Sign In or Create an Account.

By continuing, you agree to the Terms of Service and acknowledge our Privacy Policy

Climate

How the Heat Dome Stole Christmas

You’re a mean one, climate change.

Two boys and a brown Christmas tree.
Heatmap Illustration/Getty Images

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.”

Blue

You’re out of free articles.

Subscribe today to experience Heatmap’s expert analysis 
of climate change, clean energy, and sustainability.
To continue reading
Create a free account or sign in to unlock more free articles.
or
Please enter an email address
By continuing, you agree to the Terms of Service and acknowledge our Privacy Policy
AM Briefing

Solar Stunner

On MARVEL’s market, a climate retraction, and Eavor’s geothermal milestone

U.S. Solar Installation Just Inched Past Last Year’s Tally
Heatmap Illustration/Getty Images

Current conditions: A nor’easter dumping as much as a foot of snow on parts of the Upper Midwest is set to dust New York City on its way to deliver heavier snow to northern New England • Temperatures nearly topped 90 degrees Fahrenheit in Charlotte Amalie, U.S. Virgin Islands, as America’s third-most populous overseas territory endures a record December heatwave • South Australia, Victoria, and Tasmania are all under severe fire warnings.

THE TOP FIVE

1. U.S. solar installations in 2025 set to beat previous year

It was the best of times, it was the worst of times, it was the age of smashing solar installation records, it was the age of phasing out the federal tax credits that so successfully spurred the boom in the first place. The United States added 2 gigawatts of utility-scale solar in September, bringing the total installed this year to 21 gigawatts. That, as Utility Dive noted of newly released Federal Energy Regulatory Commission data, is slightly above the 20 gigawatts installed in the same period last year. Of the 28 gigawatts of new generation the U.S. installed so far in 2025, 75% was solar, followed by wind at 13% and gas at 11%. Still, natural gas makes up the largest share of the U.S. grid’s electricity capacity, with 42% compared to the combined 31% that wind, solar, and hydro comprise. And the picture isn’t getting better. As Heatmap’s Jael Holzman wrote yesterday, the solar industry is “begging Congress for help with Trump.”

Keep reading...Show less
Yellow
Sparks

The Solar Industry Is Begging Congress for Help With Trump

A letter from the Solar Energy Industries Association describes the administration’s “nearly complete moratorium on permitting.”

Doug Burgum and Donald Trump.
Heatmap Illustration/Getty Images, Library of Congress

A major solar energy trade group now says the Trump administration is refusing to do even routine work to permit solar projects on private lands — and that the situation has become so dire for the industry, lawmakers discussing permitting reform in Congress should intervene.

The Solar Energy Industries Association on Thursday published a letter it sent to top congressional leaders of both parties asserting that a July memo from Interior Secretary Doug Burgum mandating “elevated” review for renewables project decisions instead resulted in “a nearly complete moratorium on permitting for any project in which the Department of Interior may play a role, on both federal and private land, no matter how minor.” The letter was signed by more than 140 solar companies, including large players EDF Power Solutions, RES, and VDE Americas.

Keep reading...Show less
Blue
Economy

The Future of Climate Tech Is Emerging in Some Unexpected Places

A new model from Johns Hopkins’ Net Zero Industrial Policy Lab uses machine learning to predict tomorrow’s industrial powerhouses.

Green tech and countries.
Heatmap Illustration/Getty Images, Johns Hopkins Net Zero Industrial Policy Lab

It’s no secret that China, Japan, and Germany are industrial powerhouses, with vast potential in clean tech manufacturing. So how’s a less industrialized nation with an eye on the economy of the future supposed to compete? Are protectionist policies such as tariffs a good way to jumpstart domestic manufacturing? Should it focus on subsidizing factory buildouts? Or does the whole game come down to GDP?

According to a new machine learning tool from Johns Hopkins’ Net Zero Industrial Policy Lab, none of the above really matters all that much. Many of the policies that dominate geopolitical conversations aren’t strongly correlated with a country’s relative industrial potential, according to the model. The same goes for country-specific characteristics such as population, percentage of industry as a share of GDP, and foreign direct investment, a.k.a. FDI. What does count? A nation’s established industrial capabilities, and the degree to which they cross over to climate tech.

Keep reading...Show less
Green