I think you missed his point -- I don't think he was saying so much that we are not technically able to do anything about it but instead he was saying that he didn't think we'd be able to do anything about it due to our own innate conflicted natures.
I read it differently, not with one main point but two main points and several side points.
A1) he strictly defined "it" to be "our long term self interest" not "the health of the planet"
A2) we are not capable of doing anything long term (insert conflicted notes here)
B1) natures' machinery out there is bigger than us
B2) we incur consequences that can easily have continuing existence and persistence independently of our own self-interest or survival
Taking point B1) independently of the others (and it can be, just as much as A2), hockeydave
's post is actually directly on topic.
, the solar astronomers said "look for a cooler winter" back in April, the Arctic ice is saying "look for a cooler winter" now, what was the problem again?