Photo of the Day 30 March 2008

Mastiff on Mountain, North America, 1967
Photograph by Christopher Knight
Crumbling ice makes for a precarious journey for this mastiff sliding down a slope in North America.

As global warming pushes temperatures higher each year, scientists predict that permanent snow lines of mountains around the world will rise, closing skiing resorts, hurting tourism, swelling major rivers, potentially submerging low-lying areas, and significantly changing landscapes.