Oct. 24, 2009: 350.org's Global Day of Climate Action

Bill McKibben has been one of the country's most prominent and productive environmental writers for the past two decades. And one might be excused for associating the author of something titled The End of Nature with a greater knack for delivering hard truths than with one for happy spin.

His recent appearance on The Colbert Report (video may be found here) was certainly eye-opening and earnest, and as such, not inconsistent with his body of work.

But it was also quite entertaining. And, by the way, it was incredibly hopeful.

McKibben's current focus is 350.org, which he recently founded. Referring to it as the most important number in the world, 350 is the concentration of atmospheric carbon dioxide, measured in parts per million, that we need to work together to achieve, as is explained in their mission statement.

Here's the rub: Before the Industrial Revolution, and for millennia prior, atmospheric carbon dioxide was at 275 ppm. Today, we stand at 390. While a decade ago a working estimate for a 550 ppm upper limit for CO2 was kicked around, the past few years have provided an increasing body of evidence that we've probably already passed a threshold: changes in mountain glaciers, in ice caps, in permafrost, and in other key natural systems indicators are happening much, much sooner than anticipated.

The goal of 350.org, accordingly, is to bring things back down a bit. McKibben is confident that we can do it. And he's certain that there's room for all of us to help.

Time is critical, and not just because more finely tuned climate analysis increasingly suggests that we're beyond where the planet can comfortably maintain its systems. Time is also short because in December, there's to be an important global climate summit taking place in Copenhagen. McKibben and 350.org are keen to influence the proceedings.

As announced in his recent interview, McKibben and 350.org have asked us to set aside October 24 as a day of action. On their website, you can read more about the group's mission, about the science supporting its foundation and focus, and learn about and join — or plan and launch — climate awareness actions in your local community.

350.org asks us all: So, what are you doing on the 24th of October?

Photo of Bill McKibben courtesy of Nancie Battaglia, via Wikimedia Commons