Communicating the Impact of Climate Change on Extreme Weather in India, the United Kingdom, and the United States

As climate change increasingly affects the likelihood and severity of extreme weather events such as flooding and heat waves around the world, it is more important than ever to encourage both mitigation and adaptation. As an important step, people need to understand the links between climate change and extreme weather. We conducted a preregistered online randomized experiment with over 10,000 participants across India, the UK, and the USA, three countries that are large annual emitters but have different patterns of extreme weather. We tested the impact of different numerical frames (percentage versus times) and types of extreme weather (heat waves versus flooding) on beliefs that climate change made extreme weather in 2023 more likely. All four message treatments had a significant effect, increasing the percentage of participants who believed climate change made extreme weather more likely by 4.5 to 6.1 percentage points. However, there was no main effect of specific event type or numerical framing. We found message treatments also increased worry about climate change in general, although impact on policy support or information-seeking behavior was limited. The findings of this study contribute to the scarce literature on which messages are effective at communicating extreme weather event attribution.