“The risks of increasing temperature at night were frequently neglected,” said researcher Yuqiang Zhang, Ph.D. “However, in our study, we found that the occurrences of hot night excess (HNE) are projected to occur more rapidly than the daily mean temperature changes. The frequency and mean intensity of hot nights would increase more than 30% and 60% by the 2100s, respectively, compared with less than 20% for the daily mean temperature.”
How heat affects consumers’ health
For the study, the researchers created two climate change models for nearly 30 cities across South Korea, China, and Japan. Their models tracked heat-related deaths from 1980 through 2015 and then projected what daytime and nighttime temperature increases might look like from 2016 through the 2100s.
The study showed that as nighttime temperatures increase, the risk of death also increases. When the temperature is excessively high at night, the mortality risk could be 50% higher than on nights when the temperature isn’t as high.
Additionally, the findings highlighted that nighttime temperatures are expected to increase more over time than daytime temperatures. This means that the risk of death as a result of exposure to extreme heat is even higher. Between 2016 and 2100, the mortality risk is projected to increase by six times; this is much higher than the projections related to daytime temperature increases.
While these findings were focused strictly on cities across Asia, the researchers hope more work can be done globally to address climate concerns. They also hope policymakers step in to help consumers protect themselves against rising nighttime temperatures.
“To combat the health risk raised by the temperature increases from climate change, we should design efficient ways to help people adapt,” Dr. Zhang said. “Locally, heat during the night should be taken into account when designing the future heatwave warning system, especially for vulnerable populations and low-income communities who may not be able to afford the additional expense of air conditioning. Also, stronger mitigation strategies, including global collaborations, should be considered to reduce future impacts of warming.”