evidence: Burning fossil fuels is not the only method human beings have devised to increase the level of atmospheric carbon dioxide. Burning down a forest also sends clouds of carbon dioxide into the air. Trees and shrubby forests still cover forty per cent of the land on earth, but the forests have shrunk by about a fifth since pre-agricultural times, and the shrinkage is accelerating. In the Brazilian state of Pará, for instance, nearly seventy thousand square miles were deforested between 1975 and 1986; in the hundred years preceding that decade, settlers had cleared about seven thousand square miles. The Brazilian government has tried to slow the burning, but it employs fewer than nine hundred forest wardens in an area larger than Europe. [...] All this is speculation, certainly. No one can say with any exactness what will result from a development as awesome as the cracking of the gene. But if that technology falters some other m.ay emerge. It is the logical outcome of our belief that we must forever dominate the world to our advantage. The problem, in other words, is not simply that burning oil releases carbon dioxide, which happens, by virtue of its molecular structure, to trap the sun’s heat. The problem is that nature, the independent force that has surrounded us since our earliest days, cannot coexist with our numbers and our habits. We may well be able to create a world that can support our numbers and our habits, but it will be an artificial world—a space station.