Environmental impacts of current biofuels
Low greenhouse gas saving
Common first-generation biofuels usually have a well-to-wheel GHG saving ranging anywhere between 10 and 90% compared to fossil fuel. In principle biofuels are carbon neutral: in order to grow, plants absorb carbon dioxide through photosynthesis. When using that plant as bioenergy this carbon dioxide is returned to the atmosphere with no net changes in the amount of carbon. However, the savings on GHG depend on the source of the biomass and it's land-use effects as the CO2 emitted when burned is rougly the same per unit of energy regardless of the source ( IPCC 2006). A lot of calculations that deliver high savings ignored two important factors, which make the stated GHG saving highly uncertain, sometimes even negative.
1) Nitrous oxide (N2O) emission through fertilizer use
N2O is released to the atmosphere through nitrogen fertilizer application and has nearly 300 times the global warming potential of the same mass of CO2. Even though it is not as abundant in the atmosphere as carbon dioxide it currently represents the third most important gas causing global warming. In addition recent evidence suggest that the figures assumed (set by the Intergovernmental Panel on Climate Change) may have been underestimated by up to 5 times.
A study leaded by Nobel laureate P.J. Crutzen et al. (2008) has shown that common first-generation biofuels crop such as rapeseed requires high amount of fertilizer input, and thus can contribute as much or more to global warming by N2O emission than cooling by fossil fuel savings. For rapeseed biodiesel, the analysis indicates that the global warming by N2O is on average about 1.0-1.7 times larger than the cooling effect due to ‘saved fossil CO2’ emission, excluding the fossil energy input.
2) Emission through land-use change
It takes land to cultivate biofuel feedstocks, and this creates both direct and indirect land-use change that affects the biodiversity as well as releasing carbon stored on the land.
Direct land use-change
Carbon stored in undisturbed natural soils and forests is released if the land is cleared to produce the extra crops needed as a result of an increase on biofuels demand.
The green-house gas emissions from land use change vary widely between the location and the previous existing ecosystem. Depending on the previous ecosystem, a certain carbon stock was retained by the coverage, which if removed, leads to a carbon loss. Forests, peatlands and grasslands are among the ecosystems with higher carbon stock. In some cases dedicating land to biofuels can potentially reduce the emissions but only if by doing so, there is an increase in the carbon benefit on land.
In the EU, domestically produced rapeseed oil are increasingly used for biodiesel production, which leads to a considerable gap in EU food oil supplies. This has resulted in an increased import of about 2.5 million tons of food oil since 2002, significantly exceeding historic growth rates (Thoenes, 2006). This gap in food oil supplies is filled mainly by palm oil produced in South East Asia. Together with the increasing use for biofuel, such huge demand in palm oil will translate into more deforestation in tropical countries, particularly in Indonesia and Malaysia. So even if biofuels crops are not grown on biodiverse land directly, using available cropland to cultivate feedstocks can divert food production to other area, encouraging deforestation elsewhere. Due to forest and peatland destruction, Indonesia has become in recent years the 3rd largest carbon emitter in the world (Wetlands International 2009).
Indirect land-use change
Indirect land use change happens when as a result of using available cropland to cultivate feedstocks, food production is diverted elsewhere, encouraging deforestation and degradation of preserved ecosystems.
There are evidences suggesting that the promotion of corn ethanol in the US leads to near doubling soya prices, which in turn has driven conversion of rainforest and savannah in Brazil for soya bean cultivation (Laurance, 2007; Morton et al., 2006). A study published in Science by Searchinger et al. (2008) estimated that large biofuel mandates for US corn ethanol would displace food production to other countries, doubling GHG emission over 30 years and increasing GHG for 167 years.
The Gallagher report ( February 2008) ordered by the UK’s Secretary of State for Transport Ruth Kelly concluded that “ the displacement of existing agricultural production, due to biofuel demand, is accelerating land use change and, if left unchecked, will reduce biodiversity and may even cause greenhouse gas emissions rather than savings”.
Even though assessing the impacts of indirect land use change is more complex than direct land use change there are available calculations carried out by the US Environment protection Agency (EPA) and the Californian Air Resources Board (CARB). The state of California finalized on April 2009 its 'Low Carbon Fuel Standard' (LCFS), a law which promotes fuels on the basis of their ability to reduce greenhouse gas emissions. Efforts are currently being undertaken also in Europe to develop methodologies to account for the emissions linked to Indirect Land Use Change (ILUC).
Threatening valuable wildlife habitatsBrazilian Cerrado
The Cerrado, located in Brazil’s central highlands, is a particular concern. The Cerrado is the world’s most wildlife-rich savannah, and listed as a biodiversity hotspots with a high level of endemism by Conservation International . It contains 837 bird species, including the critically endangered Cone-billed Tanager Conothraupis mesoleuca, and nearly 200 species of mammals, with threatened species such as the Giant Anteater, Pampas Cat and Maned Wolf. Together with around 7000 species of plants and hundreds of species of reptiles and freshwater fish (Klink & Machado, 2005), this area is of huge importance for wildlife.
By 2004, large-scale soya bean and other farming had reduced the size of this unique habitat to 43% of its original size. Around 1% of the remaining Cerrado is lost every year (Butler, 2007) and only 2.2% of the Cerrado is legally protected.
Moreover, the Cerrado soil and vegetation have high levels of stored carbon. If Cerrado is cleared to cultivate soya bean for biodiesel production, it is estimated that it would take 37 years to repay the carbon debt created by the land conversion (Fargione et al. 2008).
Due to the recent boom in biofuels, much land under the Common Agricultural Policy set-aside scheme has been turned into maize and rapeseed crops. This has caused further reduction in habitats available for many European farmland birds, such as Little bustard Tetrax tetrax and Red kite Milvus milvus.
Many studies have confirmed the beneficial role of fallow pockets like set-asides on farmland birds (Bracken & Bolger, 2006; Wretenberg et al., 2007) and mammals (Macdonald et al., 2007). Such land is important for birds because it provides food in winter and undisturbed nesting sites in spring. However, the European Commission has completely abolished compulsory set-aside from 2008 as part of the CAP Health Check, jeopardizing biodiversity conservation. The justification put forward for this abolition has been the high price of cereals, partly driven by the growth in biofuels.
Wider pollution and water impacts
Large-scale cultivation of food crop often involves heavy use of pesticide, herbicide and fertilizers, and their effects could extend far away from the actual plantations. In Brazil, evidence suggests that wide-spread pesticide use in soya bean farms is threatening the down-stream Pantanal wetland area (WWF, 2003). This area is one of the world’s largest and most important wetlands and provides refuge to hundreds of bird species, including the endangered Hyacinth macaws Anodorhynchus hyacinthinus, Jabiru Jabiru mycteria and some healthy nesting sites for Wood storks Mycteria americana. Pantanal is rich in mammals and reptiles as well, including jaguars, alligators, giant otters, iguanas, anacondas, anteaters and capybaras.
Besides pollutions by runoff, the irrigation needed for biofuel crops would impact the surrounding wildlife, particularly on wetland ecosystems. A current example is a large-scale sugarcane plantations development project in the Tana River Delta on the northeast coast of Kenya. Developers plan to establish a 20 000 hectares of sugarcane plantation 30km upstream of the delta, partly for bioethanol production. The project intends to extract 28 m3/second of water (a third of river water volume during the dry season) from the Tana River to irrigate the sugarcane (Mireri et al., 2008). This huge irrigation will cause severe competition for water resources between the sugar project, other development projects and downstream domestic, livestock, wildlife, fisheries and ecosystem needs, affecting not just wildlife, but local livelihoods as well.
The Tana River Delta consists of a series of complex and seasonally flooded habitats, and is an Important Bird Area (IBA: KE022) with more than 345 species of birds including the threatened Basra Reed Warbler Acrocephalus griseldis and Tana River Cisticola Cisticola restrictus. No less than 22 species with internationally important populations have been recorded there, making the delta one of the key sites in Kenya for bird conservation.
After been made public in 2007 strong advocacy and awareness campaigns against the project were raised and a court injunction temporarily stopped it. However, in June 2009, Kenya’s High court ruled in favour of the project, allowing the Government to give tenure rights and ownership to the developers for the growth of maize and rice.
Bracken, F. and Bolger, T. (2006) Effects of set-aside management on birds breeding in lowland Ireland. Agriculture Ecosystem & Environment 117 (2-3): 178-184.
Crutzen, P.J., Mosier, A.R., Smith, K.A., and Winiwarter, W. (2008) N2O release from agro-biofuel production negates global warming reduction by replacing fossil fuels. Atmos. Chem. Phys., 8: 389-395. Available at: http://www.atmos-chem-phys-discuss.net/7/11191/2007/acpd-7-11191-2007-print.pdf
Fargione, J. et al. (2008) Land clearing and the biofuel carbon debt. Science 29 February 2008 319:1235-1238.
Friends of the Earth (2005a) The oil for ape scandal: How palm oil threatens orang-utan survival.
Gallagher (2008) The Gallagher Review of the indirect effects of biofuels production. Renewable Fuels Agency. Available at: http://www.renewablefuelsagency.org/_db/_documents/Report_of_the_Gallagher_review.pdf
International Council for Science (2009) Rapid assessment on Biofuels and the Environment: Overview and Key Findings. The Scientific Commitee on Problems of the Environment (SCOPE).
IPCC (2006). IPCC Guidelines for National Greenhouse Gas Inventories, prepared by the National Greenhouse Gas Inventories Programe. ( Institute for Global Environmental Strategies, Tokyo, Japan, 2007).
Klink, C.A. & Machado, R.B. (2005) Conservation of the Brazilian Cerrado. Conservation Biology 19(3): 707-713.
Laurance, W.F. (2007) Switch to corn promotes Amazon deforestation. Science 14 December 2007 318: 1721.
Macdonald, D.W., Tattersall, F.H., Service, K.M., Girbank, L.G. and Feber, R.E. (2007) Mammals, agri-environment schemes and set-aside – what are the putative benefits? Mammal Review 37 (4): 259-277.
Mireri, C., Onjala, J., and Oguge, N. (2008) The economic valuation of the proposed Tana Integrated Sugar Project (TISP), Kenya. Report commissioned by Nature Kenya. Available at: http://www.rspb.org.uk/Images/tana_tcm9-188706.pdfMorton, D.C. et al (2006) Cropland expansion changes deforestation dynamics in the southern Brazilian Amazon. PNAS 103(39): 14637-14641.
Searchinger, T. et al (2008) Use of US cropland for biofuels increases greenhouse gases through emission from land use change. Science 29 Feb 2008 319: 1238-1240.
Thoenes, P. (2006) Biofuels and commodity markets – palm oil focus. Paper represented in AgraInforma conference, Brussels, 24-25 October 2006. Available at: http://www.fao.org/es/esc/common/ecg/122/en/full_paper_English.pdf
Wretenberg. J., Lindstrom, A., Svensson, S. and Part, T. (2007) Linking agricultural policies to population trends of Swedish farmland birds in different agricultural regions. Journal of Applied Ecology 44: 933-941WWF (2003) Oil palm, soybeans & critical habitat loss. A review prepared for the WWF Forest Conversion Initiative.
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