The biomass energy industry, US Senators, and the FAO would have you think that burning wood to produce electricity is a good idea for the climate. Think again.
Forests provide an important source of energy for poor households in developing countries. Fuelwood and charcoal are on average the most valuable forest products to communities that live in and around forests. But according to a new study by Winrock International, woodfuel accounts for 30 percent of climate emissions from forest degradation across the tropics. And the health impacts of burning wood for cooking and heating are severe, especially for women and girls, so many international initiatives are underway to improve access to modern energy services and reduce reliance on wood for fuel.
In some industrialized countries, a reverse trend has been underway, as burning wood for electricity is now being promoted as a climate-friendly source of renewable energy. Ships are sailing across the Atlantic bound for the UK and Europe, laden with wood pellets from North American forests. Some of those pellets are the processed remains of bottomland hardwood forests in my home state of North Carolina.
The emergence of the wood-based electricity industry in rich countries is largely policy-driven, and based on a fallacy: that burning biomass for energy is carbon neutral. After all, trees grow back, right? It’s not a simple as that.
Debunking the carbon neutrality fallacy
A newly released study published by Chatham House meticulously debunks the carbon neutrality fallacy. According to that report, felling entire trees for energy will almost all always lead to higher carbon emissions than burning fossil fuels. When a tree is harvested for energy, the planet loses a piece of its natural carbon capture and storage infrastructure, and mature trees sequester carbon at much higher rates than smaller trees. Further, harvesting whole trees disturbs soils and leads to additional carbon losses.
But what about burning the left-over residues from wood harvesting and processing? Wouldn’t that be okay? Unfortunately, the answer is still often “no.” Why not? There are several reasons:
Incentives for additional harvesting: Whole trees are often misclassified as “residues,” and according to investigations by the Dogwood Alliance, industrial pellet facilities in the US Southeast such as those in North Carolina rely on clearcuts of “low value” timber.
Supply chain emissions: emissions from burning are only part of the story. Full life-cycle accounting for the impacts of wood fuel would take into account the emissions from processing and transporting the wood as well.
Use of harvesting residues: Unless they would have otherwise been burned on site, such wood waste left in the forest would decay more slowly, delaying emissions, and would provide soil nutrients that promote future forest growth.
Use of processing residues: Most sawmill waste already goes to uses such as particleboard, so using them for fuel would increase emissions in the near term.
Fundamentally, the time dimension is critical: burning wood now releases carbon into the atmosphere that will warm the planet and take decades if not centuries to recapture through forest regrowth. To slow climate change, we simply don’t have the luxury of waiting for that to happen, and instead should be working overtime to enhance forest carbon stocks now—with forests one of the only near-term options for negative emissions—rather than settling for break-even eventually.
Based on these considerations, legislation championed by Maine’s delegation to the US Senate that would declare forest biomass to be carbon neutral is a very bad idea.
The FAO fuels the fire
Regrettably, the FAO has apparently fallen for the carbon neutrality fallacy. It has selected “Forests and Energy” as its theme for this year’s International Day of Forests (March 21st), and praises the use of wood energy for “mitigating climate change and fostering sustainable development”. The featured video depicts a woodsman strolling through fall leaves in a temperate forest with a little girl collecting sticks in a basket. The voice-over asks, “What if there were a way to save it all, and use it when we want?” After clips of wood being felled, processed, and burned, the voice-over assures us that “Using wood sustainably keeps a balance for future generations.”
While the tagline of FAO’s video is “The forest: nature’s powerhouse,” growing and burning trees is not a very efficient way to convert sunlight into electricity. According to William Moomaw of Tufts University, burning wood should be compared to the efficiency of photovoltaic panels, which convert solar energy to electricity at about 20 percent efficiency, with no emissions. His back-of-the envelope calculations suggest that this is about 80 times more efficient than growing and burning wood, which generates more emissions per unit of electricity than burning coal.
Déjà vu? Carbon accounting rules are part of the problem
A quirk in how greenhouse gas emissions from biomass energy are reported under the UNFCCC creates perverse incentives for countries to use biomass rather than fossil fuels for energy, even when it’s worse for the climate. To avoid double counting, emissions from biomass are included in land sector reporting rather than energy sector reporting. So when a UK power plant burns wood pellets imported from elsewhere, no emissions are reported. But there’s a problem. According to the Chatham House study, accounting practices for the land-use sector in many countries have the potential to leave emissions from woody biomass unaccounted for.
We’ve seen this movie before: As described in our recent book, Why Forests? Why Now? (drawing on a policy paper by CGD Senior Fellow Kimberly Elliott), EU biofuel policies drove a surge in imports of palm oil from Southeast Asia as a feedstock for biodiesel, and to replace other vegetable oils diverted to produce biofuels. Yet palm oil was being produced on Indonesia’s carbon-rich peatlands—rendering them vulnerable to chronic fires, which in late 2015 generated higher daily emissions than the entire US economy. Not taking into account the emissions from such land-use change makes biodiesel appear to be more climate friendly than it actually is. (See this WRI working paper for more on how accounting errors have led to overstatements of the potential of bioenergy.)
What’s this got to do with development?
The energy mix promoted by policies in industrialized countries has a profound effect on development through its contribution to climate change, which threatens to unravel decades of progress in human well-being. It’s also a small part of a broader set of climate justice issues. Given that we have a fixed planetary limit on the amount of greenhouse gas emissions that can be released into the atmosphere and still keep global warming below 2 degrees Celsius, any additional emissions from rich countries means fewer available to poor countries.
Surely no one could miss the irony: some of the same rich countries that urge strict scrutiny of carbon stock baselines for tropical forests in the context of REDD+ are getting away with fuzzy accounting on the implications of burning wood for the carbon stocks of temperate forests.
Whether temperate or tropical, we can’t have our forests and burn them too.