Environmental Terrorist

This grandfather really annoys me; I do hope that my dad is not as bad as this, but it does explain a little why we have global warming. He sits every day outside my daughters' school with his engine running for up to 20 minutes, come rain or shine and has done so for at least a year. I have indicated to him on several occassions that he should switch off his engine; he does so at the time, but then the next time I notice, it's on again. It can't be that he is running the a/c since he often has the window open. Worse, he often has the car in gear (mostly reverse) with his foot on the brake. Is he a tool or just, as my school colleagues would have put it, ignorant?