Environmentalism is not just about replacing one set of technologies with another. Technological change is important, but it will protect the biosphere only if we also tackle issues such as economic growth, consumerism and corporate power.
Quite, that really is the argument in a nutshell.
All the reasonable people are arguing that replacing carbon emitting technologies with non such (or low such to be accurate) will solve the problems. All the nutters are screaming that we have to build a New Man, a non-consumerist, non-economic growth one.
As the move from horse shit to carbon emissions showed, the move to a new technology is simple enough over the course of a few decades. As the Russian experiment in creating a New Soviet Man showed, 70 years of trying will end in entire and utter failure.
Which is why reasonable people argue for the technological route, the nutters for let\’s try and elect a new species one.