The big news about yesterday’s extraordinary call for climate action, staged in more than 180 countries, was not that activists rallied in scuba gear underwater at Australia’s Great Barrier Reef, or that soldiers in Afghanistan spelled out 350 with grain bags, or that Masai children sat in Kenya’s dry, red dust and spelled out 350 with their bodies to call attention to Africa’s struggle with drought. The big news was that the event made the news. Everyone from CNN to the New York Times to PBS covered activist Bill McKibben’s International Day of Climate Action.

A refresher: 350 is nature’s carbon cap. It’s the greatest amount of carbon dioxide (measured in parts per million, or ppm) that our planet can sustain in the atmosphere while still supporting life as we know it. Right now we’re at 389ppm; NASA’s James Hansen, Bill McKibben, and hundreds of other scientists and leaders say we can avoid the worst of climate change if we get back down to 350ppm, stat.

McKibben’s approach to climate change activism is nothing if not community-oriented. He wants you to feel you’re part of a family – he wants to get your blood and your fist pumping, and he uses every tool modern technology has to offer to get the job done. Facebook, Twitter, email, the Colbert Report, you name it; the only thing McKibben doesn’t use is snail mail, which is hugely refreshing considering how many conservation groups still send hard copy letters and funding requests. The organization even sent out mass text message blasts to members, as early as the start of October, in preparation for the big Oct 24 event.

“October 24 began an hr ago with sunrise in New Zealand,” 350 texted US members on the 23rd. “Are you ready to rock the USA? Find an event near you at + ask yr friends to txt READY to 30644.”

And on the evening of Oct 24:

“You just made history by taking part in the largest ever global day of action!”

If Activism 2.0 is what we have on our hands here, it seems to be working. A little jarring, sure, to see McKibben, who got his start as a New Yorker staff writer and is a very serious, earnest sort of guy, using abbreviations like “txt” and “yr.”  And it must be said that McKibben had trouble treating his heavy message with the levity it needed on the Colbert Report, even when Colbert threw him softballs like: “What’s the dillyo with 350? I thought it was Anderson Cooper 360,” or “Where are we now? We’re at 390 now? So it’s game over, we should all have end of the world sex!” But reached all corners of the globe yesterday, so it would seem McKibben’s doing something right.

Now that the big day is over, it’ll be interesting to see what kind of mischief gets up to in the month remaining before December’s crucial climate talks in Copenhagen (COP15). You can bet McKibben’s got something up his sleeve, and you can bet he’s determined to keep making the news.

Check out this powerful slide show of 350 images, which ran yesterday on the New York Times’ site.