Published online by Cambridge University Press: 21 September 2018
Sustainability Concerns about Biofuels
Biofuel is distinguished from fossil fuel by the fact that its raw materials (feedstocks) are sourced from biomass such as agricultural crops and other biodegradable matters. Fuels were produced from biomass, such as starch crop and vegetable oil, even before fossil fuels were popularized – Rudolf Diesel's first engine was designed to run on peanut oil. Biofuels regained popularity since the mid- 1970s when Brazil and the United States began to use sugarcane and corn to produce ethanol as transport fuels for energy security and rural development purposes. More recently, reducing greenhouse gas (GHG) emissions in the transport sector has become the key objective of promoting biofuels as a substitute for fossil fuels. Based on the three-fold objective in energy security, GHG emission reduction, and rural development, governmental support has played a major role in the increased production and consumption of biofuels worldwide.
In effect, instead of being applauded for the assumed contribution to energy security, rural development, and GHG emission reduction, biofuels are increasingly subject to criticism for their potential negative impacts on environmental and socioeconomic sustainability (see Table 1). From the environmental perspective, the criticism concentrates on the ecological and climate change impacts during the biofuel production process, particularly with regard to the effects of the changes in land use. It has been pointed out that using a large area of land to grow biofuel feedstocks, which are mainly starch- and oil-rich crops, may threaten biodiversity by deforestation, monoculture, and invasive species, and may also cause air, water, and soil pollution and degradation in the processes of crop cultivation. Moreover, although biofuels are promoted for reducing GHG emissions, the actual contribution to GHG emission reduction has been seriously doubted, especially when emissions during the life cycle of biofuels from direct and indirect land use changes are considered. Apart from environmental concerns, biofuels are also criticised for causing negative social effects particularly for people in poverty, since the feedstocks used for producing biofuels are mostly food sources and their diverted use for biofuel production may give rise to food availability and accessibility problems, as well as land acquisition for biofuels that affects the land use rights of local and indigenous communities.