Pandemic leads to biggest drop ever in global emissions, but trend not expected to last

A locked-down pandemic-struck world cut its carbon dioxide emissions this year by seven per cent, the biggest drop ever, new preliminary figures show.

The Global Carbon Project, an authoritative group of dozens of international scientists who track emissions, calculated that the world will have put 34 billion metric tonnes of carbon dioxide in the air in 2020. That's down from 36.4 billion metric tonnes in 2019, according a study published Thursday in the journal Earth System Science Data.

Scientists say this drop is chiefly because people are staying home, travelling less by car and plane, and that emissions are expected to jump back up after the pandemic ends. Ground transportation makes up about one-fifth of emissions of carbon dioxide, the chief man-made heat-trapping gas.

"Of course, lockdown is absolutely not the way to tackle climate change," said study co-author Corinne Le Quéré, a climate scientist at the University of East Anglia.

The same group of scientists months ago predicted emission drops of four to seven per cent, depending on the progression of COVID-19. A second coronavirus wave and continued travel reductions pushed the decrease to seven per cent, Le Quéré said.

I am optimistic that we have, as a society learned some lessons that may help decrease emissions in the future.- Chris Field, Stanford Woods Institute for the Environment

Emissions dropped 12 per cent in the United States and 11 per cent in Europe, but only 1.7 per cent in China. That's because China had an earlier lockdown with less of a second wave. Also China's emissions are more industrial based than other countries and its industry was less affected than transportation, Le Quéré said.

Canada's emissions were not part of the study. However, Le Quéré told CBC News in an email that Canada's emissions were calculated to have dropped 7 per cent.

The calculations — based on reports detailing energy use, industrial production and daily mobility counts — were praised as accurate by outside scientists.

Even with the drop in 2020, the world on average put 1,075 metric tonnes of carbon dioxide into the air every second.

Final figures for 2019 published in the same study show that from 2018 to 2019 emissions of the main man-made heat-trapping gas increased only 0.1 per cent, much smaller than annual jumps of around three per cent a decade or two ago. Even with emissions expected to rise after the pandemic, scientists are wondering if 2019 be the peak of carbon pollution, Le Quéré said.

"We are certainly very close to an emissions peak, if we can keep the global community together," said United Nations Development Director Achim Steiner.

Chris Field, director of the Stanford Woods Institute for the Environment, thinks emissions will increase after the pandemic, but said "I am optimistic that we have, as a society learned some lessons that may help decrease emissions in the future."

"For example," he added, "as people get good at telecommuting a couple of days a week or realize they don't need quite so many business trips, we might see behaviour-related future emissions decreases."