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Remember This: 350 Parts Per Million By Bill McKibben
This month may have been the most important yet in the two-decade history of the fight against global warming. Al Gore got his Nobel in Stockholm; international negotiators made real progress on a treaty in Bali; and in Washington, Congress actually worked up the nerve to raise gas mileage standards for cars.
But what may turn out to be the most crucial development went largely unnoticed. It happened at an academic conclave in San Francisco. A NASA scientist named James Hansen offered a simple, straightforward and mind-blowing bottom line for the planet: 350, as in parts per million carbon dioxide in the atmosphere. It's a number that may make what happened in Washington and Bali seem quaint and nearly irrelevant. It's the number that may define our future.
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Consider: We're already at 383 parts per million, and it's knocking the planet off kilter in substantial ways. So, what does that mean?
It means, Hansen says, that we've gone too far. "The evidence indicates we've aimed too high -- that the safe upper limit for atmospheric CO2is no more than 350 ppm," he said after his presentation.
But what may turn out to be the most crucial development went largely unnoticed. It happened at an academic conclave in San Francisco. A NASA scientist named James Hansen offered a simple, straightforward and mind-blowing bottom line for the planet: 350, as in parts per million carbon dioxide in the atmosphere. It's a number that may make what happened in Washington and Bali seem quaint and nearly irrelevant. It's the number that may define our future.
.
.
.
Consider: We're already at 383 parts per million, and it's knocking the planet off kilter in substantial ways. So, what does that mean?
It means, Hansen says, that we've gone too far. "The evidence indicates we've aimed too high -- that the safe upper limit for atmospheric CO2is no more than 350 ppm," he said after his presentation.