USA Today: How well do you understand climate change? About 63% of the U.S. public understands that global warming is happening, a new survey shows, but only 8% would get an “A” or “B” on a climate science test. “For most people, this is an invisible issue,” says Anthony Leiserowitz of the Yale Project on Climate Change Communication, which produced the survey report. The June and July survey of 2,030 adults has a plus or minus 2% margin of error. “There never has been a national strategy or …