The pan-African Great Green African Wall (GGW), a lush strips of vegetation capable of supporting birds and other animals, would stretch from Djibouti in the Horn of Africa in the east to Dakar, Senegal in the west on the southern edge of the Sahara.

FORBES: Great Green Wall Plans to Stop Sahara

So is the success of clean energy a flash in the pan, or does green-tech have a long-term future?

CNN: The smart money's on green

But Pan Yue, the best-known advocate of green concerns within the Chinese government, says ancient creeds, like Taoism, offer the best hope of making people treat the earth more kindly.

ECONOMIST: Religion and ecology

Instead, the summit percolated with a kind of pan-ideological bonhomie -- as in the Crossfire green room, one imagines, but bigger and with even worse food.

CNN: Why Johnny Can't Surf