I read his book, Waging Heavy Peace, largely because it was given to me as a gift.. but i seem to remember buying some his records back in the early 70s.. and consider him a gifted (at times) songwriter and artist.
Anyway the book was a kind of bizarre hodge podge of sentiment drenched reminiscences, incoherent technological, social and philosophical speculations, and notes on a luxurious, classic car obsessed, lifestyle in California and Hawaii.. absolutely none of which recommend him as qualified or competent to address the issues of oil sand development in Canada.. i mean its not like he needs the jobs it provides to feed his family.
So he should stick to things he has a talent for.
I reached the same conclusion. He does have a penchant for writing (which he comes by honestly; his dad was a sportswriter for the Winnipeg Free Press), but it is definitely the work of an undisciplined mind. I did enjoy the parts about his close relationship with his severely disabled son, Ben.
However, I don't think you have to have any political or technical expertise to care about the environment.