Hot town, summer in the city

The already-sweltering summers of NYC are set to get hotter through the next 60 years, with an accompanying rise in temperature-related deaths (heatstroke and other forms of hyperthermia). The rate of temperature-related deaths in Manhattan could rise by 20% in the 2020s, and by up to 90% in the 2080s, scientists from Columbia University recently reported in Nature Climate Change.

Global warming impacts cities and countryside differently: cities heat up more quickly – the urban heat island effect. Temperatures in New York rose a full 2°C in the 20th century – more than the national or global average. Last year was the hottest on record, and the last three have each seen summer temperatures in excess of 38°C – normal body temperature.

Using 16 different climate models, the scientists adapted them to Manhattan, and made projections under two sets of conditions – one with few limits to CO2 emissions and where rapid growth continues, and one wherein CO2 emissions decrease by 2040 under slower growth. In all 32 scenarios they projected, heat-related deaths increased, and significantly quickly as time went on. Winters would be warmer too, so there would be fewer deaths from cold, but the increase in heat-related deaths more than offsets this.

As with any projection, this research looks at what could happen, not what will. Adaptations to increasing heat may help save lives… but the research may also underestimate the magnitude of the problem.