Gross air from winter inversions has become a fact-of-life for Salt Lake City residents. That doesn’t mean other parts of Utah that typically experience cleaner air are immune.
In fact, the meteorological phenomenon known as inversion already happens all over the state. It leads to especially bad air quality along the Wasatch Front largely because it's the state’s most densely populated area, said Heather Holmes, who studies inversion pollution at the University of Utah.
“Other communities in Utah have less people — so, maybe less air pollution — but they can still have an inversion,” the associate professor of chemical engineering said. “Any pollutants that are emitted during that time period will still accumulate in that location and could impact them.”
If the state’s continued growth brings more emissions to places beyond the Wasatch Front, those outlying inversions could someday become more hazardous, too.
“While inversions are very meteorologically driven, we as humans are contributing to pollution during those events that then make them harmful for us,” Holmes said.
Typically, air is warmest at ground level and cools as it gets higher in the atmosphere. During an inversion event, however, that dynamic is flipped. Cold air is trapped near the valley floor with a layer of warmer air on top of it. That warm layer acts like a cap, preventing the cold air mass from escaping.
Then any pollution produced from vehicles, factories or other emission sources gets trapped there too, leading to the icky haze inversions are known for. Exposure to this type of air can lead to serious health issues, such as asthma attacks and pregnancy complications.
Any community in the West that’s flanked by mountains can experience inversion and likely already does, Holmes said.
Northeast Utah’s Uinta Basin, for example, has its own air quality problems tied to these conditions. Like the Salt Lake Valley, it sits in a bowl surrounded by mountains and plateaus. Increased oil and gas production there has fueled excessive levels of ozone.
Other regional examples include Phoenix, California’s Central Valley and Las Vegas, where local authorities recently called for residents to stop using wood-burning fireplaces and stoves to avoid creating unhealthy air.
It might someday catch up with St. George in southwest Utah, where the population is projected to double by 2050.
“It wouldn't surprise me,” said Logan Mitchell, a climate scientist and energy analyst with environmental group Utah Clean Energy. “If there's more cars — more combustion cars — and [the] population’s growing rapidly … there could definitely be problems.”
That’s on top of the summertime smoke that threatens air quality in St. George and the rest of Utah as climate change fuels increasingly intense wildfires.
In rural mountain valley communities, Mitchell said it’s already common to experience extended air quality problems fueled by inversion and wood burning, but that often flies under the radar. Traditionally, there hasn’t been good air quality monitoring there, he said, so we don’t know as much about the air quality in rural areas. With the cost of air monitors dropping, he’s hopeful more of those communities can collect local data and take action.
Especially as more people crowd into the state, it’s important for Utah to grow the right way. Electrifying transportation and buildings could be the next big step in improving the air, he said.
“It's our choice, as a society and as a state,” Mitchell said. “When we adopt those technologies, we will improve our air quality. And so whether we do that in the next decade or in three decades, that's up to us.”
Climate change will likely increase the frequency and duration of inversions in the coming years, Holmes said, as high pressure systems become more prevalent in the West. There’s also a chance warming global temperatures might counteract that a bit by weakening the intensity of those events.
When Utahns see the inversion, Holmes said it’s easy to think it’s hopeless. Over the past two decades, however, she’s seen a noticeable shift in people’s mindsets about the things they can do to help — from turning down the thermostat to biking to work.
“If everybody makes these small changes, they add up and can be really helpful,” Holmes said. “Our future really relies on everyone wanting to make those adjustments.”
