Newsweek's cover story this week -- The Greening of America -- continues the green is the new black media moment, but nicely captures the tension between the faddishness of green lifestyles, the exciting progress being made designing bright green products and systems, and the sheer scale of the planetary problems we face:

All over America, a post-Katrina future is taking shape under the banner of "sustainability." ... Looked at one way, these are thrilling times, the beginning of a technological and social revolution that could vault our society into a post-post-industrial future. "If you mention green tech or biotech in a presentation," says Lane, the venture capitalist, "you'll get your funding before you get to your third slide." On the other hand, we may just be kidding ourselves. Can bicycles and switch grass really offset the effects—in pollution, resource depletion and habitat destruction—of a billion Chinese lining up to buy cars for the first time?... Is the relevant statistic that sales of hybrid cars doubled last year to 200,000—or that they were outsold by SUVs by a ratio of 23-1?