This
wonderful piece by Julian Morris of the UK states quite succinctly why
the modern environmental movement should be viewd as a religious
movement and not a public policy movement based on sound science. This
quote sums it up nicely:

Environmental evangelists are
therefore not interested in pragmatic solutions to climate change or
technological fixes for it. They are even less interested in evidence
that if we were really serious about reducing carbon emissions we could
do so by large amounts without significantly affecting our economies or
our lives. Windmills on roofs and cycling to work are insignificant in
practical consequence, but that is to miss their point. Every ideology
needs rituals of observance which demonstrate the commitment of
adherents.