This book exists? That alone is wild. This little, unknown book from 50 years ago, published by a long-dead press, predicts and informs arguments that would not come around for 40 or 50 years. It is an argument for degrowth, although that term did not exist then; it is also from an explicitly Christian perspective, which will likely turn off a lot of people interested in the topic.
I think it does a better job of summarizing the problem and applying theory than it does in finding any actual solution; it suggests a destination with neither map nor guide. Also, the nature of this book (eight independent radio programs from the early 1970s) leads to a lot of repetition by its very nature when read as a single book; by the fifth or sixth episode, you can start skimming pretty hard.
But that aside: it does give a lot to think and chew on, on the nature of our problems (economic, social, political, environmental) and how to view them in new lenses. It is also a fascinating historical artifact, given that we have spent the intervening 50 years with the pedal to the floor and are now in the act of increasingly reaping what the author was afraid his generation was sowing.