mass extinction Center for Biological Diversity becoming extinct going extinct Center for Biological Diversity dozens of extinctions are occurring going extinct going extinct 1,000 times the worst mass extinction event the worst mass extinction event sixth mass extinction disrupted going extinct background extinction rate 1-5 species go extinct each year slide rapidly toward extinction currently experiencing 1,000 to 10,000 higher than the natural state becoming extinct unprecedented period of mass extinction sixth mass extinction Center for Biological Diversity going extinct going extinct going extinct Center for Biological Diversity Center for Biological Diversity - The Extinction Crisis 1,000 to 10,000 times higher Center for Biological Diversity literally dozens of species are going extinct every day losing dozens of species every day currently experiencing sixth mass extinction Center for Biological Diversity Center for Biological Diversity unprecedented The Center of Biological Diversity becoming extinct 6th mass extinction becoming extinct becoming extinct 10,000 times faster Sixth Mass Extinction Center for Biological Diversity becoming extinct going extinct 10,000 times faster becoming extinct rate 1,000 times higher Sixth Mass Extinction destructive actions upon the earth has been daunting