UMBERTO BACCHI FAMED for his daring descents down the untracked slopes of hard-to-reach peaks from Norway to Alaska, snowboarding pioneer Jeremy Jones enjoys being alone in nature. Yet the 45-year-old would be happy to see a few more people crowding the mountains he loves - because they are under threat, he said, and he is on a mission to get more people to care. "If you look at (past) environmentalists, none of them were like 'Man, I was hanging in my apartment in New York City, just scrolling through social media, and decided I wanted to become an environmentalist'," Jones…