Death risk from excessively hot nights could rise six-fold due to climate change

Death risk from excessively hot nights could rise six-fold due to climate change
Rising night-time temperatures could lead to immune system damage and higher heart disease risk

The risk of death from excessively hot nights could increase nearly six-fold by the end of the century, according to a new study that explains how rising night-time 温度 due to 气候变化 may disrupt the human body’s physiology.

科学家们, including those from the University of North Carolina (UNC) at Chapel Hill in the US, say disruption of 睡觉 in people across the world brought on by climate change could lead to immune system damage and a higher risk of heart disease, 慢性病, 炎, and mental health conditions.

The study, published last week in the journal 柳叶刀行星健康, found that the average intensity of hot night events would nearly double by 2090, from 20.4C (68.7F) 至 39.7C (103.5F) 穿过 28 城市.

Researchers say rising night-time temperatures would disrupt normal sleeping patterns and increase the burden of disease due to excessive heat.

“The risks of increasing temperature at night were frequently neglected,” study co-author Yuqiang Zhang from the Gillings School of Global Public Health at UNC Chapel Hill said.

Dr Zhang said such “hot night excess (HNE)” could become more frequent and rapid than changes in the daily mean temperatures.

“炎热夜晚的频率和平均强度将增加超过 30 百分比和 60 到 2100 年的百分比, 分别, 与小于相比 20% increase for the daily mean temperature,“ 他加了.

The latest findings come on the back of a study published in May which found that the climate crisis could erode about 50-58 hours of sleep per person every year by 2099 due to altering ambient temperatures across the globe.

In the new research, scientists estimated the mortality due to excess heat in 28 中国城市, 韩国, and Japan between 1980 和 2015.

They then applied the projections to two climate change models that aligned with carbon-reduction scenarios adapted by the respective national governments.

Scientists found that between 2016 和 2100, the risk of death from excessively hot nights could increase nearly six-fold.

“From our study, we highlight that, in assessing the disease burden due to non-optimum temperature, governments and local policymakers should consider the extra health impacts of the disproportional intra-day temperature variations,” study corresponding author Haidong Kan from the Fudan University in China said.

“A more complete health risk assessment of future climate change can help policymakers for better resource allocation and priority setting,” Dr Kan added.

Scientists also found that regional differences in temperature accounted for many of the variances in nighttime temperature.

They say areas with the lowest average temperature are estimated to have the largest warming potential.

Researchers believe the findings may help craft better heatwave mitigation measures.

“在当地, 在设计未来的热浪预警系统时应考虑夜间的热量, 特别是对于可能无法负担额外的空调费用的弱势群体和低收入社区,” Dr Zhang explained.

“还, 更强的缓解策略, 包括全球合作, should be considered to reduce future impacts of warming,“ 他加了.

Citing a limitation of the study, researchers said they assessed data from only 28 cities in three East Asian countries, adding that the extrapolation of the results to other regions “should be cautious.”

Potential urban land-use expansion after future urbanisation may also amplify night-time heat exposure, 他们说.

Scientists are hoping to extend the analysis in future studies to other parts of the world to get a global picture of the potentially deadly nighttime heat on health.