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Shifting the Conversation about Climate Change

The Science of Science Communication

Matt Nisbet

Skeptical Inquirer Volume 40.2, March/April 2016

Late last year at the United Nations climate change summit in Paris, world leaders reached a historic accord committing their countries to lowering greenhouse gas emissions over the next two decades and beyond.

The combined commitments by countries fall short of what many scientists say is needed to avoid the worst impacts of climate change, but the Paris accord marks an essential first step. World leaders pledged to revisit their commitments every five years with the goal of ratcheting up efforts to rapidly reduce emissions.

Yet over the next decade, as the United States joins with other countries in a quest to decarbonize the world economy, it will be essential to also ratchet up U.S. public opinion.

The challenge is to move the majority of Americans who remain ambivalent about the issue toward greater support for government action.

Recent studies, including several that I have conducted, suggest a portfolio of related communication strategies that can help shift the conversation about climate change, building public demand for solutions.

Talking Up Consensus

As simple as it might sound, perceptions of scientific consensus on climate change serve as a key “gateway belief,” influencing other beliefs about the issue, which in turn shape support for policy action, report Sander van der Linden and colleagues (2015) in a recently published study.

Even for individuals who closely follow the issue, it is impossible to track the latest scientific findings or studies about climate change, much less parse the many complexities involved. Instead, as with medical questions or technology issues, most people use what they perceive as the consensus opinion of relevant experts as a mental short cut.

On the issue of climate change, the problem is that many members of the public are not very good at accurately estimating the true level of scientific consensus. Surveys of climate scientists and comprehensive reviews of thousands of peer-reviewed studies confirm the same basic fact: at least 97 percent of climate scientists say that human-caused climate change is happening (see Doran and Zimmerman 2009; Anderegg et al. 2010; Cook et al. 2013). One study, in fact, indicates the consensus is actually as high as 99.9 percent (Powell 2015). Yet recent surveys find that only one out of ten Americans correctly estimate agreement among climate scientists as greater than 90 percent (Leiserowitz et al. 2014).

To evaluate strategies for correcting perceptions of expert consensus, van der Linden and his colleagues (2014) tested the effects of different variations on the same message: “97% of climate scientists have concluded that human-caused climate change is happening.” In one experimental condition, subjects were presented just with the text of the message. In a second condition, the text was paired with a pie chart visually conveying the level of consensus. In other conditions, subjects were presented with variations on a relevant metaphor such as, “If 97% of engineers concluded that a particular bridge is unsafe to cross, would you believe them? 97% of climate scientists have concluded that human-caused climate change is happening.”

Across each of their experimental conditions, boosting awareness of scientific consensus increased beliefs that climate change is happening, that it is human caused, and that it is a worrisome problem. These shifts in beliefs in turn increased subjects’ support for policy action, with some of the biggest increases observed among Republicans, who tend to be more dismissive of the issue (van der Linden et al. 2015). Interestingly, in comparison to the tested metaphors, subjects who received either the simple text statement or the pie chart displayed the greatest increase in their beliefs.

Metaphors are especially useful for explaining complex mechanisms related to climate science, reasoned van der Linden and his colleagues (2014), but when trying to convey the strength of scientific consensus, “presenting information in a way that is short, simple, and easy to comprehend and remember seems to offer the highest probability of success for all audiences examined,” they concluded.

Reframing the Debate

As we educate the public about scientific consensus, evidence suggests we also need to reframe the focus of debate. Americans tend to view climate change as a scientific or environmental issue, but not as a problem that affects them personally or that connects to issues that they already perceive as important.

Successfully reframing climate change means remaining true to the underlying science of the issue while applying research to tailor messages to different audiences, making the complex issue understandable and personally important (see Nisbet 2009).

For example, in a series of studies conducted with several colleagues, we examined how Americans respond to information about climate change when the issue is framed as a public health problem. A public health focus stresses scientific findings that link climate change to an increase in the incidence of infectious diseases, asthma, allergies, heat stroke, and other health problems, risks that differentially impact children, the elderly, and the poor.

To test the effects of this frame, in an initial study, we conducted in-depth interviews with seventy respondents from twenty-nine states, recruiting subjects from six previously defined audience segments. These segments ranged on a continuum from those individuals deeply alarmed by climate change to those who were deeply dismissive of the problem. Across all six audience segments, when asked to read a short essay that framed climate change in terms of public health, individuals said that the information was both useful and compelling, particularly at the end of the essay when locally focused policy actions were paired with specific benefits to public health (Maibach et al. 2010).

In a follow-up study, we conducted a nationally representative online survey in which respondents from each of the six audience segments were randomly assigned to three different experimental conditions allowing us to evaluate their emotional reactions to strategically framed messages about climate change. In comparison to messages that defined climate change in terms of either the environment or national security, talking about climate change as a public health problem generated greater feelings of hope among subjects. Research suggests that this emotion helps promote greater public involvement and participation on the issue. Among subjects who tended to doubt or dismiss climate change as a problem, the public health focus helped defuse anger in reaction to information about the issue, creating the opportunity for opinion change (Myers et al. 2012).

Working with a Diversity of 
Opinion Leaders

The research on consensus messaging and framing suggest easy-to-adopt talking points and novel lines of emphasis that scientists and other experts can use in face-to-face conversations, presentations, meetings, media interviews, and via social media. Yet to ratchet up public engagement with climate change, scientists and experts will also have to be joined by a variety of opinion leaders from across sectors of society, trusted voices that can influence otherwise difficult-to-reach audiences (see Nisbet and Kotcher 2009).

Studies, for example, have identified TV weathercasters as an especially important community influencer. Local TV broadcasts remain the top news source for a majority of Americans, and most say they watch the local news primarily for the weathercast. Given their training, visibility, reach, and trusted status, weathercasters hold the unique ability to describe how local weather conditions, such as heat waves, drought, or heavy precipitation, may be related to climate change.

Connecting the dots on such events is important. Research shows that when people understand that they have personally experienced the effects of climate change, they are more likely to be concerned about the issue and to support a variety of policy actions (Placky et al. 2015). To date, more than 250 local weathercasters in the United States representing 185 stations and 105 media markets have been recruited to include regular “Climate Matters” segments as part of their broadcasts, using easily adopted visuals that are localized to specific audiences.

A longitudinal study evaluating a pilot program at a local TV station in Columbia, South Carolina, found that after one year of regular Climate Matters segments, viewers of the station’s broadcast had developed a more science-based understanding of climate change than viewers of other local news stations (Placky et al. 2015). Pope Francis’s recent effort to reframe climate change in terms of religious duty and social justice is another example of the impact that trusted voices can have on public opinion.

Following the release of the pope’s encyclical on the subject and his visit to the United States this past year, 17 percent of Americans and 35 percent of Catholics reported that the pope’s position on climate change had influenced their views. In comparison to six months prior to the pope’s visit, significantly more Americans were likely to say that climate change is a moral issue, a social fairness issue, and a religious issue (Maibach et al. 2015). These findings provide strong evidence that the pope’s reframing of climate change had an impact on how the public thinks about the problem, connecting to widely shared values that transcend political differences.

The Need for Compromise

Ratcheting up public support for government action on climate change not only requires a sophisticated, research-based understanding of effective communication approaches but also an acceptance that there are strong limits to what even the best-funded and most carefully planned strategy can accomplish. Research findings evaluating different communication strategies are often messy, complex, and difficult to translate into practice. They are also subject to revision based on new research, changes in the dynamics surrounding an issue, or in applying across policy decisions and social contexts. Moreover, no matter how knowledgeable and adept experts and their partners might be in applying research to their communication efforts, progress on climate change will ultimately require the different sides in the debate to give ground, negotiate, and compromise. In the case of climate change, the major question therefore is whether public demand for action and the openness to compromise will happen too late, preventing society from successfully avoiding the most serious risks.


Matt Nisbet

Matthew Nisbet is Associate Professor of Communication at Northeastern University and a CSI technical consultant.