A must read.

Shadow of Extinction
by George Monbiot

It is old news, I admit. Two hundred and fifty-one million years old, to be precise. But the story of what happened then, which has now been told for the first time, demands our urgent attention. Its implications are more profound than anything taking place in Iraq, or Washington, or even (and I am sorry to burst your bubble) Wimbledon. Unless we understand what happened, and act upon that intelligence, prehistory may very soon repeat itself, not as tragedy, but as catastrophe. The events that brought the Permian period (between 286m and 251m years ago) to an end could not be clearly determined until the mapping of the key geological sequences had been completed. Until recently, palaeontologists had assumed that the changes that took place then were gradual and piecemeal. But three years ago a precise date for the end of the period was established, which enabled geologists to draw direct comparisons between the rocks laid down at that time in different parts of the world.

Having done so, they made a shattering discovery. In China, South Africa, Australia, Greenland, Russia and Svalbard, the rocks record an almost identical sequence of events, taking place not gradually, but relatively instantaneously. They show that a cataclysm caused by natural processes almost brought life on earth to an end. They also suggest that a set of human activities that threatens to replicate those processes could exert the same effect, within the lifetimes of some of those who are on earth today.
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