From reviewing your CVs, I see that each of you comes from a different research background. Professor Mildenberger, you study the politics of climate change, whereas Professor Hazlett, you focus on methodologies that allow researchers to make causal claims in a variety of fields. Coming from those two perspectives, how did this study come about?
Chad Hazlett and Matto Mildenberger: We are both very interested in work that carefully seeks to characterize what can and cannot be claimed about the effects of real-world events on real-world behaviors. Thinking about how to apply this in the area of climate change, we tossed around a few ideas. Initially, we were interested in how power outages caused by hurricanes might affect support for costly pro-climate ballot initiatives. While we tried to get data on outages from power operators and from satellite imaging, this proved unreliable. Eventually we both ended up in California, however, and before long it became obvious to us that wildfires are a real threat that could influence beliefs and behaviors, and that ballot measures are widely employed here, offering a real, politically relevant outcome.
As you note in the article, the negative effects of climate change are already upon us. This study looks at the effect of proximity to climate-related disasters (in this case, wildfires) on support for climate policies. What did your research find?
CH and MM: We found that within two years after a wildfire occurs within 5 kilometers of an area, support for climate-related ballot measures is on average 5-6 percentage points higher. This estimate comes from within-location variation, so effectively leverages randomness in “when” a place that is susceptible to wildfires experiences one. The estimated effect decays to nearly zero as distance grows to 15 kilometers. Moreover, these estimated effects are driven by large effect sizes in highly Democratic areas, whereas highly Republican areas show almost no effect. We thus conclude that experienced climate threat likely enhances willingness to support costly pro-climate actions, but only in Democratic areas.
We know that wildfires are linked to climate change. However, we also know that other factors, such as forest fuel buildup, also contribute to wildfires. Did your design attempt to address whether study subjects attributed the wildfires they experienced to the negative effects of climate change?
CH and MM: We did not address this directly. Indeed, one downside of focusing on a very real political outcome—actual vote on ballot initiatives—is that we cannot go back and ask additional questions of this kind. That said, we find that the effect of experienced wildfire on political behavior is concentrated in highly democratic areas. One might reasonably argue that this occurs because, in highly Democratic areas, voters are more likely to believe in climate change and to attribute the increased rate of wildfires to them.
How do the findings from this study advance our knowledge of what drives support for climate mitigation and adaptation measures?
CH and MM: One political barrier to enacting climate policies has been the temporal mismatch between short-term climate policy costs and long-term climate policy benefits. However, as the impacts of climate change realize, the costs of inaction might become more salient to the public, increasing political incentives to take the threat seriously. In previous work, we have reviewed the empirical evidence for this idea that direct experience with climate change might shape climate opinions. Contrary to what advocates hope, that empirical evidence is mixed. Although many studies have found evidence of a weak effect of local temperature and extreme weather events on climate opinion, these effects are often ephemeral. Further, most studies focus on attitudinal dependent variables or, at best, self-reported behavioral intentions. Our paper adds to this literature with its ability to use realized political behavior (climate policy voting outcomes) as its dependent variable. We are thus able to explore the effect of direct experience on climate opinion in a real-world setting.
What are the policy implications of these findings? In particular, what conclusions can we draw from this study to inform expectations for climate policy support in more politically heterogeneous (or outright climate crisis-denying) parts of the world?
CH and MM: As is so often the case, when we try our best to learn the effects of some things (wildfires) on other things (political behavior), we might not like the answer, and the answer might not lead to obvious policy recommendations. Here, it is a mixed bag. That wildfire experience might spur higher willingness to pay for pro-climate policies is superficially promising: as the effects of climate change become ever more apparent, we can hope this spurs action, even if earlier action would have been cheaper and more effective. On the other hand, it remains worrying that this effect falls off quickly with distance to wildfires, and that we do not see this relationship in heavily Republican areas—where ample prior work has shown that fewer voters to believe in or be concerned about climate change. These results suggest that direct experiences with climate change may increase issue prioritization among voters who already accept climate science, but will be unlikely to change the minds of voters who do not. Of course, we do not know how far this work generalizes, and look forward to seeing future work on other types of disasters and outcomes and in other areas.