Here's a quote from the article: > In 2017, the California Air Resources Board issued a warning that may seem incredible but has not been seriously challenged:

Here's a quote from the article: > In 2017, the California Air Resources Board issued a warning that may seem incredible but has not been seriously challenged: By 2020, gas-powered leaf blowers, lawn mowers, and similar equipment in the state could produce more ozone pollution than all the millions of cars in California combined. Two-stroke engines are that dirty. Cars have become that clean.