COVID-19 lockdowns have led to a 17% drop in daily CO2 emissions

The COVID-19 pandemic has forced countries around the world into lockdowns, and such halts have led to a 17% drop in daily global CO2 emissions—or 17 million tonnes of carbon dioxide each day—during the peak of coronavirus confinement measures in early April. But without structural changes in our economic, transportation, and energy systems, researchers warn that the lower emissions are unlikely to last.

Researchers from University of East Anglia published a study today in Nature Climate Change looking at how the global lockdown has had an “extreme” effect on daily carbon emissions, using energy, activity, and policy data available up to the end of April 2020 to estimate changes in daily emissions, and comparing that change to the mean daily emissions globally in 2019. The drop in emissions comes from a variety of sectors, including power, aviation, public buildings, residential, industry, and surface transport. The study analyzed 69 countries, all 50 U.S. states, and 30 Chinese provinces, “which represent 85% of the world population and 97% of global CO2 emissions,” per the paper.

With billions of people staying inside and reducing their daily travel during the COVID-19 pandemic, emissions from surface transport, such as driving, account for 43% of the decrease in global emissions during the peak of confinement, which researchers say was April 7. Even though the aviation industry has been hard hit economically by travel restrictions and stay-at-home orders, it only accounts for 10% of the decrease in emissions during this pandemic. Together, industry (which includes industrial activity in China and steel production in the U.S.) and power accounted for another 43% of the decrease in daily global emissions.

The residential sector was one that saw an increase in activity, but this small growth in emissions “only marginally offsets the decrease in emissions in other sectors,” the researchers wrote. The pandemic’s estimated total change in emissions comes to 1,048 million tonnes of carbon dioxide through the end of April.

This drop in CO2 emissions is “extreme and probably unseen before,” the researchers wrote, but these benefits are most likely going to be temporary. If we return to pre-pandemic activity levels by mid-June, the researchers project that total 2020 annual emissions will only see a total decline of around 4%. If countries keep some restrictions in place through the end of the year, that annual drop will be around 7%. Previous research has said that global emissions must drop 55% by 2030 to meet climate goals and limit global warming to 1.5 degrees C.

“The social trauma of confinement and associated changes could alter the future trajectory in unpredictable ways, but social responses alone, as shown here, would not drive the deep and sustained reductions needed to reach net-zero emissions,” the researchers wrote. Changes that cities have made to allow social distancing, like closing streets to facilitate more walking and biking over car use, could help cut back on CO2 even after confinement measures are eased, and how much world leaders factor emissions targets into their economic recovery plans—for example, including clean energy deployment—will likely affect our global CO2 emissions for decades.

“The drop in emissions is substantial but illustrates the challenge of reaching our Paris climate commitments,” Rob Jackson, a professor at Stanford University and Chair of the Global Carbon Project who coauthored the analysis, says in a statement. “We need systemic change through green energy and electric cars, not temporary reductions from enforced behavior.”