Air Quality Was Worse During COVID Shutdown Despite Far Fewer Cars on the Road, Data Shows

In some heavily polluted parts of the world like China and India, the economic shutdowns that resulted from attempts to slow the spread of the COVID-19 virus resulted in cleaner air. However, in Minnesota, the air was actually less clean during Governor Walz’s shutdown than the previous five-year average.

According to data from the U.S. Environmental Protection Agency (EPA) and the Minnesota Department of Transportation (MNDOT) air quality was actually worse in Hennepin County during the COVID-19 shutdown even though traffic volumes were down around 40 percent.

The first graph shows air quality data from March 16, 2020 through June 10, 2020. The EPA’s Air Quality Index data show the air quality in Hennepin County was worse during Governor Walz’s shutdown than it was during the previous five year average. That being said, the air quality was still far below levels that are considered hazardous.

Now, let’s look at the air quality compared to traffic on the roads. The AQI for 2020, as shown in the gray line, shows upticks in pollution even though traffic was down by about 40 percent during this time.

This data is the opposite of what people would probably expect. However, this is actually very good news, because it shows that Minnesota’s air quality is already very good, and that other factors have a larger influence on our air quality than vehicle emissions.

Data from the Minnesota Pollution Control Agency already show this. Emissions for fine particles, nitrogen dioxide, carbon monoxide and sulfur dioxide are already far below federal standards established to protect human health, as you can see in the graph below.

Neighborhood sources of air pollution like backyard fires and home heating contribute more to levels of fine particulates than on-road cars and trucks, according to MPCA. This helps explain why taking 40 percent of the cars off the road in the Metro did not result in better air quality than the previous five-year average.

While American Experiment has spoken out against the Walz administration’s heavy-handed shutdown of the economy, it does provide a natural experiment on the environmental impact of future regulations on cars, particularly the Walz administration’s attempt to force Minnesota to comply with California’s car mandates.

The Walz administration has yet to release it’s draft of the rule, but the final version will almost certainly be marketed as reducing pollution by taking “the equivalent of a yet-to-be determined number of cars off the road.” This number will almost certainly not be the equivalent of taking 40 percent of the cars in the Metro off the road, which means the rule will not have any measurable impact on air quality in the region.

Whether Governor Walz realizes it or not, his shutdown of the economy has greatly undermined a significant part of his justification for imposing these vehicle mandates, and that’s a nice silver lining to this COVID cloud.