What are we prepared to give up? The reality is that we have to accept some major trade-offs here. The situation is too grim, too urgent, to duck them.
The world's billion and a half poorest people -- the quarter of humanity malnourished to the point of brain damage and deformity -- are mostly rural and live on mostly arid lands. Global warming will increase the stock of such lands, especially in Africa.
Birdwatching used to be seen as the ultimate geeky pastime. But combine it with new online technologies and it can reveal new truths about how our world is stitched together.
The reports of our death were greatly exaggerated. Was it really only two years ago that we were struggling to digest the dismal message of an essay called "The Death of Environmentalism"? Mass-market magazines are now awash with green-themed cover stories and special features.
Wall Street analysts are thrilled by the discovery of vast new oil fields deep beneath the Gulf of Mexico. But the oil companies will have to cope with the threat of hurricanes and underwater earthquakes.