(Colorado News Connection) A new rule, requiring 82 percent of new car and truck sales in Colorado to be zero-emissions vehicles by 2032, could begin to turn the tide on the state's persistent unhealthy air quality. 

The transportation sector is the largest contributor to ground-level ozone, a potent combination of pollutants with particulates small enough to lodge in lungs. 

Sarah Clark - a lead organizer at the Sierra Club - said ozone contributes to multiple health issues, including asthma, lung disease, chronic obstructive pulmonary disease and even premature death.

"Air pollution and ozone threatens public health across Colorado," said Clark, "particularly in communities struggling with poverty and communities of color where folks are more likely to live near busy highways, refineries, and oil and gas production sites."

Aurora and Denver have the sixth highest average number of ozone alert days in the nation, according to the American Lung Society, with other Front Range cities not far behind. 

Ozone pollution causes over one million premature adult deaths each year, with children and older residents most at risk.

The Colorado Automobile Dealers Association says it was optimistic about the Air Quality Control Commission's rule - which bumps targets of EV sales from 25 percent to 51 percent by 2028, and 68 percent by 2030. 

EVs accounted for 17 percent of sales between July and August of this year. 

Clark said governments and utility companies are also investing billions to create a network of charging stations.

"Automakers know the transition is happening, and that's why we're seeing big commitments to expanding the number of zero emission vehicles around the country," said Clark. "There's actually a surprising amount of excitement and momentum from the auto industry."

Some critics of the new rule wanted Colorado to follow California's more ambitious goal requiring 100 percent of vehicles on dealership lots to be zero-emissions by 2035. 

The commission will revisit the rule in 2029. Clark believes Colorado's 82 percent requirement is a good first step.

"This rule is a crucial step in meeting the goal of two million EVs on the road to reduce greenhouse gas emissions," said Clark. "We look forward to 2029 when we can come back and adopt the full 100 percent rule."