Let's clear the air about Houston's air pollution: A recent report from the American Lung Association ranks Houston the ninth worst U.S. metro area for ozone pollution and the 17th worst in the broad category of long-term particle pollution.

Yet the future might not be so cloudy for Houston's atmosphere.

A newly published study in the journal Atmospheric Environment indicates that replacing at least 35 percent of Houston's gas- and diesel-powered cars and trucks with electric vehicles by 2040 could improve air quality by 50 percent. And if electric vehicles replaced 75 percent of traditional cars and trucks by 2040, air quality could improve by 75 percent, according to the study.

This conversion to electric vehicles would enable residents of the Houston area to "breathe easier, live longer, and enjoy a better economy," the researchers say.

"The population in 2040 Houston will see a huge increase, but we can apply new technology to reduce emissions, improve air quality, and think about health," says one of the researchers, Shuai Pan, a postdoctoral associate in civil and environmental engineering at Cornell University.

Pan earned a doctoral degree in atmospheric science from the University of Houston in 2017.

Kevin Douglass, president of the Houston Electric Auto Association, tells InnovationMap that the study does a good job of emphasizing "the alarming situation that Houston is in with reference to its air quality and how electrification of the transportation system is a … way to improve the bad-air-quality situation."

The nonprofit Houston Electric Auto Association comprises EV owners, hobbyists, educators, and enthusiasts who promote the benefits of these vehicles.

Douglass says he's confident about the progression of the EV evolution in Houston.

"It only took a decade to go from horse-drawn carriage to automobile in the U.S.," he says. "One and a half decades from now, in 2035, at least half of the cars on the road will be electric. Thirty years from now, the vast majority of vehicles will be electric and autonomous."

Houston — which the nonprofit Smart Energy Consumer Collaborative praises as one of the 10 friendliest U.S. cities for EVs — already is on the road toward enhancing air quality by putting more electric vehicles (EVs) on the road. In fact, a 2018 report from the Environment Texas Research and Policy Center predicts the number of EVs in Houston will rise to 65,000 by 2030.

An estimated 9,500 EVs were being driven by Houston motorists in 2018, according to a presentation given in May by Michael Conklin, external engagement manager at Houston-based utility CenterPoint Energy. And by 2028, that number could reach 110,000, the presentation says.

"Electric cars aren't the future — they're already here, and they work," Douglass said in 2018. "As more people learn about them, they will enjoy owning and driving them."

Among Houston's highest-profile EV champions is Mayor Sylvester Turner, who's leading the charge to shift the city-owned fleet away from traditional vehicles and toward hybrids and EVs.

"Transportation is responsible for 48 percent of Houston's greenhouse gas emissions — the highest per capita of all U.S. cities — and something we must address to move our city forward," Turner, co-chair of the Climate Mayors organization, said in 2018.