"Two profound events triggered the split between those advocating a pragmatic or "liberal" approach to ecology and the new "zero-tolerance" attitude of the extremists. The first event, mentioned previously, was the widespread adoption of the environmental agenda by the mainstream of business and government. This left environmentalists with the choice of either being drawn into collaboration with their former "enemies" or of taking ever more extreme positions. Many environmentalists chose the latter route. They rejected the concept of "sustainable development" and took a strong "anti-development" stance.
"Surprisingly enough the second event that caused the environmental movement to veer to the left was the fall of the Berlin Wall. Suddenly the international peace movement had a lot less to do. Pro-Soviet groups in the West were discredited. Many of their members moved into the environmental movement bringing with them their eco-Marxism and pro-Sandinista sentiments.
"These factors have contributed to a new variant of the environmental movement that is so extreme that many people, including myself, believe its agenda is a greater threat to the global environment than that posed by mainstream society. "