land

National biomass feedstock assessments (Perlack et al., 2005; DOE, 2011) have focused on cellulosic biomass resources, and have not included potential algal feedstocks. Recent research (Wigmosta et al., 2011) provides spatially-­‐explicit information on potential algal biomass and oil yields, water use, and facility locations. Oak Ridge National Laboratory and Pacific Northwest National Lab are collaborating to integrate terrestrial and algal feedstock resource assessments. This poster describes preliminary results of this research.

A broad-scale perspective on the nexus between climate change, land use, and energy requires consideration of interactions that were often omitted from climate change studies. While prior analyses have considered how climate change affects land use and vice versa (Dale 1997), there is growing awareness of the need to include energy within the analytical framework. A broad-scale perspective entails examining patterns and process at divers spatial and temporal resolutions.

IN THEIR REPORTS IN THE 29 FEBRUARY ISSUE (“LAND CLEARING AND THE BIOFUEL CARBON debt,” J. Fargione et al., p. 1235, and “Use of U.S. croplands for biofuels increases greenhouse gases through emissions from land-use change,” T. Searchinger et al., p. 1238), the authors do not provide adequate support for their claim that biofuels cause high emissions due to land-use change. The conclusions of both papers depend on the misleading premise that biofuel production causes forests and grasslands to be converted to agriculture. However, field research, including a meta-analysis of 152 case studies, consistently finds that land-use change and associated carbon emissions are driven by interactions among cultural, technological, biophysical, political, economic, and demographic forces within a spatial and temporal context rather than by a single crop market (1–3). Searchinger et al. assert that soybean prices accelerate clearing of rainforest based on a single citation (4) for a study not designed to identify the causal factors of land clearing. The study (4) analyzed satellite imagery from a single state in Brazil over a 4- year period and focused on land classification after deforestation. Satellite imagery can measure what changed but does little to tell us why. Similarly, Fargione et al. do not rely on primary empirical studies of causes of landuse change. Furthermore, neither fire nor soil carbon sequestration was properly considered in the Reports. Fire’s escalating contribution to global climate change is largely a result of burning in tropical savannas and forests (5, 6). Searchinger et al. postulate that 10.8 million hectares could be needed for future biofuel, a fraction of the 250 to 400 million hectares burned each year between 2000 and 2005 (5, 6). By offering enhanced employment and incomes, biofuels can help establish economic stability and thus reduce the recurring use of fire on previously cleared land as well as pressures to clear more land (7–9). Neither Searchinger et al. nor Fargione et al. consider fire as an ongoing land-management tool. In addition, deep-rooted perennial biofuel feedstocks in the tropics could enhance soil carbon storage by 0.5 to 1 metric ton per hectare per year (10). An improved understanding of the forces behind land-use change leads to more favorable conclusions regarding the potential for biofuels to reduce greenhouse gas emissions.

Relationships between people and their environment are largely defined by land use. Space and soil are needed for native plants and wildlife, as well as for crops used for food, feed, fiber, wood products and biofuel (liquid fuel derived from plant material). People also use land for homes, schools, jobs, transportation, mining and recreation. Social and economic forces influence the allocation of land to various uses. The recent increase in biofuel production offers the opportunity to design ways to select locations and management plans that are best suited to meet human needs while also protecting natural biodiversity (the variation of life within an ecosystem, biome or the entire Earth). Forethought and careful planning can help society balance these diverse demands for land. At the same time, current energy infrastructure must become less reliant on the earth’s finite supply of fossil fuels because they contribute to greenhouse gas emissions, cause environmental pollution, and jeopardize energy security. The sustainable development of renewable fuel alternatives can offer many benefits but will demand a comprehensive understanding of how our land-use choices affect the ecological systems around us. By incorporating both socioeconomic and ecological principles into policies, decisions made regarding biofuel production can be based on a more sustainable balance of social, economic, and ecological costs and benefits. Researchers are actively studying the potential impacts of biofuels production on land use and biodiversity, and there is not yet a firm consensus on the extent of these effects or how to measure them. In this report, we summarize the range of conclusions to date by exploring the features and benefits of a landscape approach to analyzing potential land-use changes associated with biofuel production using different feedstocks. We look at how economics and farm policies may influence the location and amount of acreage that will ultimately be put into biofuel production and how those land-use changes might affect biodiversity. We also discuss the complexities of land-use assessments, estimates of carbon emissions, and the interactions of biofuel production and the US Department of Agriculture Conservation Reserve Program. We examine the links between water and biofuel crops and how biofuel expansion might avoid “food versus fuel” conflicts. Finally, we outline ways to design bioenergy systems in order to optimize their social, economic and ecological benefits.

The U.S. Department of Energy Biomass Program sponsored the Land-Use Change and Bioenergy workshop in Vonore, Tennessee, from May 11 to May 14, 2009. More than 50 experts from around the world gathered to review the state of the science, identify opportunities for collaboration, and prioritize next steps for the research and data needed to address key issues regarding the land-use effects of bioenergy policies. A key outcome of the workshop was the
identification of research areas that may improve our understanding of land-use change in a bioenergy context.