(CN) — As climate change tightens its grip, heat waves and heat wave-related deaths are on the rise, with high-income areas being hit the hardest, according to a new study that researchers say challenges our assumptions about how wealth and preparedness influence the risks of heat waves on human health.
Researchers analyzed data from 750 locations across 43 countries or regions from 1990 to 2019 in a study published Tuesday in PLoS Medicine, finding that over 30 years, heat waves caused over 153,000 deaths per warm season, with nearly half occurring in Asia.
According to Yuming Guo, an Environmental Health and Biostatistics professor at Monash University and head of the school's Climate, Air Quality Research Unit, previous studies examining the rise in deaths due to heat waves have mainly focused on limited areas.
"Our research, showing variations across different regions the past 30 years, suggests the need for tailored adaptation strategies and risk management measures at the local level," he said in a phone interview.
The research team from Monash University in Melbourne, Australia, in collaboration with Shandong University and the London School of Hygiene & Tropical Medicine, found a surprising trend when looking at regional variations — while low-income regions experienced a decrease in heat wave-related deaths over time, high-income areas saw a rise in fatalities.
Furthermore, Southern and Eastern Europe, along with polar and alpine areas, recorded the highest rates of heat wave-related mortality, whereas fewer deaths occurred in tropical regions.
Guo attributes this disparity to factors such as the higher concentration of elderly populations and access to cooling infrastructure.
"One possibility is that in high-income countries, there's a larger elderly population, which is more vulnerable to heat waves," Guo said. "And individuals in high-income countries, having adapted to air conditioner use, might experience more pronounced impacts from increased heat waves."
Moji Sadegh, a civil engineering researcher and professor at Boise State University, questioned the researcher's conclusions regarding the varying effects of heat waves on different socioeconomic locations.
Sadegh argued that low-income areas are still considered to suffer the most due to limited resources to cope with extreme heat.
"In wealthier countries, there's a greater capacity to adapt to climate change. European cities have already implemented measures like green streets and corridors to mitigate rising temperatures," Sadegh said. "In low-income countries, the focus tends to be more on development rather than environmental initiatives like greening urban areas."
Guo underscored the significance of assessing death ratios over absolute numbers when contrasting various countries. This method factors in variations in population size, he said, offering a more precise foundation for comparison.
"I think it's better not to simply report the death numbers but to adjust for population size. For instance, comparing deaths in China and India would naturally show higher numbers due to their large populations — but this doesn't reflect the true death rate," Guo said.
"Now that we've provided the data, further studies should explore the reasons behind the patterns and how to solve it," he added.
Global surface temperatures have risen by 34.05 degrees Fahrenheit or 1.14 degrees Celsius over the past three decades, according to researchers. Projections suggest a further increase of 32.74 to 38.14 F or 0.41 to 3.41 C by the end of the century, with an expected correspondence to more frequent and intense heat waves.
To address the growing threat of heat wave-related deaths, we need to take urgent action, particularly through effective policies, Guo said.
"First and foremost, we need to reduce the number of hot days per warm season," Guo said. "We need policies to combat climate change and reduce carbon emissions to achieve this."
Heat waves pose serious health risks, including overheating and exacerbating existing health issues, according to researchers. They also raise the likelihood of heat-related illnesses, such as heat exhaustion and stroke, with those with psychiatric disorders being especially vulnerable.
At the local level, Guo suggests measures like expanding public facilities such as libraries and government buildings, providing free access to water, planting more trees and improving parks to help lessen the impact of heat waves.
"We need to pay attention to the heat waves ourselves — when venturing outdoors, plan ahead," he said.
Guo also stressed the importance of community care, particularly for the elderly and vulnerable individuals living alone.
"Check on their well-being and extend a helping hand to those who may need it most," he said.
Subscribe to Closing Arguments
Sign up for new weekly newsletter Closing Arguments to get the latest about ongoing trials, major litigation and hot cases and rulings in courthouses around the U.S. and the world.
