Heat waves driven by climate change have cost the global economy trillions of dollars since the early 1990s, a new study finds.
From 1992-2013, nations lost an estimated $16 trillion to the impacts of high temperatures on human health, productivity and agricultural output, according to the study, published in Science Advances on Friday.
And the world’s poorest and lowest carbon-emitting countries have suffered the most from the financial effects of severe heat, the authors observed.
“Accelerating adaptation measures within the hottest period of each year would deliver economic benefits now,” first author Christopher Callahan, a doctoral candidate in geography at Dartmouth College, said in a statement.
“The amount of money spent on adaptation measures should not be assessed just on the price tag of those measures, but relative to the cost of doing nothing,” Callahan continued, adding that there is “a substantial price tag to not doing anything.”
To draw their conclusions, Callahan and his colleagues said they combed through newly available, in-depth economic data for various regions around the world for the 1992-2013 period.
They then cross-checked that information with the average temperature for the hottest five-day period each year — a metric commonly used by scientists to gauge heat intensity.
The researchers calculated that during this time frame, heat waves statistically coincided with variations in economic growth and generated $16 trillion in economic losses.
“The true costs of climate change are far higher than we’ve calculated so far,” senior author Justin Mankin, an assistant professor of geography at Dartmouth, said in a statement.
These findings are a testament to the need for policies and technologies that protect people during the hottest days of the year, the authors contended.
“No place is well adapted to our current climate,” Mankin said, noting that those with the lowest incomes are suffering the most.
“As climate change increases the magnitude of extreme heat, it’s a fair expectation that those costs will continue to accumulate,” he added.
While climate models have long included heat waves among other climate-induced weather extremes, the waves have what Callahan described as “a unique signature.”
Not only do they tend to occur on shorter timescales than droughts, but they are also expected to feature rapid temperature surges as human activity further influences climate change, according to the authors.
“Heat waves are one of the most direct and tangible effects of climate change that people feel, yet they have not been fully integrated into our assessments of what climate change has cost and will cost in the future,” Callahan said.
In the wealthiest regions of the world, the authors found that economic losses due to extreme heat average 1.5 percent of gross domestic product per capita.
But in low-income regions, those losses were about 6.7 percent of gross domestic product per capita.
“Almost no country on Earth has benefitted from the extreme heat that has occurred,” Mankin said.
Low-income countries are home to disproportionate numbers of outdoor workers, but these individuals are generating raw materials that are critical to global supply chains, according to Mankin.
“There is absolutely the potential for upward ripple effects,” he added.