Then there's cap and trade, a system under which the government would issue permits limiting the amount of greenhouse gases companies can emit, then allow them to sell these permits to each other.
At first blush 59 percent support the idea, and that rises to 74 percent given the argument that a similar system has worked to curb emissions that cause acid rain.
There is price sensitivity: Compared with the 59 percent level, support holds steady, 57 percent, if a cap-and-trade system raised electric bills by $10 a month. But it's lower, 47 percent, with 51 percent opposed, if the price tag hit $25 a month.
Again, cap and trade is more popular among Democrats, less so among Republicans. Still, in the most basic measure, 52 percent of Republicans support cap-and-trade, vs. 66 percent of Democrats and 60 percent of independents.
In an open-ended question 25 percent of Americans identify global warming as the single biggest environmental problem in the world, down 8 points from last year but still well up from 2006. There's been a scant 4-point rise in the number who cite energy or oil, now 11 percent.
There's also an 8-point drop in this poll, to 33 percent, in the number who think rising temperatures are caused mainly by things people do, rather than natural causes or both about equally.
At the same time, when those who blame both equally are asked which contributes more, the number citing human activity rises to 58 percent. (It's 63 percent when "things people do" is expanded to include commercial and industrial activities.)
Eighty percent, as noted, think global warming is occurring; it peaked at 85 percent in 2006.
There's also a slight, 5-point dip in the number who say global warming is important to them personally, now 47 percent. When those who take a middle position are asked how they lean, the number calling it personally important rises to 66 percent.
The declines in these measures come at a time of reduced media attention on global warming, in a year when the election and the economy have taken center stage.
A database search finds 50 percent fewer news stories on global warming in the month before this poll was conducted, compared with the month before last year's survey; and a similar 45 percent fewer in the six months prior.
The perceived immediacy of threat remains a factor in concern.
Thirty-seven percent of Americans think that if nothing is done to address global warming it'll pose a serious threat to them in their own lifetimes – a new high, by a narrow margin, in polls since 1997. But far more, 73 percent, think it'll pose a serious threat in their children's lifetimes. And 81 percent think it'll pose a serious threat to "future generations." Naturally, those who feel threatened now are much more likely to call it personally important, 69 percent vs. 33 percent.
Nearly six in 10 think global warming is making weather events like droughts and storms more frequent. But looking at specific events, a majority ties only one, the melting of polar ice, to global warming – 74 percent. Many fewer, 50 percent, think global warming is associated with the recent severe storms in Southeast Asia, and fewer associate it with the recent flooding in the Midwest (45 percent) or fires in the West (38 percent).