(NEXSTAR) – Global carbon emissions, which are a major contributor to global warming and climate change, decreased by 6.4% as COVID caused the global economy to come to a screeching halt.

The finding emerges from a new study, published last week in the journal Nature.

“The decline is significant — roughly double Japan’s yearly emissions — but smaller than many climate researchers expected given the scale of the pandemic, and is not expected to last once the virus is brought under control,” the researchers said.

After the decline, carbon emission rates quickly bounced back in 2020 as the economy picked up again, squelching scientists’ hopes that the drop would remain.

The U.S. contributed most to the decline, the authors said, with a nearly 13% decrease in emissions, largely due to a drop in vehicle transportation that began amid March lockdowns and continued as the pandemic escalated at the end of the year.

The energy sector most affected by the lockdowns was aviation, whose emissions fell by 48% from their 2019 total.

“The emissions decline is already less than what we expected,” says Zhu Liu, an Earth-system scientist at Tsinghua University in Beijing, who co-leads the international Carbon Monitor program that provided the study’s data. “I imagine that when the pandemic ends, we probably will see a very strong rebound.”

The 6.4% dip will register as “little more than a blip in the global carbon record,” according to David Waskow, who leads the international climate program at the World Resources Institute.

“Historical experience would lead us to expect that we will return to our previous trajectory, and that means we need to do other things to cut emissions.”

The United Nations Environment Program estimates that the world would need to cut its carbon emissions by 7.6% each year over the next decade to prevent the planet from warming more than 1.5 degrees Celsius above pre-industrial levels. The goal was set at the 2015 Paris climate agreement.