climate crisis Tim Radford

Heat Waves Cost Trillions and Hit Poorest Countries Hardest


By Tim Radford | The Energy Mix

Summer heat waves driven by climate change do more than harm health and claim lives, a new study shows. They also blight national economies, and hit the poorest hardest of all.

In 21 years, soaring temperatures worldwide have fuelled an estimated US$16 trillion in economic losses, U.S. scientists have just calculated.

And these costs are borne by the people least likely to afford them, and who have also done least to drive global heating to dangerous levels. The researchers estimate that the poorest nations in the hottest regions may have seen an economic downturn of 6.7% of gross domestic product as summer temperatures climbed between 1992 and 2013. The richest nations—Canada, the United States, and Europe, for example—may only have seen GDP losses of 1.5% during those decades.

The total economic loss is truly enormous: one calculation made just in the first six months of the COVID-19 global pandemic put the economic cost of the virus at precisely that—$16 trillion, about nine-tenths of U.S. GDP in one year.

But what a virus can do in a hurry, the burning sun can do more insidiously. And this is just the beginning.

“No one has shown an independent fingerprint for extreme heat and the intensity of that heat’s impact on economic growth,” said study co-author Justin Mankin, a geographer at Dartmouth College in New Hampshire. “The true costs of climate change are far higher than we’ve calculated so far.”

The study “shows that no place is well adapted to our current climate,” he added. “The regions with the lowest incomes globally are the ones that suffer most from these extreme heat events. As climate change increases the magnitude of extreme heat, it’s a fair expectation that those costs will continue to accumulate.”

Like all products of climate and economic models, the research arrives with careful caveats and prudent provisos. The two researchers based their study on annual temperature data and the records of the five hottest days of each year: what counts as a heat wave in Norway, however, is very different from extreme heat in Mali, or Brazil. They also concede that there are problems with the economic calculations: detailed data is always more available from the richest economies, and sometimes sketchy in the more impoverished.

But their study, in the journal Science Advances, confirms something economists have already observed: when it’s just too hot to work safely, productivity falls. During the decades in question, it dropped by at least $5 trillion and possibly as much as $29.3 trillion.

When it’s too hot in the fields, soil moisture evaporates, blooms shrivel, crops wilt, harvests dwindle, and workers stay in the shade. And such conclusions have already been repeatedly tested in the real world. Grape pickers in the vineyards of Cyprus found that temperatures as high as 36°C correlated with labour losses of up to 27%, as the soaring mercury took its toll on human metabolism and cardiovascular efficiency. The summer of 2013-2014 in Australia was the hottest ever, at a cost to the economy of $6.7 billion.

And because raw materials are part of the global traffic, heat extremes in one zone can cost economies in another. Researchers in Germany in 2016 followed 26 industry sectors—mining, textiles, forestry, quarrying, agriculture, and so on—through to sales in 186 countries to test the same evidence, and they too found that as temperatures soared, productivity fell.

Since then, the world has continued to become hotter, and promises in some regions to become lethally hot. Summertime, too, could continue to endure longer, to almost half of the solar year.

And, as the latest study makes clear, the costs of climate change are not fairly or evenly shared. The world’s biggest carbon emitters such as Europe and North America are affected least, and could—in theory at any rate—even welcome some warmer summers.

“We have a situation where the people causing global warming and changes in extreme heat have more resources to be resilient to those changes, and, in some rare cases, could benefit from it,” Mankin said. “It’s a massive international wealth transfer from the poorest countries in the world to the richest countries in the world through climate change—and that transfer needs to be reversed.”

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  1. more ruling class propaganda—-US imperialism most supported by Bernie NATO sanders is the problem, not fake climate change

  2. The points the article puts forwards basically fall into two groups:
    (1) it’s getting hotter and that’s damaging
    (2) the burdens aren’t equally distributed across the world population
    (3) North America and Europe are the culprits.

    I think that most people would agree on (1) and (2). It’s item (3) where the problems begin.
    For starters, the story on (3) is a whole lot more complex than the article suggests. For example, take a look here for the sourcing of carbon dioxide emissions:

    Where the article in passing dumps all the blame on the West, the actual numbers paint a different picture. Especially China is up there with the main polluters. According to this article though: China’s efforts paint a mixed picture. On the one hand it’s said to be on-track for peak CO2 emission by 2030 (it’s stated policy goal) which is no mean achievement. On the other hand it’s use of coal to backstop all and any less polluting energy sources puts it on course for being responsible for a 3 degree increase in global temperature rather than an 1.5 degree one:

    “In contrast, our projections show China’s emissions are likely to continue increasing to 2025 before dipping only slightly to 2030 roughly back to today’s levels. Coal will remain the dominant fuel source well past this decade, in contrast to a global decline of 75% below 2019 levels in 1.5C pathways. As a result, our assessment is that China’s currently planned energy and climate developments imply an emissions trajectory to 2030 that – if applied at the global level – would be consistent with 3C of warming, well above what would be necessary to keep warming below 1.5C. ”

    While the CO2 emissions of the EU seem to be decreasing over the 1970 -2018 timeline, those of China and India are seen to grow significantly. This is defended bij e.g. India by stating that Western world should bear the brunt of the effort. Not entirely unreasonable, but to what extent?

    Therefore, while not disagreeing with the actual figures put forward by the article, let’s not fall into the trap of mindless West-bashing the article so invitingly holds out.

  3. Recently more figures have been published regarding which (Western) countries are shouldering their fair share of the burden. See

    As usual in these events, countries like China (and to some extent also India) aren’t taken to account.

    Regardless of the fact that China’s emissions (and hence contributions to the Greenhouse effect) are way larger than those of the EU, Japan, the UK, Korea etc. In fact they are on par with those of the US. Somehow China still manages to sidestep responsibility where the US is named and shamed for not pulling its weight.

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