Why do Republicans and Democrats disagree about the existence of climate change in the U.S.? One key factor has been the politicization of climate science. Politicization occurs when an actor accentuates the inherent uncertainty of science as a way to cast doubt on the existence of scientific consensus. The result is that individuals become uncertain about whether to trust politicized scientific information – especially conservatives and Republicans who receive messages from credible sources engaging in politicization on the issue of climate change.
Unfortunately, my recent work with James N. Druckman and Fay Lomax Cook shows how far the impact of politicization extends: not simply to the public, but to congressional staffers and even energy scientists. We conducted three simultaneous surveys of the U.S. public, scientists who are actively publishing research on energy technologies in the U.S., and congressional staffers in August 2010. The survey asked whether global warming is happening and, if so, the degree to which human actions is responsible for the observed warming trend. We find that partisanship and ideology are strongly associated with beliefs about human-caused global warming among all three groups. Although scientists and congressional staffers were more likely than the public to say that human-caused global warming is happening, we find that partisanship and ideology influenced beliefs in all three samples.
Moreover, we included a series of factual knowledge questions about science, energy, and politics on each survey. We find that as conservatives and Republicans become more knowledgeable about energy, politics, and science, they become less likely to say that human-caused global warming is happening.
This result casts doubt on a scientific literacy model of opinion formation in which the public simply needs to be educated about the existence of a scientific consensus as a way to generate greater concern and support for action. Unfortunately, our work along with other similar work by Dan Kahan, demonstrates that increases in scientific knowledge levels lead to increasing levels of polarization among individuals in the U.S. who possess different political identities and cultural worldviews. This is due to the prevalence of identity-protective motivations that lead citizens of diverse identities to acquire, interpret, and form opinions with an underlying motivation to uphold existing loyalties and group commitments. This may be individually rational, because it helps to uphold social identities, and personal worldviews, but it is collectively detrimental to society because it undermines the ability of science to contribute to the public discourse on issues where it could otherwise inform citizens. Once a debate has become politicized, educating the public about the facts associated with global warming has little persuasive impact.
Scientists have reached a consensus on human-induced climate change. More must be done to make certain all segments of the public are aware of this for a meaningful discussion to proceed in the U.S. on how to address the problem. The challenge is finding ways to counteract politicization, and thereby stop political actors from attempts to undermine support for changes to the policy status quo.