Science, Tech & Environment

Carbon dioxide tipping point

Today, the amount of CO2 in the atmosphere is 385 parts per million and organizers of a new environmental group called say that's got to come down. 350 parts per million maybe the new atmospheric gold standard for some, but Richard Alley, professor of Geosciences at Penn State University says it's not gospel:

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ALLEY: "It is certainly not a sacred or a magic number. People have tried asking experts, 'How high before you get scared?' "How high before YOU get scared?" And the experts came back and said, 'Scared about what?'

"If we're worried about rare and endangered species, even a little bit that starts forcing them to migrate out of their little island of ecosystem and there's nowhere to go 'cause there's a corn field in the way, makes you really nervous. If you're worried about the global economy, you might be able to bump it up a little bit higher. And so this 350 is some experts, some thinkers looking at the whole weight of things and saying, 'That's where I get nervous.'

So how do we reduce our parts per million from 385 to 350?

ALLEY: "There's this huge recipe of possibilities that you can do. You can take the CO2 out of the air and put it back in the ground. You can take it from the power plant or take it from the air and people are trying to figure out how to do that. You get more economy out of the fossil fuel that you use. You replace the fossil fuel with something else that doesn't raise CO2."

Hosted by Steve Curwood, "Living on Earth" is an award-winning environmental news program that delves into the leading issues affecting the world we inhabit. More "Living on Earth.