Rifkin excerpt

From his latest HuffPo post:

"The Earth's ecosystems cannot readjust to a disruptive change in the planet's water cycle in such a brief moment in time and are under increasing stress, with some on the verge of collapse. The destabilization of ecosystem dynamics around the world has now pushed the biosphere into the sixth extinction event of the past 450 million years of life on Earth. In each of the five previous extinctions, Earth's climate reached a critical tipping point, throwing the ecosystems into a positive feedback loop, leading to a quick wipeout of the planet's biodiversity. On average, it took upward of 10 million years to recover the lost biodiversity. Biologists tell us that we could see the extinction of half the Earth's species by the end of the current century, resulting in a barren new era that could last for millions of years. James Hansen, the former head of the NASA Goddard Institute for Space Studies, forecasts a rise in the Earth's temperature of 4 degrees Celsius between now and the turn of the century -- and with it, the end of human civilization as we've come to know it. The only hope, according to Hansen, is to reduce the current concentration of carbon in the atmosphere from 400 ppm to 350 ppm or less."