[EXCLUSIVE] Is Biomass Energy Renewable? New Report Says No

– by Josh Schlossberg, The Biomass Monitor

A new law review article questions whether biomass should count as renewable energy, arguing that carbon dioxide and air pollutant emissions disqualify the controversial energy source.

Wood Burning, Biomass, Air Pollution, and Climate Change, by Christopher D. Ahlers, Adjunct Professor of Law at Vermont Law School, explains that the term renewable is a “subjective policy judgment” that must take into account the health and environmental impacts of a given energy source.

Currently, biomass energy makes up 50 percent of renewable energy in the U.S., according to the U.S. Energy Information Administration, with half of that tally coming from wood products.

Ahlers, legal support for the Philadelphia-based Clean Air Council, contrasts biomass energy from solar and wind, and instead compares bioenergy to fossil fuels, as “both involve the extraction of solid material from the earth, for the purpose of combustion.” He also discusses the time difference between growing a new tree (decades to centuries) and the formation of new fossil fuel deposits (millennia).

The Carbon Question

The idea of separately accounting for the carbon emissions of fossil fuels and bioenergy—biogenic carbon—is “ambiguous,” according to the report, which references the U.S. Environmental Protection Agency’s ongoing “uncertainty” on the topic.

While wood gradually emits carbon dioxide as it decomposes in the forest, Ahlers points out that wood burned in a biomass facility releases the CO2 in one immediate pulse. Still, he notes the issue involves a “complex factual question” that climate scientists have “wrestled with.”

Biomass101, a coalition of organizations representing the forest products industry, thinks biomass energy should be considered renewable, while acknowledging that the bioenergy carbon cycle is complicated. In an email to The Biomass Monitor, a representative writes that biomass energy is “part of a complex process of carbon capture, storage, and emission that carries on much the same whether trees become forest bioenergy, or are lost to insects, disease, storm damage, wildfires and the like.”

The organization contends that “biomass is carbon neutral where American forests are capturing as much or more carbon as energy production is emitting, and where sustainable forest management is reinforcing that dynamic.”

When it comes to directly measurable smokestack emissions, Ahlers writes that biomass energy generates “nearly as many carbon dioxide emissions as coal and significantly more carbon dioxide emissions than natural gas.”

Specifically, the EPA attributes 208.6 MMT (million metric tons) of carbon dioxide emissions per year to the commercial, industrial and residential burning of woody biomass. 120.2 MMT comes from the industrial sector, 59.8 MMT from residential burning, 21.3 MMT from the electricity sector, and 7.2 MMT from commercial biomass.

Public Health

The EPA and proponents of biomass energy have distracted attention away from its public health impacts by “framing the issue of biomass around climate,” writes report author Christopher Ahlers, in an email exchange with The Biomass Monitor. Ignoring air pollution, he says, has resulted in “limiting the engagement of environmental groups,” many of which are either tangentially involved with the issue, or not at all.

The report delves into the air pollution concerns from the combustion of biomass, citing World Health Organization estimates of seven million annual deaths worldwide attributed to air pollution.

All forms of combustion, including biomass, emit nitrogen oxides and fine particulates, along with hazardous air pollutants (formaldehyde, benzene, toluene), mercury, and other chemicals. The EPA has linked nitrogen oxides to respiratory problems, and when it comes to particulate matter, the agency has “not identified a threshold below which there are no adverse effects on human health.”

Therefore, the report concludes that biomass energy “contributes to the formation of the country’s two most significant air pollution problems.”

Because of its air emissions, biomass is “more similar to coal, oil, and natural gas (non- renewable energy), than it is to wind and solar power.”Ahlers determines that “many people have erroneously become fixated on biomass, even though it presents harm to public health.”

Culture of Wood Burning

Wood Burning, Biomass, Air Pollution, and Climate Change also tackles the issue of residential wood burning, including wood stoves and fireplaces.

New England is a hot bed of wood heating, with Vermont, New Hampshire, and Maine ranked first, fourth, fifth in per capita air emissions from wood burning. The report notes a “broader pattern of elevated asthma levels” in these states.

Ahlers compares emissions from fireplaces and woodstoves, calculating that fireplaces release twenty times the amount of particulates as an EPA-certified woodstove. An EPA-certified woodstove, meanwhile, emits 169 times more particulates than a gas furnace.

Because of what he calls a “cultural affinity for wood burning,” when it comes to wood stoves, some states are “refusing to enforce more stringent standards for the protection of public health.”

Outside of the U.S., burning wood and biomass for cooking and heating is responsible for “millions of annual deaths from household air pollution in developing countries.”

Renewable or Not?

According to Biomass101, the fact that trees cut for bioenergy eventually grow back means the energy source is “inherently renewable.”

However, Clean Air Council believes the expansion of biomass energy is less a science-based decision and more the “result of political and cultural choices being made by both consumers and corporations.”

Ahlers makes the point that nuclear energy could theoretically be considered renewable, because of its lack of direct air emissions, and the fact that uranium isn’t a fossil fuel, however it’s been denied the label mostly because of its health and environmental impacts.

The report concludes that the same restrictions applied to nuclear power should be applied to biomass energy, “due to the health and environmental impacts in the form of fine particulates and harvesting of trees.”


  • From a public health perspective, wood smoke in any form is a really bad idea. Although health boards generally are aware of
    this issue, the public is not. There is serious pushback to any attempt to limit residential heating with wood and a concerted effort
    needs to be made to educate the public. I have suffered serious health problems due to neighbors who heat with wood and I welcome a broad based effort to educate and regulate.


  • Though I can agree with this from the perspective of using ‘non-renewable’ biomass.. ..or, clear-cutting forests, shoddy crop-types, etc. but, from the perspective of a much more sustainable feedstock, this is nonsense.

    Switchgrass, miscanthus, tree farms, algae, ‘waste’ biomass from various industries, most notably the tree trimming crews where their wood chips would otherwise go to landfill..,the list goes on. Combined with gasification be it through anaerobic digestion or pyrolysis.. ..or both in a two stage process, vs incineration biomass is incredibly clean, sustainable, and when the pyrolysis results in the creation of a biochar after-product, then biomass becomes not only ‘another renewable energy source’, but the *only* energy source (period) that’s carbon-*negative*.

    Essentially every byproduct formed during pyrolysis has value… from the wood vinegar to the biochar to the flue stack emissions being compressed, stored, and sold back to the biomass industry (greenhouses) for CO2 & N2 fertilization.

    Now, clear-cutting virgin woods with the intention of incinerating and emitting out a smoke stack? That may not be very renewable, but ‘there are other ways’.


    • Rolf Cachat-Schilling

      No one is proposing a waste biomass model for real use here. That would be different. Perhaps we could take a step and industry could at least harvest biomass waste. All the proposals in action in this region are to burn healthy, live trees for energy. The other problem with harvesting waste biomass is expending carbon fuels to harvest waste. If you truck materials around, you are working against efficiency in terms of carbon footprint. I work with biomass research in China, but these are located where the waste is produced and is harvested efficiently. Biomass in Springfield, for instance, hasn’t sourced a local waste product. The other problem of harvesting everything of value from biomass burning is that much of it cannot be harvested at competitive cost, or without adding cost, under current economic models.

      The other big part is that nothing is in place to harvest post-burn materials or to source renewable waste biomass. So, even though some materials could be harvested post-burn at little cost and perhaps viable quantity, that’s a bit of gain at the end of a long line of logistical and infrastructure steps that don’t exist and have little impetus that i can see.


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