Browsing by Author "Polasky, S."

Now showing 1 - 2 of 2
  • Land clearing and the biofuel carbon debt
    Fargione, J.; Hill, J.; Tilman, D.; Polasky, S.; Hawthorne, P. (Sciencexpress, 2008)
    Increasing energy use, climate change, and carbon dioxide (CO2) emissions from fossil fuels make switching to low-carbon fuels a high priority. Biofuels are a potential low-carbon energy source, but whether biofuels offer carbon savings depends on how they are produced. Converting rainforests, peatlands, savannas, or grasslands to produce food crop-based biofuels in Brazil, Southeast Asia, and the United States creates a "biofuel carbon debt" by releasing 17 to 420 times more CO2 than the annual greenhouse gas (GHG) reductions that these biofuels would provide by displacing fossil fuels. In contrast, biofuels made from waste biomass or from biomass grown on degraded and abandoned agricultural lands planted with perennials incur little or no carbon debt and can offer immediate and sustained GHG advantages.
  • Measures of the effects of agricultural practices on ecosystem services
    Dale, V. H.; Polasky, S. (Elsevier B.V., 2007)
    Agriculture both affects and is affected by ecosystem services such as soil conservation, biodiversity, water quantity and quality, carbon sequestration, pollination, nutrient cycles and others. Different agricultural management approaches have varying impacts on ecosystem services, ranging from detrimental to neutral to positive. Although challenging, it is necessary to develop indicators to evaluate the impacts of agricultural practices on ecosystem services so that more sustainable, beneficial methods can be identified, developed, and implemented. This paper provides a framework of factors to consider in choosing indicators and reviews current knowledge on the interactions of agricultural methods with land use change, erosion, and chemical use.