There was an article (Sports Illustrated maybe?? Not sure, can't remember) about the impact of warming on outdoor sports, specifically hockey. They focused on Canada and the number of 'skate days' if you will. That is to say the number of skate able, outdoor rinks per winter day. The decline in skate days was depressingly remarkable. Im sure if applied the same thing to say, snow mobile days we would find similar results. I know skiing here in CT isn't what it used to be and Many places have folded.