You’re out of free articles.
Log in
To continue reading, log in to your account.
Create a Free Account
To unlock more free articles, please create a free account.
Sign In or Create an Account.
By continuing, you agree to the Terms of Service and acknowledge our Privacy Policy
Welcome to Heatmap
Thank you for registering with Heatmap. Climate change is one of the greatest challenges of our lives, a force reshaping our economy, our politics, and our culture. We hope to be your trusted, friendly, and insightful guide to that transformation. Please enjoy your free articles. You can check your profile here .
subscribe to get Unlimited access
Offer for a Heatmap News Unlimited Access subscription; please note that your subscription will renew automatically unless you cancel prior to renewal. Cancellation takes effect at the end of your current billing period. We will let you know in advance of any price changes. Taxes may apply. Offer terms are subject to change.
Subscribe to get unlimited Access
Hey, you are out of free articles but you are only a few clicks away from full access. Subscribe below and take advantage of our introductory offer.
subscribe to get Unlimited access
Offer for a Heatmap News Unlimited Access subscription; please note that your subscription will renew automatically unless you cancel prior to renewal. Cancellation takes effect at the end of your current billing period. We will let you know in advance of any price changes. Taxes may apply. Offer terms are subject to change.
Create Your Account
Please Enter Your Password
Forgot your password?
Please enter the email address you use for your account so we can send you a link to reset your password:

I’m not normally concerned about having the perfect home — though I’m also not normally interviewing Mr. Christmas Tree himself from my living room, with a scraggly, disco-lit Nordmann fir in the background of my Zoom shot.
A high-quality tree should have “up-turning branches, so they’re not drooping,” he was telling me. “They have really nice dark green needles” and “what I would consider to be a uniform density, all the way to the top of the tree.” As he talked, my eyes slid to the corner of my computer screen, where I noticed that the topper on my rather limp and gappy specimen was also crooked.
But in the true spirit of the holiday season, Gary Chastagner — a plant pathologist at Washington State University whose extensive research on ornamental holiday conifers has earned him his jolly nickname — was generous. He added that there’s also a robust market for imperfect “Charlie Brown” Christmas trees, to the point that growers will actually avoid culling arboreal oddballs that might attract people like, well, me.
Soon, they may not have much choice. The normally cold and rainy Pacific Northwest is the Christmas tree-growing capital of the U.S., producing more than 5.4 million trees every holiday season, many of which get exported to places like New York, where I procured mine from a sidewalk lot. But back in 2021, a heat dome pushed temperatures in the Northwest to nearly 120 degrees Fahrenheit. The event killed the year’s seedlings and browned new growth on older trees — the consequences of which we’re already seeing in the form of patchy trees and shortages, and will continue to feel for years to come.
Unlike most farmed products, Christmas trees grow slowly; it can take seven to 12 years for a seedling to reach 8 feet tall, depending on the species. To ensure a consistent stock of Christmas trees for the years ahead, most growers plant the same number of seedlings each season with the expectation that there will be some amount of loss along the way.
But the heat dome was exceptional; it “killed off virtually every seedling that was planted on farms in 2021, plus some from the year before,” Sheila McKinnon, a former grower and representative of the Puget Sound Christmas Tree Association, in Washington state, told me over email. One dismayed grower told CNN at the time, “There are literally fields with hundreds of acres of dead seedlings. Just 100% mortality across the entire field.”
The timing couldn’t have been worse. Because the heat dome occurred in early summer, young trees as well as the new shoots and buds on older trees had not yet “hardened,” and were therefore especially vulnerable to the high temperatures. Additionally, prevailing drought conditions in the Pacific Northwest in 2021 limited the available groundwater to rehydrate the superheated plants. “They just shut down because they couldn’t get enough water; they literally just cooked,” Judith Kowalski, a researcher in the Christmas tree program at Oregon State University, explained to me.
Not all trees — or tree farms — were affected equally. Nordmann, Turkish, and some Noble firs mature later in the season than Douglas firs, so their tissues were softer and “just fried,” Kowalski said. Regional differences mattered, too. For example, it didn’t get quite as hot in the southern Willamette Valley in Oregon, and trees there faired a little better. But even microclimates could mean the difference between life and death. “On a hill, where there was a breeze, it made a lot of difference,” Kowalski said. By that same token, so did “a little valley, where trees didn’t get any air circulation.”
Some unlucky growers lost as much as 90% of the year’s seedlings; by one estimate, 70% of the Noble fir seedlings planted in Oregon in 2021 died. McKinnon sounded fatalistic when she described the damage. “There is no way to recover from this loss,” she said. “Some folks tried to buy more seedlings the following year,” but “instantly doubling the supply wasn’t possible.”
Call them the Ghosts of Christmas Yet to Come — because conifers take so long to mature, the effects of the 2021 heat dome will cascade into the future, causing shortages of certain trees at certain heights for a decade or more. If the typical Noble fir takes roughly 10 years to grow 8 feet, for example, then the 2021 heat dome could cause shortages of 9-foot-tall Nobles that won’t be felt until 2032.
The good news is, customers don’t usually shop for a specific species and height of Christmas tree; they just want something that looks good (or, in my case, passable) in their living room. While there might be a 9-foot-tall Noble tree shortage in 2032, customers in the market for a large tree that year will probably switch to buying a Douglas fir or some other variety, instead. Unless a grower depends heavily on one specific type of tree that was widely killed off by the heat dome, the impacts of 2021 can “kind of get absorbed” by the other stock, Kowalski said.
Of course, all that assumes that there is only one bad year.
“The heat dome is part of a pattern that we’re seeing of increased frequency of very high temperatures, much more than normal,” Chastagner told me. “2022 was one of the driest summers on record. We only had half of an inch of precipitation during the summer. And unlike other areas, the growers in the Pacific Northwest generally do not irrigate trees.”
Chastagner’s research indicates that trees in the Pacific Northwest have been so stressed by the region’s dry summers that it’s making them vulnerable to diseases like armillaria, a root rot caused by a fungus, “which we normally didn’t see.” And high temperatures don’t just affect a tree’s growth; warmer autumns also lead to worse needle retention once the tree is cut, meaning more needles on your floor in mid-December. And while one summer of extreme temperatures might lead to shortages that other stock can absorb, that stops being true when there are back-to-back heat domes. As Tom Norby, the president of Oregon Christmas Tree Growers Association, told The Oregonian after the 2021 heat dome, “One year is not a catastrophe. Two years becomes a big problem. Three years, it’s a catastrophe.”
With that in mind, Chastagner and his team at WSU — as well as Kowalski and the researchers at OSU — are exploring everything from introducing irrigation to farms (which is complicated and expensive, but also effective) to determining what conifer varieties will be better suited to a hotter future in the region. Already, the makeup of tree farms in the West is changing: In 2017, native Noble firs made up about 54% of the trees grown in the Pacific Northwest, with Nordmann and Turkish firs (which are native to Turkey and Georgia) only making up about 4%. Now, more and more growers are planting exotic Nordmann and Turkish firs due to their drought tolerance.
But don’t worry: Charlie Brown Christmas trees aren’t going anywhere. Heat or no, there will always be evergreens that require aggressive pruning or otherwise turn out a little bit, well, special. “When I get asked to give talks on what the perfect Christmas tree is,” Chastagner said with — did I only imagine it? — a kindly glance over my shoulder, “I say it’s all in the eye of the beholder.”
Log in
To continue reading, log in to your account.
Create a Free Account
To unlock more free articles, please create a free account.
France’s deadliest heat wave since 2003 killed more than 2,700 people — and possibly as many as 5,700.
More than 5,700 excess deaths were recorded in France during this summer’s record-breaking heat wave, the country’s health agency announced today. That makes the event — which ran, by the official reckoning, from June 17 to July 2 — the country’s deadliest heat wave in more than 20 years.
That’s in line with other estimates we’ve heard. EuroMOMO, a network of European public health agencies that track excess mortality, found that the continent saw more than 10,000 excess deaths during the same period. Roughly 90% of those victims were older than 65, it said. (France’s cohort seems similar: Adults older than 75 made up about two-thirds of the victims, the government said.)
These numbers are staggering — and much larger than some astute Heatmap readers might anticipate. If you read my colleague Jeva Lange’s piece on why it’s so hard to estimate heat deaths last week, she cited a much smaller estimate: Roughly 2,700 died in France during the most recent heat wave. That tally came from Christopher Callahan, an Indiana University scientist who studies climate change’s economic and social costs.
Why is there such a gap between the figures? I emailed Callahan to find out. He shared a few thoughts. First, he uses a different (and theoretically more rigorous) method than the French government: “Our approach uses a statistical relationship between temperature and mortality to explicitly quantify how many additional deaths are associated with a given day’s temperature,” he wrote. “France’s report of excess deaths is just based on how many more people died in late June compared to previous Junes - but we don’t know if those people died because of the heat or some other factor.” (Carbon Brief recently published a Q&A on these varying approaches.)
That might mean his estimate is right, in which case France has misidentified roughly nearly 3,000 deaths. But it could also mean his model, which is trained on data from 2004 to 2019, is “missing something,” he said, like a post-Covid change to public health risk. Last year, Callahan and his colleagues used a similar model to estimate deaths from France’s worst-ever heatwave, a 2003 episode that overwhelmed morgues and killed about 16,000 people. Even 23 years ago, global warming helped make that disaster larger than it needed to be: Some 6,000 of those deaths were due to climate change, their paper found.
Either estimate of the 2026 heat wave, of course, is shattering. As Jeva wrote, even the lower figure would mean the 2026 heat wave killed as many people as died in three years of French homicides. But the divergence in estimates tells us something else too: Even as climate change breaks records and alters our world, we’re never going to quite agree on where it ends and normal randomness begins.
The AI data center boom does not seem close to ending. Google’s parent company, Alphabet, announced its second quarter results this evening, and it beat Wall Street’s expectations, nearly quadrupling its profit on a year-over-year basis. Among the drivers: Its cloud business grew 82% compared to the same quarter last year. (As I’ve written, that rapid growth is helping to turn Alphabet and other hyperscalers into light industrial firms.)
The company’s AI bets seem to be paying off so far — so Google is now planning on spending even more on data centers, energy infrastructure and AI development this year than it once anticipated. It raised its estimates of 2026 capital expenditure to $195 billion to $205 billion, which is above earlier projections and twice as much as it spent in the same category last year. 2027 could be even bigger, it signaled. The company’s shares fell slightly on the news in after-hours trading, but from an energy and climate wonk perspective, the message is clear: For now, the AI demand surge transforming the power sector — and the real economy — continues to chug along.