If it seems as if summers are getting hotter, they are — at least from the perspective of more days when people are exposed to extreme heat, according to a new study.
Across the country, including New Jersey, climate change is making heat waves hotter and more frequent, according to an analysis by the Natural Resources Defense Council.
Nearly two-thirds of Americans are facing increased extreme-heat days, the analysis found, intensifying health risks associated with severe heat. In New Jersey, 56 percent of the state lives in counties where there is an average of more than nine extreme-heat days, according to the NRDC.
As uncomfortable as that may be, New Jersey fares better than more than 20 other states where 75 percent of the population experiences extreme heat on nine or more summer days.
Climate change is fueling hotter summer days and increasing the intensity and frequency of heat waves, while raising the risk of heatstroke and other heat-related illnesses.
In New Jersey, heat stress causes more than 950 emergency room visits and nearly 150 hospitalizations a year. In 2011, 14 heat-related deaths were reported, according to the analysis.
“Extreme heat isn’t just an inconvenience — it can kill,’’ said Dr. Kim Knowlton, senior scientist and deputy director of the NRDC’s Science Center. “This analysis gives a sense of the degree to which the present is not like the past. Climate changing is fueling more extremely hot days that pose a clear and present threat to the public health.’’
The most vulnerable populations, which face the biggest health risks, are children and the elderly.
The analysis defines “extreme heat days’’ as June to August days in 2007 to 2016 on which the daily maximum temperature exceeded the 90th percentile calculated from 1961 to 1990 at each weather-monitoring station. In total, 210 million Americans experienced a greater number of extreme-heat days in the past 10 years than in prior decades.
Average temperatures in New Jersey climbed about 3 degrees Fahrenheit since the early 1900s, according to the study. By the end of the century, if high pollution levels from greenhouse-gas emissions continue globally, temperatures are projected to exceed historical records by 10 degrees Fahrenheit.
The study suggested the establishment of early-warning systems, cooling centers, and health preparedness plans to reduce problems posed by extreme heat, as well as switching to cleaner sources of energy.