Often, people ask: “In real world terms, how does a planet at 350 look any different than a planet at 450.”

There are approximately 2.7 gazillion ways to answer that question, but here’s just one: a planet at 350 has coral reefs. A planet at 450 does not.

Just yesterday, a team of scientists (along with Sir David Attenborough—who we’re hoping will be our next 350 messenger) issued a warning: a planet that stays above 350 for too long is a planet which “condemns coral reefs to extinction in the future, with catastrophic effects for the oceans and the people who depend upon them.”

Still think a planet at 450 might be OK?  Check out Bill McKibben’s thought’s on targets.  Also, yesterday’s post from the San Francisco Chronicle puts it quite concisely:

350 or 450? There’s a split in scientific and political communities about which number—both represent parts per million of carbon dioxide in the atmosphere—is the tipping point into dangerous climate change. Actually, it goes sort of like this: Most scientists agree that 350 is the more realistic number, but most politicians say 450 is the best we can shoot for.

Hmm, well put. I guess it’s back to organizing the world to get politicians to change their minds. Is your community signed up for an action on October 24 yet?  If not, get to it: www.350.org/oct24