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In 1945, as World War II came to a close, scientists logged a record drop in carbon dioxide emissions. They reckoned that global CO₂ emissions fell by some 790 million metric tons—a record that stood for more than 70 years.

Then 2020 rolled around.

Global emissions fell 1,550 million metric tons in the first half of 2020, according to a study published yesterday in Nature Communications, obliterating the 1945 record and underlining the depths of the economic damage wrought by the coronavirus pandemic this year.

The study, conducted by a team of 43 scientists from across the world, confirms earlier research on the emissions impact of the pandemic (Climatewire, May 20). It at once highlighted how much emissions have fallen as a result of the virus and the difficult road facing the world as it seeks to meet the targets of the Paris climate agreement.

The world essentially would need to replicate 2020’s emission reductions every year for the next decade to have any chance of limiting warming to 1.5 degrees Celsius by century’s end, according to the United Nations’ Intergovernmental Panel on Climate Change.

“Considering how disruptive the pandemic has been in all our lives, it seems like a small number,” said Steven Davis, a professor at the University of California, Irvine, who contributed to the study. “The task of decarbonizing our planet will not mean just changes in personal behavior but changes in the energy structure.”

In the immediate term, the study’s largest impact may be on emissions monitoring itself. Researchers compiled a lengthy list of real-time energy and emissions statistics from countries around the world.

The authors described the effort as a major step forward for a field that has traditionally relied on previous years’ data to develop emissions estimates.

“The pandemic has really forced our hand to do better and find these data sources where they are,” Davis said, noting that researchers plan to continue the emissions monitoring efforts. “What is critical is we need to shorten the feedback cycle from the policymaker putting some policy in place to the scientific community telling the policymaker whether that has had an effect on emissions.”

The data sources allowed researchers to pinpoint the locations of emission reductions as the pandemic rolled across the world. The year began with deep reductions in emissions in China, where the shutdown of heavy industry and resulting drop in power demand led to big decreases in CO₂. Emissions from the Chinese cement industry, about 22% of the country’s industrial emissions, fell by a combined 30% in January and February compared to 2019 levels.

But cement emissions began to surge as the Chinese economy jolted back to life. By April, Chinese cement emissions were up 3.8% over the same month last year. The rebound in Chinese economic activity, and cement in particular, helps explain the relatively modest 3.7% reduction, or 187 million tons, in overall Chinese emissions over the first half of 2020.

By the spring, the pandemic had the United States and Europe in its grasp. There, the emissions reduction story was largely about transportation. American transportation emissions, the largest source of CO₂ emissions in the U.S., were down 24% over the first seven months of 2020. Overall U.S. emissions fell 13.8% compared to 2019 levels or by 338 million tons, the largest absolute drop in the world.

Still, the study suggests the pandemic has not altered the worldwide energy system in a fundamental way. Emissions across the globe were rebounding quickly as large parts of the world began to shake off the virus over the summer. The research team has continued to monitor emissions beyond the time period in the Nature Communications study. By August, they showed that world emissions had fallen 1,481 million tons since the start of the year, suggesting that some of the reductions from earlier in the year already have been offset.

Reprinted from Climatewire with permission from E&E News. E&E provides daily coverage of essential energy and environmental news at www.eenews.net.