Is biomass carbon neutral?

8 05 2012

Global climate change is the major environmental issue of current times. Evidence for global climate change is accumulating and there is a growing consensus that the most important cause is humankind’s interference in the natural cycle of greenhouse gases. (Greenhouse gases get their name from their ability to trap the sun’s heat in the earth’s atmosphere – the so-called greenhouse effect.)

CO2 emissions are recognized as the most important contributor to this problem. Since the turn of the 20th century the atmospheric concentration of greenhouse gases has been increasing rapidly, and the two main causes have been identified as:

  1. burning of fossil fuels and
  2. land-use change, particularly deforestation.

And now the world has discovered plants.  People seem to think there is some magic in nature – that they can keep taking and things will grow back.  We can buy “carbon offsets” to mitigate our guilt – trees planted to “offset” our energy consumption for, maybe, a plane ride to Hawaii.

Because the carbon emitted when plants are burned is equal to that absorbed during growing, it seems self-evident that biomass is a zero carbon (or carbon neutral) fuel.[1]  The thinking goes like this:  Plants are busy converting CO2 to stored (“sequestered”) carbon in their branches, roots, stems and leaves – so when that plant is burned, the carbon which is released (as CO2) is replaced by another plant which is busy sequestering that carbon.

Why is burning fossil fuel – which  also releases CO2 when burned  – not considered to be carbon neutral?  As far as I can tell, it’s a matter of definition.  Today, the definition of carbon neutral means that the greenhouse gases released  by burning fuel is the same or less than the carbon that was stored in recent history (translation = plants, which grow and mature within 100 years or so, i.e., “recent history”). Releasing carbon that was stored in ancient history, such as  burning fossil fuels (which comes from plant material millions of years old)  introduces extra carbon to the environment. Because fossil fuels contain carbon that was in the environment in ancient times, by burning fossil fuels we release greenhouse gasses that wouldn’t naturally be there!

That concept took off.  Beginning with the Koyoto Protocol, which overlooked reduction targets for biomass, others embraced the concept of using biomass as a carbon neutral fuel:  the EU Emissions Trading Scheme counts biomass as “carbon neutral” as do UK Building Regulations, the World Business Council for Sustainable Development and the World Resources Institute –  despite the recognition that this definition is problematic.[2]  Biomass burning is being ramped up all around the world in the name of green energy.

The concept of biomass as being carbon neutral is so popular that the European Union’s energy objectives for 2020 include the requirement that 20% of the total be from renewable sources, made up from biomass such as wood, waste and agricultural crops and residues.[3]  And the biomass industry in the US asked for an exemption from the Environmental Protection Agency’s greenhouse gas regulations because, it claims, biomass is carbon neutral.  In January 2011, the EPA gave them a 3 year exemption.

This loophole gives oil companies, power plants and industries that face tighter pollution limits a cheap means to claim reductions in greenhouse gas emissions. According to a number of studies, applying this incentive globally could lead to the loss of most of the world’s natural forests as carbon caps tighten.  A very frightening scenario indeed, since deforestation is responsible for up to 20% of the world’s greenhouse gas emissions – more than all cars, trains, planes, boats and trains in the world combined. [4]

I found a great blog post on this subject by Jeff Gibbs on Huffington Post Green, and I’ve relied on it for much of this post.  Here are just two of the issues:

Issue 1:  “Trees not harvested will eventually die and be decomposed by insects, fungi, bacteria, and other microorganisms which will release all the carbon dioxide that burning would. This cycling process has been going on for half a billion years, long before humans had a hand in it, and will continue with or without us.”

Here’s what Jeff Gibbs has to say:

  • “Actually nature has plans for that dead tree. For one it’s food for the next generation of forest life. And it turns out trees are pretty good at transferring their CO2 to the soil rather than the atmosphere when they fall over dead. Underground roots of mushrooms called mycorrhiza digest the wood and keeps the carbon the trees had sucked from the air in the forest soil.   The proof? It’s called coal.  Millions of generations of plants and trees have taken in carbon from the air and deposited it as mountains of coal. It’s what trees and plants do. Because trees and plants took the CO2 out of the atmosphere we have the nice comfortable climate we enjoy today. It’s not their fault we’re releasing everything they worked so hard to lock away, and if we cut then down they are going to have that much more difficult of a time soaking the carbon back up.”

Issue 2:  “Carbon dioxide –  released by burning biomass – is carbon dioxide that was taken from the air as the trees grew, and the trees that replace the harvested biomass will grow by taking in carbon dioxide again.”

This is so fraught with different issues that we have to break it down into manageable segments to understand why this is not as simple as it seems:

  1.   When you cut down a fully mature, multi-ton tree, how long do you think it will be before the one-ounce sapling that replaces it will be able to replicate the carbon uptake of the multi-ton tree?  Some trees take 100 years or more to mature.  When burned for energy, a mature tree (80-100 years old) takes minutes to release its full load of carbon into the atmosphere, but its replacement, if grown, takes a full century to re-sequester that carbon. For those 100 years, the CO2 is still aloft in the atmosphere helping push the climate toward the point of dangerous change, and yet carbon accounting rules treat it as non-existent.  After the initial release of carbon sequestered in a standing forest, a well-managed forest will start re-growing and at some point in time will achieve approximately the same concentration of carbon sequestration as the original forest.  But during that time, the atmospheric concentration of heat trapping gasses has been higher than it would otherwise have been, increasing associated environmental damages, and we have foregone the sequestration that would have happened in the original forest![5]
  2.  Chopping down forests to burn for ethanol production — even if replanted as tree plantations — is like biting the hand that feeds you. “Natural forests, with their complex ecosystems, cannot be regrown like a crop of beans or lettuce,” reports the nonprofit Natural Resources Defense Council (NRDC), a leading environmental group. “And tree plantations will never provide the clean water, storm buffers, wildlife habitat and other ecosystem services that natural forests do.”[6]
  3.  Recent studies show that there is more biomass contained IN the soil than in what grows ON the soil above ground.   This soil carbon can be disturbed and released by harvesting and reforestation activities.[7]
  4.  In a study published by the Manomet Center for Conservation Sciences, it was found that burning  trees emits about 30% more carbon pollution than coal, which the report calls the “carbon debt” of biomass. [8]   According to the study,  under normal forest management   it takes over 21 years just to re-absorb the extra pollution that is released in the first year of burning the wood.    Also, the energy content of biomass is about 40% lower than that of regular fossil fuels, so you need to burn more of it to get the same power, which means more CO2. (to read more about this, click here.)
  5.  It is simply not possible to plant sufficient numbers of trees to deal with the increased carbon dioxide emissions that are expected over the next half century.  According to Harpers Index, the number of years the United States could meet its energy needs by burning all its trees is … 1.
  6.  Recent evidence suggests that global warming itself is stressing ecosystems and turning forests and forest soils into failing forests and, in the long run, into net sources of CO2. Thus, if we don’t curb our use of fossil fuels, it won’t matter how many trees we plant because these forests will be overcome and die as the climate continues to warm.[9]
  7.  Old-growth forests are often replaced by tree-farm plantations that are heavily managed (including with chemicals and fossil fuel-intensive machinery) and do not offer the same biodiversity benefits as natural forests.
  8.  Investment in forestry offsets does not contribute to reducing society’s dependence on fossil fuels, something that is ultimately needed to address climate change. Responding to climate change means fundamentally changing the way we produce and use energy.
  9.  All biomass is not created equal.  According to Jeff Gibbs, some biomass plants burn old tires; others shovel in old houses and creosote soaked railroad ties. I don’t know what’s “bio” about all this but the energy you get is considered carbon neutral and renewable.

Here are Jeff Gibb’s seven truths that the Lorax would have us remember:

  1. Saving our forests (and that doesn’t mean more tree plantations) is the best way to stop global warming and save humanity.
  2. Deforestation is just as likely to result in the end of humanity as climate change and it’s right on track to do so.
  3. Burning things is the most insane way to stop global warming since doctors drilled holes in skulls to let the demons out and gave you a bill for it.
  4. There is no extra in nature and there is not enough “bio” on the planet to be burned, turned to ethanol, biodiesel or jet fuel, or bio-charcoal.
  5. Woody biomass falsely deemed renewable energy increases the CO2 in the atmosphere, destroys forests, and prevents renewables from being fully explored.
  6. Geo-engineering the forests, atmosphere or oceans to stop global warming isn’t going to work. We can’t even figure out how to stop carp from taking over a river or bugs from eating a forest.
  7. There is a possibility that the only way to heal the planet is to get control of our own numbers and consumption while letting nature do the work she has done for three billion years: run the planet.

[1] Grant, Nick and Clarke, Alan, “Biomass – a burning issue”, http://www.aecb.net/UserFiles/File/Biomass%20-%20A%20Burning%20Issue%20-%20published%20September%2020101.pdf

[2] Johnson, Eric, “Goodbye to carbon neutral:  Getting Biomass footprints right”, Atlantic Consulting, Gattikon, Switzerland, November 2008.

[3] Neslan, Arthur, Guardian Environment Network, April 2, 2012. http://www.guardian.co.uk/environment/2012/apr/02/eu-renewable-energy-target-biomass

[4] Greenpeace, “Solutions to Deforestation”;  http://www.greenpeace.org/usa/en/campaigns/forests/solutions-to-deforestation/

[5] Natural Resrouces Defense Council comments with respect to draft Policy DAR-12, June 17, 2010.

[6] Scheer, Roddy and Moss, Doug, “EarthTalk”, E-The Environmental Magazine.  http://azdailysun.com/news/science/earthtalk-biomass-hardly-carbon-neutral/article_7111cb33-c27f-5e95-a5a7-133fc8b123db.html

[7] David Suzuki Foundation, “The problems with carbon offsets from tree-planting”, http://www.davidsuzuki.org/issues/climate-change/science/the-problems-with-carbon-offsets-from-tree-planting/http://www.davidsuzuki.org/issues/climate-change/science/the-problems-with-carbon-offsets-from-tree-planting/

[8] “Biomass Sustainability and Carbon Policy Study”, Manomet Center for Conservation Sciences, June 2010

[9] David Suzuki Foundation, Ibid.





What kind of wood is best for your new “green” sofa?

13 01 2010

From last week’s post, I explained that most people who want to buy a “green” sofa look at two major components:  the wood and the foam.  But our blog post demonstrated how your fabric choice can trump the embodied energy of both these components – in other words, depending on which fiber you choose, fabric can be almost  triple  the embodied energy of wood and foam combined.  But embodied energy is a complicated concept,  and difficult to figure out without lots of time on your hands.  Our next steps will be to examine other issues associated with each of these choices – remember the ecosystem is a vast interconnected network, and we can’t pull any one component out and evaluate it out of context.   Each week we’ll look at one of the components  -  this week it’s wood.

Everybody knows that wood, a natural product, comes from trees,  but it’s important to know much more than whether the wood is cherry or mahagony – it’s also important to know that the wood did not come from an endangered forest (such as a tropical forest, or old growth boreal forests) – and preferably that the wood came from a forest that is sustainably managed.   Well managed forests provide clean water, homes for wildlife, and they help stabilize the climate. As the National Resources Defense Council says:

“Forests are more than a symbolic ideal of wilderness, more than quiet places to enjoy nature. Forest ecosystems — trees, soil, undergrowth, all living things in a forest — are critical to maintaining life on earth. Forests help us breathe by creating oxygen and filtering pollutants from the air, and help stabilize the global climate by absorbing carbon dioxide, the main greenhouse gas. They soak up rainfall like giant sponges, preventing floods and purifying water that we drink. They provide habitat for 90 percent of the plant and animal species that live on land, as well as homelands for many of the earth’s last remaining indigenous cultures. Forests are commercially important, too; they yield valuable resources like wood, rubber and medicinal plants, including plants used to create cancer drugs. Harvesting these resources provides employment for local communities.  Healthy forests are a critical part of the web of life. Protecting the earth’s remaining forest cover is now an urgent task.”

Unsustainable logging, agricultural expansion, and other practices threaten many forests’ existence.  Indeed, half of the Earth’s original forest cover has been lost, mostly in the last three decades.

According to the World Resources Institute (WRI), only 20% of Earth’s original forests remain today in areas large enough to maintain their full complement of biological and habitat diversity and ecological functions.[2]

More than 20% of  worldwide  carbon emissions come from the loss of forests[1], even after counting all the carbon captured by forest growth.  

A sustainable forest is a forest that is carefully managed so that as trees are felled they are replaced with seedlings that eventually grow into mature trees. This is a carefully and skilfully managed system. The forest is a working environment, producing wood products such as wood pulp for the paper / card industry and wood based materials for furniture manufacture and the construction industry. Great care is taken to ensure the safety of wildlife and to preserve the natural environment.

Forest certification is like organic labeling for forest products:  it is intended as a seal of approval — a means of notifying consumers that a wood or paper product comes from forests managed in accordance with strict environmental and social standards. For example, a person shopping for flooring or furniture would seek a certified forest product to be sure that the wood was harvested in a sustainable manner from a healthy forest, and not clearcut from a tropical rainforest or the ancestral homelands of forest-dependent indigenous people.

Choosing products from forests certified by the independent Forest Stewardship Council (FSC) can be an important part of using wood and paper more sustainably.  The FSC, based in Bonn, Germany,  brought together three seemingly antagonistic groups: environmentalists, industrialists and social activists. Its mission and governance reflects the balance between these original constituents in that FSC seeks to promote environmentally appropriate, socially beneficial and economically viable management of the world’s forests. Each is given equal weight.   Formed in 1993, the FSC has established a set of international forest management standards; it also accredits and monitors certification organizations that evaluate on-the-ground compliance with these standards in forests around the world.  Today nearly 125 million acres of forest are FSC certified in 76 countries.

But not all certification programs are credible. Spurred by the success of the FSC and consumer demand for certified products, at least eight other forest certification programs have formed internationally, such as the American Tree Farm System (ATFS), the Canadian Standards Association (CSA) forest certification, and the European Programme for the Endorsement of Forest Certification schemes (PEFC).  However, these programs are often backed by timber interests and set weak standards for forest management that allow destructive and business-as-usual forestry practices.

The most well known of these alternative certifications is the Sustainable Forestry Initiative (SFI).   Created in 1995 by the American Forest & Paper Association (AF&PA), an industry group, SFI was originally created  as a public relations program,  but it now represents itself as a certification system.

There are significant differences between the two systems.  FSC’s conservation standards tend to be more concrete, while SFI’s are vaguer targets with fewer measurable requirements. Here is what is allowed under the SFI standard:

  • Allows large clearcuts
  • Allows use of toxic chemicals
  • Allows conversion of old-growth forests to tree plantations
  • Allows use of genetically modified trees
  • Allows logging close to rivers and streams that harms water supplies

By comparison,  the FSC:

  • Establishes meaningful limits on large-scale clearcutting; harvesting rates and clearing sizes can not exceed a forest’s natural capacity to regenerate.
  • Prohibits the most toxic chemicals and encourages forest practices that reduce chemical use.
  • Does not allow the conversion of old-growth forests to tree plantations, and has guidelines for environmental management of existing plantations.
  • Prohibits use of genetically modified trees and other genetically modified organisms (GMOs).
  • Requires management and monitoring of natural forest attributes, including the water supply; for example,  springs and streams are monitored to detect any signs of pollutants or vegetative disturbance.
  • Requires protection measures for rare old growth in certified forests, and consistently requires protection of other high conservation value forests.
  • Prohibits replacement of forests by sprawl and other non-forest land uses.[4]

Certifiers also grant “chain-of-custody” certifications to companies that manufacture and sell products made out of certified wood. A chain-of-custody assessment tracks wood from the forest through milling and manufacturing to the point of sale. This annual assessment ensures that products sold as certified actually originate in certified forests.

Nearly a decade and a half after the establishment of these two certification bodies, there is a battle between FSC and SFI which is crescendoing in a showdown over recognition in the LEED system, the preeminent green building standard in the U.S.  Since its inception in 2000, LEED (Leadership in Energy and Environmental Design) has recognized only lumber with the FSC label as responsibly sourced. Up until now, credits such as MR 7 – Certified Wood, has awarded points based on the usage of FSC certified wood only (NOTE:  this is not specific to wood;  LEED  only awards points automatically  for Indoor Air Quality to products which are GreenGuard certified) .  Intense timber industry pressure has led the U.S. Green Building Council (USGBC), LEED’s parent,  to evaluate the certified wood credit in LEED, which has been FSC exclusive since inception, and determine whether other certification systems, such as the industry-driven Sustainable Forestry Initiative, should be given credits as well.  As a result, the USGBC  is currently writing new rules about wood-product sourcing.

This would replace the simple FSC monopoly with generalized benchmarks for evaluating systems claiming to enforce sustainable forestry and open up considerations for other “green” wood labeling systems.

Opponents of this action feel that it opens the door to destructive forestry practices under the guise of “green” –  and  to pass off status-quo business practices as environmentally friendly.  One of the leading arguments for loosening the wood credit — and thus lowering the bar for the standards governing the origins of the wood — is that the FSC system doesn’t have enough supply to meet demand.  To which the rejoinder is that the volume of SFI wood speaks to laxness of standards.  SFI contends that since only 10% of the world’s forests are certified sustainable, the important fact to concern us should be to work on the problems plaguing the remaining 90%.

The battle is heating up:  it was reported as recently as the 22nd of December, 2009, that a law suit was filed on behalf of a group calling itself the “Coalition for Fair Forest Certification” against the Forest Stewardship Council (FSC) alleging unfair and deceptive trade practices.  It is believed that the Coalition members are also members of the Sustainable Forestry Initiative.   (see http://greensource.construction.com/news/2009/091222Deception.asp )

We can only hope that USGBC’s certification decision takes place with keen regard to the organization’s guiding principles — high-minded values like “reconciling humanity with nature” and “fostering social equity.” It’s a critical decision that has the potential to help preserve forests by providing incentives for great management and cooling the planet down at the same time.

Once you’ve established whether the wood is from a sustainably managed forest, it’s also important to note whether the wood products in the sofa are composites.  Composites are typically made of wood and adhesive – examples of such composites are laminated veneer lumber (LVL), Medium density fiberboard (MDF), Plywood, and Glue Laminated Beams (Glulam).  Because these products are glued together using phenol formaldehyde resins, there is concern with formaldehyde emissions.  In fact, a bill  introduced in September, 2009, in the U.S.  Senate would limit the amount of allowable formaldehyde emissions in composite wood products.   In addition, the embodied energy in these products is typically higher than that for solid timber.  Based on a  study done by the    School of Engineering, University of Plymouth in the United Kingdom,
the embodied energy in air dried sawn hardwood (0.5 MJ/kg) is considerably less than that of glulam (4.6 to 11.0 MJ/kg)


[1] Van der Werf, G.R, et al, “CO2 Emissions from Forest Loss”, Nature Geoscience, November 1, 2009, pp 737-38.

[2] “Guidelines for Avoiding Wood from Endangered Forests”, http://www.rainforestrelief.org/documents/Guidelines.pdf

[3] Examples of SFI certified companies’ harmful practices are at www.dontbuysfi.com.

[4] iGreenBuild.com:  Forest Certification:  Sustainable Forestry or Misleading Marketing?  http://credibleforestcertification.org/fileadmin/materials/old_growth/dont_buy_sfi/sfi_facts/2_-_Still_Not_Equal_igreenbuild.pdf








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