Preface. Incredibly, this article doesn’t address the fact that after you cut down a forest and convert the wood into pellets destined to be burned in European furnaces for “clean energy”, the next forest won’t grow back with nearly as much lumber. So CO2 isn’t being replaced, not even after 100 years.
Forests don’t regrow to their former magnificence because logging causes soil erosion, depletes the water retained in soil needed for regrowth, and compacts the soil (Elliot 1999). Therefore the new growth won’t be able to absorb as much CO2 as their burned parents emitted because they contain less biomass, and since it takes half a century for a forest to regrow, whatever CO2 replacement occurs will take an awfully long time. Too long given the State of the World.
But left out of the equation is the lost soil carbon. Clearcutting disturbs the soil, which gets oxidized, which releases carbon that would remained stored, and a lot of it: According to the US Forest Service, soil can sequester up to twice as much carbon as the above ground forest ecosystem (Ellis 2016).
The article also doesn’t mention the energy returned on invested. Think of all the fossils used to drive logging trucks and heavy equipment to the forests, cut them down, lift entire trees with giant grappling buckets, chopped on the site for different uses (pellets, lumber), loaded and driven to the pellet factory where the wood is heated in massive drying units to get the water out, then send the wood through “a labyrinth of massive tubes and conveyors that ferry treetops, sawdust, and whole trees up to 26 inches in diameter through grinders, dryers, and presses. The resulting pellets are loaded into the contains of 27 ton transfer trucks, driven to a port, shipped to Europe, taken by truck to the European power plant, and finally up a conveyer belt for their final doom in the furnace.
Like coal and natural gas, two-thirds of the wood energy will be lost to heat, and another 10% over the electric lines. That can’t possibly be net energy positive. Or carbon neutral, since all of these transportation and industrial processes emitted CO2 long before the pellets were even burned.
That’s one reason some scientists estimate that burning wood could release 1.5 (Hanson 2017) to three times as much CO2 as coal. Biomass plants also produce more than twice as much nitrogen oxide, soot, carbon monoxide, and volatile organic matter as coal plants. Worse yet, many wood-burning power plants are partly fueled with contaminated waste wood which can emit toxic compounds like dioxins; heavy metals including lead, arsenic, and mercury (Upton 2014).
Much of the wood sent to Europe comes from the south-eastern US, from private land with zero regulations. Large-scale clear cutting is routine and old growth and endangered forests fall to the chainsaws as well. Worse yet, much of this destruction is done with an extensive use of chemical herbicides (BLI 2014).
After fossils are gone, people will turn back to wood to heat their homes and cook, make bricks, ceramics, metals and all the other things wood used to do before coal and oil took over starting in the 19th century
So I’m sad and alarmed that Europe is going after American forests. We’re going to need them someday. They are not renewable. They are not zero carbon. Related post: Wood, the fuel of preindustrial societies, is half of EU renewable energy
Alice Friedemann www.energyskeptic.com author of “When Trucks Stop Running: Energy and the Future of Transportation”, 2015, Springer and “Crunch! Whole Grain Artisan Chips and Crackers”. Podcasts: Practical Prepping, KunstlerCast 253, KunstlerCast278, Peak Prosperity , XX2 report
Cornwall, W. 2017. The burning question. Science 355: 18-21
It took half a century for an acorn to grow into the 20-meter-tall oak tree standing here in a North Carolina hardwood forest near the banks of the Northeast Cape Fear River. But it takes just seconds to turn the oak into fuel for the furnace of a European power plant.
With a screech, a spinning blade bites through the trunk. Ultimately, the thickest bits of this tree and hundreds of others from this forest will be sliced into lumber. But the limbs from large trees like this, along with entire small or crooked trees, go to a specialized mill to be squeezed into tiny wood pellets. Shipped across the Atlantic Ocean, they will likely end up fueling a giant power plant in the United Kingdom that supplies nearly 10% of the country’s electricity.
The trans-Atlantic trade in wood pellets is booming due to a push by policymakers, industry groups, and some scientists to make burning more wood for electricity a strategy for curbing carbon dioxide (CO2) emissions. Unlike coal or natural gas, they argue, wood is a low-carbon fuel. The carbon released when trees are cut down and burned is taken up again when new trees grow in their place, limiting its impact on climate.
European wood burning power plants claim that this emits zero carbon. Which is totally untrue – some actually emit more CO2 than coal or natural gas, partly because wood has a higher water content and extra energy goes to boiling the water off. Regulators designated wood as carbon-neutral anyway which led to many countries building new wood-fired plants or converting coal plants to burning wood. The UK even provided subsidies that make wood pellets competitive with fossil fuels.
To feed these European plants, wood is imported from all over the world. The Southeast sends more than 6.5 million metric tons of wood pellets today.
Critics counter that favoring wood could actually boost carbon emissions, not curb them. Some scientists also worry that policies promoting wood fuels could unleash a global logging boom that trashes forest biodiversity in the name of climate protection. It basically tells the Congo and Indonesia and every other forested country in the world: ‘If you cut down your forests and use them for energy, not only is that not bad, it’s good.
Scientists disagree about whether burning wood is carbon-neutral because so many assumptions are made that a model could spit out results that were only true for a particular kind of tree, the assumption of how long the CO2 of burned trees takes to be absorbed, and other factors. Also time is a factor – widespread wood burning will cause emissions spikes for half a century, more than a coal power plant would have. So it’s possible for scientists using a 100-year time frame to say that forests will have regrown in a century and recapture the carbon of their burned ancestors.
And after a forest is cut down, it doesn’t necessarily return to being a forest, but instead might become housing lots or farms and never grow more trees to suck up the excess carbon.
And there’s no guarantee forests will keep returning after being mowed down. Asko Noormets, a North Carolina state ecologist, has been running an experiment for 11 years that shows that every year each square meter of forest loses about 125 grams of carbon to the atmosphere. Over time, logging is likely to wear this fertile, peat-based soil down to the sandy layer below, releasing most of its carbon and destroying long-term productivity. And this is true of other managed forests around the world he adds.
Right now carbon accounting is only for the burning of the wood itself, but clearly needs to also add in the soil carbon being lost as well.
Plus add in land use changes. Just as rainforests are being mown down to plant soybeans, hardwood forests may be logged to establish fast growing pine plantations. As much as 10% of North Carolina hardwood ecosystems could be lost by 2050.
BLI. 2014. Wood pellet industry cheats on sustainability evidence shows. Bird Life International.
Elliot, W.J. et al. 1999. The effects of forest management on erosion and soil productivity. Chapter 12 in Lal, R., ed., Soil Quality and Soil Erosion. CRC Press. 195-208.
Ellis, E. G. 2016. The senate says burning trees is carbon neutral. Oh really now? Wired.com
Hanson, C., et al. 2017. Why burning trees for energy harms the climate. World resources institute.
Upton, J. 2014. What’s worse than burning coal? Burning wood. Grist.org