Chapter One - Agronomic and Ecological Implications of Biofuels

Abstract

Abstract Biofuels can be alternative energy sources which simultaneously reduce dependence on fossil fuels and mitigate climate change by reducing greenhouse gas (GHG) emissions. In the US, over 50 billion liters of ethanol produced in 2010 is mandated to increase to 136 billion liters by 2022. Globally, approximately 33.3 million ha (Mha) of land under production of biofuels in 2008 may increase to as much as 82 Mha by 2020. Whereas data on the energy efficiency and GHG balances for biofuels are available, information on agronomic and ecological consequences of large-scale production of bioenergy crops is sparse. Thus, this paper describes the potential effects that bioenergy production may have on ecosystems. Conversion of land to biofuel crops may have significant impacts on ecosystem services such soil and water quality, GHG emissions, wildlife habitat, net primary productivity, and biological control, and plant diversity at both the landscape and the regional levels. Production of exotic species for feedstock may increase the risk of escape from agriculture and invasion into natural ecosystems. Several feedstocks, while suitable on the basis of energy and GHG assessments, may have negative ecosystem impacts (i.e., increased N export in the Gulf of Mexico). Bioenergy feedstock may compete with food crops for land, water, and nutrient resources, resulting in higher prices for food as well as potential increases in malnutrition and food insecurity. Biofuels can be a sustainable and renewable source of energy, but assessments must include ecological impacts, economic costs, and energetic efficiencies.