In 2006, a Pew poll reported that 79 percent of Americans saw global warming as a serious problem; in 2010 the number fell to 63 percent; and a recent poll reported that the number has risen to 69 percent. Similarly, in 2009, 57 percent of Americans accepted that there was “solid evidence of [global] warming”; in 2015, 68 percent agree.
How do we explain the fluctuations? There are a number of possible answers. First, people trade off fears about climate change with fears about economic growth. When the economy tanks, people worry that environmental regulations will cripple recovery; when the economy recovers, people start to worry about the environment.
Second, the deep polarization of American politics causes the party out of power to swing against whatever the party in power proposes. In a classic example of this, in March 2015, 53 percent of Republicans supported automatic registration of all eligible voters. Recently, Hillary Clinton endorsed this proposal. Now, only 28 percent of Republicans support automatic registration of all eligible voters. Many Republicans responded to the push by the Democrats for major climate legislation in 2009-2010 by clinging to their skepticism about climate change. Still, this hardly tells all of the story. For one thing, apparently, male Democrats are slightly less interested in the issue of climate change than are female Democrats, and the Democrats couldn’t get their climate change bill through Congress when they controlled both houses in 2010. For another thing, what’s sauce for the goose is sauce for the gander. The Republicans now are the “party in power” in both houses of Congress. If parties become more intensely opposed to the position of the party in power, then perhaps the spike in climate change belief really reflects a knee-jerk response among Democrats.
The economy always fluctuates, but climate change is a continuing problem. The changing salience of climate change as a problem suggests something not very quantifiable about the continual intrusion of short-term concerns into the response to long-term problems. Parties alternate in power, sometimes every two years, but climate change is a continuing problem. The changing salience of climate change as a problem suggests something not very quantifiable about the continual intrusion of irrationality and passion into politics. Americans have no monopoly on this trait, as the bitter Greek debt negotiations show.
 David Leonhardt, “Americans’ Concern Over Climate Change Is Again on the Rise,” NYT, 17 June 2015.
 “Poll Watch,” The Week, 19 June 2015, p. 15.
 I know, I know: “super-majority,” “filibuster,” “gerrymandering,” and “the Koch Brothers.” However, Senate Majority Leader Harry Reid could not even muster the support of all the Democrats. See: Carl Hulse and David Herszenhorn, “Democrats Call Off Climate Bill Effort,” NYT, 22 July 2010.