“Although biomass is a renewable resource, much of it is currently used in ways that are neither renewable nor sustainable.”
– Christopher Flavin and Nicholas Lenssen (Worldwatch Institute), Power Surge. New York: W. W. Norton, 1994, pp. 176–77.
“We write to raise strong concerns about the November 19th, 2014, memo from Acting Assistant Administrator for the Office of Air and Radiation Janet McCabe (McCabe memo), which would credit use of woody biomass for energy with reducing emissions, when it actually increases them…. Burning biomass instead of fossil fuels does not reduce the carbon emitted by power plants. In fact, as EPA itself acknowledges, burning biomass degrades facility efficiency and increases day-to-day emissions over emissions when fossil fuels are burned alone.”
– Letter from Dr. Viney P. Aneja et al. to EPA Administrator Gina McCarthy, February 9, 2015 (reprinted below).
Biomass, like hydro, is the stepchild of the politically-correct family of renewable energies. I called it the air-emission renewable in my 1997 essay, “Renewable Energy: Not Cheap, Not ‘Green’.” Energy expert Tom Tanton has long called biomass baby coal.
In 2001, the International Energy Agency in Toward a Sustainable Energy Future (Paris: Organization for Economic Cooperation and Development, 2001, p. 204) concluded:
Biomass energy is generally considered to be CO2-neutral, as long as it is consumed in a sustainable manner, i.e., the stock of biomass does not diminish. This is not the case in many developing countries, where over-consumption of biomass fuels leads to deforestation and hence to the reduction of forest-based CO2 sinks.
Scientists Against the Biomass PTC (2012)
Just over two years ago, a letter to the House and Senate leadership from 40 left-of-center environmental-related nonprofits, groups, and businesses urged that biomass be excluded should the renewable-energy Production Tax Credit be extended past 2012.
Addressed to Majority Leader Reid, Minority Leader McConnell, Speaker Boehner, and Minority Leader Pelosi, the December 11, 2012, letter read:
We, the undersigned organizations and individuals, understand that many of our colleagues in the environmental community have urged you to extend the Production Tax Credit (“PTC”) in Section 45 of the Internal Revenue Code for wind and other renewable generation technologies.
Although we strongly support policy efforts to reduce greenhouse gas emissions and health-damaging air pollution from fossil fuels, we are concerned that the PTC includes support for biomass combustion technologies that both contribute to climate disruption and threaten public health.
Recent published, peer-reviewed science has shown that combustion of biomass, especially woody biomass sourced from forests, can increase carbon dioxide emissions relative to fossil fuels over a time span of decades to centuries. A large-scale shift to biomass generation could cause carbon pollution to increase at precisely the time scientists are telling us we need to make rapid and steep emissions reductions.
Moreover, unlike other renewable generation technologies, biomass combustion produces air pollutants (including particulate matter and nitrogen oxides) that have well-known and adverse effects on public health.
New Scientist Letter to McCarty (2015)
The pushback continues. The February 2015 letter to EPA Administrator Gina McCarthy, signed by seventy-eight scientists, was cc’d to Ralph Cicerone, National Academy of Sciences, National Research Council; Sarah Dunham, EPA Office of Atmospheric Programs; Joseph Goffman, EPA Office of Air and Radiation; and John P. Holdren, Executive Office of the President of the United States.
The letter follows.
Dear Administrator McCarthy,
As the Environmental Protection Agency strives to limit greenhouse gas (GHG) emissions, it is critical for the carbon accounting rules to be correct. Rules that improperly credit activities for reducing emissions when they actually increase them create powerful perverse incentives.
We write to raise strong concerns about the November 19th, 2014 memo from Acting Assistant Administrator for the Office of Air and Radiation Janet McCabe (McCabe memo), which would credit use of woody biomass for energy with reducing emissions, when it actually increases them. Because EPA can expect its accounting rule to be applied globally, it is likely to lead to the additional harvest or conversion to agriculture of large areas of the world’s forests. Burning biomass instead of fossil fuels does not reduce the carbon emitted by power plants. In fact, as EPA itself acknowledges, burning biomass degrades facility efficiency and increases day-to-day emissions over emissions when fossil fuels are burned alone. Growth of additional biomass beyond business-as-usual or recovered from waste can help to offset those emissions, but peer-reviewed science indicates this process takes several years to several decades.
This conclusion was the basis of a report issued by EPA’s Science Advisory Board (SAB) in 2012, which criticized EPA’s 2010 Draft Framework for Biogenic CO2 Accounting (the Framework) because it would have claimed carbon savings for harvests of wood that diminished the growth of forest stocks in the US and much of the world. By itself, diverting biomass from existing uses in food, paper and timber cannot reduce GHG emissions (except at the cost of food, paper and timber). At the same time, burning biomass, such as trees, that would otherwise continue to absorb and store carbon comes at the expense of reduced carbon storage.
The McCabe memo proposes to treat as “carbon-free” all woody or agricultural feedstocks so long as they are derived “from sustainable forest or agricultural practices.” At maximum, “sustainability” implies that forest harvesting does not exceed growth, which is a necessary, but not sufficient condition for carbon neutrality, as found by the SAB. At minimum, sustainability practices can help reduce soil erosion and other environmental impacts of forestry or agricultural production.
But such practices have little-to-no bearing on the carbon implications of biomass use. Including such exemptions for broad categories of biomass fuels in a final rule would not only encourage large-scale harvesting of wood to replace coal and other fossil fuels but also place no limits on the diversion of the world’s agricultural land to energy use, requiring conversions of forests and grasslands to meet food needs.
The potential implications of these exemptions are large because even small quantities of bioenergy require large quantities of wood. For example, the US Energy Information Agency estimates that treating woody biomass as carbon free with modest carbon restrictions would result in an additional 4% of present US electricity from wood by 2035.
That would require an increase of wood equivalent to 70% of the US timber harvest, which for perspective would be far greater than if we were to abolish all paper and cardboard recycling in the US. The International Energy Agency estimates that treating bioenergy as carbon free globally, coupled with strong carbon policies, would lead to reliance on woody biomass for 6% of electricity by 2035, and that would require more than a doubling of global commercial timber harvest.
According to common estimates, the world likely needs 70-100% more food in the next forty years—and possibly a comparable increase in commercial wood products. These demands are placing great stress on the world’s forests, woody savannas and wetlands and their carbon storage. The proposed EPA policies would greatly add to this stress to produce small quantities of energy.
In addition, the exemptions in the McCabe memo are likely to lead to increased US emissions of CO2. The exemptions would, in effect, allow power plants and factories to ignore the loss of carbon from forests when they harvest trees for energy, but the US must count this carbon when it reports national emissions under the UN Framework Convention on Climate Change.
Numerous studies have shown that when whole trees are harvested to replace coal, the result is an increased transfer of carbon to the air for decades due to the lower carbon efficiency of using wood than fossil fuels. Ignoring this carbon in US law cannot change what the atmosphere sees, and does not change our obligations to report those emissions accurately to the world.
The creation of such an accounting loophole in the EU has resulted in European power plants setting up large wood pellet facilities in the US—primarily in the Southeast— and rapidly increasing pellet exports to Europe. Although they are incorrectly claiming GHG reductions for burning these wood pellets, their actions are increasing our reported emissions. The US should be objecting to these activities, not creating a similar accounting loophole in US law. Doing so would seriously undermine President Obama’s admirable pledge to reduce US emissions 20% by 2020 and 30% by 2030.
The approach proposed in the McCabe memo would harm efforts, to which the US is an active party, to protect forests around the world, particularly tropical forests. The exemption for “sustainably-derived” wood would not exclude tropical forests from feeding the US energy market or replacing US wood diverted from pulp and paper into energy production. Neither can the US expect other countries to abstain from claiming similar GHG reductions by cutting down their forests for energy. In effect, the proposed exemption would operate to reverse the Reduced Emissions from Deforestation and Forest Degradation (REDD) program. It would reward forest managers for the carbon in their trees but only if they cut those trees down.
This approach would also undercut incentives to use biomass that is truly low in carbon. For example, power producers would have little incentive to focus on wastes and residues—which can result in lower net emissions compared to burning fossil fuels, but can be expensive to collect and transport—if EPA credits those feedstocks with no more benefits than harvesting whole trees.
We urge you to reconsider the approach to biomass as proposed in the McCabe memo and instead employ a scientifically valid system for counting the global warming effects of biomass.