One of the most obvious implications of global warming is an increase in extreme heat, but it is unclear how heat waves will affect the economy. Extreme heat brought on by human-driven climate change is causing significant economic losses right now.

According to a study published in the journal Science Advances, global warming-related heat waves have already cost the economy trillions of dollars since the early 1990s, with the poorest and lowest-carbon-producing nations bearing the brunt of the economic damage.

According to the study, these unequal economic outcomes also contribute to growing inequality around the world.

"The cost of extreme heat from climate change so far has been disproportionately borne by the countries and regions least culpable for global warming," Dartmouth College professor Justin Mankin, one of the authors of the study, told AFP. "And that's an insane tragedy."

"Climate change is playing out on a landscape of economic inequality, and it is acting to amplify that inequality," he said.

However, poorer countries have lost roughly 6.7 percent of their yearly per capita GDPs, whereas the richest countries have only lost about 1.5 percent due to heat waves.

The obvious explanation for this gap is that poorer nations are frequently located closer to the tropics, where temperatures are already warmer. They heat up significantly more during heat waves.

Heat waves have been included in climate models and earlier research alongside other extreme occurrences brought on by climate change, such as more frequent flooding and more intense storms, according to first author Christopher Callahan, a doctoral candidate in geography at Dartmouth. But according to him, heat waves have a distinct character. They happen more quickly than droughts do, and as long as human activity fuels climate change, the hottest days of the year are expected to warm up far more quickly than the average global temperature.

The findings, according to the researchers, demonstrate the urgent need for legislation and technical developments that protect people during the warmest days of the year, particularly in the world's hottest and most fragile economies.