THE BIGGEST obstacles to slowing climate change are political. Although carbon emissions can be slashed with current technologies, such cuts are perceived to require sacrifices today in order to reduce the risk of calamity in future. Many voters refuse to shoulder these costs.

Global temperatures are already rising fast. Even if today’s weather extremes may look mild by future standards, they are still more severe than those of the past. In theory, unusual weather events like dry or warm spells might have a silver lining: providing a wake-up call to complacent voters. A recent paper by Roman Hoffmann, Raya Muttarak and Jonas Peisker of IIASA, a think-tank, and Piero Stanig of Bocconi University finds evidence for this pattern, with a caveat. It shows up mostly in rich countries with cool climates.

To test the link between weather and environmentalism, the authors compiled data on wildfires, droughts, floods and temperatures in 1,239 European administrative areas in 1994-2019. They also tracked two measures of public concern about the environment: responses from a long-running European survey, and the performance in European Parliament elections of green parties, whose voters tend to be particularly focused on climate change.

The researchers found that unusual weather, particularly in the form of heat, did focus people’s minds on climate. The more unseasonably warm days (when compared with the average in 1971-2000) in a given region during the year preceding a poll or European election, the more people in that area said that they were concerned about the environment, and the greater the share of votes green parties went on to win. The same was true of droughts, and to a lesser degree of wildfires.

The impact of other types of weather was much less clear. Cold snaps did seem to help green parties, but to a lesser degree. Extreme wet periods had little effect. And green parties may in fact have fared worse in elections following floods (though further study is needed to confirm this effect). The authors speculate that use of the specific term “global warming” rather than the broader “climate change” may prevent the public from attributing weather events other than heatwaves or droughts to human activity. Another study found a similar discrepancy in America: hot, dry days raised the chances that poll respondents said they believed in climate change, but floods and low temperatures did not.

Even high-temperature episodes do not consistently strengthen environmentalism. Instead, the effect is limited to specific contexts. It is greatest in the temperate and colder regions of northern and western Europe, and mostly absent in the arid Mediterranean basin. One possible explanation is that southern Europeans are already used to hot weather, and may be less perturbed by extreme heatwaves. They are also more likely to have air conditioning.

Another source of variation is income. In rich parts of the EU, such as Brussels, votes for green parties tend to surge following high temperatures. No such increase occurs in poor areas like western Bulgaria, where green parties are uncompetitive regardless of recent weather. For families struggling to put bread on the table, worrying about the fate of the planet decades hence might seem like a luxury. ■

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Source: “Climate change experiences raise environmental concerns and promote green voting”, by R. Hoffmann et al., Nature Climate Change, 2022