This is the essential point of it. If not animal rights or environment they would push some other agenda (abortion?). But this does go against the "... multiply and subdue the earth" commandment.
These globalist forces know that Christianity must at least be co-opted into the coming "world religion", or destroyed. They figure the other religions will eventually be assimilated; as indeed mainstream or lukewarm Christianity will be. They may also be wrong about some Islamicsts.