How do climate-based natural disasters affect politics? António Valentim presents insights from four studies featured at the 2025 LSE Festival exhibition.

Research by António Valentim is featured at the 2025 LSE Festival exhibition, Visions for the future.

As climate change accelerates, its consequences become more apparent. Yet, how do political actors and institutions respond when the crisis hits their doorstep? And when they don’t, can citizens shift the needle?

At this year’s LSE Festival exhibition, Visions for the future, a panel showcases new social science research addressing precisely these questions. The four papers presented here are part of that panel and focus on different stages of political response to climate change – from elite (in)action to party responsiveness and grassroots mobilisation.

Extreme weather events do not increase political parties’ environmental attention

Contrary to expectations, European political parties largely fail to respond to extreme weather events by increasing their attention to environmental issues. This study, which I published with Tim Wappenhans, Heike Klüver and Lukas Stoetzer, analyses over 260,000 press releases from 68 political parties across nine countries (2010-2020). It combines a difference-in-differences design with supervised learning algorithms to track changes in climate-related communication to test whether deadly extreme weather events (such as floods, wildfires, storms and heatwaves) lead political parties to talk more about environmental issues.

We find that only Green parties exhibit a short-lived increase in climate messaging, usually just in the week of the event. All other parties, across ideological families and institutional roles (government or opposition), show no consistent change in their attention to environmental topics. This finding challenges the intuitive belief that as climate impacts become more tangible, political elites and policy will naturally follow.

Green parties often fail to capitalise on climate-based emergencies

But what about the parties most likely to benefit from climate salience? In this paper, I zoom in on the English Green Party to ask a more focused question: when climate issues become electorally salient, specifically after flooding, do Green parties strategically allocate more candidates in affected areas to capitalise on this?

Because the Greens are the issue owners on environmental issues and could be seen as a niche or smaller party in this context that could benefit from grievances against incumbents, they are likely to benefit from floods. Using geospatial data on floods and survey data, I test whether this is the case, showing that floods do increase the salience of environmental issues and make voters penalise the incumbent. I then test whether the Greens respond to these events by allocating more candidates to these affected areas.

While floods do appear to influence voters (they raise the salience of climate change and they increase protest voting), the Green Party does not respond by fielding more candidates in affected areas. Using data on campaign expenditure and interviews with party insiders, I suggest that smaller parties often operate with limited information and resources, which might constrain their ability to respond to voters. The Green Party does not have the resources to collect information on voters’ preferences or does not prioritise doing so.

My findings complicate the standard model of rational party responsiveness, suggesting that even when climate politics becomes electorally advantageous, institutional and informational constraints can prevent meaningful elite adaptation.

Climate protests can influence voters

While the first two papers highlight the limits of elite responsiveness, this third study turns the spotlight onto citizens by asking whether climate protests can influence electoral outcomes. I examine the Fridays for Future (FFF) climate protests to examine their impact on elections, arguing that a key characteristic of effective protests is their ability to repeatedly expose voters to their message.

Using a novel dataset of Fridays for Future protests and municipal election results in Germany, I use a difference-in-differences design, finding that exposure to Fridays for Future protests increased vote share for the German Greens, especially when the protests were repeated.

The effect appears to be driven by increased voter turnout and changes in climate attitudes (particularly among those who are less interested in politics), rather than issue salience alone. Importantly, the findings replicate across six other European countries, but not to other pro-environmental behaviours, such as bicycle commuting. This contributes to a growing body of evidence that nonviolent, repeated protest can influence electoral behaviour, which might benefit parties that are perceived as competent on the issue.

Climate shocks can change who runs for office

Expanding the lens beyond Europe, the final study, which I conducted with Guilherme Fasolin, investigates how floods affect candidate entry in Brazilian mayoral elections. While most research thinks of these events as an opportunity for voters to learn about climate change, we build on work from across the social and natural sciences that show these events have important socio-economic consequences.

Specifically, we study whether extreme weather events change the composition of political candidates, potentially exacerbating or attenuating pre-existing inequalities. Using a novel dataset of flooding events and mayoral candidates in Brazil (2000-2020), we employ a difference-in-differences design to assess the impact of floods on the demographic composition of the mayoral candidate pool.

In general, we find that floods reduce the average age and educational attainment of political candidates. Using data on federal transfers, corruption audits, surveys and elite interviews, we show the effects on education can be driven by rent-seeking and outside options, whilst mobilisation and recruitment patterns drive the age effects. This study suggests that climate shocks can change who becomes a politician, particularly the young and those with less formal education, who tend to participate in politics at much lower rates.

Note: This article gives the views of the author, not the position of EUROPP – European Politics and Policy or the London School of Economics. Featured image credit: Vicente Sargues / Shutterstock.com