Urban Heat Across Scales: Implications and Considerations

Cities are known to increase local temperatures compared to their background climate. These higher temperatures are expected to have public health consequences, prompting the need for urban-scale heat mitigation strategies. Cities are also highly heterogeneous, leading to spatial variability in heat exposure, with warmer areas often coinciding with disadvantaged neighborhoods. In this talk, I will give an overview of previous work on quantifying the local urban warming signal - or the urban heat island effect - at multiple scales (global, to regional, to city) and using various methods (satellite observations, in situ measurements, and numerical models). Additionally, I will discuss distributional inequality in urban heat exposure in cities and the role of vegetation in reducing this potential disparity. Finally, I will elaborate on some major sources of uncertainties in both measured and modeled estimates of the urban warming signal. One such critical topic is the variability of surface temperature versus air temperature versus moist heat stress within urban areas and their urban-rural differences across cities. This talk will summarize the lessons learned from multiple past studies to guide future urban climate research and provide some recommendations on how to get more actionable quantitative estimates to inform policymaking.