Doing the Math
I did a little arithmetic. Given the size of St. Paul and the average wind speed, St. Paul typically gets a complete air change once an hour, and the Earth has hundreds of years of supply to provide them. Given how air is mixed, naturally polluted, naturally cleansed, and otherwise affected by civilization, the effect of Coleman's policy simply cannot be measured for thousands of years, if ever.
Next time I'm in St. Paul, I'm going to eat a big plate of beans.