Earth has entered its sixth mass extinction with animals now dying out at 100 times the normal rate, scientists have warned. Humans have created a toxic mix of habitat loss, pollution and climate change, which has already led to the loss of at least 77 species of mammals, 140 types of bird since and 34 amphibians since 1500. They include creatures like the dodo, Steller’s Sea Cow, the Falkland Islands wolf, the quagga, the Formosan clouded leopard, the Atlas bear, the Caspian tiger and the Cape lion. Scientists at Stanford University in the US claim it is the biggest loss of species since the Cretaceous-Tertiary mass extinction which wiped out the dinosaurs 66 million years ago. “Without any significant doubt that we are now entering the sixth great mass extinction event," said Professor Paul Ehrlich, at the Stanford Woods Institute for the Environment. “Species are disappearing up to about 100 times faster than the normal rate between mass extinctions, known as the background rate. “Our calculations very likely underestimate the severity of the extinction crisis. There are examples of species all over the world that are essentially the walking dead.”
Using fossil records and extinction counts from a range of sources, the researchers calculated the normal ‘background rate’ of extinctions and compared it with a conservative estimate of current extinctions.
Natural population changes in the wild usually lead to two species of mammals dying out every 10,000 years. But the current rate is 114 times that level.
And humans have been responsible for animal decline going much further back. In the islands of tropical Oceania, up to 1800 bird species are estimated to have gone extinct in the last 2,000 years.
It is likely that early humans were also responsible for wiping out the huge megafauna which used to live in Australia including a huge giant wombat a marsupial lion and a flesh-eating kangaroo.
Currently one in four mammals is at risk of going extinct and 41 per cent of amphibians. Many now only survive in captivity.
Source: The Telegraph, 19 June 2015
http://www.telegraph.co.uk/news/uknews/11687091/Earth-has-entered-sixth…
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