As people cut back on traveling and the global economy slows, carbon emissions have dropped significantly, most notably in China. Unfortunately, reducing carbon emissions at the expense of public health is far from sustainable.

By late February, China’s economy had already taken a hit. Coronavirus containment measures had reduced key industrial sectors by 15% to 40%, according to Carbon Brief. Industrial output and electricity demand were far below usual levels, including a 36% drop in coal consumption, a 34% drop in utilization of oil refining capacity and a 5% to 10% rate of flight cancellations globally. Both international flights from China and domestic flights within China are down by more than half.

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As Chinese refineries shut down, ships become floating storage units for oil. About 87 million barrels of petroleum products are currently stored at sea, plus many more onshore, awaiting buyers.

map showing carbon emissions in China before and after coronavirus

Some NASA satellite images taken in February are especially startling. The images show Wuhan’s usual yellow cloak of nitrogen dioxide — a gas produced by vehicles and industry — in early January of 2020, compared with nearly clear skies by mid-February. By the time of the latter photo, Chinese authorities had ordered a city-wide quarantine to prevent the spread of coronavirus. The images showed that nitrogen dioxide in the Wuhan skies was down 10% to 30%. “This is the first time I have seen such a dramatic drop-off over such a wide area for a specific event,” Fei Liu, an air quality researcher at NASA’s Goddard Space Flight Center in Maryland, said in a statement accompanying the satellite photos.

map showing nitrogen dioxide emissions in China before and after coronavirus

Coronavirus and Chinese New Year

Every year, China sees a drop in carbon emissions during the 10-day Chinese New Year celebration. Shops close, construction sites take a break and many industries cut back on operations. Scientists have measured the reduction in energy demand and the resulting emissions. Coal-fired power generation usually drops by half for the 10-day period.

This year, coronavirus hit in Wuhan, China just before the start of Chinese New Year. By the time people started traveling home to see family for the holiday, more than 900 cases had been reported worldwide. The numbers and panic increased over the course of the usually celebratory time. Instead of things returning to business as usual after the celebration, the reduction in industry — and carbon emissions — continued.

According to The New York Times, after three weeks of coronavirus, the decline in Chinese carbon dioxide emissions was about 150 million metric tons, or the amount of carbon dioxide the state of New York produces in a year.

archive photo of medics in face masks during 1918 influenza pandemic

Historic precedents

This isn’t the first time carbon emissions have plunged during a time of human sickness or panic. Global emissions dropped significantly from 2008 to 2009. During this time, U.S. unemployment doubled, the housing market crashed and the stock market tumbled. Global emissions decreased about 1.4%, or about 450 million tons of carbon dioxide. Unfortunately, the drop was brief, and soon emissions soared to even higher levels than before the Great Recession.

During the Great Depression, as U.S. unemployment climbed to 25%, global emissions dropped by 25% between 1929 and 1932. It wasn’t until 1937 that emissions reached their pre-1929 levels again. Of course, global emissions were much lower then than they are today.

The worst pandemic in semi-recent history was the influenza pandemic of 1918-1919, in which 50 million people died globally. That year, carbon dioxide emissions shrank by more than 400 million tons. Other factors, such as the end of World War I and the resulting decrease in the steel and arms industries, may also have contributed to this decline.

silhouettes of coal power plant against a sunset

Carbon emissions after the coronavirus

At the time of writing, coronavirus is still spreading worldwide. Soon we may see countries with similar reductions in emissions as quarantines spread across nations.

But for now, China is the most interesting example, because it’s the epicenter of the virus and has such a vast economy. Scientists and the climate-concerned are already looking toward a future when the virus is contained and China fires up industry full-tilt. China had planned for 2020 to be the crowning year for a decade of economic accomplishments aimed at “building a moderately prosperous society.” But the virus has dire consequences on everybody, from big to small businesses to householders in China, who may fail to pay their debts because the virus has temporarily put them out of work. Chinese president Xi Jinping has expressed an opinion that the virus response has gone overboard, but local governments are more prone to tighten controls on movement and urge businesses to remain closed in an effort to contain the virus.

Experts worry that China’s post-virus economic comeback will quickly reverse any ecological gains it has made during this time of reduced industry. “The reductions are substantial, but they are most certainly only temporary, and there will likely be a rebound effect,” said Joanna Lewis, an expert on China’s energy sector at Georgetown University. “Once people go back to work and factories restart, they may try to make up for lost time. This could result in a surge in emissions.”

Images via Shutterstock and NASA’s Earth Observatory