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The Oscar-winner and El Capitan free solo-er talks to Heatmap about solar panels, fatherhood, and his new docuseries, Arctic Ascent.

In 2017, rock climber Alex Honnold went on Jimmy Kimmel Live! to promote Free Solo, the then-new documentary about his unassisted climb of Yosemite’s El Capitan. “Is there anything bigger than that?” Kimmel prompted as a closing question.
“I mean, there are technically some bigger walls in the world,” Honnold said. “But they’re in very remote places — like Greenland.”
Five years and an Oscar later, Honnold was scrambling off a boat at the base of Ingmikortilaq, a crumbly sea cliff that towers nearly 1,000 feet higher than El Cap over an iceberg-ridden fjord in eastern Greenland. His intended first ascent was the culmination of a six-week adventure across ice fields and glaciers.
This time, Honnold wasn’t alone. The Greenland expedition included two other legendary climbers, Hazel Findlay and Mikey Schaefer, as well as Aldo Kane, who provided safety and technical support; Adam Kjeldsen, a Greenlandic guide; and perhaps most surprisingly, Heïdi Sevestre, a French glaciologist who helped set up or run 16 different studies to collect data for scientists around the world.
The team’s adventure is captured in Arctic Ascent with Alex Honnold, a three-part docuseries that premieres on Hulu and Disney+ on February 5. Ahead of its release, I spoke separately with Honnold and Sevestre about the expedition, the importance of climate science, and their respective climbs. (While Sevestre, previously a non-climber, didn’t attempt Ingmikortilaq, she did scale a 1,500-foot rock face known as the Pool Wall while drilling rock cores for samples.) Our conversations have been lightly edited and condensed for clarity.
Unlike a lot of other outdoor sports like mountaineering or skiing or even surfing, rock climbing doesn’t seem as obviously imperiled by climate change. How did this become the cause you wanted to devote your time and money to?
Oh, I think climbing is more imperiled by climate change than most other sports. I mean, you’re right that maybe it’s not as impactful as to skiing, but it’s way more impactful than almost every other sport.
You’re still in the mountains. Wildfire smoke every summer — that’s now a thing that just didn’t exist when I was growing up climbing. Even if you’re just rock climbing, you’re always approaching in the mountains. Nowadays, most couloirs [chutes between rocks that might typically fill with snow in the winter] have melted out. Stable snow fields that have existed for generations are now melted out. Piles of teetering rubble are falling down mountainsides, and also a lot of routes are just less safe. The mountainsides themselves are collapsing, like the Aiguille du Midi gondola in Chamonix. Which, actually — one of the things we were installing in Greenland were temperature sensors on one of the cliffs, related to studying how rocks thaw out, what happens when permafrost melts. I would say that climate change is still incredibly relevant for us.
Your way into climate was through your climbing, then?
A big part of my environmental awareness in general is because of the experiences I’ve had outdoors as a climber. But long before [the Greenland expedition], I started a foundation in 2012 where I’ve been supporting community solar projects around the world and caring about the transition to renewables. I’ve cared about climate change forever. I think this was just the first opportunity to do it on mainstream television.
I saw that Arctic Ascent purchased carbon credits to compensate for production emissions. I was hoping you could talk about that decision, and how else you might have minimized your impact on the expedition, since I don’t think people are aware of how energy intensive film and TV productions can be.
In this case, other than the obvious expense of all of our flights getting to Greenland, we had a relatively low carbon footprint because we were camping the whole time. I think you’re right that a lot of television is kind of insane when you have all the RVs and everyone’s in their own thing and there’s hair and makeup and it’s just crazy with, like, a million cameras. In this case, it was basically a bunch of people camping on a glacier for six weeks, so it’s not quite the same as a Hollywood set.
But yeah, I think the idea to purchase offsets was the obvious bare minimum for a project like this. If you’re going to be doing a whole story around sea level rise, you have to do something.
The Honnold Foundation focuses on bringing solar panels to vulnerable communities, but these are fairly small projects compared to the expansive solar farms we might more traditionally think of. Why did you choose to focus your time on something that might seem, at least on paper, to be of a smaller scale than, say, electrifying the grid?
It’s a totally fair question. In 2012, it wasn’t totally clear that the world was transitioning to renewables at all. It seemed like it was inevitable, but you’re never really sure — you know, back then people were into hydrogen and you’re like, “Oh, maybe we’re going to have hydrogen cars, or maybe battery electric really takes off,” blah, blah, blah. Anyway, now it seems totally clear that the world is transitioning to renewables. Within some timeframe, like 20 to 50 years, the world will be 100% renewable.
The thing is, we currently live in a world where something like a billion people don’t have access to power, and transitioning to renewables will still leave us in a world where a billion people don’t have access to power. [Editor’s note: The number of people living without electricity today is actually closer to 760 million.] As the system changes, there are so many people who are left behind. What the Honnold Foundation tries to do is find that sweet spot in helping with the transition, helping the people who are being left behind.
Part of that is just by necessity — I’m a professional rock climber, I’m not a tech billionaire. So the small-scale grants just make more sense to some extent, but they also have the biggest impact on human lives because when you do these small-scale projects, you can fundamentally change the way people live. That’s a huge impact.
I live in Las Vegas, and you see huge solar farms around the desert. It’s great; the grid is going 100% renewable. I’m into that. But realistically, the only difference it makes in most people’s lives is maybe a small change in their utility rate. Really, the people that benefit are the utility shareholders — it’s some Warren Buffett-owned utility in my case, NV Energy. That really isn’t that inspiring. This is my long rant to say that the Honnold Foundation is trying to help the humans who need it the most.
Did you get a chance to use solar panels on the Greenland expedition?
On this trip, no, because they were running a generator for production and it was charging, like, 50 batteries.
It’s funny because we did an expedition in Antarctica where we made a little climbing film as well. And on that trip, they planned to take a generator and then somebody just forgot the fuel. So we got there and we were like, “Oh, no,” and we wound up doing the whole trip off solar and it totally worked.
This was your first expedition since becoming a father. You’ve worked on the climate cause for a long time now, but I’m curious if your perspective has changed at all since your daughter June joined your family — and I know you have another daughter on the way!
Yeah, soon! No, I don’t think my perspective has changed too much. I’ve always cared about these kinds of issues. The bigger change is in the way that I spend my time. Having a family forces me to be a little bit tighter about the choices that I’m making, what expeditions I choose to go on. That makes a trip like this even more worthwhile, where you get to do great climbing and there’s a real purpose behind it, and you get to share important knowledge about things that matter.
Can you tell me a little more about the decision to bring Heïdi on board? I heard her version of the story earlier this week but I’m curious about how you found her and roped her in.
Isn’t she so amazing?
She was delightful!
That’s the thing with Heïdi. Because when you spend time with her, she just makes you care about about ice. And I don’t even like ice. It’s not my thing; I like rocks. But she made me much more knowledgeable and much more caring about that type of world.
Do you consider yourself an optimist when it comes to climate change?
I think so, which is weird because I’m optimistic despite all the data to the contrary. I understand the predictions, but there’s so much to gain. So far it’s been 20 years that I’ve been reading environmental nonfiction and we haven’t really chosen to make anything of this opportunity, but we still have this incredible opportunity to build a better world to live in, a cleaner world. We can still choose that at any point. And I just keep thinking that at some point, we’re going to choose it. You can’t keep ignoring the obvious thing forever.
How did you get involved in the Arctic Ascent expedition?
This was an absolute dream come true for me — I felt extremely lucky to get a call from the team. It is extremely challenging to go to that one remote location, one of the least studied places on Earth. But Alex, as you know, is a firm believer in the scientific work. The planets really aligned. It took about a year prior to the expedition to design the work we could do with boots on the ground.
I wanted to know what it was like to put together scientific objectives for an expedition like this. It’s a little bit unconventional because there’s a film crew and there was climbing involved.
I think it was extremely brave and extremely daring of the entire team to have the willingness to invite the scientists on board. Because not only did we have the best climbers in the world climbing in a very challenging and hostile environment, we’re also filming a series of documentaries and we have to do some of the very best possible science. So it’s not that easy! But what we did is, we took it step by step. We contacted all the universities and labs and institutions interested in data from this part of the world — and also interested in training me on how to collect this data. Because I really felt — it’s what I was thinking the whole time — I really felt like I was an astronaut on the ISS. I was the only one, and I had to do the best possible work.
We ended up with 16 different protocols to do on this expedition, so it was really major. And, you know, we worked with NASA, we worked with research institutes in Denmark, the University of Buffalo, and the University of Kansas, for example. So it was challenging but a dream come true to be trusted by the scientists.
Your first big polar expedition was actually to Greenland, back in 2011. Had you been back to the island between that research trip and this one?
I had spent a tiny bit of time — not so far in the field as East Greenland, but around the coastlines. But what I was doing there was mostly science communication with people who wanted to learn about the impacts of climate change on the Greenland ice sheets. So I hadn’t been on a big research expedition to Greenland since 2011. And the changes were absolutely massive.
That was going to be my question!
The Arctic is one of the fastest-warming places on Earth. Everything that’s taking place in Greenland is impacting the rest of the world, so I felt that we had a duty and a mission — on top of climbing these incredible monoliths, we actually had to bring something back to society.
In the series, you talk about how remote and understudied East Greenland is by climate scientists. But during the expedition, you were being assisted by support helicopters and by boats. So why aren’t expeditions like this one happening all the time? Is it an issue of funding or a lack of scientific interest in this particular region?
It’s crazy to think of how little data we have from the ground [in East Greenland]. We have satellites — we have as many satellites as we want. But it is very tricky to get there. What you have to understand about this place is that for 10 months of the year, there is sea ice blocking access to this field. Ten months of the year! So the rest of the year — yes, we can access by plane, we can access by boat, but it’s very expensive.
What was great about this project is that we had in mind, “How can we lower our carbon footprint?” This is why, for example, we worked with fishermen who had boats from a nearby village at the entrance of the field. It was very important for us to use local means of transportation. Of course, we had to use helicopters every now and then, because there was no other way. But it’s remote, it’s expensive, and on top of everything, it is extremely hostile.
Oh my gosh, the bashing you get when you go there! This is something that we really wanted to show in the series — how powerful nature can be. And climate change is accelerating and making these changes even more violent. So I think it’s important to show that when nature starts to be a bit destabilized, it can get very angry.
There was a paper in Nature that came out earlier this month that said nearly every glacier in Greenland has thinned or retreated over the past few decades. In the series, there’s a bit of good news, which is that the Daugaard-Jensen Glacier is a little bit more stable than you were anticipating. Do you have any insight into why that might be?
What’s so great is, it keeps part of the mystery! I like that we still don’t totally understand what’s taking place.
The scientists we’ve been working with have told us — this is a bit technical — but it has to do with the shape of the bedrock. It seems that the glacier is resting on a little ridge that might be holding everything together. This might be the reason why the glacier is still stable; also, this part of Greenland still receives a lot of snow.
But we’ve seen some cracks in this perfect picture. You know, the NASA float [that we launched on the expedition] has told us that the temperature of the water in the fjords is increasing. So it’s not all perfect. The environment around it is definitely changing, but it seems that it has some advantages.
Were there any findings from the expedition that you are particularly excited about?
All of them! But science takes a very long time, so at the moment, we’re still waiting on a lot of the results from these different protocols. But what I want to share is something that is very simple: Greenland holds a lot of ice, and if we lose the ice, it means 6 to 7 meters of sea-level rise. As you saw in the paper that was published by Nature, at the moment, Greenland is losing 30 million tons of ice per hour. What is crucial to understand is that every action we conduct back home to reduce our carbon footprints and to preserve our climate helps Greenland and helps our collective future. All this data will help us to prepare for the things to come.
Last question: Have you taken up rock climbing?
I’ll be honest: no. I think I’m a bit traumatized in a good way. I think I needed a minute to recover. But I really want to start climbing again — now, with the launch of this series, I know that it’ll be my mission for this year. Otherwise, I think Alex and Hazel will never forgive me.
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Facing down a sea change, the automaker has staked its next EV bet on a compact, sporty pickup.
“Full fathom five, your father lies,” the invisible spirit Ariel sings early in The Tempest, as a handsome and grieving prince listens, rapt. The song tells of a shipwrecked skeleton transforming into something else — its eyes have become pearls, and its bones pink coral — as it undergoes, yes, a “sea change.” It is the first time that phrase appears in the English language.
Ford is now facing its own kind of sea change. Over the past decade, the automaker has doubled down on its most profitable and exciting vehicles — pickups, SUVs, and the Mustang muscle car — and dropped from its line-up the cheap, boring cars that once made it famous. It embraced, then backed off, the transition to electric vehicles, in part because it failed to make money from them; and it began to reckon with the surge of cheaper, cleaner, and “far superior” EVs from Chinese producers that are transforming global auto markets around the world.
Locked into its aging but reliable line-up, yet unable to innovate at the low end, Ford might seem like the epitome of a company facing disruptive innovation. No wonder its stock has traded flat from where it was five years ago — even as the broader market has surged by more than 70%.
Its solution is an EV skunkworks, run by Tesla alumni, where it can develop a new “universal EV platform” to undergird future vehicles. Today, we got a peek at the first car to emerge from that secret shop: an all-electric compact pickup that will hit the roads by the end of next year. Its name? The Ford Fathom.
We know very little about the Fathom, as our correspondent Andrew Moseman wrote today. It will retail for just over $28,000, and even with mandatory delivery costs and other add-ons will stick to this side of $30,000. That makes it only a smidge more expensive than the gas-burning Ford Maverick, a sporty, compact, and popular pickup that starts around $27,000.
Ford promises that the Fathom will have as much seating capacity as Toyota’s RAV4, America’s best-selling car that isn’t a truck. (Ford’s own F-150, of course, holds the true No. 1 spot.) Those dimensions suggest the Fathom will sport a four-door crew cab, like the Maverick, making it more acceptable to families with kids — or young professionals who want to give their friends rides on the weekend. It will also have a frunk.
Beyond that, though, we don’t know much. We don’t know its range, for instance, and its price point shouldn’t inspire too much confidence on that front. Nor do we know, frankly, whether Ford can pull it off: When the automaker announced its first electric truck, the F-150 Lightning, in 2021, it claimed a price point of less than $40,000. Eighteen months of inflation later, it actually sold them for closer to $55,000 — and it still lost money on every EV that it made. Fixing the latter problem is part of why the skunkworks exists in the first place, and Ford now has an additional half-decade of experience making EVs. But consumers hoping for a miraculously priced electric pickup from the Blue Oval have been burned before.
If the Fathom disappoints, though, then consumers will soon have other options. The American car market is about to be deluged with sporty, compact pickup trucks — a welcome change from just a few years ago, when the segment was almost entirely dominated by mid-size and half-ton models. The Jeff Bezos-backed startup Slate will start delivering two-door, all-electric pickups starting at $25,000 at the end of this year. The automaker Stellantis, which owns the Dodge and Jeep brands, says it wants to bring another compact pickup — it’s almost more of a ute — called the Rampage to North America soon.
That’s welcome news for me — I love these little trucks — but I’m a little worried I’ll be outside my pickup-buying years by the time they actually make it to market. In the meantime, I’ll keep you posted on other updates about the Fathom. Will “sea nymphs hourly ring its knell”? No, but it will have Apple CarPlay and Android Auto.
The company confirmed its plans to market research company Cleanview.
The data center buildout has hit a new inflection point. It has long been true that artificial intelligence is fueling climate change by driving up power demand; more recently, tech companies have started directly financing new natural gas plants in their quest for AI glory. Now one is backing the biggest fossil fuel-fired power plant ever to exist in the United States — exclusively to power an AI data center complex.
That company is Amazon, according to the market research company Cleanview, which reported on Friday that the tech giant is building an AI data center campus in Texas powered by an up to 7.65-gigawatt off-grid natural gas plant.
That’s larger than any other power plant in the country — fossil or otherwise. The next biggest plant is the Grand Coulee hydroelectric plant in Washington State, at 7 gigawatts, followed by Arizona’s 4-gigawatt Palo Verde nuclear plant, and the West Count Energy Center, a 3.7-gigawatt natural gas plant in Florida.
The new power plant’s developer, Pacifico Energy, announced in January that it had secured permits from Texas regulators for the project, dubbed “GW Ranch.” The site is also permitted for up to 750 megawatts of solar and 1.8 gigawatts of battery energy storage.
It was not clear who the customer for all this energy would be until earlier this week, when Cleanview uncovered construction permits Amazon filed showing that the company owned the GW Ranch site. The company confirmed to Cleanview that it acquired the site and planned to buy power from Pacifico’s plant.
Not only will this natural gas plant be larger than the one in Florida, it will also use far less efficient technology. Pacifico’s permit says it plans to build 35 “simple cycle” generating units, which are typically installed in rarely-used peaker power plants and waste a lot more fuel potential than the modern “combined cycle” natural gas plants that serve as baseload power for the grid today. These more efficient turbines are essentially on backorder for years, and power-hungry developers have increasingly turned to the simpler versions as a quick fix as they race to bring facilities online.
According to its permit, the GW Ranch plant is allowed to emit as much as 33 million tons of CO2 per year. That’s twice as much as the most-polluting power plant in the country, the James H. Miller Jr. coal plant in Alabama, emitted in 2023, the most recent year for which data is available.
In a statement to Cleanview, an Amazon spokesperson said the company “believes in paying the full costs of powering our operations,” and that this Texas project “does just that: it’s powered by new on-site generation that won’t raise electricity costs for Texas families and designed to transition to grid-connected service as interconnection timelines allow.”
Some researchers disagree on that point, however. In an opinion piece for Utility Dive, Energy Innovation director Jeffrey Rissman and senior fellow Eric Gimon argue that the proliferation of off-grid natural gas generation for data centers will increase costs for regular people more than if the data centers connected to the grid, because they will be competing with utility companies for gas supply. “Data centers can buy gas in bulk and sign long-term contracts (as we’ve seen in Texas, Pennsylvania and New Mexico), giving them access to cheap gas, even if this unfairly drives up prices for everyone else,” they write.
Jane Flegal, a senior fellow at the Searchlight Institute, has also argued that building off-grid natural gas plants to serve data centers locks in emissions for decades because the plants don’t face competitive pressure from other resources. When a new natural gas plant is hooked up to the grid, by contrast, there’s a far greater chance that cheaper, cleaner resources will displace its generation over time.
The Rhodium Group recently developed a scoring system to help investors differentiate between projects that are likely to accelerate the energy transition, those that will have little effect one way or the other, and those that will actively slow it down. They used it to assess options for powering data centers, and found that off grid natural gas plants scored the worst, falling at the bottom of the latter category.
Regardless, Amazon still, somehow, asserts that it is committed to achieve net zero emissions by 2040.
The smoke pouring into Seattle from Spokane is particularly bad, but there’s also no such thing as good smoke.
I wrote this story from inside a cloud of smoke. Owing to some funky meteorology in the Seattle area this week — a pressure ridge paired with a thermal trough — the region’s usual westerly winds reversed, causing smoke from the fires burning in the eastern half of the state to pour through the mountain passes and river valleys of the Cascades and pool over the populous Puget Sound lowlands, where I live.
Though it’s cleared up some today, I’m still running my air purifier on full blast because I know what’s in the lingering smoke. Unlike the still blazing wildfires in Ontario that are burning through mostly uninhabited forests, the smoke in the Seattle area this week came to us partially from Spokane, where the Old Trails fire razed at least 700 buildings and homes last weekend. That means that beyond the usual organic matter associated with wildfire smoke, the pollution that has hung over Seattle has likely also contained particles and chemicals from burned plastics, batteries, cars, and household appliances.
But how can the average person be sure whether their wildfire smoke is the bad kind or the worse kind? (At least assuming that well-adjusted people do not obsessively watch the animations on AirNow.Gov, as I do.) I turned to Coty Jen, an associate professor of chemical engineering, and Albert Presto, a research professor of mechanical engineering, both of Carnegie Mellon University, to learn more about the chemistry of wildfire smoke.
“There is no safe smoke,” Jen said, setting me straight immediately. “It’s all bad. It will piss your body off.”
While it’s true that some smoke is more toxic than other smoke, what you might call the “all natural, organic” variety will still spike hospital emission rates and exacerbate pre-existing respiratory diseases, even if it is mostly burning trees.
Under ideal conditions, when cellulose or lignin — the main structural components of trees and plants as well as leaf litter and soil, the largest sources of carbon during a forest fire — heat up and combust, the chemical reaction creates carbon dioxide, water, heat, and light. But wildfires don’t burn cleanly, and the chemical reactions often stall midway through that process due to things like oxygen availability and temperature variation, producing intermediate products like carbon monoxide or partially broken-down bits of carbon, often called soot. The tiniest of these particles can be smaller than 2.5 micrometers across — 30 or more could fit across the width of a human hair — and are measured collectively as PM2.5, a catch-all term that refers to the size of the particle rather than what it is. What’s important, though, is that these particles are small enough to penetrate deep into our lungs and potentially enter our bloodstream, factors that add to the known mortality associated with PM2.5 exposure.
Different kinds of forests create different emissions — heavy duff, or leaf litter, which is common in pine forests, creates some of the densest smoke conditions. Wetter fuels also burn “dirtier,” creating more pollution. Different topographies also impact air quality in myriad ways; it’s no surprise that some of the worst pollution from the Spokane wildfires pooled in mountain valleys as a warm overhead layer of air trapped the particles near the ground.
Even “natural” wildfires can be extra toxic; burning eucalyptus, which grows in Southern California, is not something you want to inhale. Pine smoke can cause mutations in bacterial DNA, a common lab test for a substance’s potential to cause cancer. Wildfires that smolder are worse than those that burn fast; researchers have found that PM2.5 can be up to 70 times higher when fuels aren’t actively on fire. “You can even see this if you’ve ever built a fire yourself,” Presto explained. “There’s a period where everything is big and flaming, and then, if you’re burning a log, it eventually goes down to smoldering. The emissions are different.”
In the case of something like a house burning down in a wildfire, however, it’s not only cellulose and lignin combusting. “We’re good at engineering materials that are extremely robust, but when they burn, they release very exotic compounds,” Jen said. She pointed to the common plastic PVC, which is used for everything from exterior siding to plumbing and window frames. When it combusts, PVC releases chlorine, “which is very bad for you,” Jen told me. “It’s like how bleach is bad for you — it’s a pretty nasty chlorine compound. PVC isn’t releasing bleach, but it is releasing radical chlorine molecules that produce some crazy compounds.”
If you’re following a smoke event at home, the answer is “not really.” PM2.5 is measured in micrograms per cubic meter, which tells us how much small stuff is floating around, but not what that small stuff is. “It is pretty difficult to measure all the different compounds that wildfires, or broadly any pollution, will emit,” Jen said. “The easiest way to quantify it is to literally suck air onto a filter and measure how heavy it got.”
Measuring what exactly is in that mass requires instruments that cost in the ballpark of half a million dollars, which is not financially feasible at every air monitoring station, Jen went on. But while there are certainly academic applications for that kind of knowledge, a person trying to decide whether or not to go for their run in wildfire smoke doesn’t need that level of granularity.
“Some smoke is definitely more dangerous,” Jen said. “But as innocent bystanders, it’s not like we can pick and choose what smoke floats over to us. You just have to live with it, so the best mentality is to treat all smoke as bad.”
In a 2026 Science Advances study that attributed more than 24,000 deaths per year to wildfire smoke in the U.S., researchers found no safe threshold for PM2.5 exposure. Every 0.1 microgram per cubic meter increase in a county’s average annual PM2.5 from smoke was associated with nearly 5,600 excess deaths nationwide, even though most counties saw only trace amounts of smoke — about 0.4 micrograms per cubic meter a year. While it’s “orange sky” days, when the pollution spikes into triple-digit AQI numbers, that get the most media attention, even low exposure that you can’t smell or even see can be affecting your health.
PM2.5 is just one component of wildfire smoke — the other is gases, including benzene and formaldehyde. Many gases chemically transform as they move from where the fire is to where you inhale them. “The atmosphere is extremely oxidizing — it likes to add oxygen molecules onto compounds,” Jen said.
Some of those compounds react faster than others, “so it depends how downwind you are,” Jen went on. That’s why people closer to a wildfire — maybe a day or less downwind — get the distinctive campfire smell, mainly from the “young” vapors and volatile organic compounds. But for people on the East Coast who were subject to the Ontario smoke several weeks ago, the smoke had to travel several days to reach places like Pittsburgh and New York, and by then the sharper-smelling compounds had transformed into new pollutants like ozone.
The AQI only measures a few specific gases that are considered “criteria pollutants” under the Clean Air Act, which means, as Presto told me, “during these fires, you could emit a whole bunch of different other gases that don’t have an AQI number.”
Instead, you can look at the PM2.5 number to get the gist of how prevalent wildfire gases are. “If your PM 2.5 is high, it’s impossible for the bad gasses to be low,” Jen said. “The way we think about it is, there’s a bunch of junk on the particle, and if the same junk’s not also in the gas, it will evaporate off the particle into the gas. They always exist together.”
You might notice by now that I’ve written little about the actual AQI number, that score that appears on your weather app and runs from zero to 500 (or, confusingly, even higher). That’s because while the AQI is a great communication tool, it doesn’t offer us much in the way of the science of wildfire smoke.
The AQI measures five different pollutants — PM2.5, ozone, carbon monoxide, sulfur dioxide, and nitrogen dioxide — with the EPA setting specific concentration thresholds for each one, as my colleague Emily Pontecorvo has explained. “If local concentrations of any one of them tick up above those protective standards, the AQI will jump from green to a more alarming color,” she wrote. “The higher the level of pollution is, the higher the AQI and the darker the color will be.”
If you want to impress your friends, though, you ought to zero in specifically on the PM2.5 concentration — again, because the prevalence of the tiniest particulates is a good indicator of all the other gunk you can assume is in the air, too. (You can find the specific PM2.5 concentration usually by clicking for more information about the AQI on your weather app or checking IQ Air’s widget.) For example, at the time of this writing, my local PM2.5 concentration is 50 micrograms per cubic meter, more than triple the World Health Organization’s 15 micrograms per cubic meter threshold for 24-hour exposure. (The EPA’s 24-hour threshold is much more lenient, at 35 micrograms per cubic meter.)
When I asked Jen how she stays sane knowing all she knows about smoke exposure, she laughed. “I have just generally become more terrified of all campfires and all barbecues, but people already think I’m weird, so I might as well add to it,” she told me.
In all seriousness, though, she told me the answer is air filters, and her confidence in their ability to work. When wildfire smoke rolled through Pittsburgh, she had two running that she moved from room-to-room with her family, as well as a whole-house air filter. “We were getting PM2.5 concentrations in our house of about 80 micrograms per cubic meter when it was 150 outside,” she said. “But with the air filter on, we could drop that down to less than eight.”
Jen pointed out, though, that many people do not run their air filters properly. Filters are rated at their highest blower level, “so for them to be effective, you need to crank them to their highest setting to get all the air through,” she said. Most people keep their filters on auto or low because they’re so loud — myself included, until I learned otherwise.
Additionally, while an air filter is a rather large appliance, it really ought to be placed in the center of your room to be the most efficient, rather than up against a wall. (Again, my bad.) “When these wildfire events happen, the most effective place for the air filter is where you are, and you have to run it loud, which kind of sucks,” Jen said. “But it is better than breathing in gross air.”