How well do you understand climate change? A new Yale University survey finds that 63% of U.S. adults believe global warming is occurring, but many do not understand why. Only 10% say they are "very well informed" on the issue.

According to the survey, 57% know that the greenhouse effect refers to heat-trapping gases in the atmosphere and 45% understand that carbon dioxide traps heat from the planet's surface. Only 25% are aware of coral bleaching or ocean acidification. You can learn about coral bleaching at this site.

The "Americans Knowledge of Climate Change" study found significant misconceptions, including the incorrect belief that the hole in the ozone layer, toxic waste, aerosol spray, and acid rain cause global warming. As a result, its authors say only 8% know enough to earn an A or B grade and more than 52% would flunk.

Average U.S. surface temperatures would increase 5 to 9 degrees Fahrenheit by the end of the century if global greenhouse gas emissions continue to increase, according to a 2009 U.S. Global Change Research Group report recently cited by USA TODAY colleague Dan Vergano.

The Yale Project on Climate Change Communication looked at a demographically representative mix of 2,030 American adults between June 24 and July 22, 2010, with a margin of error of plus or minus 2 percentage points. Its study was funded by the National Science Foundation.