Biomass Carbon Neutrality in the Context of Forest-based Fuels and Products Al Lucier, NCASI Reid Miner, NCASI May 2010

2 Production Category Dry Weight in Millions of Tons Products & Feedstock from Forests249 Corn to Ethanol18 Other45 Total322 Annual U.S. Production of Renewable Materials and Biomass Energy Feedstock Circa 2005

Forest Sector & Climate Mitigation “ In the long term, a sustainable forest management strategy aimed at maintaining or increasing forest carbon stocks, while producing an annual sustained yield of timber, fiber or energy from the forest, will generate the largest sustained mitigation benefit.” IPCC 4 th Assessment Report (2007)

Atmosphere Biomass Carbon Biogenic CO 2 CO 2 Biogenic carbon is part of a relatively rapid natural cycle that impacts atmospheric CO 2 only if the cycle is out of balance Fossil Fuel Atmosphere Non-biogenic CO 2 Fossil fuel combustion transfers geologic carbon into the atmosphere. It is a one- way process The “neutral” biomass carbon cycle VS Carbon transfers from geological reserves 4

In Real Landscapes, Carbon Uptake & Release Vary in Time & Space

Harvested Area In forests managed sustainably, carbon losses due to harvest are offset by carbon uptake by growing trees. 6

Implications for Carbon Accounting Fossil Fuels: CO 2 emissions at point of combustion are dominant factors in “carbon footprints.” Forest Biomass Fuels: Changes in forest carbon stocks can be dominant factors in “carbon footprints.” This is why there are different carbon accounting methods for fossil fuels and biomass fuels. 7

Biomass Carbon Neutrality (BCN) Practical Contexts: – National Greenhouse Gas Inventory & Reporting – Cap & Trade Programs – EPA Regulation of CO 2 8

National GHG Inventory & Reporting BCN means that a CO 2 emission factor of zero is used for biomass fuels at point of combustion. – Emissions associated with the production of biomass fuels are measured where they occur. National GHG Inventory has two main components: (1) Emissions other than biogenic CO 2 (2)Changes in carbon stocks Biogenic CO 2 emissions are captured in (2). – To avoid double counting, a CO 2 emission factor of zero is used for biomass fuels at point of combustion. 9

Cap & Trade Programs BCN is used in cap & trade programs to: – encourage use of biomass fuels in place of fossil fuels. – maintain consistency with National GHG Reporting. Some stakeholders have expressed concerns about unintended consequences of incentives in cap & trade programs to use biomass and other energy options. 10

EPA Regulation of CO 2 BCN is being discussed in context of EPA’s plan to regulate CO 2 as a pollutant under the Clean Air Act. Key topics include: – Legal basis for distinguishing between fossil and biomass sources of CO 2. – Concerns about excessive use of biomass. – Concerns that regulating CO 2 from biomass would encourage switching from biomass fuels to fossil fuels. 11

Why Would Eliminating BCN Encourage Switching from Forest-Based Biomass Fuels to Fossil Fuels? At point of combustion, CO 2 emissions per unit of energy produced are generally higher for biomass fuels than for fossil fuels. – This is due primarily to the higher water content of biomass fuels. CO 2 emissions at point of combustion could be reduced by shifting fuel mix away from biomass. – However, overall CO 2 emissions would increase in most cases. 12

Biomass Carbon Neutrality Does not measure reductions in GHG emissions attributable to using bioenergy instead of fossil energy. 13

Quantifying GHG Benefits of Bioenergy Construct scenarios. Estimate cumulative emissions for each scenario. 14

Net Cumulative CO2 combustion emissions Cumulative CO2 combustion emissions Biomass energyFossil fuel energy What if a new biomass production system is gradually replacing forest that has higher carbon stocks? Net cumulative emissions for biomass system increase to reflect stock losses, but stop increasing after all plots have been converted to production forest. Time 15

Net Cumulative CO2 combustion emissions Cumulative CO2 combustion emissions Biomass energyFossil fuel energy This increases the time required for biomass to show net benefits, but after the “break even point” the benefits of biomass continue to accrue. Time Biomass lower from here forward 16

Net Cumulative CO2 combustion emissions Cumulative CO2 combustion emissions Biomass energyFossil fuel energy If reductions in land-based carbon are lower, the time to “break even” is reduced. Time Biomass lower from here forward 17

Net Cumulative CO2 combustion emissions Cumulative CO2 combustion emissions Biomass energyFossil fuel energy Of course, the opposite can happen. Land can be converted to higher carbon stocks to provide biomass energy (e.g. afforestation). Time Cumulative net biomass emissions remain below zero Cumulative fossil fuel carbon emissions continue to increase indefinitely 18

Net Cumulative biogenic CO2 emissions Convert land to much lower carbon stocks Convert land to somewhat lower carbon stocks Keep land in same general forest type Afforestation or other increase in carbon density Time In the United States, carbon stocks on wood-producing land are stable or increasing, so the national situation is best represented by this line. This means that the forest biomass carbon placed in the atmosphere is offset by new forest growth on wood- producing land 19 So, we have seen that the net cumulative emissions of biogenic carbon vary depending on whether and how the overall carbon stocks on the land are changing.

Timberland Growth/Removal Ratio By Region Source: Forest Resources of the United States, 2007 – Table Growth-removal ratio is calculated based on annual growth on timberland divided by annual removal as of reported years. No specific data for growth and removal in between reported years.

“Life Cycle” Emissions of Greenhouse Gases Other than Biogenic CO2 Data sources: IPCC, USDOE USLCI Database, other public life cycle databases 21

Summary US Forest Sector – A world leader in biomass energy production & use. – Part of the solution to greenhouse gas mitigation. Biomass Carbon Neutrality (BCN) – In theory, an attribute of biomass energy systems where the biogenic carbon cycle is in balance. – In practice, an accounting convention in national greenhouse gas inventories. 22

Summary In the United States, – forest carbon stocks are stable or increasing; – therefore, GHG emissions per unit of energy are much lower for forest biomass fuels than for fossil fuels. EPA is considering whether to eliminate BCN for purposes of regulating CO 2 as a pollutant under the Clean Air Act. – EPA deferred decision on BCN in “tailoring rule” – Eliminating BCN in this context would encourage replacement of biomass will fossil fuels, resulting in substantial increases in GHG emissions. 23