New Study Confirms Climate Risks of Burning Forest Biomass to Produce Electricity

This week, yet another study was released that points to the need to reassess biomass policies both in Europe and the US. The analysis, published by the World Resources Institute, challenges the assumptions of "carbon neutrality" that underpin renewable energy policies for burning biomass as a substitute for fossil fuels. Absent sound carbon accounting mechanisms and other environmental safeguards, not only do these policies risk driving massive destruction of forests and diversion of land away from food production, but also increasing carbon emissions at the very moment when we need to be rapidly transitioning our electricity sector to truly clean technologies.

Until recently, burning biomass to produce electricity was widely considered a "renewable" resource, along with technologies like solar, wind, and geothermal. Many players looked to this technology as an alternative to coal and natural gas that would help reduce greenhouse gas emissions. Working from this premise, policymakers in the European Union put in place aggressive renewable energy targets and generous subsidies for renewable technologies, including biomass in all forms.

But over the last 4-5 years, emerging science has concluded time and again that not all biomass is created equal. Some forms of biomass fuel, such as sawdust and bark from sawmills, construction wood waste, and dedicated energy crops, have the potential to reduce carbon emissions compared to fossil fuels. But other forms, most notably whole trees that are chipped and manufactured into "pellets," are significant carbon polluters. In fact, numerous studies show that burning whole trees for electricity increases carbon emissions compared to coal and other fossil fuels for decades.

In light of these risks, scientists from around the country recently urged the EPA to carefully evaluate the carbon emissions impacts of burning different types of biomass fuels, and to put in place science-driven regulations that help clean up the biomass energy industry.

Yet despite these warning signals from the scientific community, the biomass market is heading in the wrong direction. In particular, in the southeast US, we are seeing industrial-scale production of wood pellets using significant quantities of whole trees.

Demand for these pellets is growing exponentially in Europe, where more than 3 million tons of wood pellets from southern forests were burned in 2013, and this demand is expected to jump to 5.7 million tons in 2015. These exports to Europe are driven by generous renewable energy policies and subsidies in the EU and UK that treat all biomass as carbon-neutral, despite what the science is telling us.

This massive additional demand for wood now also risks destroying ecosystems that can never be replaced. Increased use of wood from natural forests by wood pellet manufacturers like Enviva and other biomass companies will lead to additional fragmentation of forests that are already highly fragmented, decreasing landscape integrity, water quality and flood storage, wildlife corridors and habitats, and recreational resources. Greater use of plantation pine will incentivize future conversion of the few remaining natural and semi-natural forests to intensive plantations, which bear little resemblance to natural forests in terms of the biological diversity and wildlife habitat they support.

Nearly 90% of southeastern US forests are privately owned, and few laws or regulations exist in the region to curb even the most damaging forestry practices, such as clearcutting and conversion of natural forests to plantations. The biomass industry likes to argue that it's only using "residues" and "wastes," but it has been documented that wood pellet manufacturing giant, Enviva, is using whole trees - including trees from clearcut wetland forests, some over 100 years old.

With demand for their trees on the rise, landowners have little incentive to keep forests standing as carbon sinks, despite the clear value of forests in absorbing and sequestering carbon out of the atmosphere.

This industry could even further expand in the US without rules in place for power plants on this side of the Atlantic. EPA is taking on the task of curbing carbon pollution from US power plants - our single largest source of greenhouse gas emissions - and the agency faces key decisions in drafting new guidance for large biomass-burning facilities. It is important that the agency acknowledge what the scientific community has demonstrated: that an across-the-board pass for biomass as a "carbon neutral" fuel is not scientifically supportable. Just as US regulators distinguish between high-sulfur and low-sulfur coal, they now must distinguish between high-carbon biomass and low-carbon biomass.

If the EPA doesn't acknowledge that many forms of biomass fuel have negative impacts on the climate, then we risk repeating the mistake made in Europe: where utilities are perversely rewarded for using fuels dirtier than coal. EPA has an opportunity to show tremendous leadership as it develops new rules for domestic power plants burning biomass. Following the science should make these decisions much clearer.

About the Authors

Sami Yassa

Senior Scientist

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