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We read the Heritage Foundation’s Project 2025 playbook so you don’t have to.

When former President Donald Trump exited the Oval Office in January 2021, he left behind a record of environmental rollbacks unrivaled in modern U.S. history. Over his 1,461 days as commander-in-chief, Trump replaced, eliminated, or otherwise dismantled more than 100 environmental rules — at least — from repealing the Clean Air Act to allowing coal plants to dump toxic wastewater into lakes and rivers to declaring open season on endangered gray wolves.
President Joe Biden then rolled back most of the rollbacks, largely before their full impacts could be felt, which is why some experts say the most significant climate consequence of Trump’s presidency was actually the loss of four years that could have moved the green transition forward.
Had all Trump’s policies gone into effect, the nonpartisan Rhodium Group estimated at the end of 2020, they would have added an additional 1.8 gigatons of CO2-equivalent to the atmosphere by 2035 — more than the annual energy emissions of Germany, Britain, and Canada combined. But even though we never felt the full brunt of them, the medical journal The Lancet estimated that the policies undertaken during his presidency were responsible for 22,000 deaths in 2019 alone due to sharp increases in things like asthma, heart disease, and lung cancer.
Now Trump is once again the presumed Republican nominee and currently leads Biden in general election polls. Were he to win, he has a ready roadmap for building on his dubious environmental legacy: Project 2025, a 920-page document developed by the right wing think tank The Heritage Foundation.
Project 2025 isn’t just a climate plan, or course — it’s a comprehensive proposal, covering everything from immigration to abortion, education, pornography, and child labor. Though billed as a “presidential transition project,” its wishlist includes numerous actions that would require Republican control of both chambers of Congress (admittedly possible, though currently looking like a longshot) to enact. Undaunted, the document sets its sights on the Inflation Reduction Act, Biden’s landmark climate legislation, which — since the U.S. is the world’s second-largest greenhouse gas emitter — is all but necessary to keep the planet off the path to 1.5 degrees Celcius.
Here is how, precisely, Project 2025 aims to gut the IRA, shrink environmental protections, and slow forward momentum on climate change.
“‘Cheap grace’ aptly describes the Left’s love affair with environmental extremism. Those who suffer most from the policies environmentalism would have us enact are the aged, poor, and vulnerable. It is not a political cause, but a pseudo-religion meant to baptize liberals’ ruthless pursuit of absolute power in the holy water of environmental virtue … They would stand human affairs on their head, regarding human activity itself as fundamentally a threat to be sacrificed to the god of nature.”
Republicans have cannily turned “climate” into another culture war buzzword. As with Critical Race Theory before it, this rhetoric strategy divorces the climate movement from what it actually is — a disparate and diverse constellation of ideas for how to move forward in the face of the reality of human-driven global warming — and flattens it into a boogeyman that voters can easily dismiss. Rather than allow for honest debate over the upsides and drawbacks of LNG or of preserving ecosystems versus quickly building out renewables, the effect is to shut down any and all conversation before it can even start.
Project 2025 both outlines and embodies this strategy. In the foreword, Heritage Foundation president Kevin D. Roberts bafflingly characterizes climate as a “pseudo-religion”; elsewhere in the document, “climate extremism” is often lumped alongside “abortion, gender radicalism … and other woke ideas.”
For good measure, the Project 2025 playbook also uses religious metaphors to code any concern about the environment as being morally wrong or even evil. Republicans have already picked up on this cue: “We should not be bending the knee to this new religion … We are flogging ourselves and losing our modern way of life bowing to this new god of climate,” Florida Governor Ron DeSantis argued during a Republican presidential debate last year.
“The National Labs have been too focused on climate change and renewable technologies. American science dominance is critical to U.S. national security and economic strength.”
As part of the Inflation Reduction Act, the Biden administration channeled $1.5 billion to the Department of Energy’s national laboratories for “innovative research in clean technologies” and “advancing U.S. energy security.” This has been essential for “de-risking” the otherwise prohibitively expensive technological advancements necessary for reaching net zero.
Project 2025, naturally, wants none of that: “The three National Labs run by DOE’s [National Nuclear Security Administration] should continue to focus on national security issues,” Bernard McNamee, the former commissioner of the Federal Energy Regulatory Commission under Trump, writes in the document’s chapter on revamping the department. Additionally, the “ill-advised attempt to expand the National Science Foundation’s mission from supporting university research to supporting an all-encompassing technology transition” (a mischaracterization) should be reconsidered, and “there should be a review to measure, prioritize, and consolidate DOE programs based on a range of beneficial factors, including degree of relationship to national security.” (While addressing the nation’s climate goals is an NSF priority, it is not done at the expense of supporting university research. Also, the current director of the NSF is a Trump appointee).
The Trump administration was memorably hostile toward science, and there are no signs he’ll change his heart during a second term; he’s already vowed to revive “Schedule F,” which reclassifies many government researchers and scientists as at-will employees, making them easier to “clean out” if they “frustrate his policies.”
Still, it does appear that the Heritage Foundation sees some usefulness for scientists: “The next administration should fund the design, development, and deployment of new nuclear warheads, including the production of plutonium pits in quantity,” Project 2025 says.
“The next conservative Administration should rescind all climate policies from its foreign aid programs (specifically USAID’s Climate Strategy 2022–2030 ); shut down the agency’s offices, programs, and directives designed to advance the Paris Climate Agreement; and narrowly limit funding to traditional climate mitigation efforts.”
The United States is the single greatest historical contributor to climate change, but Project 2025 has little sympathy for nations that might be suffering as a result. “The [Biden] administration has incorporated its radical climate policy into every USAID initiative,” Max Primorac, a Heritage Foundation research fellow, complains in the document. “It has joined or funded international partnerships dedicated to advancing the aims of the Paris Climate Agreement and has supported the idea of giving trillions of dollars more in aid transfers for ‘climate reparations.’”
Notably, Biden has not promised climate reparations — despite Trump and other Republicans’ frequent claims to the contrary. And while climate change is “a top driver of humanitarian need and human suffering, particularly for the poorest countries,” according to the United Nations, the former president slashed $200 million from environmental initiatives in his 2019 budget, including investments to help nations move away from heavy carbon-emitting industries.
“Taxpayer dollars should not be used to subsidize preferred businesses and energy resources, thereby distorting the market and undermining energy reliability.”
Among the programs and offices Project 2025 wants to eliminate (or at least substantially reduce) funding for are: the Climate Hub Office; the Clean Energy Corps, the Office of Domestic Climate Policy; the Office of Energy Efficiency and Renewable Energy; the Grid Deployment Office; the Interagency Working Group on the Social Cost of Carbon; the Conservation Reserve Program; the Office of Clean Energy Demonstrations; the Office of Environmental Justice and External Civil Rights; “the activities of EPA advisory bodies”; the Office of State and Community Energy Programs; ARPA-E; the DOE Loan Program Office; the Office of Fossil Energy and Carbon Management; “grant programs for things like energy storage and the testing of grid-enhancing technologies”; “carbon capture utilization and storage programs”; the Greenhouse Gas Reporting Program; the Bureau of Energy Resources; the Office of Emergency Management; the National Flood Insurance Program; and the National Oceanic and Atmospheric Administration (more on that below).
“Support repeal of massive spending bills like the Infrastructure Investment and Jobs Act and Inflation Reduction Act, which established new programs and are providing hundreds of billions of dollars in subsidies to renewable energy developers, their investors, and special interests, and support the rescinding of all funds not already spent by these programs.”
Project 2025 opposes green subsidies across the board. It’s especially twitchy about programs aimed at helping “the private sector deploy and market clean energy and decarbonizing resources” — because, supposedly, the “government should not be picking winners and losers.”
Still, while it’s uncertain how much damage a Republican president could do to the Inflation Reduction Act without the help of a conservative-controlled Congress, Project 2025 makes clear there are lots of places conservatives can chip away, including going after “subsidies of electric vehicles,” “subsidies for transit expansion,” and subsidies renewables like wind and solar. Additionally, the Office of Energy Efficiency and Renewable Energy “is a conduit for taxpayer dollars to fund progressive policies, including decarbonizing the economy and renewable resources.” That won’t do: “Eliminate EERE,” it says, or otherwise defund it.
“While individual investors may prefer to invest in ‘green’ companies, ‘woke’ companies, or companies with greater board diversity, and may even be willing to sacrifice some financial gains to do so, the question relevant to [the Department of Labor] is whether, and under what conditions, fiduciaries should be permitted to follow this path as well.”
If we’re being honest, though, isn’t the whole “ESG is evil” thing kind of last year?
“The new Administration’s review will permit a fresh look at past monument decrees and new ones by President Biden. Furthermore, the new Administration must vigorously defend the downward adjustments it makes to permit a ruling on a President’s authority to reduce the size of national monuments by the U.S. Supreme Court.”
President Trump was responsible for the most significant reduction in protected land in U.S. history. When he took office, Biden reinstated the protections — mainly in Utah’s Bears Ears and Grand Staircase-Escalante. Project 2025 prioritizes rolling back the rollback of the rollback, but making it stick by taking the case to the conservative-controlled Supreme Court.
The former acting Bureau of Land Management director under Trump, William Perry Pendley, writes in the section on reforming the Department of the Interior that Biden is “abusing National Environmental Policy Act processes, the Antiquities Act, and bureaucratic procedures to advance a radical climate agenda,” and directs an incoming Republican president to “seek repeal of the Antiquities Act.” Republicans and Democrats alike have used the Antiquities Act over the decades to protect scenic and culturally significant places, including the Grand Canyon, Zion, and Olympic National Parks. Any Supreme Court ruling could effectively curb the ability of future presidents to protect scenic and culturally important parts of the country.
“NOAA consists of six main offices ... Together, these form a colossal operation that has become one of the main drivers of the climate change alarm industry and, as such, is harmful to future U.S. prosperity.”
Thomas F. Gilman, writing on reforms for the Department of Commerce, gets right to the point: “Break up NOAA.” The agency’s “emphasis on prediction and management seems designed around the fatal conceit of planning for the unplannable,” he claims, adding, that “its current organization corrupts its useful functions.”
In practice, that would mean the National Weather Service should “fully commercialize its forecasting operations,” since “Americans rely on weather forecasts and warnings provided by … private companies such as AccuWeather,” Gilman writes. It’s a notable shoutout: Barry Lee Myers, the former CEO of AccuWeather, was briefly a Trump nominee to, uh, run NOAA.
Gilman has ideas for the Office of Oceanic and Atmospheric Research, too, writing that it “provides theoretical science” and is “the source of much of NOAA’s climate alarmism,” and should therefore be “disbanded.” Data from the National Hurricane Center is further ordered to be “presented neutrally, without adjustments intended to support any one side in the climate debate.”
Echoing the Trump administration’s hostility toward the sciences, he goes on to allege that “scientific agencies like NOAA are vulnerable to obstructionism … if political appointees are not wholly in sync with administration policy” — never mind that disagreement is one of the most essential parts of scientific research and progress.
But don’t worry: Project 2025 also calls for an elevation of … “the Office of Space Commerce.” Phew.
Republicans are going to make dishwasher cycle times a culture war or die trying.
Project 2025 dictates that “Congress should reform the Natural Gas Act” to “eliminate political and climate-change interference in DOE approvals of liquefied natural gas exports.” Currently, the DOE must decide if it is in the “public interest” to allow LNG exports to non-free trade agreement countries — the only part of the permitting process that could even potentially consider the export terminal’s impacts on frontline communities or their effect on climate change more largely
How? By narrowing the Natural Gas Act to only consider “whether there is a need for the natural gas” and the “impacts of the actual pipeline itself, not indirect upstream and downstream effects.”
The next Republican president should “immediately” reopen the Arctic to drilling, expand the controversial Willow drilling project, max out offshore oil and natural gas lease sales, and restart coal leasing in Wyoming and Montana, the authors write.
Mandy Gunasekara, Trump’s former Environmental Protection Agency chief of staff, details almost gleefully how the agency’s regulatory powers will be dismantled, from preventing downwind states from “over-controlling” their upwind neighbors to loosening car emission standards and beyond.
Since 1968, California has been allowed to set stricter vehicle emission limits than the federal government thanks to a Clean Air Act waiver; other states are welcome but not required to opt in. As president, Trump revoked California’s right to include greenhouse gases in its emissions considerations and barred other states from adopting its criteria. That seems like it’s back on the table — and could be headed to a consequential decision in the Supreme Court.
Project 2025 proposes a fleet-wide average of 35 miles per gallon, far below current benchmarks of 49 miles per gallon by 2026 and 58 miles per gallon by 2032.
There is no question that the management of wild horses and burros is a big problem for the Western United States. But Project 2025 waves off strategies like “expanded adoptions” and “more effective use of fertility controls” as “not enough,” writing that “Congress must enact laws permitting the BLM to dispose humanely of these animals.”
Project 2025 aims not only to gut the Endangered Species Act, but also to “direct the Fish and Wildlife Service to end its abuse of Section 10( j) of the ESA,” which is being used to reintroduce grizzly bears in Washington state and wolves in Colorado.
Project 2025 says that “the Department of Energy should end the Biden Administration’s unprovoked war on fossil fuels, restore America’s energy independence, oppose eyesore windmills built at taxpayer expense, and respect the right of Americans to buy and drive cars of their own choosing, rather than trying to force them into electric vehicles and eventually out of the driver’s seat altogether in favor of self-driving robots.” But as far as roadmaps go, that doesn’t look much like a way forward — it looks like holding back the inevitable. If that’s the case, then self-driving robots start to look good.
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Senator Martin Heinrich’s new bill, which would make it easier to hook up new power plants in much of the U.S., is an encouraging sign for bipartisan permitting reform.
An important part of a bipartisan permitting reform deal may be falling into place.
Senator Martin Heinrich of New Mexico introduced a bill on Thursday that would make it easier for new power plants to hook up to electricity markets across the country.
The legislation, which applies to all types of generation, would allow new power plants to connect to the grid without waiting for the arduous technical studies — and without paying the exorbitant equipment upgrade fees — now required in much of the country.
Instead, the bill would let power plants opt into a much faster safety study and offer what it cheekily dubs “basic access service for energy-only delivery” — that is, BASED service — to the local electricity market.
A similar approach is already used in Texas, which has added more new generation than any other U.S. power market in recent years. In effect, Heinrich hopes to bring that cheaper, faster, and more laissez-faire method to the rest of the country.
“As electricity demand grows, we need to find better, faster ways to add more affordable, reliable power to the grid,” Heinrich said in a statement. “Right now, unnecessary delays are slowing projects that could help lower energy costs and deliver the low-cost energy we need.”
Outside experts have pushed for wider adoption of Texas’s approach, which is dubbed “connect and manage,” for some time. Although Heinrich’s proposal would apply to all kinds of power plants, Texas has been particularly successful at bringing new solar, battery, and natural gas power plants online in recent years — and it has done so while keeping connection costs lower than other markets.
“We’re seeing the success of the free market in Texas,” Sarah Toth Kotwiss, an electricity researcher at the energy and climate think tank RMI, told me, noting the state has added far more generation in recent years than much bigger and more populous U.S. grid zones. “They’re leading the way, and replicating that free market attitude could go a long way in the rest of the U.S.”
More broadly, the proposal is the kind of legislation that would slot into the bipartisan permitting package expected later this year — and as soon as next month. Heinrich’s proposal may be a sign that the senator, the ranking Democratic member of the natural resources committee, takes the prospect of reaching a deal seriously.
Across much of the country, a new power plant can only connect to the power grid after the local grid operator completes what’s called an “interconnection study” — an intensive technical account of how that new plant will affect the overall system.
These studies examine a slew of worst-case scenarios, simulating how the plant would behave at full capacity under extremely congested grid conditions, such as during a heat wave. The new plant’s developer is then required to pay for the grid and transmission line upgrades that would allow their project to run at full blast at those moments of maximum stress.
In theory, that approach maximizes the amount of money a developer can make on a new power plant. But because the grid is a big, interconnected system, that method can cause long delays and rippling costs in practice. In one case, a new 300-megawatt plant in North Dakota near the Canadian border could not start operating until it paid nearly $3 million to upgrade power lines and transformers in Missouri — more than 1,000 miles away.
And because interconnection studies try to model a proposed power plant’s influence on the power grid for years into the future, a single cancellation can have a cascading effect. When a power plant pulls out of the interconnection queue, every project in line behind it sometimes needs to be studied again, causing delays and costs to spiral even further.
In one famous example, a solar and battery plant in Maryland was initially told that it needed to pay for $1.25 million to connect to the local grid. But after a series of cancellations and new rounds of study, that figure was revised — to nearly $72 million. The solar project got shelved.
While interconnection queues used to be relatively quick, the process of hooking up a new power plant to the grid can now regularly take eight years, Kotwiss said.
As I discussed with the electricity researchers Tyler Norris and Claire Waymer on Heatmap’s podcast Shift Key in 2024, these lengthening wait times have changed how power plant developers behave. Many developers now “spam the queue,” filing study requests for any project that they could ever conceivably want to build. That has led delays to spiral even further.
The end result of all this spamming is that the total capacity of power plants asking to connect to the grid now exceeds the size of the U.S. grid itself. At the end of 2025, more than 2,000 gigawatts of new generation or storage projects were waiting in interconnection queues, according to the Lawrence Berkeley National Lab. The country’s operating power plant fleet is only about 1,400 gigawatts.
To be clear, most of those proposed projects will never be built — they are hypothetical queries submitted by developers who are trying to claim a place in line. Yet even switching on a small set of plants could transform the power grid.
These long wait times aren’t the norm in Texas. In the Lone Star state, it takes less than four years to bring a new plant online.
That’s because new power plants in Texas can hook up to the grid — and start generating power — as soon as the local grid operator completes a more rudimentary engineering and safety study. Then during moments of peak grid congestion, power plants must curtail their own generation, reducing their electricity production to the level that the overall grid can support. While this means that a given solar farm or natural gas plant might not run at full bore all the time, the overall approach gets that plant up and running much sooner, allowing it to sell energy into the grid during most of the year.
Heinrich’s law would order electricity markets and grid operators to make this faster option available to new power plants across the country. It would let power plants opt into receiving a much simpler and faster study, one that checks only that adding the new power plant will be safe for the immediate grid.
A power plant that opts into the new BASED service would still have the option of entering the traditional interconnection queue. Doing so would let it eventually increase its operation over time, paying for grid upgrades so that it can participate in capacity markets and other auctions.
Expanding Texas’s approach to other states could help cut costs for electricity consumers by bringing more energy onto the market faster, Kotwiss said. Even in complicated power markets that include additional auctions — for capacity, for instance, or reliability — energy still makes up most wholesale costs.
It could also help ease the strains on the grid — especially in congested regions like the Mid-Atlantic — caused by artificial intelligence data centers and new factories.
The Texas-inspired technique could help the solar and battery industries, because it keeps a given project’s upfront expenses low and allows those technologies’ low costs to dominate their economics. Solar has boomed in Texas in recent years, and the state now has more utility-scale solar installed than California does.
But the BASED approach would likely help natural gas plants and other forms of newer, cheaper generation, too, because it strengthens new entrants as compared to incumbents. Jacob Mays, a Cornell engineering professor, has studied how slow and wonky interconnection queues can prevent electricity markets from functioning well. The existing interconnection approach used in most of the country “amounts to a significant barrier on new entry to new generation,” he told me, and it has “some anticompetitive impacts.”
Heinrich has said that he plans on introducing more electricity system reforms soon, including a bill to push utilities to adopt technologies that get more capacity out of their existing equipment.
I think it’s an encouraging sign for permitting reform advocates that ranking Senate Democrats are advancing these kinds of technology-neutral power market bills. An eventual deal will likely ultimately rest on Democrats’ willingness to support policy like this — and whether they can strike a deal with Republicans to rewrite parts of long-standing environmental or permitting laws, including the National Historic Preservation Act and Clean Water Act.
But just as importantly, it will depend on Republicans — and the White House — reining in President Trump’s powers to kill energy projects by fiat. With this bill, Democrats are suggesting they’re willing to be, well, a little BASED. Whether the president will join them remains to be seen.
Your mileage may vary — but you’ll probably want to keep the outdoor runs to a minimum.
I became a runner in the spring of 2020. My run streak was my sourdough starter. Those were the Wild West days of respiratory spray warnings, when I’d get dirty looks from strangers even if I passed them while wearing my Under Armour running mask. But I wasn’t about to let a deadly pandemic — much less the wildfire smoke that descended on New York that fall — get in the way of logging my miles.
These days, I am at least a little bit older and wiser. I’ve also learned a lot about wildfire smoke in the interim — how it kills more than 20,000 people in the U.S. every year, how there’s a lot of freaky stuff in it that you don’t want in your body, and how there’s no safe threshold for exposure. But while it’s clearly a bad idea to go for a run right now if you live in Milwaukee, where the air is literally yellow due to the fires in Minnesota and Ontario, it’s maybe less clear if you’re somewhere where the AQI is still only moderate or “unhealthy for sensitive groups.” Do you really, actually need to skip your run in those conditions? Can you just go to the gym instead?
At the end of the day, everyone should make decisions based on their own risk tolerance. But John C. Quindry — a professor of integrative physiology and athletic training at the University of Montana, who described his team as “first to the party” when it comes to understanding the risks of exercising in the smoke — said his research shows that not only is exercising in the smoke hazardous to otherwise healthy individuals, there’s also a class of people for whom it might be extra dangerous, and they might not even know it.
Our conversation has been edited and condensed for clarity.
Why is exercising in the smoke worse than, say, commuting in the smoke?
If you exercise, you take more breaths per minute, and you take deeper breaths, so the total volume of air you breathe at a given time is greater.
Inhaling wildfire smoke is sometimes compared to smoking cigarettes. Some back-of-the-envelope math puts a run in Chicago this morning at the equivalent of smoking a couple of cigarettes, which sounds pretty minimal. Why take this seriously?
We don’t know for sure that when you exercise outside, it’s equivalent to, in this case, smoking a couple of cigarettes or a pack. We’ve been working for years trying to actually figure out how bad it is, and we just don’t know.
One of the things that complicates this is that not all smoke is created equal. Wildfire smoke in the West is different from wildfire smoke east of the Mississippi, where there are many different types of vegetation. And separately, if a wildfire consumes a house and all the plastics, organic solvents, and things in the roof, that’s certainly worse than just biomass burning — and that is all separate from cigarette smoke. So the chemicals that you inhale are part of it; it’s not just the particulate.
I don’t think it’s inappropriate to say we know how much particulate a filtered cigarette is going to deliver on a puff-by-puff basis and try to equate it to inhaling wood smoke or being downwind of a fire event. Those back-of-the-envelope calculations can make it one-to-one. But what is the impact on health? We don’t know.
Going back to something you said, is smoke in the West or East worse? Why?
We don’t really know, and one reason is that smoke that starts in the West goes east. There are some really good studies that look at the rates of emergency room visits and deaths downwind of fires. You can apply some pretty fancy math, and it’s clearly demonstrated by multiple research groups that whatever the source of the smoke is, there are people who are extra sensitive to it, and they show up in the emergency room more frequently. Tragically, to a smaller degree, they also occasionally die more frequently.
But if we put those data aside and say, “What does the smoke look like from Western biomass versus Eastern biomass?” We know the Western biomass, at least this time of year, is much drier. And when it’s dry, it tends to burn a little “cleaner,” which is to say, if you were to take a certain number of grams of pine wood — which burns fairly cleanly — how much PM 2.5 do you get? You’re going to get a higher PM 2.5 from wet wood. That’s the effect when you start to move to the middle or eastern part of the country. Deciduous trees, even when they’re dry, put out more PM 2.5 unit by unit.
Now, is that worse for the body in the short or long term? We really don’t know. Once you breathe in the smoke, it’s pretty easy to measure what’s in the blood: You just take a blood sample before and after the exposure. You can try to gauge how bad the smoke is by looking at what appears in the blood. Do you get oxidative stress? Do you get inflammation? Is there something else there? Has it changed metabolism?
We also look at exhaled breath condensate. It’s the immune cells, which are the first line of defense when you’re exposed to particulates, that are really sounding the alarm. In some people, that alarm gets sounded more than in others. So we’ve been trying to figure out what are these subtle but important biochemical and physiologic signals? How do they go together? They tell us how bad the smoke is, but it’s taken us years to unfold this story.
I saw in your 2025 study that half of your participants had a heightened response to physiological stress, and that you selected them for that reason. I was hoping you could tell me what a “heightened response to physiological stress” means and why it was important to include those candidates.
This is critical. Let me give you the backstory. When we would do these studies, we would put participants in the lab and burn Western locally sourced pine dried out to 15% humidity. We’d burn it carefully, measure the dose of PM 2.5, and have people breathe it in. We’d conduct studies before and after exercise, whether on a bike or a treadmill, and we varied the intensity and duration. And we didn’t find very much when we looked at the blood and exhaled breath condensate for how well the blood vessels constrict or how reactive the body’s autonomic nervous system was in controlling cardiovascular function. We’d find subtle changes, but statistically speaking, we could never really draw firm conclusions.
But we would notice that, on a person-by-person basis, there would be notable spikes in what we were looking at. We’d see, “Oh, these three or four people really seem to have this notable response, and everybody else really didn’t.” We’d publish our studies and essentially say, “Yeah, we didn’t find much.” It was honest data, and people believe it when you publish negative data that says, “We went through that much trouble, we spent $100,000, and we found nothing.” But we found these people who were a little bit different than the others.
So we’d sit around and spitball. These were normal people, by the way; we were not taking asthmatics or people with [chronic obstructive pulmonary disease]. They were not diabetic. There are people we know full well will have an exaggerated response, and we didn’t look at any of them. We looked at what are called “apparently healthy people” — the people who go to the physician and are told nothing’s wrong with them.
My doctorate was not in exercise science; it was in biomedical science, from a medical school environment. Somewhere along the line, I was exposed to something called the cold pressor test. It has been around longer than both of us. Physicians 80 years ago would have somebody come into their lab or clinic, and they’d say, “Hey, we’re going to put your hand in a bucket of ice water for two minutes and see what that does to your blood pressure.” It almost sounds like a fourth-grade sleepover prank for the first kid to fall asleep.
But we started doing the test, and we took a pretty conservative approach, meaning that if we put someone’s hand in the ice water and their systolic blood pressure — that’s the top number, 120 over 80 is sort of the high end for good blood pressure — and if their systolic number went to at least 20 millimeters of mercury, then we call them cold pressure test positive, or CPT positive.
None of these were people who were hypertensive. They had normal blood pressure. Nothing was wrong with them as far as their medical team could observe. But how many of these [CPT positive] people are sitting around? If you take the average population, 10% to 15% will be cold pressor test positive. We don’t necessarily know if this is a bad thing. It may be contextual, but these are people we can verifiably measure with something as simple as a blood pressure cuff and a bucket of ice water. You can verify their physiology is more reactive within a couple of minutes than someone else’s.
We suspected that if we took these people and then exercised them in the smoke, they would have an exaggerated response compared with people who weren’t CPT positive. And so that’s what we did, and that’s what we found.
That’s fascinating. So the practical takeaway is, unless you’ve done this test yourself, you don’t know if you’re one of these people who’s particularly reactive to wildfire smoke?
You have to always be careful that you don’t make big, broad, blanket applications from one study. We would need to confirm or refute it with additional studies, and that’s a matter of getting grant money and conducting those next-generation investigations.
But here’s something we can glean: We know that people who have an exaggerated response to a cold pressor test are more likely to have hypertension. And they’re more likely to have it earlier — instead of getting high blood pressure at 50, 60, or 70, they’re going to get it at 30 or 40. We know they’re more likely to eventually suffer from heart failure; it seems to develop more in people who have this sort of reactive response. While the cold pressor test response is not predictive in and of itself of anything — future diabetes, heart failure, heart attacks, hypertension, none of that — people with all of those conditions are more likely to be cold pressor test positive.
The way I would take it is, if you are somebody who is not in great health, isn’t fit, or if you have creeping blood pressure or a family history of heart disease, blood pressure, or metabolic derangement like diabetes, you are the kind of person who needs to be a little bit more careful [in the smoke].
Is there an air quality level at which you would tell a young, healthy person “Don’t go for your morning run?”
An educated guess is the best we can do right now. Every study is a brick in the bigger metaphorical wall of understanding this. What we can say is: If you are young and apparently healthy, the threshold would be maybe even up into the “unhealthy for sensitive groups” number. They’re probably okay. But then again, how hard are they working? How long are they outside? If you’re working very hard, your ventilatory rate is much, much higher. And how long are you staying out? What is the long-term impact year after year?
There are epidemiologic studies that can demonstrate that if you’ve lived downwind from major wildfire events for decades, it’s going to impact your health. That’s not debated. But what is the short-term impact? We don’t know.
Indoor air pollution is a major issue during these events, too. Would you advise someone to skip the gym on a particularly smoky day?
When it’s smoky outside, it makes sense to say, “Let’s just stay indoors.” But then the question is, is some of that smoke getting indoors? Sure enough, it is. Then the question is, how much? And the answer is, it depends on the air handling systems in the building; how many people are coming in and out; whether the windows open; how many doors are there; are they left open; what are they using to heat and cool the place; do they have high-volume HEPA filtration; and are they changing that filtration?
But let’s dial back. We have two ends of a spectrum. You have a leaky building. Doors are open. Windows are open. Lots of people are coming in and out. In that scenario, the air inside is only about 20% or 30% better than the air outside. And that’s not very good.
But then let’s go to the other end of the spectrum, to a building that is being kept shut. They’re controlling who can come in and out, and there are two sets of doors to help buffer that. Which is better in a smoky situation? The places with the HEPA filtration, high-volume air turnover, and where they change the filters. But in that case, you’re still going to have 25% of that particulate matter inside, even if you can’t perceive that it’s there. That’s not good news.
What are the health risks? How can I protect myself? And will my plants be okay?
If you live anywhere near the Great Lakes or Mid-Atlantic (or certain parts of the Mountain West), odds are it’s smoky where you live. Wildfires raging in western Ontario are sending smoke cascading south and east across the U.S., prompting widespread air quality alerts affecting millions of Americans.
The good and — very bad — news is that we’ve been here before. Here’s a look back at some of Heatmap’s coverage from the summer of 2023, when smoke produced by forest fires in Quebec blanketed 128 million people in a murky haze and turned the New York City skyline an ominous shade of orange.
One day — even just one hour — of smoke inhalation can exacerbate pre-existing health conditions and increase an individual’s chance of premature death by 12%. To stay safe, Jeva Lange recommends avoiding prolonged outdoor exposure and masking up when you go outside.
Wildfire smoke is full of tiny pollutants that can leak into your apartment even when the windows and doors are sealed tight. That’s where air purifiers come in, Matthew Zeitlin writes.
Tinted skies are now a rare, remarkable event. But decades ago, before targeted policy interventions, this was everyday life for New Yorkers. Here’s Jeva with more on the legacy of the Clean Air Act.
Before you step out for a run, read Emily Pontecorvo’s guide to what the Air Quality Index is and isn’t telling you.
People should not inhale smoke because of its dangerous health effects. But plants, interestingly, may actually thrive. Allow Jeva to explain.