From the article: The facts were indeed increasingly daunting. The first decade of the 21st century was shaping up to be the hottest in recorded history. In 2007, the Arctic sea ice shrank to a level not seen in centuries. That same year, the NASA climatologist James Hansen, who has been ringing the climate alarm since the 1980s, announced that in order to elude the most devastating consequences, we’d need to maintain carbon dioxide in the atmosphere at a level of 350 parts per million. But we’d already surpassed 380, and the figure was rising. (It has since reached 400 p.p.m.) Animal and plant species, meanwhile, were dying out at a spectacular rate. Scientists were beginning to warn that human activity — greenhouse-gas emissions, urbanization, the global spread of invasive species — was driving the planet toward a “mass extinction” event, something that has occurred only five times since life emerged, 3.5 billion years ago.
Posted on: Sat, 19 Apr 2014 21:52:54 +0000
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