The Development of Public Beliefs and Attitudes about Global Warming
(with Penny Visser, Allyson Holbrook, & Laura Lowe)
In September, 1995, the international community of scientists who study the environment announced that they had come to a new consensus that global warming has been occurring as the result of human activities and that it will have very significant and costly consequences for the world unless some steps are taken to slow its development. This new consensus was reported to Americans via television news programs and in newspapers, but these two media carried slightly different messages. Whereas the television messages simply acknowledged the new scientific consensus, newspaper stories acknowledged that a minority of scientists disagreed with this position, and newspaper stories published in October and November, 1995, were especially skeptical.
In December, 1995, we conducted a telephone survey of a representative sample of Ohio adults to study the diffusion and impact of this information. And in short, we found that people formed their beliefs about whether or not global warming is real using both news media information and their own personal experiences. Television exposure did indeed encourage people to believe more in the existence of global warming, whereas newspaper exposure discouraged such a belief. But these media effects occurred only among people who were highly trusting of scientists to provide accurate information. People who were distrusting of scientists based their assessments of the existence of global warming on their own first-hand observations of changes in temperature and air pollution levels in recent years. Those who thought temperatures had gotten warmer and who thought pollution had increased were especially likely to believe in global warming.
We also examined the origins of people's attitudes toward global warming. Although most people thought global warming would be negative, some felt it would be neither positive nor negative, and a few actually thought it would be positive overall. And these attitudes were apparently driven by people's beliefs about impact on factors immediately relevant to people's daily lives: food, water, and shelter. People who believed global warming would hurt food and water supplies and would flood coastal living areas held negative attitudes. In contrast, global warming?Ns perceived impact on the beauty of natural scenery, on processes of plant and animal species extinction, on animal migration, and the like were inconsequential. Therefore, it appears that people's attitudes were driven by their beliefs about the immediate material interests of society.
This survey project also allowed us to explore some general issues in the attitude literature. For example, we examined whether four dimensions of attitude strength (attitude importance, prior thought, certainty, and perceived knowledge) are all reflections of a single underlying construct. And although a factor analysis of them yielded a single factor, they were correlated quite differently with demographic variables, psychological antecedents, and a measure of the magnitude of the false consensus effect. This evidence reinforces the general conclusion that attitude strength is not a unitary construct.
In September and October, 1997, we conducted a telephone survey or a representative sample of adults. In December, 1997 through February, 1997, we re-interviewed a portion of those interviewed in September and October, as well as an additional representative sample of adults who had not previously been interviewed. Between these two sets of interviews, the White House Conference on Global Climate Change occurred, and hundreds of stories on global warming were broadcast on television and radio, and published in newspapers and magazines across the country. Our goal was to re-examine our findings from the Ohio survey with a national sample and to study how this media coverage changed public beliefs and attitudes about global warming.
On the surface, American public opinion about global warming did not seem to change in response to media coverage of the issues. However, changes did occur when party identification was considered. Strong Democrats moved in the direction of the message coming from the White House (i.e., that global warming would happen, that it would be bad, and that something should be done about it) while strong Republicans moved in the opposite direction. So even though overall attitudes did not change, opinions polarized along party lines. In addition to this partisan polarization, the media attention led the public to do more thinking about the issue of global warming and to be more certain of their opinions about global warming. People were also able to report their opinion about global warming more quickly during the second set of interviews, one indicator that people's opinions about global warming were more crystallized after the media campaign.