MainAs extreme weather events become more intense and frequent with climate change1, the role of such events in shaping public awareness and prompting climate action has been a subject of considerable debate2,3,4. Researchers have proposed that these events may act as catalysts for capturing attention, raising awareness and spurring action to combat climate change5,6,7,8. While evidence suggests that extreme weather events can influence climate change engagement, this influence seems to depend on individual differences such as a person’s political affiliation6,9,10. Especially in polarized political contexts such as in the USA, political affiliation may shape whether extreme weather is understood as evidence of climate change or dismissed as unrelated, thereby influencing how people seek and process climate-relevant information.Among the individual factors that shape responses to extreme weather, political affiliation is one of the strongest predictors of climate change beliefs11. Individuals aligned with more liberal (versus conservative) political parties are more likely to believe in climate change and to support climate-relevant behaviours and policies12,13,14, particularly in the USA14,15. Despite extensive evidence linking political affiliation to climate beliefs and behaviours, much less is known about how it shapes the psychological processes through which people seek out, attend to and use climate-relevant information, particularly in the context of varying exposure to extreme weather events. These processes may include whether individuals notice and evaluate the carbon footprint of products before purchase, compare environmentally responsible investment opportunities or consider political candidates’ positions on climate action. Understanding how political affiliation influences these information-processing pathways may help explain why similar environmental experiences lead to different patterns of climate engagement and decision-making.To address this gap, our study investigates how individual characteristics (that is, political affiliation) and physical-level determinants (for example, exposure to extreme weather) jointly shape climate-relevant information search and decision-making. In doing so, we respond to calls for climate-behaviour research that accounts for the variety, complexity and interconnectedness of behavioural determinants16,17. We use visual attention to climate-relevant information as an indicator of these underlying processes measured with a MouselabWEB paradigm, which allows us to examine how people allocate attention to may provide insights relevant to future research on communication strategies and policy measures aimed at fostering bipartisan engagement in climate action18,19.Accordingly, this study seeks to address three core research questions: (1) Does political affiliation impact how individuals search for and attend to information during climate-relevant decision-making? (2) Does exposure to extreme weather events interact with political affiliation to shape these information search processes? (3) Does the interaction of exposure to extreme weather events and political affiliation on information search processes depend on individuals’ subjective attribution of these events to climate change?While the primary emphasis of this study is on information search processes (that is, attention allocation), we also aim to examine how climate-relevant choices (that is, the outcomes of preceding decision-making processes) are influenced by these factors. Specifically, we aim to explore how political affiliation, exposure to extreme weather events and the subjective attribution of such events to climate change impact the actual choices made. In doing so, we provide a comparative analysis of how attention allocation during information search and the resulting choices are shaped by these variables and their interactions.To answer our research questions, a representative sample of US participants completed a new variant of the Carbon Emission Task (CET)20 while we tracked their decision-making processes using web-based process-tracing technology (MouselabWEB)21. The CET is a paradigm that has been shown to be externally valid20, as it mirrors the critical dynamics and interdependencies between actions and outcomes that characterize many real-world, climate-relevant decision-making situations22,23,24,25. Many everyday choices reflect this balance between short-term convenience and long-term sustainability—such as driving a car instead of walking or biking to reduce emissions, or taking long, hot showers despite their higher water and energy consumption (see Supplementary Information, section 2.3.1 for more examples).Importantly, the carbon emissions in the task are real and are implemented by trading carbon emission certificates in a cap-and-trade system, where polluters must hold emission certificates to offset their carbon output20,26 (Methods). Using a MouselabWEB paradigm, information about bonus payments and carbon emissions is concealed and revealed only when participants move the mouse cursor over the corresponding attribute21 (Fig. 1). Here we focus on dwell time—an established measure of attention allocation during information search—to examine how participants allocate attention to bonus payments and carbon emissions. This measure allows us to capture the psychological trade-offs individuals make between personal benefits and climate consequences during decision-making.Fig. 1: Example trial of the new variant of the CET.Full size imageParticipants choose between two options with different bonus payments and carbon emissions. a, Initially, this information is occluded by boxes. b, Participants can reveal the specific details of each option by hovering over the boxes with their mouse. Moving the mouse outside of a box occludes the information again. c, By visiting all boxes, participants can acquire all available information in a trial (all boxes opened simultaneously for demonstration purposes only). The position of the bonus and carbon information (top versus bottom) is randomized between participants, while the position of the option maximizing the bonus (left versus right) is randomized within participants between trials. Each trial starts by clicking a fixation cross button in the centre of the decision matrix, ensuring equal distance for all box visitations.To examine how attention allocation is shaped by both political affiliation and objective exposure to extreme weather events, we linked participants to county-level records from the National Oceanic and Atmospheric Administration. These data provide high-resolution records of objectively measured extreme weather events and have previously been used to study climate-related perceptions and behaviour27,28. For each participant, we assessed exposure during the 30 days preceding study participation (and up to 360 days in sensitivity analyses), while also deriving measures of event severity and abnormality.We formulated three hypotheses corresponding to our primary (and secondary) research questions (summarized in the Design Table in Supplementary Information, section 2.6). Theoretical accounts of climate change polarization propose that political attitudes shape attention to climate-relevant information, influencing climate-related judgments and behaviour29,30,31. Consistent with this view, prior research shows that liberals and conservatives differ in their attention to climate information. In an attentional blink task, liberals concerned about climate change more accurately identified climate-related than neutral words, whereas conservatives with low climate concern showed no such advantage32. Similarly, eye-tracking research found that liberals, compared with conservatives, allocated more visual attention to periods of rising rather than stable global temperatures30. Together, these findings suggest that political attitudes shape attention to climate-relevant information. Accordingly, we hypothesized:Political affiliation hypothesis (H1): Democrats (compared to Republicans) prioritize attention to carbon over bonus information in the CET.Previous research on the relationship between various metrics of exposure to extreme weather and climate beliefs, attitudes and behaviours has produced mixed results. While some studies found that exposure to extreme weather increased climate change concern and engagement28,33,34,35 and attention to climate change in news media, social media content and Google searches27,36,37,38, others reported little to no evidence for such relationships39,40,41,42,43. These inconsistencies may arise because the effects of extreme weather depend on other factors4,10,44, particularly political affiliation and subjective attribution of events to climate change9,45,46,47,48. For example, exposure to wildfires increased support for climate-related ballot measures only in Democratic voting areas49, and extreme weather generated more climate-related discussion in Democratic than Republican communities, especially when the events were attributable to climate change6. Similarly, personal experience with severe flooding predicted mitigation responses only among individuals who attributed the event to climate change47. Thus, previous research suggests an intricate interplay between political affiliation, exposure to extreme weather events and their attribution in affecting engagement with climate change. However, most previous studies relied on self-reported measures of both exposure and attribution, raising concerns about common method bias23,26. By combining objective measures of extreme weather exposure with subjective attribution, our study addresses this limitation. To this end, we test whether extreme weather exposure amplifies political differences in attention allocation and climate engagement, and whether this relationship depends on subjective attribution. Accordingly, we derived the following hypotheses:Extreme weather hypothesis (H2): The difference in time spent on carbon versus bonus information in the CET increases after exposure (versus without) to extreme weather events between Republicans and Democrats.Subjective attribution hypothesis (H3): The amplifying effect of exposure to extreme weather events on the polarization in information search processes between Republicans and Democrats is more pronounced for individuals who attribute these events more strongly to climate change.In addition to examining information search processes, we also aimed to investigate how these factors—political affiliation, exposure to extreme weather events and the subjective attribution of these events to climate change—affect the actual choices participants make in the CET. Specifically, we propose that the same interactive dynamics observed in information search will extend to choices in the CET. Thus, we formulate the following secondary hypotheses for climate-relevant choices:HS1: Compared to Republicans, Democrats are more likely to make choices that prioritize climate protection over personal financial gain in the CET. That is, Democrats have a higher probability of making pro-climate choices compared to Republicans.HS2: Exposure to extreme weather events amplifies the polarization in climate-relevant choices, increasing the difference in climate-protecting choices made by Republicans and Democrats.HS3: The amplifying effect of exposure to extreme weather events on the polarization in climate-relevant choices between Republicans and Democrats is more pronounced for individuals who attribute these events more strongly to climate change.ResultsData were collected between August and September 2025. The sample (N = 2,000) was quota-matched to the US population on political affiliation, age, sex and region, with a deviation tolerance of