Fig. 4: Non-survivable conditions for older people seeking shade.
The proportion of non-survivable conditions during historical and extreme heat waves for older people (65+ years) seeking shade computed from ERA5, combined with estimated population density for the same age group computed from WorldPop; a the location of each historical event analysed; b the Middle East heat wave during June 2024; c the South Asian heatwave of April 2024; d the North and Central American heat wave during July 2023; e the Australian heatwave during January 2019; f the Indian heatwave during June 2015; and g the European heatwave during August 2003. Yellow indicates combined low population ( < 5 persons/km2) and proportion of non-survivable days ( < 25%), whereas black indicates combined high population (50–100 persons/km2) and proportion of non-survivable days ( > 75%). All other colours indicate a progressive and increasing combination of the two variables, reaching darker shades when variable values increase. The location of each city examined in greater detail for the observed event and future projections is indicated by the magenta dot. For specific details of each event, its location, and corresponding city, please see “Methods” and Table 1 in the Supplementary Information. Please see “Methods” for details regarding ERA5 WorldPop and non-survivability calculation.
