Contemporary (1995-2014) and Projected (2041-2060) Heat Hazard and Population Exposure Metrics

Data used in \"A U.S. heat disaster? Intersection of social vulnerability and temperature extremes exacerbated by mid-century climate change and population shifts\" [https://iopscience.iop.org/article/10.1088/2752-5309/adb902/meta]. Please see the paper for detailed methodology. Median projected acute (95% maximum temperature, hot days (>37.5C)) and chronic (cooling degree days) heat hazard are assessed in contemporary (1995-2014) and projected (2041-2060) epochs across 25+ climate models under three shared socioeconomic pathways (SSP245, SSP370, SSP585) against contemporary social vulnerability index (SVI). We aggregate historical and projected (2050) population at the census tract in addition to various heat measures. The product of heat measures and population is used to estimate population heat exposure. We estimate multiple heat hazard metrics across three shared socioeconomic pathways and 32 total global climate models (GCMs). We estimate cooling degree days as the annual average (per epoch) cumulative sum daily average temperature degrees over 24C and 18C thresholds. We estimate hot days as the annual number of days where the daily maximum temperature exceeds 37.5C across epochs, and alternatively as the annual number of days where the daily maximum heat index (derived from temperature and specific humidity) exceed 40C. We estimate the 95th percentile for temperature and heat index. Population heat hazard is estimated by combining heat exposure with population growth projections (Gao et al., 2020). Outputs here are provided at the census tract level for all models, and for the median heat hazard and population heat exposure across models. The median metrics are the main source of data used in the paper.