New Delhi, Mar 20: Rising temperatures driven by climate change could be reducing sleep duration and quality worldwide, particularly among children, potentially widening global inequality and causing significant economic losses, according to a new international study.
The research, published in the journal Nature Sustainability, was led by scientists from Nanjing University in China, with contributions from institutions in the United States and Australia.
The study suggests that higher nighttime temperatures can disrupt human sleep, with the optimal range for rest estimated between 15 and 19 degrees Celsius.
Children are especially vulnerable to heat-related sleep disturbances, which may affect memory, attention, and cognitive development — factors closely linked to future productivity and earnings.
Using simulations across 198 countries and regions, researchers combined multiple datasets, including sleep patterns tracked through wearable devices and corresponding temperature records.
Under a high-emissions scenario, where global temperatures rise by around 4 degrees Celsius above pre-industrial levels, people could lose an average of over 16 hours of sleep annually compared to the 2000s, the study found.
In contrast, under a lower-emissions pathway aligned with international climate targets, annual sleep loss could be limited to just over three hours.
The researchers also examined how reduced sleep may influence cognitive outcomes in children aged 5 to 14 and estimated associated productivity losses.
Their findings indicate that the global economic impact of such sleep deprivation could run into trillions of dollars.
Regional disparities are likely to be significant, with the greatest sleep loss projected in parts of the Middle East, Southeast Asia, and Africa, while relatively smaller effects are expected in Europe and Oceania.
Some of the most affected regions could see annual sleep losses exceeding 20 hours per person under high-emissions conditions.
The study highlights that lower-income regions, which have contributed less to global emissions, may face disproportionately higher economic consequences, potentially exacerbating existing inequalities.
Researchers said the findings underscore the importance of climate mitigation and adaptation strategies, including reducing emissions, improving housing conditions, and enhancing cooling solutions, especially for vulnerable populations such as children.
Recent data from global weather agencies indicate that temperatures have continued to rise, with several of the past years ranking among the hottest on record, reinforcing concerns over the broader social and economic impacts of climate change.
