Here's my final quote (earlier quotes here and here) from Stuart Brand's Whole Earth Discipline: An Ecopragmatist Manifesto, a quote which sums up the thesis of the book:
Accustomed to saving natural systems from civilization, Greens now have the unfamiliar task of saving civilization from a natural system…
Brand is talking about climate change and in particular the possibility of rapid, difficult to reverse, tipping points in climate. Brand has a challenging message for environmentalists: If we take the threat of climate change seriously we must recognize that Cities are Green, Nukes are Green and Genetic Engineering is Green.
Brand's long history with the environmental movement should give his message credibility with that group. Brand's rationalism, reasonableness, and pro-technology, pro-civilization outlook gave his environmental message credibility with me.