Wood is increasingly being used to replace coal as a source of electricity generation in many regions such as the European Union, where policymakers have declared it “carbon neutral.” However, new research from researchers at MIT, Climate Interactive and UMass Lowell reportedly reveals that displacing coal with wood for power generation can make climate change worse for many decades or more.
In the new study, "Does replacing coal with wood lower CO2 emissions? Dynamic lifecycle analysis of wood bioenergy," the researchers"—John Sterman, the Jay W. Forrester Professor of Management at MIT Sloan School of Management; Juliette Rooney-Varga, director of the UMass Lowell Climate Change Initiative and associate professor of environmental biology; and Lori Siegel, PhD, senior modeler for Climate Interactive—examine the climate impact of replacing coal power generation in the EU and UK with wood pellets sourced from forests in the Southern United States.
The researchers found that wood pellets burned in European and UK power plants, such as the Drax facility in North Yorkshire—which has transitioned some of its coal power generation capacity to wood pellets with the support of UK government subsidies—actually emit more CO2 per kilowatt hour than that generated by coal. This is because wood is reportedly both less efficient at the point of combustion and has larger processing and supply chain emissions than coal. Their research shows that using wood instead of coal in power generation increases the amount of CO2 in the atmosphere, worsening climate change until—and only if—the harvested forests regrow.
Prof. Sterman sums up the findings this way: “It’s like an investment in which you give your bank $1,000 today. They promise to pay you back, but only over 80 years, and only if they don’t go out of business first or decide there’s something else they’d rather spend your money on. You’re better off if you keep your money. In the same way, it’s better to keep the trees on the land and keep all that carbon out of the atmosphere.”
Critically, the analysis does not support continued coal use as it is the most carbon intensive fuel and a major contributor to climate change. The researchers stress energy efficiency, solar, wind and storage as the cheapest, safest, and quickest ways to cut greenhouse gas emissions while providing the goods and services people need.
Read more about the study here.