LiveScience: Residents in California are much more worried about the warming planet than those in parts of the central United States, according to a new set of interactive maps showing public opinion on climate change. As a nation, 63 percent of Americans think the planet is warming and 48 percent of Americans think these changes are caused by humans. But "Americans don't speak with a single voice on the issue," said Anthony Leiserowitz, director of the Yale Project on Climate Change Communication and co-author...