The good in bad

Remember all those stories you read about how global warming was increasing the number of forest fires in Alaska, and those forest fires burning deep into soils were, in turn, accelerating warming by adding more carbon dioxide (CO₂) to the atmosphere?

“Spike in Alaska wildfires is worsening global warming, US says,” the Guardian headlined in 2016.

“The increasing frequency of big fire seasons (in Alaska) is also a heavy contributor to carbon dioxide emissions, creating a positive feedback loop wherein global warming begets more warming,” Audubon magazine reported in 2019.

This was conventional wisdom.

“…The burning of trees, dead biomass and soil sends huge pulses of carbon to the atmosphere,” wrote Carly Phillips, the Kendall Fellow for Protecting Carbon in Alaska’s Boreal Forests with the Climate & Energy program at the Union of Concerned Scientists at that time.”In carbon-rich areas like boreal forests, arctic tundra, and peatlands, the impact of fire on climate change is further amplified.”

Only now come indications that at least when it comes to the boreal forests of Alaska, burning them down might not be so bad. Over the span of decades, it is even possible those fires might help reduce carbon emissions and slow climate change.

“…The deciduous trees replacing burned spruce forests more than make up for that loss, storing more carbon and accumulating it four times faster over a 100-year fire interval,” Phys.Org, a website for science, reported in summary. “The study, led by a team of researchers at the Center for Ecosystem Science and Society at Northern Arizona University (NAU), suggests that these faster-growing, less flammable deciduous forests may act as a stabilizing ‘firebreak’ against escalating fire patterns and nutrient loss in the region.”


Science is complicated. Open-minded scientists who go looking for data to determine how the world around us works don’t always find what they expect.

When Michelle Mack from NAU joined researchers from the University of Alaska Fairbanks, Auburn University, the University of Florida and the University of Saskatchewan tracking Alaska black spruce forests going up in flames in 2004, she was pretty sure of what she’d find.

“In 2005, I thought that there was no way these forests could recover the carbon they lost in this fire,” the biology professor confessed to the NAU News.  “The literature is full of papers suggesting deeper, more severe fires burn more carbon than can be replaced before the next fire.”

That isn’t, however, what the Alaska research found.

“….Not only did we see (new) deciduous trees make up for those losses, they did so rapidly,” said Mack, who ended up as the lead author on a peer-reviewed study published in “Science” yesterday.

The paper would indicate the carbon freed in these fires is offset by the carbon sucked up by new, leafy, green vegetation in the regrowth that follows. The study suggests it is possible the net effect is that more carbon is taken out of the atmosphere over the course of time than the fires add during their short, flaming existence.

“Severe burning of organic soils shifted tree dominance from slow-growing black spruce to fast-growing deciduous broadleaf trees, resulting in a net increase in carbon storage by a factor of five over the disturbance cycle,” the scientists wrote. “Reduced fire activity in future deciduous-dominated boreal forests could increase the tenure of this carbon on the landscape, thereby mitigating the feedback to climate warming.”

Not only that, a warmer Alaska might be making it more likely that the fires that consume the state’s boreal spruce forests do so in such a way so as to encourage the growth of CO₂ sucking deciduous trees.

“In boreal forests,” the team of scientists concluded, “climate warming is shifting the wildfire disturbance regime to more frequent fires that burn more deeply into organic soils….we found that shifts in dominant plant species catalyzed by severe fire compensated for greater combustion of soil carbon over decadal time scales.”

Bigger debate

The fate of Alaska’s boreal forests is part of a much bigger debate about the function, or not, of “positive feedback loops” in the carbon cycle.

Positive feedback loops are those that fuel reactions rather than stabilize them.

“A positive feedback loop increases the effect of the change and produces instability, as the National Oceanic and Atmospheric Administration (NOAA) describes this process. “In climate change, a feedback loop is something that speeds up or slows down a warming trend. A positive feedback accelerates a temperature rise, whereas a negative feedback slows it down.

The thinking before the latest study was that the Alaska fires created a positive feedback loop to accelerate warming. The new study indicates the negative feedback loop that follows fire could alter everything.

But it’s not that simple either because all plants eventually die, and “after plants die, they decay, releasing the carbon to the atmosphere,” the Earth Observatory of the National Aeronautics and Space Agency (NASA) notes.

Big plants or small plants, 5,000-year-old bristlecone pines or short-lived bamboo, they all die.

“The faster a plant grows, the more carbon dioxide (CO₂) it will use up per second. (And) by that measure, bamboo might be the best at sucking up CO₂. However, fast-growing plants tend not to live long and when a plant dies, all the carbon in the plant is broken down by insects, fungi and microbes and released as CO₂ again,” write Luis Villazon at Science Focus. 

“So the plants that are considered the most adept at removing CO₂ from the atmosphere and locking it up are the longest-living ones, with the most mass – hardwood trees. It’s all temporary though. Eventually every plant returns all the carbon dioxide it uses back to the atmosphere.”

And, of course, land plants aren’t the only plants on the planet. There is more plant life in water, which covers about 71 percent of the planet’s than on land, and the ocean uptake of CO₂ by plants, which use CO₂ as the food of photosynthesis no matter where they grow, removes CO₂ from the atmosphere.

Plus the water itself works like a sponge for CO₂.

When winds mix water (H2O) with air loaded with CO₂, the two react to create carbonic acid (H2CO3) that mixes with the water. As a result, the water becomes more acidic.

The rate at which the ocean can absorb CO₂ and how much is another big global warming question as is that as to what the slow but steady acidification of the ocean does to marine ecosystems.

“Oceanographers started out wanting to know if the ocean was keeping up with the amount of carbon dioxide people are putting into the atmosphere,” Holli Riebeek of NASA’s Earth Observatory has observed. “Instead, they found that people aren’t the only players changing the ocean carbon cycle.

“Over decades, natural cycles in weather and ocean currents alter the rate at which the ocean soaks up and vents carbon dioxide. What’s more, scientists are beginning to find evidence that human-induced changes in the atmosphere also change the rate at which the ocean takes up carbon. In other words, it turns out that the world is not a simple place.”

And that might be an understatement.










Click to access PSA_analyzing_a_feedback_mechanism.pdf



6 replies »

  1. And I’m not convinced of this global warming story. Yep! I admit it. I’m a denier but maybe it’s because i’ve dug a little deeper than what the warmers are telling us. Manhattan was supposed to be under water by the year 2000 along with some islands in the Philippines and lets not forget about all the snow from the top of the Himalayas. That was supposed to be gone by the year 2000. And when they tell you that a huge amount of ice has broken free near the south pole and is floating north they conveniently forget to tell you it does that every year Btw, at the time of the dinosaurs the estimate is there may have been as much as 5 times the co2 in the atmosphere as now. While there probably is some snow melting in the northern hemisphere, it is accumulating in the Southern Hemisphere. Personally, I think this warming story is bull do do to put it politely.

  2. A truly green revolutionary technology. Other aspects aside, the vortex bladeless wind turbin can be scaled from 3 to 100 ft. Adapted to hydro power , no moving parts, except a switch or 2. Question of CO2 is moot. Who thinks they can stop a million underwater volcanos , spewing megatons of CO2 , from warming and acidifying the oceans of the world. How do you think all those hydrates got down there? Think you need to rethink your biases 😉
    PS : Largest active volcanic field in the world is under W Antarctica ice!!
    That you didn’t know is not an accident.

  3. There are some in the environmental movement who are starting to see that the last few decades of environmental science have been filled with misinformation, science has a way of rooting that out and some people actually believe in science and don’t merely pay it lip service. Cutting down trees isn’t inherently bad, if we can lock up the carbon molecules on a long term basis (hundreds of years) we might be able to affect a level of change to atmospheric carbon levels. There are homes, buildings, and log cabins that were built hundreds of years ago still standing…all that carbon is sequestered. When a forest is logged and old growth removed it allows new growth and new carbon sequestration to occur, by locking up old growth forests we are complicit in increasing atmospheric carbon. Spruce is a particularly good wood for building timbers, it bends but does not break the way other timbers might…there’s a reason the largest aircraft ever built was called the spruce goose. Logging is a sustainable practice of forest management, one reason the US Forest Service is under the USDA. Instead of closing out forest of to allow them to burn and release their stored carbon into the atmosphere, we should be capitalizing on this renewable resource.

  4. Okay I see now the old reply block is the proper one.

    On the topic of the tree life cycle: I have the opinion that standing beetle killed trees should be removed and used for firewood (burning also) wherever practical. Primarily for the benefit to the younger healthier trees and other vegetation. The exception would be migratory bird nesting trees. Although squirrels do enjoy all the cones from these dying, dead trees and woodpeckers thrive on the beetle in the bark, there are so many beetle trees that they will never run out of food.
    Many overgrown forests also abound where thinning of the trees would provide overall environmental benefits. But in our top-down system of government control it is not economic to perform this type of work.
    If we actually had real “foresters”, they could permit individuals to commercially harvest 5 acres of these trees at a time at no cost to the government (other than the time to do a site review and mark the “save” trees).
    The US Forest Service and ADFG used to intentionally burn thousands of acres at a time for habitat improvement and fuel reduction purposes.

  5. Name: chris nyman



    Message: I got burned by this new comment block the last time. How sad the world will never see my fantastic comment about spring breakup.
    So this is a test.
    PS the old reply block is still there at the bottom of the story.

    So the above comment was submitted in the new block and now I am sending it in the other block

Leave a Reply