Examining Shifts in Public Opinion: Global Warming Policy Trends 2010-2012

Jon Krosnick is a frequent collaborator with Ipsos Public Affairs on methodological and public opinion issues. Prof. Krosnick is a professor of communication, political science and psychology at Stanford University and University Fellow at Resources for the Future. This post is published on Prof. Krosnick’s behalf to discuss the implications of the recently released research found here

Our research team at Stanford has been tracking American public opinion on global warming since the mid-1990s, and Americans’ views on this issue have changed much like people’s views on other political issues change over time: slowly.  The civil rights movement led to a change in public attitudes about race, but the change happened gradually.  Likewise, the public health community convinced Americans that smoking cigarettes is dangerous to human health, but again, the proportion of people endorsing this view grew slowly over decades.  Despite tremendous amounts of public discussion and debate about whether global warming is real and a threat during the last decade and a half, the proportions of Americans who have expressed various opinions on the issue have remained remarkably consistent.

2007 was an unusual year, in two respects.  First, the American news media devoted a tremendous amount of attention to global warming that year, publishing and broadcasting many, many more stories than they had the year before or the year after.  It was hard to get through a day without running into some news coverage of the issue.  Secondly, we saw a small increase in the proportions of Americans expressing belief in the existence and threat and importance of global warming.  Over the next two years, from 2007 to 2009, we saw small declines in these percentages.

But during this time period, we never saw notable movement in the proportions of Americans endorsing a range of policies intended to reduce future greenhouse gas emissions and reduce future global warming.  The nation has been very supportive of government mandates and of tax incentives to businesses to encourage emissions reductions.  And very few people have been supportive of taxes on gasoline and electricity for consumers intended simply to manipulate public behavior, with no accountability for what the raised revenue would be spent on.  The proportions of people endorsing these various government efforts have remained strikingly steady over time.

Until now.

During the last two years, we have seen for the first time a small downward trend in the proportions of people endorsing these policies.  On average, the trends is 5 percentage points per year.  That’s not zero, but it’s also not huge.  Even after the decline, majorities of Americans, even a majority of Republican citizens, endorse these policies.  So the signal to government about what the public wants to see happen has not changed.

Nonetheless, there has been a meaningful decline in the proportions of people endorsing the most popular policies.  And for an academic like myself, the interesting question is why.  In fact, there is little value in documenting a trend like this without an understanding of its causes, so that policy-makers (and students of public opinion) can learn from the experience and interpret the meaning of the change.

Our research points to two explanations.  First, 2011 was an unusually cool year world-wide.  Most Americans trust natural scientists on the issue of global warming and are not influenced by year-to-year fluctuations in world temperature.  But the minority of Americans who do not trust climate scientists do appear to rely on this information.  Those people were especially likely to manifest the downward trend in policy support between 2010 and 2012.

Second, the recent Republican presidential nomination campaign brought out many expressions of views from the candidates on the issue of global warming.  And all but Jon Huntsman expressed skepticism, some expressing profound doubts.  This constituted a shift in the messages that Republican citizens have been hearing from Republican leaders on this issue – during the months before the campaign began, it was rare to hear a prominent Republican express any view about global warming at all, and some, such as Newt Gingrich, had published a book and taken other steps to express what we might call “green” views on the issue.

Republican citizens paying attention to the primary campaign are likely to have been aware of the new, nearly universal skepticism among Republican candidates.  And this awareness may have influenced the views of some such citizens.  As a result, we saw the largest decline in policy support among Republican citizens who did not trust climate scientists.

It’s also important to note what we didn’t find: any evidence that growing hesitation about climate policy is concentrated among citizens suffering economically.  In fact, our analysis suggested that if anything, people who were more economically comfortable were more likely to manifest declines in their support for emissions reduction policies.  Thus, in the minds of Americans, such policies do not appear to be luxuries that we can afford to enjoy only when times are good.  Rather, support for global warming reduction in the future appears to be a priority that withstands the profound economic shock the nation has experienced recently.

With this in mind, it will be interesting to watch opinions on this issue during the coming months.  If world temperatures rise again in 2012 or 2013, endorsement of the existence and threat of global warming by citizens who do not trust scientists may rise.  And if President Obama pushes a green position on global warming during his campaign in the near future, we may see the proportion of Democrats endorsing this view rise.  If the President and the Republican nominee debate the issue face to face or indirectly via campaign speeches or paid advertising, Independent voters will hear the arguments and may be moved one way or another.  We shall see.

But in the meantime, we see no change in the message to legislators about whether the public does or does not support global warming policy.  Majority support for many policy approaches remains.