Burying burnt wood after wildfires could help the climate

Welcome to our weekly newsletter where we highlight environmental trends and solutions that are moving us to a more sustainable world.

I’m Nick Logan and I spent plenty of time as a kid digging holes to bury stuff. Who knew that it was a climate solution? OK, not really. But Johanna Wagstaffe and I recently looked at the possibility of burying trees killed in wildfires to lock away their stored carbon.

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This week:

• Burying burnt wood after wildfires could help the climate
• The Big Picture: Heat wave vapourizes western U.S. snowpack
• How China is charging forward with EV adoption as Canada prepares to welcome its cars

Burying burnt wood after wildfires could help the climate

Have we just been sitting on a way to prevent gigatons of carbon from being released into our atmosphere in the aftermath of wildfires? 

Kinda. Let me explain. 

It all started back in 2013, when University of Maryland climate scientist Ning Zeng was conducting research looking into the potential of burying dead wood as a means of carbon sequestration. 

Buried under a couple of metres of soil and a thick layer of clay, in a farm field outside of Montreal, Zeng and his fellow researchers uncovered what turned out to be an Eastern red cedar log that was mostly intact. 

He remembers thinking at the time that he might not even need to continue with his own burial experiment. 

“We already have the evidence,” he said in an interview with CBC Radio’s What On Earth. 

The cedar log wasn’t rotted or decayed, and Zeng says carbon dating later revealed it was more than 3,700 years old. 

Not only that, he says, it contained 95 per cent of its stored carbon. 

From that discovery, he was able to show that wood preserved in a sort of earthen bunker would not break down, because this oxygen-deprived environment prevents those fungi and microbes that normally cause biomass to decay from surviving.  

That’s why Zeng is excited about the potential carbon storage that might come with burying dead or wildfire-burnt trees.

Zeng’s finding inspired Grant Canary. He’s the CEO of Mast Reforestation, a Washington state-based company that led one of the first commercial-scale wood burial projects. 

On a ranch in Montana, his company facilitated the burial of some 10 million pounds (about 4.5 million kilograms) of trees that were burnt in a 2021 wildfire. 

He said it doesn’t include wood that could be burned for energy or milled into useful products. 

“We don’t touch that stuff,” he told What On Earth guest host Johanna Wagstaffe.

He explains that the company excavates a pit about six metres into the ground, in an area with a good amount of clay, piles in the trees and covers them with a 2.5-metre clay cap, a layer of gravel and then replaces the topsoil. 

The company also sets up sensors to ensure no carbon is leaking from the bunker, as well as a non-profit endowment to cover its maintenance for the next century. 

Carbon storage is just one part of what Mast is aiming to do. The other part is in the company’s name: reforestation.

The company was already in the business of using drones to reseed land after devastating wildfires. Canary wants to sell carbon credits for the wood Mast buries as a means of funding reforestation efforts. 

Mast Reforestation has already sold 80 per cent of the credits it created from its burial project to buyers like the Royal Bank of Canada (RBC). Canary hopes the company can eventually do this post-wildfire carbon burial on an even larger scale. 

But Alana Clason, a researcher at the Bulkley Valley Forest Research Centre in Smithers, B.C., says she has concerns about how this could affect ecosystems.

“How does that impact the nutrient cycling, the water processes, the ability for the decaying processes that need to happen?” she said. 

Questions like that aren’t lost on Zeng. He believes there needs to be a framework for carbon burial to be done responsibly and effectively. 

“It’s important, actually, to do it the right way,” he said. “It’s not just randomly digging a hole or burying something.” 

WATCH | Can we just bury our excess CO2:

— Nick Logan, with files from Johanna Wagstaffe

Old issues of What on Earth? are here. The CBC News climate page is here. 

Check out our podcast and radio show. In our latest episode: Flying emits a ton of greenhouse gases. So what’s a climate-conscious traveller to do? What On Earth‘s climate justice columnist Chúk Odenigbo tells us about his sustainable beach vacation and shares some tips on how to plan your next getaway with the climate in mind.

What On Earth drops new podcast episodes every Wednesday and Saturday. You can find them on your favourite podcast app or on demand at CBC Listen. The radio show airs Sundays at 11 a.m., 11:30 a.m. in Newfoundland and Labrador.

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Check the CBC News Climate Dashboard for live updates on record-breaking weather and current conditions across the country. Set your location to find out how today’s temperatures compare to historical trends. 

Reader feedback

Last week, Nicole Mortillaro wrote about the millions of birds killed each year by people’s cats. Karla Marsh of Fort St. John, B.C., shared a photo of her friend’s cat Bella, who lives in Kelowna, B.C., and wears a collar called Birdbesafe. “Apparently it reflects light in a way that birds can see,” she wrote. “It fits over the collar.” 

Kirsten Pendreigh of West Vancouver, B.C., sent us a scientific article showing that the collars reduced the number of birds killed by cats and brought back to their owners by two-thirds or more, depending on the time of year. The study did not account for prey that may have been left outside and not found by owners, or was entirely eaten by the cat.

The last issue also included an article about a study that found most discarded electronics still work. Several readers, including Barbara Herring of Peterborough, Ont., wrote to share similar experiences: “Last year, I was forced to discard both an e-book [reader] and a laptop computer. The computer was not big enough to hold the new Windows, and the company would no longer upgrade the older Windows versions, so they would be wide open to viruses. Similarly, the e-book [reader] runs a library app called CloudLibrary. That company produced a new version that would not run on my old e-book. And the old software stopped functioning. Your article sounds like replacement is a fashion statement on the part of the consumer. This made me angry because it ignored the engineered obsolescence that I was subjected to last year alone.”

Kean Mitchell of Crowsnest Pass, Alta., pointed out that even if your electronics aren’t working, you may still be able to extend their lifespans. “I co-ordinate a repair cafe in my community and we repair many of the items listed. There are many locations [of] repair cafes across the country. Some have volunteers who can repair these items. Some don’t, but they are a great resource for people who want to repair but don’t have the skills to make their own repairs or money to pay someone to do it for them.”

Write us at [email protected] (and send photos there too!)

The Big Picture: Heat wave vapourizes western U.S. snowpack

March is typically the time of peak snowpack for the Sierra Nevada mountain range that stretches through California and Nevada (centred in the NASA satellite images above). But this year, you can see that the snow has gotten pretty thin in the past month.

As of Monday, snowpack was on track to be the lowest on record at almost every western U.S. ski destination. That’s thanks to an intense spring heat dome — deemed “virtually impossible” without human-caused climate change — that cooked the western U.S. for most of the second half of March, breaking statewide heat records in more than a dozen states. To make matters worse, the record heat came after a winter when Colorado had already seen record-low snowfall. 

Early snow-melt has been linked to a longer fire season, as it dries out the landscape and provides more time and opportunity for fires to ignite and spread, said Jared Balik, a research scientist at Western Colorado University in Gunnison, Colo. Less snow means drier, more flammable trees — and more severe fires. Balik’s team demonstrated this by relating satellite measurements of snowpack to satellite measurements of forests before and after wildfires over many fire seasons.

Already, fire season has had a head start in both Colorado and neighbouring Nebraska, and fires have also been reported in California.

John Abatzoglou, a professor of climatology at the University of California Merced, said everything is “lining up for a potentially nasty fire season across the west … the warning signs are flashing.”

You can read more about the link between snowpack and fires here, including what this means for both the U.S. and Canada.

— Emily Chung

Hot and bothered: Provocative ideas from around the web

How China is charging forward with EV adoption as Canada prepares to welcome its cars

Hundreds of robots hum on a factory floor in Ningbo, just south of Shanghai, their long arms swooping and twisting, welding together different models of custom-ordered electric vehicles (EVs).

Robots also move briskly in the corridors delivering parts to different areas of the plant, playing elevator music to alert the few humans who work there to their presence. 

This “dark factory” — where the lights don’t need to be on for the work to be completed, such is the extent of its automation — produces Zeekr vehicles, a luxury EV line owned by Geely, the parent company of Volvo and Polestar.

With a steady, unending rhythm, the robots produce about 300,000 cars a year. The plant employs about 1,600 humans, who mostly work in robot maintenance or quality control. 

“The automated manufacturing process has obviously improved our production efficiency and helped reduce costs significantly,” said Xu Naiping, general manager of the Zeekr factory, in an interview with CBC News. “While automation does lower costs, its primary purpose is to ensure product quality.” 

The factory, along with the wider EV ecosystem being developed across China, provides a glimpse of a massive transformation of the automotive industry that could one day come to North America.

And as Canada opens the door to Chinese electric cars following a trade deal earlier this year, it’s also leaving space for this kind of Chinese innovation to enter, too.

While some say this comes with big rewards in terms of boosting EV uptake and infrastructure in Canada, others are raising concerns about the threat to North American automakers and data security.

Recliner seats and 3-minute battery swaps

Innovation has driven a boom in sales in China, with EVs comprising half of all new car purchases in September 2025. 

The adoption is evident on city streets. Green licence plates indicating an EV are everywhere. Streets are quieter, with fewer gas engines. The EVs themselves are slick, with built-in automation that allows them to, say, park themselves in an empty spot. Many of the larger, executive-style cars have recliner-style seats with built-in massage functions. 

While riding in one such vehicle, CBC News talked to a driver who goes by the surname Han. After 20 years of driving passengers around Beijing, he said he switched over from a gas-powered Buick eight months ago. 

“When I drove [my previous] car, I felt sore all over the next day,” he said in Mandarin. “This is very comfortable. My body isn’t tired anymore. And it’s all controlled by my voice.” 

The ecosystem China has built around EVs, intended to bolster manufacturing and spur adoption, is the result of sizeable (and controversial) government subsidies amounting to $230 billion US since 2009.

One beneficiary is EV maker NIO, which received a $5-billion injection from the Hefei municipal government in 2020, and is now cornering the market in battery-swapping stations — touted as a quicker way to recharge EVs. 

NIO now has upwards of 3,000 battery-swapping stations across China, including many at the side of highways.

In a parking lot in downtown Shanghai, drivers back their vehicles, one after another, into one such station, which looks somewhat like a car wash.

Among them is Cao Xingyu, who is watching a show on his phone as the battery swap takes place. 

Once his car is backed in, the floor of the structure opens up and a robot swaps out his car’s depleted battery for a fully charged one from underneath. There’s a timer on the station: the whole process takes about three minutes and then he’s back on his way to work. 

“It’s better than charging my battery because it saves more time,” said Cao, who added that he chose an EV as his first car because the local government has restrictions on owning a gas vehicle. 

While battery-swapping is an emerging competitor, traditional charging is still an expanding market. The largest provider of EV chargers in the country is TELD, which has about 900,000 terminals across China. 

TELD vice-president Wang Kunpeng likens EVs and the charging system to “two legs walking together.” 

“For EVs to develop, charging infrastructure must come first,” he told CBC News. “Once the infrastructure is well-built, the EV industry will thrive even more. This is a mutually reinforcing, complementary process.” 

The potential advantages of welcoming Chinese EVs into Canada include displaying their innovation and boosting EV adoption in Canada. EV drivers and environmental groups have long pushed for more choice that would spur competition and drive down prices.

At the same time, the Canadian auto industry is incensed by the arrival of a competitor to its own EVs, as it faces a crisis brought on by Donald Trump’s tariffs. Ontario Premier Doug Ford has also referred to EVs from China as “spy cars,” tapping into a fear that the vehicles will collect drivers’ data and hold it in China — a concern refuted by some in the industry.

Small door, big implications

While the Canadian auto market officially opened to Chinese-made EVs on March 1, it might be a while before Canadians can buy cheaper models from BYD, Chery or Geely, with exporters likely to prioritize more expensive models among the relatively small quota of 49,000.

Though no Chinese companies have outright said they’re interested in sending their cars to Canada, there are signs some are preparing to do so — including reports that BYD is looking at opening dealerships. 

Zeekr, meanwhile, trademarked its name in Canada last year. And in December, Geely opened a sprawling safety testing centre near its Zeekr plant so its vehicles can meet global standards. 

Entering the Canadian market would serve as a litmus test of sorts, said Zhang Xiang, secretary-general of the International Intelligent Mobility Association in Shanghai.

“If they can enter Canada, it proves their vehicles can meet the strictest regulatory standards in the world. With that success in Canada, it becomes much easier for them to sell cars in other countries — even markets that were previously hard to enter.” 

While the 49,000 cars about to enter Canada represent less than three per cent of the country’s market, Zhang said it is a hugely significant number in a different sense. 

“Chinese cars have already been sold in many parts of the world  — Europe, Asia, Africa — but they have never really been able to enter North America,” he said. 

“The U.S. has basically been blocking access. Now, Canada has opened a small door.” 

That door may be necessary to keep China’s EV sector going, considering domestic demand is stagnant and sales have started to dip. 

Zhang says Chinese automakers will likely not be making a profit from exporting their vehicles to Canada due to the huge investment, including establishing dealership networks and partners. But it could pay off in the long term. 

“For example, if NIO cars are seen on Canadian roads, their goal has already been achieved,” he said. “It’s an advertisement for them.” 

— Lisa Xing

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Editors: Emily Chung and Hannah Hoag | Logo design: Sködt McNalty