The Volkswagen air pollution cheating scandal involves a global corporation and lots of vehicles. But what does it mean for Minnesota's air?
The short answer is not much. Compared to the total number of cars on the road in Minnesota, the number of diesel-powered passenger cars is tiny. And in terms of diesel fuel consumed in the state, the vast majority of that is by trucks, construction vehicles, and farm equipment.
The pollutants in question with the scandal are called nitrogen oxides. They are linked to respiratory ills like asthma, contribute to smog formation (ozone) and are a factor in acid rain. Nasty stuff.
The MPCA doesn't regulate emissions from passenger vehicles, but it does pay attention to the pollution they create. There are air monitoring stations spread across the state that continually track ozone and fine particle pollution levels. When they reach worrisome levels, Air Quality Alerts are issued. You can see live tracking data at our Air Quality index site.
Greg Pratt, an air quality scientist at the MPCA, who also happens to own a VW diesel, thinks the German's company's trickery is shameful. But he's also worried about an unintended backlash against diesel cars. "I hope we don't throw out the baby with the bathwater. Diesel passenger vehicles are very efficient in their fuel use compared to gasoline powered versions. That means less carbon in the atmosphere adding to climate change."
And over the last 20 years, air pollution from traditional sources like factory smokestacks and power plants has significantly declined.
During that same period, vehicle-miles traveled has climbed steadily, and their tailpipe emissions along with it. Says Pratt, "A challenge of our time is dealing with vehicle pollution -- both the human health problems and the carbon."