The EU, UK, US, and other nations consider wood to be a carbon neutral fuel, ignoring the carbon dioxide emitted from wood combustion in their greenhouse gas accounting. Many countries subsidize wood energy – often by burning wood pellets in place of coal for electric power – to meet their renewable energy targets.
But can wood bioenergy help cut greenhouse emissions in time to limit the worst damage from climate change?
New research by UMass Lowell’s Climate Change Initiative Director Juliette Rooney-Varga and colleagues at MIT, Climate Interactive and Tufts University develops and uses a dynamic model to answer that question.
The argument in favor seems obvious: wood, a renewable resource, must be better than burning fossil fuels. But wood emits more carbon dioxide per kilowatt-hour than coal – and far more than other fossil fuels. Therefore, the first impact of wood bioenergy is to increase the carbon dioxide in the atmosphere, worsening climate change. Forest regrowth might eventually remove that extra carbon dioxide from the atmosphere, but regrowth is uncertain and takes time – decades to a century or more, depending on forest composition and climatic zone – time we do not have to cut emissions enough to avoid the worst harms from climate change. More effective ways to cut greenhouse gas emissions are already available and affordable now, allowing forests to continue to serve as carbon sinks and moderate climate change.