Biofuel and water cycle dynamics: what are the related challenges for hydrological processes research?

✍ Scribed by Stefan Uhlenbrook

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 103 KB
• Volume: 21
• Category: Article
• ISSN: 0885-6087
• DOI: 10.1002/hyp.6901

✦ Synopsis

The accurate analysis of environmental impacts of large-scale biofuel (Definition: Fuel with a minimum of 80% content by volume of materials derived from living organisms harvested within 10 years of its manufacture.) production is important for many reasons, but in particular it is essential to protect water resources and to assure ecological integrity as far as possible. Biofuels, or more generally bioenergy (including biodiesel, etc.), are promising renewable energy sources intended to satisfy the escalating global energy demand (e.g. Somerville, 2006) and to limit greenhouse gas emissions. The advantages of biofuels are manifold: (i) security of supply (renewable energy; biofuels can be produced locally in comparatively sustainable systems) (ii) lower net greenhouse gas emissions (biofuels recycle carbon dioxide that was extracted from the atmosphere in producing biomass) ( iii) less pollution in respect to other emissions (less sulfur, carbon monoxide and particulates; biodegradable byproducts) (iv) well suited for transport uses (high energy density and handling convenience) and (v) support for agriculture. Somerville (2006) discusses further substantial economic and strategic advantages, as for instance a larger independence of western countries with regard to fossil fuel originating from politically unstable countries. The expectations in this energy source are tremendous (e.g. Ragauskas et al., 2006); the combination of intensive agriculture, modern breeding and transgenic techniques should result in achievements greater than those of the Green Revolution in food crops, and in far less time (e.g. Koonin, 2006). Already about 15% of the total global energy consumption is now derived from biomass and the envisaged future uptake of biofuel is tremendous, particularly in the North where the energy demand is highest. The US Department of Energy proposes that 30% of ground transportation fuel should be replaced by biofuels by 2030. The current EU target is a 10% biofuel replacement by 2020, but many experts state that this is not enough to reach its environmental objectives by far. Some European countries like Sweden and Germany want to go further and would like to become much more independent from fossil fuel for transportation purposes. Brazil currently derives 25% of its transportation fuel from ethanol produced from sugarcane (Somerville, 2006), and it uses only 0•5% of its land area for this. Biofuels can be produced from different crops: (i) corn and soybeans (primarily in USA) (ii) flaxseed and rapeseed (Europe) (iii) sugarcane (Brazil) and (iv) palm oil (South-East Asia). New research is focussing on micro-algae for biodiesel and ethanol production. Recently the demand for biofuel has increased significantly and resulted in an increase in the prices of food crops (Laney, 2006). This is likely to affect food security, particularly in poor countries. This situation becomes aggravated particularly as energy efficient production of biofuels is best possible in sub-humid and humid tropical regions, due to suitable climate and soils. Consequently, on the one hand, larger biofuel production offers great economic chances for developing countries located in the tropics. The farmers could become 'energy farmers' in the South and sell highly