Anyway, Robinson was not espousing environmentalism so much as distant-future-generation-ism. That's a distinctive (but equally incorrect) moral position. Not all environmentalists subscribe to the future-generational-imperative, and vice versa.

I actually find the future-generational-imperative to be more widely and uncritically assumed by everyday people, so probably more important to point that out than just plain old environmentalism.

The main reason I tend to think of it as a secular religion is due to the close specific parallels with apocalyptic Christianity. You've got this same idea of an original state of grace (the way the indians lived) that mankind has since fallen from, the idea that people have committed sinful acts against the deity (by polluting) and have ways they should worship/repent to it (recycling, planting trees, passing on their ideology to others...). Most of all the sense that we are doomed unless we change our ways because Mother Nature will fight back and punish us for our sins against it just feels SO Christian - not in the modern sense but more the older sense of standing on a street corner with a "the end of the world is nigh!" signboard. :-)