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Smoke and Mirrors: Wood Biomass and the Environment

In the most recent attempt to convince the public that burning wood biomass is somehow bad for the environment, Friends of the Earth, Greenpeace and The Royal Society for the Protection of Birds (RSPB) have yet again failed to see the forest for the trees. In a letter submitted to The Times last week, the three NGOs, along with a dozen organizations representing forest products industries, suggested using wood biomass to generate electricity harms the both environment and the economy.

Suz-Anne Kinney first wrote about the myth that burning wood is more detrimental to the environment than burning coal three years ago this month when she cautioned Lunacy Is to Think that Natural Systems Cannot Solve Problems. Today, the story is once again at the forefront as Members of Parliament get set to debate the UK’s Energy Bill.

In its report Burning Wood for Power Generation, The Key Issues Explained, the NGOs argue the proposed greenhouse gas standard is inaccurate because the government fails to account for the CO2 released into the atmosphere when wood is burned. The government asserts forest regrowth neutralizes this CO2, but the NGOs argue burning wood creates a carbon debt.

This argument is flawed on multiple levels. The math the NGOs favor looks at a macro-level issue at a micro tree-by-tree level. It also starts the carbon clock when the tree is harvested, thereby failing to account for the carbon the tree sequestered up to that point.

Let us first consider the work of Dr. William Strauss on the importance of considering the entire harvest when calculating carbon emission. Strauss suggests a forest with 1,000,000 tons of biomass at the start of the year will, due to natural growth, have 1,010,000 tons of biomass by the end of that year. Harvesting 10,000 tons of biomass from the forest will therefore result in a carbon neutral harvest.

Additionally, Strauss proposes the carbon counter should start at the time of the last harvest. If a stand of trees is harvested after 30 years of growth, the trees have, logically, captured carbon for 30 years.

When the forest is thinned, it relinquishes the portion of carbon it accumulated over that period of time. The forest stand is replanted to begin the next cycle of growth and harvests, sequestering even more carbon this time around due to improved silviculture practices. Suz-Anne Kinney previously outlined these arguments in her piece, “Dividend-then-Benefit,” Not “Debt-then-Dividend”: Manomet Revisted.

The NGOs also favor a narrow view point when it comes to the manufacture and supply of wood pellets. These groups claim tree residues and low quality wood are limited resources and assert pellet companies use whole trees to manufacture their products. They suggest a rise in demand amid low supply will increase wood prices at the risk of existing wood products industries and jobs.

This argument assumes the existing wood supply is not available to meet rising demand, when in fact, the US South contains 199.5 million acres of private forest land ready to meet demand from all sources. Pellet manufacturers purchase pulpwood (from thinnings and other unmerchantable stock), which in the US South has an average regrowth cycle of 15 years (softwood) to 25 years (hardwood).

In contrast, the data the NGOs cite looks only at 90-100 year hardwoods that are harvested for use as sawtimber. While these calculations may hold true for sawtimber-size materials that grow in Northern climates, Southern sawtimber growth cycles average 30 years for softwood and 50 years for hardwood. The majority of harvested sawtimber goes toward lumber or other building products (floors, cabinets, etc.) that sequester carbon until the end of their useful life when they are removed to a landfill to biodegrade. Hardwood pulpwood is a natural byproduct of sawtimber harvests.

What the NGOs either fail to understand or to share with the public is their preferred data – based on trees used for sawtimber – simply does not apply to wood pellets sourced from pulpwood. Bioenergy companies do not use sawtimber logs to manufacture pellets now, nor will they do so in the future. Sawtimber commands a higher price than pulpwood, and as such, bioenergy companies are as likely to purchase a more costly product as landowners are to sell valuable timber at a fraction of its worth.

Because wood pellet manufacturers purchase pulpwood, it is understandable that organizations with interests in securing pulpwood for their own products would have concerns over the potential price impacts of increased demand. However, the logic of a free market system implies supply will increase to meet demand over time. Prices will fall back in line as the market returns to equilibrium.

Increased demand for wood, whether for biomass or any other wood product, provides landowners with the financial incentive they need to replant and maintain their forest land. Without these markets in place, economic opportunities must be sought elsewhere and oftentimes results in the removal of forests through development or conversion to marginally fertile crop land.

The organizations suggested “the only rational response” to their perceived concerns is to focus renewable energy subsidies on truly green solutions such as solar, wind and wave power.  Yet an article published in The Telegraph earlier this year, Wind Farms Will Create More Carbon Dioxide, suggests wind farms disturb peatlands that store at least 3.2 billion tons of carbon within soils across the UK. It is startling the NGOs support wind power given over half of existing and planned onshore wind development is on peat soils.

Another argument favored by those who oppose the use of wood biomass is that harvesting and transportation activities involved in sourcing these materials outweigh the benefits of their use. Unlike wood biomass – which is transported across the ocean just like imported coal – wind farms require miles upon miles of new roads to reach and service the windmills. Their construction can “damage or destroy the peat and cause significant loss of carbon to the atmosphere.”

As for solar and wave power, a cursory glance into these technologies reveals the benefits they provide are not without risk to natural habitats as well. In addition, neither wind, solar nor wave power is technically capable of supplying base load power at the present time. These deficits make wood biomass one of the few renewable sources available for large-scale use today.

Just last week, as environmental groups in the UK argued against wood biomass, the Finnish Association for Nature Conservation along with the Trade Association of Finnish Forestry and Earth Moving Contractors encouraged utility companies to burn domestic wood and logging waste because it is cheaper and more environmentally friendly than imported coal. Their work also claims the use of wood in such a manner creates, rather than eliminates, jobs.

 With such conflicting reports, what is the public to believe? There is no doubt that finding a clean energy solution is important. It is equally important for influential groups to stop cherry-picking arguments from complex scientific data with the intent to further their own agendas.

Wood biomass sourced from US forests is a sustainable resource subject to the requirements of a highly regulated industry. While it is true wood biomass has a carbon footprint higher than that of other renewables, its overall carbon footprint is just one-fifth to one-tenth that of fossil-based fuels. Until alternative renewable energy sources are brought up to scale, wood biomass is a reasonable solution to bridge the gap between coal and efficient, affordable renewable power.


Comments

cobus

05-21-2013

Thank you - clarifying. We have similar problems in South Africa.

Regards

Cobus