Environmental concerns, yes, but more specifically, man's self-importance and the fact that all his great works, thoughts, institutions, etc., mean nothing to an Earth that has had many life forms come and go over its long history, the insignificance of man's pomposity.
Environmental concerns, yes, but more specifically, man's self-importance and the fact that all his great works, thoughts, institutions, etc., mean nothing to an Earth that has had many life forms come and go over its long history, the insignificance of man's pomposity.