Levels of nitrogen dioxide pollution fell drastically in parts of Italy — a direct result of the country closing borders and businesses to mitigate the novel coronavirus outbreak, The Washington Post reports.

Why it matters: The drop in saturation of greenhouse gases in Italy shows the impact humans have on the environment, and how quickly emissions can plummet when people reduce the burning of fossil fuels, the Post writes. Nitrogen dioxide is not the primary greenhouse gas linked to climate change, but serves as a proxy for other emissions.

It also is a pollutant that can increase the risk of asthma, inflammation of the lungs and other harmful health conditions.

The state of play: The decrease is likely a result of the decline in cars on the road, half of which run on diesel in Italy, along with power plants and industrial sources.

Experts said the changes likely reflect the decline of driving in particular, in a nation where over half of cars burn diesel.

Yes, but: Climate advocates didn't think it would take a pandemic for pollution to dip, per the Post.

The outbreak has prevented climate action protests from taking place.

Additionally, this drop is expected to be only temporary.

The bottom line: "Beyond the public health and economic crises, [Riccardo Valentini, a professor at Italy’s University of Tuscia] said, the pandemic ultimately could trigger the most significant reduction of greenhouse gas emissions of the past century," the Post writes.

Go deeper: Italy quarantines 16M as northern region placed on coronavirus lockdown