Biomass is not health neutral

Even as Congress declares that biomass is carbon neutral, burning it puts thousands of lives at risk.

In the $1.5 trillion spending bill recently passed by Congress, lawmakers codified a declaration that biomass taken from forests is “carbon neutral.” Putting aside the many questions and conditions that need to be met in order for this to be true and the potential impacts on biodiversity, encouraging the use of biomass for energy will increase air pollution, public health impacts and environmental justice issues around the siting of these facilities. We recently published a peer-reviewed paper quantifying the health impacts of burning wood and biomass in residential and commercial buildings, industry and power plants. In it, we found that burning wood and biomass in buildings and in industry had a combined public health burden of at least 18,000 deaths, higher than that of coal-fired power plants. 

Biomass mostly comes from firewood, waste wood, wood pellets and wood chips, but it can also come from farm waste, such as the waste from corn and soybean harvesting, paper, cotton, wool and food from trash. These biomass sources are then burned to produce heat and power for buildings and industry, and to produce electricity. Like other combustion fuels, air pollution from burning biomass can cause asthma exacerbations, hospitalizations for heart attack and respiratory disease, birth defects, neurodegenerative diseases and death, among many other health impacts. 

Our research found that in 2017 in the U.S., air pollution from burning firewood in homes was responsible for 9,800 to 16,000 deaths, burning biomass in industrial boilers had a health burden of 8,000 to 15,000 deaths, and using it in commercial buildings had a health burden of 640 to 1,200 deaths. This is comparable to the 9,100 to 11,000 deaths due to the coal-fired power plants that were operating in 2017. Wood and biomass was the most impactful fuel in homes in all states, except for New York and Illinois.  

This is an underestimate since it does not include the health harms due to exposure to indoor air pollution from wood stoves. A recent study found massive increases in indoor air pollution from wood stoves, an exposure that is associated with increased respiratory illness in children, along with the many other health impacts from air pollution. 

Our study, along with many others, demonstrates that swapping out one combustion fuel for another, even if Congress considers the new fuel to be “carbon neutral,” is not a pathway to a healthy energy system. Increasing reliance on biomass fuels, at minimum, will be a missed opportunity for big public health gains. Alternatives to wood and biomass for home heating exist. These include air-source heat pumps, ground-source heat pumps, and GeoGrids — a novel home heating and cooling technology with six demonstration projects underway in Massachusetts. Biomass plays an extremely minor role on the electrical grid — generating only 1 to 2 percent of total electricity — and could be replaced with wind, solar and other renewables. 

While the use of wood and biomass has increased in both high- and low-income households and commercial buildings, declaring biomass “carbon neutral” could encourage further investment in biomass-related infrastructure. These kinds of infrastructure investments are made across the supply chain with decades-long lifetimes in mind. This makes these facilities difficult to decommission or retire early once installed, similar to the existing fossil fuel infrastructure.  

While carbon neutrality of biomass requires a variety of conditions to be met, solely focusing on carbon emissions without considering other air pollutants and health impacts can lead to shortsighted energy system planning with negative health consequences. Declaring biomass to be carbon neutral with no regard for the health consequences may set us onto a path toward further investing in an energy system with an already-serious health burden, ambiguous climate benefits and environmental justice issues in the supply chain. Committing to alternatives, or better yet, making major energy decisions using a systems-level approach with both climate and public health in mind, can set us on a pathway toward an energy system that is healthier, more just and more compatible with the recommendations of the UN Intergovernmental Panel on Climate Change.

Jonathan Buonocore, Sc.D., is a research scientist at the Center for Climate, Health, and the Global Environment at Harvard T.H. Chan School of Public Health.

Parichehr Salimifard, Ph.D., is an assistant professor at the Oregon State University College of Engineering.