When the European Commission established renewable energy mandates in 2009, one of the accepted renewable sources was biomass–the burning of trees or crops in order to generate energy. Biomass is a widely available and predictable energy source; it is particularly useful in industries where wind and solar are impractical, such as transportation and shipping.
In years since, the fuel has become widely used: almost 60% of renewable energy produced in Europe comes from biomass, usually in the form of wood pellets. Though burning wood releases carbon into the atmosphere, industry leaders argue that emissions can be offset by newly planted crops, which will eventually re-absorb carbon as they grow. The European Union has subscribed to this view and currently defines biomass as carbon neutral. As a result, member states do not need to account for emissions produced by burning biomass.
The EU’s Renewable Energy Directive does state that renewable biomass cannot be harvested from vulnerable or biodiverse ecosystems. However, even if sourced from sustainably managed forests, biomass has several fundamental issues. For one, it is highly inefficient. Research has found that biomass can be more carbon-intensive than fossil fuels, with wood generating one-and-a-half times more carbon emissions than coal for each kWh of electricity produced.
Another issue is that biomass creates a “carbon debt”: studies suggest it will take decades, if not centuries, for replanted trees to absorb the amount of carbon that is released into the atmosphere by burning biomass. Both the fuel’s general inefficiency and long-term time scale are at odds with the need to decarbonize immediately.
Biomass production also threatens forests, which are one of the most effective tools for carbon capture and are critical to climate change mitigation: the United Nations has declared that deforestation cannot continue if the Paris Agreement’s 2050 targets are to be met. Though members of the bioenergy industry tend to emphasize their use of forest residues, they also participate in logging.
A significant portion of the wood in processing facilities are whole pine and hardwood trees, which would have otherwise been purchased by paper mills. Therefore, bioenergy companies are actively driving up demand for wood harvests. As a result, ramping up biomass production would threaten macro-level forest stability. One study found that supplying 2% more global energy from biomass would necessitate doubling total wood harvests.
Demand for biofuel also contributes to indirect land use change (ILUC), which occurs when farmers are incentivized to clear forests in order to grow biofuels. Given the critical need for reforestation, harvesting wood for biomass only exacerbates the climate crisis.
Ultimately, the EU’s treatment of biomass as carbon neutral is fundamentally misleading. In order to reduce its reliance on biomass, the EU must establish accurate accounting standards. In particular, emissions calculations should incorporate the amount of time it will take for released carbon to be absorbed by replanted crops, also known as the “carbon payback period.” These standards will give a more realistic picture of biomass emissions and reduce the fuel’s prevalence in renewable energy portfolios.
The Biden administration has not yet taken a stand on the issue, though biomass does not feature prominently in the president’s infrastructure plan. However, without the specific exclusion of biomass from renewable energy mandates, countries can quickly become reliant on the fuel to reach emissions targets. The United States should not follow in Europe’s footsteps: treating biomass as a carbon-neutral energy source will only drive further wood harvests and carbon emissions at a time when reforestation and decarbonization are critical.