Connecting Subnational Climate Policies with Vulnerable Populations: Insights from Cooling Degree Days, Maximum Temperatures, and Heat Wave Risks in the United States

Heat waves are becoming more frequent and intense across the United States, posing significant risks to public health and exacerbating existing inequalities. This study investigates the relationship between state-level climate policies, cooling degree days (CDDs), maximum temperatures, and the demographic characteristics of populations most vulnerable to heat stress. By using CDDs and maximum temperatures as proxies for heat waves, this research provides a nuanced analysis of how states are responding to the escalating risks associated with extreme heat events.

Through a statistical examination of data from U.S. states (excluding D.C., Hawaii, and Puerto Rico), this study explores the correlation between climate policies adopted in 2021 and historical patterns of CDDs and maximum temperatures from 2011 to 2021. CDDs, which measure the demand for energy needed to cool indoor spaces, and maximum temperatures are both indicative of prolonged periods of extreme heat that can characterize heat waves. The findings reveal that states experiencing higher CDDs and elevated maximum temperatures do not uniformly implement robust climate policies aimed at mitigating heat wave impacts. Furthermore, demographic analysis shows that states with higher proportions of Asian American populations are more likely to adopt comprehensive climate policies, whereas states with higher percentages of residents living below the poverty line are less likely to have specific measures in place to address heat stress.

These results highlight a critical disconnect between the experience of extreme heat events and the adoption of protective climate policies, particularly for marginalized communities. The uneven distribution of policy responses suggests that socio-economic and demographic factors play a significant role in shaping climate adaptation strategies. This research calls for more targeted policies that not only respond to the immediate risks of heat waves but also enhance the resilience of those most affected by these events.

By focusing on the intersection of heat waves, environmental justice, and subnational climate policies, this presentation contributes to the conference's broader theme of building a thriving planet through equitable and evidence-based approaches. It underscores the importance of developing climate policies that are informed by both environmental data and the diverse needs of vulnerable populations to ensure comprehensive protection against the escalating threat of extreme heat.