Whither cellulosic ethanol?

We are … biotechnologists, as well as chemical engineers and have successful processes going today… Our carefully considered view, for which we will be happy to provide abundant evidence is that severe barriers remain to ethanol from lignocellulose. The barriers look as daunting as they did 30 years ago.
(The latest salvo in the Khosla-TOD debate about biofuels.)

Terra Preta: black is the new green

Amazonian Dark Earth, or terra preta do indio, has mystified science for the last hundred years. Three times richer in nitrogen and phosphorous, and twenty times the carbon of normal soils, terra preta is the legacy of ancient Amazonians who predate Western civilization…Claims for biochar’s capacity to capture carbon sound almost audacious.