Climate-Fueled Heatwaves Cost Global Economy Trillions; Poor Countries Hit Hardest: Study

A study published Friday revealed that heatwaves fueled by human-caused climate change have cost the global economy trillions of dollars over the past 30 years, with the world's poorest countries--and those least responsible for the climate emergency--bearing a disproportionate share of the burden.

"The regions with the lowest incomes globally are the ones that suffer most from these extreme heat events."

The study, published in Science Advances, reached three key conclusions. First, "increased extreme heat intensity significantly decreases economic growth in relatively warm tropical regions and weakly affects it in relatively cool midlatitude regions." Second, "anthropogenic climate change has increased the frequency and intensity of these economically consequential heat extremes." Therefore--and thirdly--"the effects of climate change on extreme heat have amplified underlying inequality, disproportionately harming low-income, low-emitting regions, with major emitters shouldering primary responsibility for billions of dollars of losses in the tropics."

According to the publication:

Human-caused increases in heat waves have depressed economic output most in the poor tropical regions least culpable for warming. Cumulative 1992-2013 losses from anthropogenic extreme heat likely fall between $5 trillion and $29.3 trillion globally. Losses amount to 6.7% of Gross Domestic Product per capita per year for regions in the bottom income decile, but only 1.5% for regions in the top income decile. Our results have the potential to inform adaptation investments and demonstrate how global inequality is both a cause and consequence of the unequal burden of climate change.

"Accelerating adaptation measures within the hottest period of each year would deliver economic benefits now," study first author Christopher Callahan, a doctoral candidate in geography at Dartmouth College in New Hampshire, 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. Our research identifies a substantial price tag to not doing anything."

Senior study author and Dartmouth assistant geography professor Justin Mankin asserted: "No one has shown an independent fingerprint for extreme heat and the intensity of that heat's impact on economic growth. The true costs of climate change are far higher than we've calculated so far. Our work shows that no place is well adapted to our current climate."

"The regions with the lowest incomes globally are the ones that suffer most from these extreme heat events," Mankin added. "As climate change increases the magnitude of extreme heat, it's a fair expectation that those costs will continue to accumulate."

The new study follows research forecasting that by the end of the century, dangerous heat driven by the worsening climate emergency will hit much of the Earth at least three times more often than today.