McKibben's Sermon: Climate = Danger - News - Litchfield County Times

WASHINGTON—The acceptable count of carbon dioxide in the atmosphere is 350 parts per million. Scientific consensus says that anything more than that will imperil the planet—the planet’s inhabitants really.
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“One thing’s become clear: This problem, this crisis, it’s coming a lot faster than we thought,” noted Mr. McKibben, who said the next century could see a five-degree rise if nothing is done. “A one-degree rise in temperature, 20 years ago we thought that would not be enough to cause widespread dislocation, but as it turns out it’s enough to cause every physical system to go out of kilter pretty profoundly.”