How Cononavirus Might Affect Pollution And Climate Change

Map depicts NO2 pollution in China. Map on the left, with the
oranges and reds, shows plenty of NO2.  During the
coronavirus lockdown in China, that pollution
largely disappeared. 

Large swaths of the world, including much of the United States, are in lockdown or near lockdown because of the coronavirus.

That means emissions from businesses, cars, planes and such are also way down.

This, I suppose, is the tiniest of silver linings from this mess is that there is less air pollution out there.

Before I go on, I want to make something crystal clear. Given a choice between a bit of air pollution and no cornonavirus, I would very obviously go with no coronavirus. I, like everybody else on the planet, wish we weren't dealing with this deadly disease.

We wish life had just gone on as normal, even with some air pollution to breath. We all would rather breathe some vagely smoggy air than air that could have that virus floating in it.

But here we are, hunkered down, trying to avoid Covid-19.

Pollution has dropped noticeably in hard hit places.  The most obvious change has been declining concentrations of nitrogen dioxide (NO2), first in China, then in Italy, and now in the United States and elsewhere.

NO2 comes from tailpipe emissions, factories, and all kinds of other sources like that. In high enough concentrations, it can cause breathing problems, including in people with asthma.  The reductions of NO2, though, won't help anyone who contracts Covid-19.  The illness is just too overwhelming.

Still, the reductions in nitrogen pollution are striking. The area around hard-hit Milan, Italy saw a 40 percent drop in NO2 compared to last March. Similar declines were seen in China.

More recently, NO2 concentrations are falling fast in cities like London and New York.

NO2 is not a greenhouse gas that causes climate change.  However, carbon dioxide, which comes from the exact same sources as NO2, does cause climate change.   So will the coronavirus blunt the effects of global warming, at least briefly and marginally?

Again, first of all, we don't want coronavirus to be a "cure" for climate change.  Everybody knows it's not worth the price, at all.

Early indications are, this won't have a huge effect on climate change.  True, the amount of carbon dioxide going up into the air will be reduced.  Coal consumption, probably the worst source of climate change pollution, declined by 36 percent in China due to the virus, for instance.

Still, the overall amount of climate changing gases like CO2 won't decline enough to slow or stop climate change.  As Bob Henson writes in the Category 6 blog, we will still be increasing the amount of carbon dioxide in the air, just at a slower rate.

Plus, there's already more than enough carbon dioxide floating in the atmosphere to keep climate change going.

There have been economic events - not as big as this one - that caused declines in fossil fuel emissions. But those emissions came roaring back once the global economy recovered.

Here's one more factor Henson brings up:  The lockdowns have also caused a sharp decrease in aerosols going up into the air.  Aerosols are tiny, tiny particles emitted from such things as power plants, vehicles and such.

Aerosols block the sun a bit, which can interfere a little bit with the effects of climate change. Less sun getting through the atmosphere because of aerosols, the less heat gets in.

With less aerosols in the air, the coronavirus could briefly make the world hotter than it otherwise would be in the coming months.

The world's climate generally was getting warmer in the first half of the 20th century until the 1940s, when it leveled off.  Some scientists thing aerosols slowed down or temporarily stopped the heating.  Pollution control legislation in the 1970s reduced atmospheric aerosols, so the temperature could resume rising.  And it did.

We don't yet know what societal changes coronavirus will bring.  Perhaps telecommunting will become a more permanent fixture in the workplace environment, which of course would help bring down fossil fuel emissions.   Perhaps more people will grow a little more food on their own properties, which would also help.

I'm not being Pollyanna here. I need to emphasize again I don't see a bright side to the coronavirus. But this crisis will change the world permanently. Whether it will ultimately be for the better or worse is up to us.