A ferment in the environmental movement, brewing for many years, has now bubbled up into the blogosphere. We are dipping our ladle in here to take a little taste of it, even though we are quite certain it is not done fermenting. Bill McKibben has been stirring the wort of whether social activism can save us for many years. In Eaarth: Making Life on a Tough New Planet, as in The End of Nature a quarter century earlier, he poignantly waffled, in elegant prose, between hope and despair.