Breathe While You Can, the Air Has Been Fresher During the Pandemic

It's not your imagination. The air really is cleaner.

The world cut its daily carbon dioxide emissions by 17% at the peak of the pandemic shutdown last month, a new study found.

But with life and heat-trapping gas levels inching back toward normal, the brief pollution break will likely be "a drop in the ocean" when it comes to climate change, scientists said.

Carbon dioxide stays in the air for about a century.

In their study of carbon dioxide emissions during the coronavirus pandemic, an international team of scientists calculated that pollution levels are heading back up — and for the year will end up between 4% and 7% lower than 2019 levels. That's still the biggest annual drop in carbon emissions since World War II.

For a week in April, the United States cut its carbon dioxide levels by about one-third. China, the world's biggest emitter of heat-trapping gases, sliced its carbon pollution by nearly a quarter in February, according to a study Tuesday in the journal Nature Climate Change.

India and Europe cut emissions by 26% and 27% respectively.

But if the world returns to its slowly increasing pollution levels next year, the temporary reduction amounts to ''a drop in the ocean," said study lead author Corinne LeQuere, a climate scientist at the University of East Anglia.

"It's like you have a bath filled with water and you're turning off the tap for 10 seconds," she said.

The study was carried out by Global Carbon Project, a group of international scientists that produces the authoritative annual estimate of carbon dioxide emissions. They looked at 450 databases showing daily energy use and introduced a measurement scale for pandemic-related societal "confinement" in its estimates.

Nearly half the emission reductions came from less transportation pollution, mostly involving cars and trucks, the authors said. 

— SETH BORENSTEIN