The world cut its daily carbon dioxide emissions by 17 percent at the peak of the coronavirus 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.

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

It will be 7 percent if the strictest lockdown rules remain for the entire year across much of the world, 4 percent if they are lifted soon.

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 percent and 27 percent respectively.

The biggest global drop was April 4-9, when the world was spewing 18.7 million tons of carbon pollution a day less than it was doing on New Year’s Day.

Such low global emission levels haven’t been recorded since 2006. 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 and part of the Global Carbon Project.

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

Climate experts praised the study as the most comprehensive yet, saying it shows how much effort is needed to prevent dangerous levels of further global warming.

“That underscores a simple truth: Individual behavior alone ... won’t get us there,” Pennsylvania State University climate scientist Michael Mann, who wasn’t part of the study, said in an email. “We need fundamental structural change.”

If the world could keep up annual emission cuts like this without a pandemic for a couple decades, there’s a decent chance Earth can avoid warming another 1.8 degrees of warming from now, study authors said. But getting the type of yearly cuts to reach that international goal is unlikely, they said.

If next year returns to 2019 pollution levels, it means the world has only bought about a year’s delay in hitting the extra 1.8 degrees of warming that leaders are trying to avoid, LeQuere said. That level could still occur anywhere from 2050 to 2070, the authors said.

— Associated Press