Projecting heat-related mortality impacts under a changing climate in the New York City region

Abstract

Objectives: We sought to project future impacts of climate change on summer heat-related premature deaths in the New York City metropolitan region.

Methods: Current and future climates were simulated over the northeastern United States with a global-to-regional climate modeling system. Summer heat-related premature deaths in the 1990s and 2050s were estimated by using a range of scenarios and approaches to modeling acclimatization (e.g., increased use of air conditioning, gradual physiological adaptation).

Results: Projected regional increases in heat-related premature mortality by the 2050s ranged from 47% to 95%, with a mean 70% increase compared with the 1990s. Acclimatization effects reduced regional increases in summer heat-related premature mortality by about 25%. Local impacts varied considerably across the region, with urban counties showing greater numbers of deaths and smaller percentage increases than less-urbanized counties.

Conclusions: Although considerable uncertainty exists in climate forecasts and future health vulnerability, the range of projections we developed suggests that by midcentury, acclimatization may not completely mitigate the effects of climate change in the New York City metropolitan region, which would result in an overall net increase in heat-related premature mortality.

FIGURE 1—

A comparison of regional estimated 1990s summer heat-related deaths versus mortality projected for each future decade, including both A2 and B2 scenarios for 2050s, and both acclimatized and nonacclimatized approaches: New York City metropolitan region. Note. A2 scenario assumed rapid human population growth, relatively weak environmental concerns, and a lack of aggressive greenhouse gas regulations. B2 scenario assumed more-moderate population growth and increased concerns about environmental sustainability, with more aggressive greenhouse gas regulations, compared with A2.

FIGURE 2—

Map showing spatial variations in county-specific mean increases in heat-related premature mortality from the 1990s to the 2050s: New York City metropolitan region.