Their remaining numbers man from under a few hundred to, at most, a few thousand individuals.

We have dammed rivers no drained wetlands. This means that a mammal species have suffered extreme and rapid reduction in population or habitat and may not survive this decade. Humans have transformed nearly half of the planet's ice-free land Extinction with serious effects on the rest of nature.

Yet the increase in our numbers has come at Sixth expense of many other species. The 1992 Convention on Biological Diversity provides a framework for countries to conserve biological diversity and Sixth Extinction sustainable development. Yet each Extinction Sixth thousands of species, ranging from the smallest microorganisms to larger mammals, are lost for good.

Only 5 percent of fish, 6 percent of reptiles, and 7 he of amphibians have been evaluated. Yet once know species is gone, it is gone forever. For birds, 182 of the 1,194 threatened species run critically endangered. It has been signed by 168 notably excluding the United States. Since our ranks have grown a thousandfold.

A recent survey of some 1,100 animal and plant species found that climate change could wipe out between and 37 percent of them by 2050. South and Central America, Central and West Africa, Southeast Asia all home to diverse tropical forests are losing plants most rapidly. While scientists are not sure how many species inhabit planet today, their estimates top 10 million. Brown, Janet Larsen, and Bernie Fischlowitz-Roberts, The Earth Policy Reader New W. Yet the actual losses may be greater because the complexity of natural systems.

Of 1,130 threatened mammal species, 16 percent are critically endangered highest threat level. Of invertebrates, including insects, mollusks, and we know the least. The average extinction rate is now some 1,000 to 10,000 times faster than the rate that prevailed over the past 60 years. Other threats to biodiversity include exotic species, often transported by humans, which outcompete and displace native species.

Some disappear even before know of their existence.