Providing input to EPA's science panel as it again tackles biomass carbon emissions from power plants
The EPA's Biogenic Carbon Emissions Panel--a group of experts convened to advise EPA on a scientifically sound approach to biogenic carbon accounting--held an in-person meeting today in which the public was able to offer oral comments on EPA's November 2014 revised Framework for Assessing Biogenic CO2 Emissions from Stationary Sources. Below is the oral statement delivered on behalf of NRDC by David Doniger, NRDC's Director, Climate and Clean Air Program.
Hello and thank you for the opportunity to speak with you today on behalf of NRDC.
NRDC commends you for your continued contributions to guiding EPA towards a scientifically sound approach to biogenic carbon accounting. Our comments address use of these accounting guidelines in the Prevention of Significant Deterioration program and their potential use under the Clean Power Plan. For either, a scientifically rigorous and policy-relevant framework must meet two key criteria:
First, as the Panel concluded in its 2012 report, emissions reductions credited against the emissions of a biomass-burning facility must be additional from the perspective of the atmosphere--i.e. they must be above and beyond what would have happened absent bioenergy.
Second, carbon sequestration used to offset the emissions of a biomass-burning facility must be achieved not in some distant future, but within a timeframe relevant to those emissions--in this case, the Administration's commitments to reducing national greenhouse gas emissions.
EPA's revised Framework fails to provide appropriate directives on either issue.
The revised Framework contemplates a "reference point" baseline approach already rejected by the Panel. As the Panel knows, this approach simply compares forest growth and removals over a specified timeframe and land base. If overall forest growth exceeds removals, biomass harvested for bioenergy is considered "carbon neutral".
Whether across a region, county, or "fuelshed", this approach neither links a facility's biomass harvesting to its atmospheric impacts nor accounts for exogenous factors. The reference point approach overlooks any increase in emissions caused by biomass harvesting for fuel, no matter how large, as long as overall forest stocks continue to grow--even if by substantially less than they otherwise would have.
NRDC is particularly troubled by the suggested--but not defined--"sustainability" exemptions in an EPA memo to regional air regulators. EPA proposes to treat "sustainably-derived" forest biomass sources as "approvable elements" in state plans under the Clean Power Plan.
Sustainable forestry considers many factors besides carbon pollution, including biodiversity, habitat, and water quality, and so is not a proxy for carbon accounting. Even if "sustainably-derived" were also defined to include consideration of forest growth and removals, it would fail to accurately account for changes to atmospheric carbon for the reasons laid out.
Moreover, the revised Framework contains no directive to account for displaced demand for wood resulting from bioenergy, which becomes more important as the scale of analysis shrinks. Instead, EPA allows self-governance, leaving the decision to include carbon leakage estimates to users.
We are particularly concerned that regulated entities may claim any biomass harvested under the reference point baseline option is per se "sustainably-derived" and therefore categorically carbon beneficial and exempt--regardless of fuel type, size, leakage impacts, or other factors influencing net emissions.
We urge the Panel to reject this rationale and reference point baseline approaches altogether, at any scale. Instead, the Panel should underscore that to assure additionality, EPA must assess changes in stored carbon using an "anticipated future" baseline, comparing emissions under scenarios with and without increased biomass harvesting for energy.
Additionally, the revised Framework entertains timeframes of analysis too long to be relevant to existing Administration climate commitments--for example, the 2030 target in the Clean Power Plan or the U.S.'s 2030 emissions reduction targets. The panel should advise EPA that any modeled carbon sequestration (or increase) accrued in the future should be assessed over a timeframe consistent with these commitments--i.e. no longer than 10-20 years.
The best available science shows that for timeframes less than 50 years, using large-diameter forest-derived biomass for electricity almost always increases emissions. Smaller-diameter size classes of biomass that would degrade quickly in the forest or be burned on-site may represent a lower-carbon source.
NRDC urges the Panel to recommend a Framework that accurately differentiates among forest-derived fuels and determines their carbon impacts, incorporates impacts of diameter size-class on carbon outcomes; relies only on "anticipated future" baseline methods to assess the additionality of claimed emissions reductions; and prescribes short timeframes relevant to reducing emissions in line with climate goals.