This report assesses the social and economic effects of extreme heat through the prism of twelve cities already enduring and addressing the dramatic impacts of heat waves. Heat’s disproportionate impact on cities—and the ironic reality that more and more people are flocking to them due to climate change’s burgeoning impacts elsewhere—compelled us to quantify and explore the seismic ramifications of our burning planet.
This report continues an economic study undertaken in partnership with Vivid Economics. In phase one of this work, released in August 2021, we found that worker productivity losses totalled $100 billion in the United States alone in 2020, which will double in 2030 and rise to $500 billion by 2050.
- Heat reduces labor productivity in a wide range of ways.
- Losses from heat-related reductions in worker productivity are high and mounting.
- These reductions in worker productivity may affect workers’ incomes.
- Cities in the global South face greater, more rapidly increasing impacts.
- Impacts fall most heavily on those least able to bear them.
- Heat has gendered impacts.
- How heat affects economies and societies varies from city to city.
- Planning/policy: Measures to enhance worker protection can, for example, limit working during very hot periods, or mandate cooling measures in building codes. For example, Los Angeles mandates regular work breaks for outdoor workers.
- Communications/outreach: Early warning systems or campaigns can promote behavioral changes such as increasing hydration and resting periods. Athens recently introduced a system of heat alerts and categorization of heat waves to help residents and visitors take appropriate precautions, while Seville introduced heat wave naming in concert with categorization that resulted in Heat Wave Zoe, in July 2022.
- Investment in the built environment and nature-based solutions: Local cooling infrastructure includes tree canopies, cool pavements, roofs and walls, cooling centers, or public fountains. Cities such as Miami and Freetown have adopted ambitious tree planting campaigns, while Los Angeles is investing in cool roofs.