This week, analysis from the Centre for Research on Energy and Clean Air estimated that government-directed quarantines and other restrictions due to the current coronavirus outbreak have temporarily reduced China’s greenhouse gas emissions by a quarter. China is currently the world’s largest emitter, even though the carbon footprints of most Chinese residents remain minuscule compared to Americans’. Much of the country’s carbon spews from energy-intensive industrial activity. Now people are staying home from work and consuming less, as wages remain unpaid, and commutes remain untraveled. Manufacturing and construction in some places have slowed or ground to a halt, and air travel throughout the country has decreased by 70 percent.

It’s no secret that certain types of misery and societal upheaval can reduce emissions—from recessions to the collapse of the Soviet Union to epidemics such as the current coronavirus. Those are hardly formulas activists should cheer, much less try to replicate going forward. But the recent statistics out of China are a reminder of the remarkable impact of working patterns on emissions levels. There is a policy that could mirror some of the emissions reductions from undesirable events such as outbreaks, while improving quality of life: a four-day, 32-hour workweek.

Though it hasn’t featured prominently in policy debates in the United States, reducing working hours is a widespread demand among unions and progressives in Europe, where workweeks are generally shorter than they are here. Reducing hours could have enormous benefits for the climate, drastically cutting the energy needed to light, heat, and cool offices—and power computers. Furthermore, eliminating one round-trip commute week after week for millions of Americans could radically reduce nationwide transportation emissions—the biggest source of carbon dioxide pollution in the U.S.

With successes like the weekend and eight-hour day, reducing hours has been a demand of labor movements since their inception. As one famous campaign slogan for the former went, “Eight hours for rest, eight hours for work, and eight hours for what we will.” For many workers, though—who piece together poorly paid part-time jobs and precarious gig work to make ends meet—even a 40-hour workweek might now sound like a luxury.

Americans are notoriously overworked. Annual working hours in the U.S. are well above the average in Organization for Economic Cooperation and Development countries, and the average American works 53 days more than the average German, whose unions—which enjoy formal representation on company boards—have reliably pushed for shorter workweeks. In France, workers fought for and won protections against answering emails from the boss on any device after business hours—the so-called “right to disconnect.” Employers are required to provide 28 days of paid vacation per year in European Union member states, and countries from Ecuador to Eritrea guarantee at least two weeks of paid leave annually. The United States has no laws mandating employers provide vacation, and many offer none at all. Last fall, the four-day workweek with no pay cuts was taken up as a demand by the British Labour Party at its annual conference, prompting a viral chant that some supporters of presidential candidate Bernie Sanders have now adopted as their own: “Jeremy Corbyn / No surrender / Four-day week / And a three-day bender.” Analysis by economists David Rosnick and Mark Weisbrot in 2006 found that, had the U.S. “adopted European standards for work hours, U.S. carbon dioxide emissions in 2000 would have been 7 percent lower than its actual 1990 emissions,” thus meeting targets outlined in the Kyoto Protocol.