CCTV America’s latest documentary “On Thin Ice” shows that the Arctic is warming twice as fast as any other place on the planet. It’s melting sea ice and bringing powerful storms that foster coastal erosion. In short, climate change is having a dramatic effect on the people who have carved out a way of life in the harsh region. It’s also threatening one of their most cherished practices, whaling. Sean Callebs reports from Barrow, Alaska.