"Hybridizing the analyses of Karl Marx with those of modern-day ecological economists, they maintain that we'll never stop degrading the ecosphere unless we tackle capitalism and the unsustainable growth that lies at its core. For at least one part of their argument -- that economic growth is out of control -- eco-socialists can call on plenty of mainstream backup. For example, the Oakland, Calif.-based group Redefining Progress reports that in 2000, human consumption and waste production had reached its highest point ever, exceeding by 15 percent the planet's biological capacity to produce and absorb. ... When I asked Kovel why capitalism is at the core of current ecological crises, he said, "The basic rules of capitalism are private ownership and competition. In such an economy, a firm must continually expand its market share and/or increase its rate of profit. Otherwise, it will go extinct." ... In a well-functioning capitalist economy, the cycle that turns money into stuff and stuff into more money runs as fast as possible, recognizes no limits, and refuses to be stretched, bent, or squeezed into any ecosystem.

"Foster reverses the sequence, putting human justice first: "I too have faith that humanity as a whole has the desire and ability to avert ecological catastrophe -- but that can happen only in a society that has eliminated class exploitation." In pressing their case, eco-socialists often run up against a formidable, two-word rejoinder: "Soviet Union." But they are painfully aware of the Communist world's grimy environmental history and reject Soviet-style central planning. Kovel says today's myriad proposals for achieving sustainability can become workable solutions only "if people can create and carry out those plans freely, not under orders from above. That is something the USSR never came close to achieving, and it was at the root of its eco-destructivity. But to believe that the Soviet road is the only way to a post-capitalist society is to have no imagination." Building a worldwide eco-socialist movement will require imagination aplenty, and fortitude as well. To go up against global capitalism at the height of its power will be no picnic. But eco-socialists see no other option when, to paraphrase Kovel, it's either the end of capitalism or it's ... The End.