Forest Science and Carbon Policy: Manage Forests to Get the Most Carbon Benefit

Thomas Huxley, the noted 19^th Century English biologist, once said that “science is simply common sense at its best.” Huxley’s observation rings true—especially for those of us in forestry and forest-related industries—when it comes to the science underpinning policy discussions about forests and carbon.

Instead of taking a common sense view, some outside of forestry choose to take a myopic view of the relationship between forests and carbon emissions, a view that reveals just part of the picture. They look at the individual tree or an individual harvest site and make generalizations that include only one aspect of the carbon story—the re-release of carbon into the atmosphere upon conversion of wood to energy. That view is not only myopic—obscuring the full story over landscapes, timeframes and end products; it also neglects to take into account the carbon benefits that accrue throughout the entire life span of the forest and of forest products. The atmospheric carbon balance is a long-term global issue. Common sense would seem to dictate a broader view.

This common sense, scientific view is the one put forth by The Society of American Foresters in the recently published Managing Forests because Carbon Matters: Integrating Energy, Products and Land Management Policy (a supplement to the October/November 2011 issue of the Journal of Forestry).

The report highlights the importance of "growing more forests and keeping more forests as forests." Focusing solely on sequestration, the report points out, misses "important (and substantial) carbon storage and substitution GHG benefits."

According to the SAF, carbon policy should be based on four basic scientific facts about forests:

1. "A sustainably managed forest can provide carbon storage and forest substitution benefits while at the same time delivering a wide range of environmental and social benefits such as timber and biomass resources, clean water, wildlife habitat, and recreation.
2. "Energy that is produced from forest biomass returns to the atmosphere as carbon that plants absorbed in the relatively recent past; it results in no net release of carbon as long as overall forest inventories are stable or increasing (as is with the United States forests).
3. "Forest products that are used in place of energy-intensive materials (i.e. metals, concretes, plastics) (a) reduce carbon emissions (because forest products require less fossil fuel-based energy to produce); (b) store carbon (for a length of time based on the products’ use and disposal); (c) provide biomass residuals (i.e. waste wood) that can be substituted for fossil fuels to produce energy.
4. "Fossil fuel-produced energy releases energy that has resided in the Earth for millions of years; forest biomass-based energy uses far less of the carbon stored within the Earth thereby reducing the flow of fossil fuel-based carbon emissions into the atmosphere."

In order to capture these scientifically proven carbon benefits from our forests, the SAF emphasizes the importance of managing forests to maximize these benefits: "US policies can encourage management of forests for all the carbon and energy benefits of forests and forest products while sustaining ecosystem health and traditional forest biomass uses."

To encourage landowners to manage their forests for these benefits, the SAF outlines three tenets for "integrating forests into a rational policy framework":

1. Keep forests as forests and manage appropriate forests for carbon.  United States forest cover has increased and its net growth has exceeded removals and mortality for more than 70 continuous years; therefore, carbon storage is increasing in the United States. Choosing not to manage forests has negative carbon consequences; mature forests are carbon-cycle neutral (because they absorb carbon at a much slower rate as their growth rates decline) or sources of carbon emissions as they decay naturally or are subject to fires, diseases or weather disturbances.
2. "Recognize that substantial quantities of carbon are stored in wood products for long periods of time and it lasts a long time in service - often a long time in service before being retired from service.  Wood is one-half carbon by weight; substantial volumes of wood go into construction products and structures, paper goes into long-term use (i.e. books) or is recovered from waste stream for energy production. Other wood--construction debris, yard waste, and unrecycled paper--winds up in landfills, where it often deteriorates more slowly than is generally assumed. In total the rate of carbon accumulation from wood products in use and in landfills was about 88 million tonnes of carbon dioxide equivalents in 2008, about 12% of the rate of sequestration in forests."
3. The substitution effect is real, irreversible and cumulative. Considerably less fossil fuel-derived energy is required to make wood products than as compared with other building materials, such as steel, aluminum, concrete, and plastic products. In addition, by substituting biomass-based energy for fossil fuel-based energy, additional non-biogenic GHG emissions are avoided.

What types of policies can help the US exact as much carbon benefit as possible from forests? According to the SAF, science is once again the key.

• Carbon offsets and credits--Offset programs are not working because they are just not practical. The science of measuring carbon benefits in this area is far from common sense: "uncertainty about acceptable methodologies for measuring forest carbon and related climate benefits has significantly limited interest in developing forest carbon projects that have large upfront costs."
• Economic incentives in the form of tax credits, subsidies or direct payments for reforestation and afforestation are effective tools for keeping forests as forests.
• Information disclosure requirements have been proven to motivate firms to modify their behavior. By encouraging entities to differentiate between biogenic and non-biogenic carbon emissions, this policy would encourage the use of forest products, which would then incent reforestation.
• Building codes and procurement strategies that specify the substitution of wood products for higher fossil-fuel intensity building materials like steel and concrete. By providing landowners with stronger markets for wood products that store carbon over long time periods, this policy would incent them to replant, keeping more forests as forests. In addition, this policy would reduce fossil fuel emissions.

The SAF report (read the full report here) adds to the dialogue about forest and carbon policy by encoraging the use of known science--and common sense--when it comes to making policy decisions. Overall, the report confirms the Intergovernmental Panel on Climate Change's view (one we've quoted here before; see Wood Emissions 4% of Coal) that "In the long-term, a sustainable forest management strategy aimed at maintaining or increasing forest carbon stocks, while procuring an annual sustained yield of timber, fibre or energy from the forest, will generate the largest sustained mitigation benefit."