Pruitt Declares Biomass Carbon Neutral, in Contrast to Facts

Source material for biomass power plants often comes from leftovers from logging operations, otherwise known as "slash." Photo: Oregon Department of Forestry, Flickr CC.
Source material for biomass power plants often comes from leftovers from logging operations, otherwise known as “slash.” Photo: Oregon Department of Forestry, Flickr CC.

In a world no longer constrained by facts, Scott Pruitt is king. On April 23, 2018, Scott Pruitt, Administrator of the Environmental Protection Agency (EPA), declared that all biomass is carbon neutral. Pruitt’s sweeping declaration is not just inaccurate, but it will also help further subsidize timber industry practices at the expense of our climate and our wallets.

Pruitt’s logic is simple but flawed. Trees sequester carbon as they grow. Although burning these trees releases carbon, more trees will grow in their place, thereby offsetting what carbon was emitted. The truth, however, is more complicated.

First, if forests are burned faster than they grow, then not only is biomass not carbon neutral, it is also helping to accelerate deforestation. But even if we accept Pruitt’s basic premise—a one-for-one trade—Pruitt’s logic doesn’t capture all of the carbon accounting.

Logging itself emits carbon, from the logging trucks, to burning slash piles, to a loss of carbon in the soil. Logging emits so much carbon that clearcut forests continue to “leak” more carbon than they store 30 years after harvest.

Transportation of the fuel also plays an important role in the carbon budgeting. Biomass does not have a high “energy density,” meaning that the amount of energy per pound is low, compared to other comparable fuels like coal. Without subsidies, biomass is difficult to pull off because the “fuel” source (i.e., a forest) needs to be within a short distance of the biomass facility—a general rule of thumb is that a biomass plant in California needs to source from within 50 miles of the site. Thus, many biomass plants are seated next to a lumber mill, where “waste” from the mill can be burned for energy. (The biomass facility in Scotia is one example of this type.)

Some biomass plants also require that the fuel be in a more refined state—like a pellet or a chip. Pelletization can increase the energy density of the biomass. This processing (also carbon intensive) is often required to ship biomass across a long distance.

By declaring biomass defacto carbon neutral, Pruitt’s announcement allows for greater subsidies for biomass power plants. With these subsidies, the transportation distance can increase dramatically, because if a power plant can pay more for fuel, biomass can be shipped from further and further distances. The timber industry is rightly thrilled, and it should be—the industry paid Pruitt’s former chief of staff and another lobbyist who served with Pruitt in the Oklahoma Senate top dollar to lobby him for this change. Increasing biomass use increases demand for its product: former trees.

Biomass may be appropriate in certain circumstances—unlike solar or wind, energy from biomass can be delivered regardless of the weather and so could be a useful component in a localized renewable power strategy, such as that being pursued by the Redwood Coast Energy Authority. However, blanket statements like Pruitt’s risk more than just playing with the facts—they risk investing in the wrong forms of electrical infrastructure, delaying our ability to move to a post-carbon energy grid and economy.

A 2018 study from MIT found that pellet biomass facilities in Europe emitted more carbon than an equivalent coal-fired plant because of the high carbon costs associated with transportation and processing of the source material. These European biomass facilities typically source their fuel from U.S. forests, shipping biomass across the Atlantic.