Is it possible for cellulosic biofuels - or liquid energy derived from wood and grasses - to become a green fuel of the future, offering an environmentally sustainable approach to meeting energy requirements? Researchers at the U.S. Department of Energy-funded Great Lakes Bioenergy Research Center believe it is viable, but with a few warnings. They state their ideas in Science.
The climate benefit of cellulosic biofuels is actually much greater than was originally thought,' said Phil Robertson, University Distinguished Professor of Ecosystem Science at Michigan State University. (CREDIT - Courtesy of MSU)
The climate benefit of cellulosic biofuels is actually much greater than was originally thought. But that benefit depends crucially on several different factors, all of which we need to understand to get right.
Phil Robertson, University Distinguished Professor of Ecosystem Science, Michigan State University and the Study’s Lead Author
Although cellulosic biofuels are still not a market force, they are regularly factored into future climate mitigation scenarios because of their capacity to displace petroleum use as well as lessen greenhouse gas emissions. Those advantages, however, are complicated by the need for massive amounts of land to manufacture cellulosic biofuels on a large scale.
"The sustainability question is largely about the impact of using millions of acres of U.S. land to grow biofuel crops," Robertson said. "Can we do that without threatening global food security, diminishing biodiversity, or reducing groundwater supplies? How much more fertilizer would we use? What are the tradeoffs for real climate benefit, and are there synergies we can promote?"
With a decade of empirical research, Robertson and GLBRC colleagues from MSU, the University of Wisconsin and the University of Maryland identify a number of emerging principles for handling the difficult environmental tradeoffs of cellulosic biofuel.
First, the research team revealed how cultivating native perennial species on marginal lands -land not used for food production due to low fertility or other reasons - avoids competition with food security, and provides the maximum potential for biodiversity and climate mitigation benefits.
Second, selection of crop is paramount. Native perennial species offer greater environmental outcomes to annual crops; however no single crop appears to be suitable for all locations. In fact, in certain cases mixed species crops gave superior profits. Third, use of nitrogen fertilizer should be avoided or reduced on account of its global warming and other environmental impacts.
According to the Researchers, these principles (as well as four more drawn in the paper) are sufficient to start guiding sound policy decisions for manufacturing sustainable biofuels. Going forward, however, the team requests for further research on planning landscapes to provide the best suite of climate, energy and environmental advantages. They suggest that understanding how best to incorporate benefits and tradeoffs will be paramount to the future success of cellulosic biofuels.
With biofuels, the stakes are high. But the returns are also high, and if we take key principles into account we can begin shaping the policies and practices that could help make cellulosic biofuels a triple win for the economy, the climate and for environmental sustainability in general.
Phil Robertson, University Distinguished Professor of Ecosystem Science, Michigan State University and the S tudy’s L ead A uthor