We hear about climate change as a force that will melt our ice caps and flood our coastlines. We hear about temperature and rainfall fluctuations affecting our crop production and causing famine. But we don’t often hear about its effect on human productivity.
That may change. New research just published in Nature Climate Change cross-referenced the latest in heat and humidity projections with everything we know about human labor capacity (seriously, they examined industrial and military guidelines). What the study found was staggering. Because the human body is a machine that uses sweat to cool itself, it can’t be as effective in hot, humid environments—which means that over the past few decades of climate trends, we’ve already lost 10% of peak human labor production during the warmest months. And it’s only getting worse.
By 2050, the study sees that labor reduction doubling, to 20%. And by 2200, you could have a capacity reduction as great as 40%. Two centuries in the future, we’d be getting about half as much done outside as we can today.
For those who think cushy desk jobs are going to mitigate our need for outdoor labor, it’s worth recognizing some of the paper’s more fleshed-out scenarios. By 2100, Washington, D.C. could be as sticky hot as New Orleans. And if global warming exceeds 11°F, we lose not just some but all labor capacity in many areas, like the lower Mississippi Valley. That doesn’t just mean you can’t dig a ditch outside—you won’t want to do anything outside. In fact, New York City would be as hot as Bahrain, and "Bahrain heat stress would induce hypothermia in even sleeping humans."
We’ve reached a horribly ironic tipping point. Since the beginning of our species, our tools have made humanity more efficient at virtually every job we do. But now, they’ve come to collect on their debt.
[Hat tip: Smithsonian]