The Nation: The Coming ‘Instant Planetary Emergency’

I discovered a set of perfectly serious scientists—not the majority of all climate scientists by any means, but thoughtful outliers—who suggest that it isn’t just really, really bad; it’s catastrophic.

“We as a species have never experienced 400 parts per million of carbon dioxide in the atmosphere,” Guy McPherson, professor emeritus of evolutionary biology, natural resources, and ecology at the University of Arizona and a climate change expert of twenty-five years, told me.  “We’ve never been on a planet with no Arctic ice, and we will hit the average of 400 ppm…within the next couple of years.  At that time, we’ll also see the loss of Arctic ice in the summers.… This planet has not experienced an ice-free Arctic for at least the last three million years.”

For the uninitiated, in the simplest terms, here’s what an ice-free Arctic would mean when it comes to heating the planet:  minus the reflective ice cover on Arctic waters, solar radiation would be absorbed, not reflected, by the Arctic Ocean.  That would heat those waters, and hence the planet, further.  This effect has the potential to change global weather patterns, vary the flow of winds, and even someday possibly alter the position of the jet stream.  Polar jet streams are fast flowing rivers of wind positioned high in the earth’s atmosphere that push cold and warm air masses around, playing a critical role in determining the weather of our planet.

The Nation:  The Coming ‘Instant Planetary Emergency’