The Ecological Impact of Biofuels

Abstract

The ecological impact of biofuels is mediated through their effects on land, air, and water. In 2008, about 33.3 million ha were used to produce foodbased biofuels and their coproducts. Biofuel production from food crops is expected to increase 170% by 2020. Economic model estimates for landuse change (LUC) associated with food-based biofuels are 67-365 ha 10 −6 l −1 , leading to increased greenhouse gas emissions for decades compared to business as usual. Biodiversity is reduced by about 60% in U.S. corn and soybean fields and by about 85% in Southeast Asian oil palm plantations compared to unconverted habitat. Consequently, the largest ecological impact of biofuel production may well come from market-mediated LUC. Mitigating this impact requires targeting biofuel production to degraded and abandoned cropland and rangeland; increasing crop yields and livestock production efficiency; use of wastes, residues, and wildlife-friendly crops; and compensatory offsite mitigation for residual direct and indirect impacts.

Biomass sorghum and maize have similar water-use-efficiency under non-drought conditions in the rain-fed Midwest U.S.

“…Meeting the cellulosic biofuel production goals established by the 2007 RFS will require the transition of existing cropland to alternative biofuel feedstocks (Fargione et al, 2010;Abraha et al, 2015). Changes in land use will alter the biophysical properties of the landscape, with subsequent effects on the flow and storage of energy, water, and carbon in agroecosystems (Bagley et al, 2014).…”

“…However, the Renewable Fuel Standard (RFS) requires that 60 billion of the 136 billion liters (L) of renewable bioethanol must be produced from non-grain (i.e. cellulosic) feedstocks by 2022 (RFA, 2010;Fargione et al, 2010;EPA, 2015). Therefore, a transition to dedicated bioethanol feedstocks will be required to meet the cellulosic bioethanol production goals established by the 2007 RFS (Rooney et al, 2007).…”

Bioenergy from “surplus” land: environmental and socio-economic implications

“…Approaches have been developed to represent difficult to quantify impacts arising from the cultivation of energy crops, such as biodiversity loss or GHG emissions (e.g. Fargione et al 2010;Urban et al 2011), or integration of market models that quantify displacement and expansion effects (Reinhard and Zah 2009;Reinhard and Zah 2011), into consequential LCA models. Still more work is needed to further improve LCA, in particular as the reliability of data used in some LCAs is called into question (e.g.…”

Global greenhouse gas implications of land conversion to biofuel crop cultivation in arid and semi-arid lands – Lessons learned from Jatropha

“…From these discussions it is recommended that biofuel s (1) should not increase greenhouse gas emissions compared to fossil fuel use, (2) should not increase direct or indirect competition with food production for land and resources (Finco and Doppler, 2010;Janaun and Ellis, 2010), (3) should avoid large carbon stock changes through direct and indirect land use changes (Fargione et al, 2008;Searchinger et al, 2008), (4) should not decrease other ecosystem services, (e.g. water quantity (Fingerman et al, 2010), and (5) should avoid impact on biodiversity (Fargione et al 2010, Wiens et al 2011). …”