CBS: The spate of severe winter weather gripping the United States this season has led to a fresh round of doubts about the climate change occurring around the world and whether mankind should try to slow the trend. But J. Marshall Shepherd, the former head of the American Meteorological Society, says the storms are no reason to start doubting that global warming is occurring. It's winter; it's January or February, we get snow storms. That's important, he said on CBS Face the Nation. Saying that...