The Association of Knowledge With Concern about Global Warming: Trusted Information Sources Shape Public Thinking

SUMMARY OF REPORT

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Introduction

Climate experts generally believe that human induced global warming is occurring and will have devastating consequences. However, public concern over global warming has lagged behind the concern among experts, with global warming being rated as the 19th most important problem facing the country out of 23 according to the Pew Research Center.

There are a variety of possible explanations for the discrepancy between climate scientists and the public in concern of climate change. One possible explanation is that the American public simply does not understand the problem. Americans have been shown to be under-informed. Perhaps if Americans were more informed, they would favor remedial action. Another possible reason could be trust in scientists. If the general public does not trust scientists, there is little reason for them to believe their views on global warming.

In this study the following questions were addressed:

  1. Is the amount of information people have about global warming related to personal concern about global warming and judgments about its seriousness?
  2. Does the relation of knowledge and concern differ between Americans who trust scientists and those who do not?
  3. Does the relation of knowledge with concern differ between Americans who identify with the Democratic Party, Republican Party, or those who identify with neither?
  4. Might the observed relationship between knowledge volume and concern be that increased knowledge volume causes increased concern?

We addressed these questions by analyzing data from two surveys of national representative samples of American adults that were conducted in 2006 and 2007, and from a panel survey conducted in 1997-1998. Four measures of concern were examined.

  1. The amount of personal importance that respondents attached to global warming.
  2. How serious a problem they believed global warming will be for the U.S. in the future.
  3. How serious a problem they believed global warming will be for the World in the future.
  4. How serious a problem they believed global warming will be in general.

We explored the relations of these measures of concern with survey respondents’ self-assessments of their knowledge volume. We also explored whether people accept the claims of reputable scientists about global warming. Finally, using the 1997-1998 data, we examined whether the associations between knowledge and concern are at least partly attributable to the causal impact of the former on the latter.

Study I: Moderated Associations of Knowledge Volume with Concern Method

Methodology

The 2006 survey was between March 9 and 14, 2006; 1002 respondents were interviewed. The 2007 survey was administered between April 5 and 10, 2007; 1002 respondents were interviewed. The samples under-represented young adults, African Americans, males, and people with relatively little education.

The respondents were asked to rate how much personal importance global warming had for them, on a scale of extremely important to not at all important. They were next asked to rate the seriousness of global warming to the US, to the world, and then in general. They responded from a range of very serious to not serious at all. They were then asked how much they felt they knew about global warming, how much they trusted what scientists say about the environment, their party ID, the cause of global warming, and whether they believed that there was agreement among scientists about whether or not global warming was happening. Demographic information was then recorded.

Results

Knowledge was positively correlated with personal importance, national seriousness, and global seriousness, though not with general seriousness. Consistent with the moderation hypothesis, the relation of knowledge with concern varied depending upon both trust in scientists and party ID. The association of knowledge with concern was uniformly positive among respondents who trusted scientists completely or a lot and among respondents who trusted scientists only a little or not at all. But among people who trusted scientists only a little or not at all, the associations of knowledge with personal importance, national seriousness, and global seriousness were zero, and the association between knowledge and general seriousness was significantly negative.

With respondents who did not identify as Republican, Democrat, Independents, and others and trusted what scientists say about the environment a moderate amount, we estimated parameters of the causal models depicted in Figures 1 and 2 with the 2006 and 2007 data. We see that increased knowledge was positively and significantly associated with greater likelihood of believing that global warming is caused by human activity and of believing that scientists agree on the existence of global warming.

Study II: A Longitudinal Test of the Impact of Knowledge Volume on Concern Method

Methodology

For the 1997-1998 panel study, a representative sample of American adults was generated via RDD and interviews were conducted by telephone by the Ohio State University Survey Research Unit. 688 respondents were interviewed between September 17 and October 5 of 1997. 497 of these respondents were reinterviewed between December 20, 1997 and February 13, 1998. The sample under-represented young adults, African Americans, males, people with high incomes, and people with relatively little education.

Respondents were asked to rate the personal importance of global warming to them, the national seriousness of global warming, their self-assessed knowledge level, their party identification, and their demographic information.

Results

As expected, person importance in the first interview was a significant predictor of personal importance in the second interview. National seriousness in the first interview was also a predictor of national seriousness in the second interview. However, the stabilities were low enough to suggest that real change in personal importance and national seriousness occurred between the two interviews.

Knowledge in the first interview was not a significant predictor of the change in personal importance or national seriousness judgments between the two interviews among Republicans. Among Democrats, knowledge measured in the first interview was significantly and positively related to a change in personal importance and national seriousness. For independents, this result held with personal importance, but not with national seriousness.

Conclusion

The findings suggest that the relationship between knowledge and concern about global warming varies as functions of trust in scientists and party ID. Knowledge was positively associated with concern among people who trusted scientists at least moderately and among Democrats and Independents. In contrast, knowledge was generally uncorrelated with concern among people skeptical of scientists and among Republicans.