February 2, 2026
- The West is home to some of the worst air pollution challenges, affected by high ozone, smog, and particle pollution.
- These pollutants are known to cause premature death, asthma, cancer, heart attacks, birth defects, and Alzheimer’s disease.
- Western Resource Advocates’ experts are implementing cutting edge state-level policy solutions to reduce air pollution — attacking the problem from every source and holding top polluters to account.
- Solutions include indirect source rules to limit pollution from vehicle fleets, prescribed burning to prevent catastrophic wildfires, and closing coal plants in favor of clean energy.
Do you remember when you didn’t have to check the air quality before starting your day?
Those days are likely over. Checking air quality metrics in weather apps or getting ozone alerts has become an all-too-common occurrence. Today, we frequently track high ozone days in the summer, wildfires during year-round fire season, and worry about smog from gas-powered cars, oil and gas production, new AI data center developments, and industry.
In 2025, 46% of Americans lived in places with unhealthy levels of ozone or particle pollution. That’s 25 million more people than the prior year. While the U.S. struggles with pollution nationwide, the West is particularly hard hit.
Many of our region’s biggest cities and counties experience some of the worst air pollution challenges in the country. According to the American Lung Association 2025 State of the Air Report:
93% of Nevada residents live in places with unhealthy air,
and Las Vegas and Reno rank in the top 25 most polluted U.S. cities.- Phoenix ranks in the top 10 most smog-heavy cities.
- Washoe County, Nevada, and Salt Lake County, Utah, rank among 30 U.S. counties that received failing grades for ozone, as well as short- and long-term particle pollution.
- Salt Lake City, Phoenix, Denver, Las Vegas, Albuquerque, and Santa Fe all sit within the top 25 most polluted cities by ozone, as do many smaller towns in the Interior West.
- Coal-fired power plants in Wyoming, Arizona, Colorado, and Utah are among the top ten regional haze polluters plaguing national parks and wilderness areas.
In mid-January 2026, Salt Lake City experienced an all-too-common winter inversion, topping the charts as the city with the nation’s worst air quality that day.
The processes that release these air pollutants — like driving gasoline cars and burning coal — are also associated with greenhouse gas emissions that drive climate change, worsening summertime ozone, trapping heat, and increasing fire risk.
Ground-level ozone develops when gases from pollution sources like cars and factories comes in contact with sunlight, reacting to form ozone or “smog.”
Pollutants like ozone are known to cause asthma, cancer, heart attacks, birth defects, Alzheimer’s disease, and premature death. Poor air quality also has outsized impacts on the most vulnerable in our communities, including infants, children, and the elderly.
Solutions to Air Pollution in the West #
To ensure our communities thrive, we must clean up our air. WRA is driving state-level advocacy, fighting for policies that will improve air quality, and our land and water along with it. Our air pollution solutions aren’t confined to a single industry. We tactfully target the many sources of the problem and ensure meaningful emissions reductions in the West.
Curbing Transportation Emissions with Indirect Source Rules#
Nationally, transportation accounts for 28% of all greenhouse gas emissions, the highest of any sector. Most policies aimed at electrifying transportation and cutting the sector’s emissions have one specific focus: reducing pollution directly from vehicle tailpipes.
But the federal government recently made this tool a less effective way to reduce emissions. The Trump administration used the Congressional Review Act in 2025 to rollback more stringent tailpipe emissions standards adopted by states like Colorado and New Mexico, a measure deemed illegal by the nonpartisan Senate Parliamentarian. Because of this, WRA is looking for creative air pollution solutions to incentivize the transition to clean transportation at the state and local levels, where policies are more durable against shifting federal priorities. In this new era, many experts have turned to indirect source rules.
An indirect source rule reduces transportation pollution not by regulating tailpipe emissions, but by requiring transportation pollution hot spots — think warehouses, shipping yards, and huge event centers teeming with cars and trucks — to take actions to reduce emissions like electrifying their fleets of vehicles. As online shopping gets more popular, warehouses are an obvious target for emissions reductions. Truck trips to and from warehouses represent around 90% of their emissions.
Warehouses are often located along highly polluted transportation corridors and industrial areas where low-income and disproportionately impacted communities tend to be located. That means these rules can directly reduce pollution in the most impacted, at-risk communities. By electrifying fleets and reducing pollution from hot spots, we are protecting communities and working toward climate goals.
Indirect source rules are just one of many promising state and local transportation electrification policies WRA analyzed in our recent report: The Ambition Road Map.
Avoiding Fossil Fuel Emissions with Clean Energy Investments #
While transportation makes up 28% of U.S. emissions, electricity power generation comes in at a close second at 25%. Nearly all of that pollution can be attributed to burning coal and methane gas for energy. It is essential that we decarbonize our grid by investing in zero-emission electricity to clean up our air and sustainably power our homes and businesses. This vision to decarbonize our grid has been core to WRA’s work for more than three decades. And seven years ago, it formed the foundation for the Climate Fix — WRA’s plan to drive deep reductions in greenhouse gas emissions through the transition to clean energy. The strategies to get there?
- Retire coal plants
- Replace their capacity with clean, pollution-free generation
- Modernize the grid to accommodate the influx of new generation from renewable energy
In 2016, WRA set out to cut emissions by 80 million tons, and we far exceeded that goal, securing 91.5 million tons of carbon dioxide reductions annually by 2030. Because of WRA’s ambitious advocacy, the West now gets 57% of its energy from nonpolluting sources like wind, solar, and geothermal.
Today, coal represents just 12% of the region’s energy generation. Of course, the work to reach 100% clean, reliable, affordable power is still ongoing, and we’re facing new and urgent threats like soaring energy demand driven by AI data centers and a federal administration that’s pro-fossil fuel.
In late 2025, the Trump administration invoked emergency powers to keep Colorado’s aging Craig 1 coal plant open just one day before its scheduled closure — an unprecedented use of the Federal Power Act. Then this January the Environmental Protection Agency rejected the state’s regional haze plan aimed at addressing pollution from coal, refineries, and cement kilns among other pollution sources. The EPA also announced it will no longer consider “lives saved” when determining new air pollution rules, and instead only assess costs to industry, ignoring the benefits to human life secured by cleaning our air.
Mitigating Catastrophic Wildfires with Prescribed Burns#
Another source of air pollution around the West is the increasingly and unnaturally severe wildfires that threaten our homes and communities. Wildfire is a natural and necessary part of many Western ecosystems. However, as extreme heat and drought worsen due to climate change, we’ve become used to more frequent and more destructive wildfires that are now a year-round threat.
Huge, catastrophic wildfires release dangerous amounts of CO2, ozone precursors, and particulate matter. With westerly winds, these air pollutants often not only affect those closest to the burn, but communities all over the Northern Hemisphere.
It might sound counterintuitive, but one of the most viable solutions to prevent catastrophic wildfires is prescribed burning. This tool is research based and has been used for thousands of years to keep landscapes healthy. Think of it like a prescription from your doctor. Modern prescribed burning is the practice of igniting fires intentionally — under carefully monitored conditions by trained professionals — to reduce unhealthy buildup of overgrown, hazardous fuels and dried vegetation. If left untouched, this fuel can ignite like a tinderbox, causing bigger, hotter, and more destructive fires.
By clearing out this dry and dense vegetation with controlled burns, we can restore health to the soil, improve wildlife habitat, keep invasive species at bay, and reinvigorate ecosystems that have historically relied on occasional low-intensity fires.
Prescribed burns also allow trained professionals to determine when, where, and under what conditions we want fire and smoke on the landscape. By paying close attention to the wind and weather conditions leading up to and following a prescribed fire, qualified professionals called burn bosses can help improve smoke dispersal, manage flame intensity, and limit the impact on nearby communities. This increases resilience in the event an unplanned wildfire starts in the area in the future.
Importantly, prescribed fire also allows experts to determine and control what is burned. A 2022 study from the American Lung Association showed an alarming difference in the toxicity and content of smoke from catastrophic fires compared to prescribed burns. Out-of-control blazes can burn through industrial or residential construction, releasing harmful chemicals in their wake.
Prescribed burns significantly reduce the chances of the next huge blaze, keeping our communities safe and our air clean. A 2025 Stanford University study found that prescribed burning can reduce the risk of subsequent wildfires by an average of 16% and lower overall smoke pollution by an average of 14%.
WRA is leading the charge in Colorado to increase the use of this essential tool. Just last year, we passed Senate Bill 25-007 to create a new Colorado prescribed fire liability claims fund. The fund enables burn bosses to use this land management tool without fear of repercussions or liability if minor damage occurs during the burn process.
Holding Top Polluters Accountable #
Essential to air pollution solutions is an acknowledgement that not every person or industry pollutes at the same rate. But it’s everyday people, and most often disproportionately impacted communities, that bear the worst effects. Oil and gas operations have many negative and long-lasting impacts on communities and the environment, like:
- Poor air quality in local communities
- Worsening climate change
- Destroying and degrading natural areas and wildlife habitat
Mitigating these harms is expensive, and the state and its residents shouldn’t be left holding the bag. It’s a pillar of WRA’s work to enact policies that hold top polluters accountable and center impacted communities in the process. That focus was the impetus for Colorado Senate Bill 24-230, passed in 2024 with advocacy from WRA. This bill created a fee on the production of oil and gas, making sure the industry is helping pay for the impacts that it causes.
The resulting fee revenue allows the state to remediate some of the environmental harm caused by the oil and gas industry’s production. The fee went into effect on July 1, 2025, and the more than $140 million in revenue generated supports conservation and restoration efforts at Colorado Parks and Wildlife and investments in local transit agencies. This new funding enhances both the ecosystems that help clean our air and the public transit infrastructure that will get more cars off the road — a win-win to reduce air pollution.
Air pollution is a complex problem. It’s often invisible to the naked eye but causes health impacts everyday people are forced to suffer and pay for. But ambitious, state-level solutions targeting air pollution at its source — vehicle fleets, fossil fuels, destructive wildfires, and top polluters — means a future of clear skies and breathable air in the West.
