In this April 26, 2020, file photo, empty lanes of the 110 Arroyo Seco Parkway that leads to downtown Los Angeles is seen during the coronavirus outbreak in Los Angeles, Calif.  (AP Photo/Mark J. Terrill, File)
In this April 26, 2020, file photo, empty lanes of the 110 Arroyo Seco Parkway that leads to downtown Los Angeles is seen during the coronavirus outbreak in Los Angeles, Calif. (AP Photo/Mark J. Terrill, File)

“The drop in emissions is substantial but illustrates the challenge of reaching our Paris climate commitments.”

The stay-at-home orders and forced closures of businesses around the world, amid the coronavirus pandemic, have caused a dramatic decrease in daily global carbon emissions. The unprecedented disruption to global commerce and typical human activity is expected to cause the largest drop in annual worldwide emissions since the end of World War II. 

The study, published in the peer-reviewed journal Nature Climate Change on Tuesday, estimated the daily global drop in carbon emissions to be 17% by early April 2020 compared with the mean 2019 levels. Emissions in individual countries decreased on average by 26% at their peak. 

A team of scientists at the Global Carbon Project, led by Professor Corinne Le Quéré from the University of East Anglia, analyzed government policies on confinement for 69 countries responsible for 97% of global carbon emissions and representing 85% of the world population, as well as data on economic impact, from January to April 2020. 

At the peak of the confinement, regions responsible for 89% of those emissions were under at least some level of restriction due to the pandemic. 

According to the study, China reduced its emissions by nearly 24% during some days in February, the European Union saw its emissions fall by over a quarter during the first week of April, while the United States cut emissions by nearly a third for almost two weeks in April. The biggest pollution declines in the U.S. were seen in California and Washington. 

The researchers noted the impact on 2020 annual emissions depends on government policy going forward. The longer the duration of confinement lasts, the lower overall emissions are protected to be on the year, with a low estimate of 4% if pre-pandemic conditions return by mid-June, and a high estimate of 7% if some restrictions remain worldwide until the end of 2020.

In order to achieve the climate objectives of the U.N. Paris Agreement, global greenhouse gas emissions would need to be cut 7.6% each year between 2020 and 2030. Carbon dioxide is the greenhouse gas most responsible for global warming.

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Fewer people driving was cited as the largest contributing factor in the drop in emissions, followed by a decrease in industrial pollution.

Le Quéré noted “population confinement has led to drastic changes in energy use and CO2 emissions,” according to USA Today, adding: “These extreme decreases are likely to be temporary though, as they do not reflect structural changes in the economic, transport or energy systems.”

“The drop in emissions is substantial but illustrates the challenge of reaching our Paris climate commitments,” said study co-author Rob Jackson of Stanford University. “We need systemic change through green energy and electric cars, not temporary reductions from enforced behavior.”

As Pennsylvania State University climate scientist Michael Mann, who was not part of the research team, told USA Today: “Individual behavior alone…won’t get us there. We need fundamental structural change.”