As forecast, carbon dioxide emissions have declined during the coronavirus pandemic. But if past crises are any indication, the environmental gains may be short-lived.

An international study of global carbon emissions found that daily emissions declined 17% between January and early April, compared to average levels in 2019, and could decline anywhere between 4.4% to 8% by the year's end.

That figure would mark the largest annual decrease in carbon emissions since World War II, researchers said.

The findings appeared today in the journal Nature Climate Change.

It's not clear how long or severe the pandemic will be, which makes it difficult to predict how emissions will be affected long-term.

And because the changes driving reduced emissions haven't fundamentally changed the economy or the energy much of the world relies on, the declines are likely to be temporary.

Additionally, 2020 is still on track to be one of the top five hottest years on record.

"I can't celebrate a drop in emissions driven by unemployment and forced behavior," said Rob Jackson, study co-author and professor in Stanford University's Earth Science Systems department. "We've reduced emissions for the wrong reasons."

The study centered on 69 countries, all 50 US states and 30 Chinese provinces, which account for 85% of the world population and 97% of all global carbon dioxide emissions.

Source: CNN