An analysis published today in the journal Nature Climate Change finds that daily global carbon dioxide emissions compared to global averages from 2019 have declined 17% globally during the height of the coronavirus pandemic.

This is believed to be the largest carbon emissions drop in recorded history.

As a result of stay-at-home orders and travel barriers, daily carbon dioxide emissions in early April decreased by about 18.7 million tons around the world compared to average daily emissions last year. These levels were last observed in 2006, according to the study.

The study uses different models to predict the annual drop in carbon emissions for this year, which could be 4% to 7%, the study found.

About 43% of the total decrease came from reduced traffic from trucks, buses, and cars. Emissions from industrial activities fell by 19%.

Emissions from air travel fell by 60%. However, that decline only accounts for 2.8% of yearly global carbon emissions.

As the drop is a result of global trauma — and not policy change — the drop will be erased, the study facilitators warn. “Government actions and economic incentives postcrisis will likely influence the global CO2 emissions path for decades,” the study’s abstract states.