Looking at the graph from 2008 on, saying that a majority of Americans "still" think global warming is real is like saying a guy who fell off his roof is "still" not injured.
BTW as that 10-14% figure for “will happen in our lifetime” hardly varies at all for a period of over twelve years, as the other categories move up and down, that says to me that we have some “dead enders” who would never change their mind as they freeze to death in the dark. Another perfect example of a data point for my tagline.