I wrote previously about 350.org, a planned offensive in a worldwide effort to bring the concentration of carbon dioxide in the atmosphere back to 350 parts per million, which is considered the safe maximum to foster a stable environment.

You're up on your climate math if you know that the world is already at 385 ppm, and is gaining about 2 ppm per year.

I learned of the idea when I heard writer and activist Bill McKibben speak at d2e back in March. Well, I checked in at the site yesterday and see a few blog posts, beginning with one dated May 5 from McKibben himself. On the right side of the page, there is a sign-up box, but the accompanying patter still talks about fully launching their effort sometime in the future.

Even so, they're taking signers, and following up with a request for signees to hold events or to send out gang e-mails to bring word of their effort to as wide a circle as possible. If you do sign up, please tell 'em I sent you, even though, uh, there's no place to do that and no indication otherwise that they'll care. So strike that. If you sign up, please ... tell me! Leave a note in the comments, or somethin'.

BTW, 350.org is on Facebook, too.