Study shows impact of market forces on bioenergy GHG emissions

By Luke Geiver | March 29, 2012

A new study completed by Christopher Galik, senior policy associate at Duke University’s Nicholas Institute for Environmental Policy Solutions highlights the important role market forces play in calculating the greenhouse gas (GHG) emissions from woody biomass used for bioenergy applications.

Market forces, Galik said, are shorthand for landowner and forestry industry response to changing market conditions created by an increased demand for forest biomass. “With changes in demand, you get changes in prices paid for forest biomass and a related change in landowner behavior—planting, management, conversion to other land uses, that sort of thing,” he said. Galik’s study, titled “The Effect of Assessment Scale and Metric Selection on the Greenhouse Gas Benefits of Woody Biomass,” shows that those changes result in more carbon being stored on the landscape, which in turn, lowers the net GHG emissions associated with widespread biomass use.

Galik, who focuses on the development of state and federal renewable energy and climate policy, said his team has worked for several years to better understand landowner and forest industry response to increased biomass demand. The current work focuses on maximizing the co-firing of coal and woody biomass in Virginia, an effort the team calculated would require about 4.9 million green tons of woody biomass at 50 percent moisture.

“Our work up to this point shows that these responses can have a big impact on the observed greenhouse gas effects of forest biomass use,” he said. “While some studies indicate that biomass use could be beneficial from an emissions perspective, others suggest that biomass could end up leading to more emissions than a fossil fuel alternative, at least in the near term.” But, Galik said, because many of these studies were conducted in different parts of the country, in different markets, and using different assumptions and different calculation techniques, it’s difficult to make an apples-to-apples comparison across studies and come up with a common conclusion.

He said his study includes three important aspects. The first is its focus. “Tracking the greenhouse gas effects of a single harvest made to supply a biomass facility is a very different exercise than trying to estimate the net greenhouse gas effects of policy-driven expanded biomass use at the state or regional level,” Galik said. How greenhouse gas benefits are calculated can significantly influence those emissions.

The next important aspect to consider is the inclusion of market forces when tracking GHG emissions at the state or regional level. Less land may be converted out of forest to other uses, more acres may be planted, and existing forests may be managed differently, Galik said 

“So, when market-driven factors such as shifts in forest area, forest type  and industrial capacity are not considered, net greenhouse gas emissions in our hypothetical scenario were much higher initially before falling over time,” he said. “But when these components were included in the hypothetical scenario, bioenergy produced greenhouse gas benefits from day one.”

The third aspect Galik hopes his study highlights is the uncertainty that comes with measuring GHG, an effort that is both resource and time intensive. “Any framework to estimate or monitor greenhouse gas emissions from biomass use should therefore weigh the benefits achieved by such an approach against administrative burden, certainty, and other considerations.”

The end goal for Galik and his research team is to help inform the conversation, he said. “Often times, subtleties in assumptions are lost in the debate. By starting with a common set of assumptions, which here includes the location and timing of our hypothetical scenario and the magnitude of increased biomass demand, we hope to draw attention to those things that can really influence the observed outcome so that an informed discussion may be had on the best way to address those issues from a policy perspective.”

To view the entire study click here