest that 12 percent?are on the brink of extinction, and I suspect that?s an underestimate, because there are many of the world?s plants that we don?t know. It?s not just in land and soils; it?s in oceans and rivers. A huge fraction of our freshwater clams and mussels are on the verge of extinction. The pattern is ubiquitous. Whenever we have sufficient data, we recognize somewhere between 10 and 40 percent of all the world?s species are already on the verge of extinction?.
– Stuart Pimm, Conservation Biologist