How is the ecological predicament of the 21st century to be conceived of? Politically, how is it to be confronted, and by whom? The basic features of the problem are plain enough, when you can stand to look. Universal carbon pollution, known by the mild term 'climate change', is already distempering the seasons with bounding extremes of heat and cold, and magnifying storms and droughts; increasingly, it will spoil harvests, spread tropical diseases, and drown coastlines. (Less well known is the threat of more frequent earthquakes and volcanic eruptions.) Excess carbon dioxide in the air, partly absorbed by the waters below, turns the oceans more acid, corroding coral reefs as well as the shells of clams, oysters and other calcifying organisms. Ocean acidification, a chief cause of the Great Permian Extinction some 250 million years ago, may come to factor in the 'mass extinction event' – a planetary culling of life-forms with few rivals in the earth's history – currently taking place. For now, fatal habitat loss, both underwater and on land, has more to do with local conditions becoming abruptly warmer or dryer; the arrival of unfamiliar species travelling in the entourage of globally mobile humans; and encroachment by farmland and roads. Farmland itself may be faring better than wilder and more biodiverse terrain, but here too there are grounds for concern: topsoil acreage is dwindling, as are glaciers and aquifers vital to irrigation, on a planet that must feed seven and, soon, nine or ten billion people. Most of this population is poor by European or North American standards and doesn't constitute any automatic constituency for ecological restraint. Governments and corporations, for their part, have little incentive to slow, much less stop the general destruction. The collective activity of humanity is sapping the ecological basis of civilisation – and no collective agency capable of reckoning with the fact can yet be discerned.
