Before they're gone

"A longtime backpacker, climber, and skier, Michael Lanza knows our national parks like the back of his hand. As a father, he hopes to share these special places with his two young children. But he has seen firsthand the changes wrought by the warming climate and understands what lies ahead ... He takes his nine-year-old son, Nate, and seven-year-old daughter, Alex, on an ambitious journey to see as many climate-threatened wild places as he can fit into a year: backpacking in the Grand Canyon, Glacier, the North Cascades, Mount Rainier, Rocky Mountain, and along the wild Olympic coast; sea…