Dissertation Extended Abstract

Threatening Messages in Climate Change Communication: Dissertation Summary

Tim Scharks, Evans School of Public Policy and Governance, University of Washington

Climate change will have disastrous consequences if left unchecked. Climate change communication represents a means to encourage conservation behavior and support for climate mitigation policies. One form of communication is to present a threat in an effort to persuade; such threatening messages are often called fear appeals. The use of fear appeals in climate change communication is oft-discussed but little studied.

This dissertation applies a popular model of fear appeals, the Extended Parallel Process Model, to examine threatening messages in climate change communication. The first chapter examines the use of threats and efficacy messages in advertisements published in The New York Times, The Times (London), and The Economist (UK Edition) from 1980 to the end of 2009 in a quantitative content analysis. While journalistic coverage of climate change has been frequently studied, this chapter is the first systematic examination of climate change-relevant advertising. It finds about half of all ads contained a mention of a threat, but, different from many other studies of persuasive public communications, threats were frequently paired with efficacy messages. Significant differences between periodicals and between the US and UK are also found, most especially that ads in the US featured a greater proportion of “negative response efficacy” messages, that is, messages that supported positions questioning or denying human agency in climate change or the risks it posed. This helps to explain the observed polarization of views over climate science and mitigation policy.

The second chapter (under review) presents an experiment of US adults (n=845) where right-leaning US respondents who viewed climate change fear appeals exhibited psychological reactance, a combination of anger and counterarguments in response to a perceived threat to freedom. Reactance suppresses support for climate mitigation policy: The net effect of a threatening communication on policy support at first appeared to be zero. But reactance polarized right-leaning respondents' support for mitigation policies, moving some towards support and others farther from it, a phenomenon known as a “boomerang effect”. This finding helps to explain some of the continued polarization of views on climate science and climate change. In a revealed preference element of the experiment, reactance also suppressed donation behavior to both liberal and conservative causes.

Finally, a third chapter examines the role of psychological distance (how closely climate change is perceived) and collective efficacy (the belief everyone can work together) on mitigation policy support in a climate change fear appeal.  The experiment gives evidence that left-leaning respondents increased their policy support with closer psychological distance (an image of an American city vs. a city in the Philippines). In another example of unintended outcomes, right-leaning respondents experienced a boomerang effect to the inclusion of a “common sense” element of an advertisement. Strong correlations between collective efficacy beliefs and policy support imply collective efficacy messages should increase policy support. Yet ads with a collective efficacy message decreased mitigation policy support among right-leaning respondents.

In sum, this dissertation has several policy implications: threatening ads have been used in English-language print media, they may serve to polarize audiences further by moving right-leaning readers farther away from mitigation policy support, and threatening messages should be considered with caution, especially through pilot testing for reactance and other unintended effects.