MINNESOTA, USA — In science, it's all about data and numbers, projections and forecasts.
For years, the models predicted that fewer vehicles on the road would lead to less air pollution, but testing out that theory wasn’t easy, — until COVID came along.
"COVID kind of provided a test case — kind of a ‘what-if scenario,’” Minnesota Pollution Control Agency meteorologist Nick Witcraft says.
In a strange way, the lockdowns of 2020 provided the perfect way to test out this theory because suddenly there were fewer vehicles on the road.
The question then became: Would this theory pan out?
"Well, initially when everyone had to stay home because of the lockdowns, we saw some reduction in nitrogen dioxide,” Witcraft explains.
"In Minnesota, I would say it was maybe a 5% to 10% reduction.”
Nitrogen dioxide gets released into the air through combustion, mostly engines like the ones in cars and trucks.
In other parts of the United States, like California and New York, Witcraft says the reductions were much higher than what we saw here in Minnesota because there are more cars driving on the road.
This reduction was even higher overseas, in countries like India and China.
"China there was an even more drastic reduction. The reductions there would have been to the orders of like 50% or 60%,” Witcraft says.
"You know, in India or China, you definitely would have noticed it."
But unfortunately this reduction didn't last long.
"The nitrogen dioxide actually returned to pretty much normal levels,” Witcraft explains.
Witcraft says he and many experts did expect the levels to go back up a little once the lockdowns were lifted, but they didn’t expect to see the numbers fall back to where they were before the pandemic started.
"It actually was a little surprising to see it bounce back all the way to pre-COVID levels,” Witcraft says.
Because so many people are still working from home.
But Witcraft says we've also seen more people traveling and going on road trips, which could have an impact.
Shipping and supply chain issues could also be a factor.
Even though the numbers are back to where they were here in Minnesota, Witcraft says the reduction we did see shows how human behavior can make a difference.
We just have to commit to it.
"A single person on their own has a very minimal effect on air quality, but collectively, if everyone took those steps to drive less, or maybe make their next purchase a hybrid, or plug in or an electric vehicle, that's going to have an impact."
Scientists are still collecting data from this current Covid wave, which could also have an impact on air quality.
A lot of companies have recently decided to go back to working from home, so there's a chance we could see some lower levels in the coming weeks.
But again, experts say it's up to us to keep those low by changing our driving habits long term.
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