Notice the way this point tries to bolster credibility by using historical (and conservative) figures such as Churchill to make a point. I just don't think the environment (as defined by The Sierra Club) is what Churchill had in mind by this quote.
It appears clear that this book--should the students buy into these principles--lays the groundwork for everything anti-American, anti-capitalist, and anti-conservative (as a polical ideology, not as an environmental one.)
I don't blame you one bit for your concerns. Question is, what are you going to do about them?
I ran a google on the quoute and the source and only came up with 5 links all from pagan pages.