Environmental Impacts of Biofuels
Cultivation of crops or foresty for food or non-food uses can have a range of environmental impacts both positive (e.g. soil stabilisation, phytoremediation) and negative (e.g. possible reduction in biodiversity, water and fertilizer issues).
Some intensive modern farming methods may have a range of negative effects on the environment, such as soil erosion, water shortage, pollution from pesticides and problems with over use of fertilizers (including eutrophication). Eutrophication, the decrease in the biodiversity of an ecosystem as the result of release of chemical nutrients (typically compounds containing nitrogen or phosphorous), is only one threat to biodiversity, which may also be impacted by the replacement of a natural ecosystem by monocultures, whether annual fields of rapeseed, sugarbeet or cereals, or large areas of coppice, energy crops or short rotation forest.
A number of projects are re-assessing the availability and environmental impact of biofuel feedstocks, while the focus of biofuels R&D&D in Europe is on second generation technologies that use waste oils and fats, agricultural residues, forest biomass or energy crops, which can be grown on marginal land, with lower requirements for fertiliser and other inputs. Work also continues to increase the efficiency and sustainability of first-generation biofuel production (see the plant bioechnology, process innovation, biodiesel and bioethanol pages). For example, Triticale has been tested as an alternative to wheat as a bioethanol feedstock. Trials in the UK in 2011 showed it offered greater yields at the same or lower levels of nitrogen inputs.
In 2015 the Scientific Committee on Problems of the Environment (SCOPE) published an extensive report on bioenergy and sustainability. This report 'Bioenergy & Sustainability: bridging the gaps' combines a comprehensive analysis of the current bioenergy landscape, technologies and practices with a critical review of their impacts. Experts from over 80 institutions contributed to the extensive evaluation of the current status of bioenergy resources, systems and markets and the potential for sustainable expansion and wider adoption of this renewable resource. As documented in the 21 chapters of the report, the use of land for bioenergy is inextricably linked to food security, environmental quality, and social development, with potentially positive or negative consequences depending on how these linkages are managed.
The ARUP and URS Consortium has launched a publication on Sustainability of Advanced Biofuels in 2014, which can be downloaded here.
In 2013 a report was produced by Winrock, IEEP and Ecofys on behalf of EC on Mandatory requirements in relation to air, soil, or water protection: analysis of need and feasibility. The report forms part of of the wider 'Study on the operation of the system for the biofuels and bioliquids sustainability scheme'.
In May 2011 the Global Bioenergy Partnership (GBEP) Task Force on Sustainability agreed on a first set of 24 relevant, practical, science-based, voluntary sustainability indicators for bioenergy. Several countries were undertaking pilot projects to test the feasibility and practicality of the indicators as a tool for policymaking. The final report aims to bring together the lessons learned to date from the GBEP pilots, using the outcomes available so far and focused discussions at a GBEP meeting in May 2013. The report is intended as a guide to help the GBEP community to further develop the indicators and enhance the practicality of the tool. It presents detailed lessons learned and recommendations per indicator. Short, medium and longer term recommendations were provided to the GBEP community to take on board to enhance the practicality of the GBEP indicators as a tool for policy making.
Impact of fertilisers and biofuel policies on the Global Agricultural Supply Chain
In November 2014, OECD published a report Fertiliser and Biofuel Policies in the Global Agricultural Supply Chain: Implications for Agricultural Markets and Farm Incomes.
This report analyses policies along the agricultural supply chain, in particular support measures for fertilisers and for biofuels. It uses the OECD Fertiliser and Biofuel Support Policies Database that covers polices in 48 countries (including the EU and its Members) and assesses the market effects of these policies with a computable general equilibrium model, MAGNET. This report finds that biofuel support policies generate additional demand for feedstock commodities and, therefore, higher incomes for crop farmers in subsidising and non-subsidising countries. In contrast, these policies increase costs to downstream industries, including livestock farmers, and to consumers. Fertiliser support policies reduce crop production costs and hence increase yields, production and incomes for crop farmers in subsidising countries. However, they lower crop farm incomes abroad, while livestock farmers in both country groups face lower feed costs and, in consequence, lower livestock prices.
Preserving biodiversity, ecology and soil quality
Generally, a certain proportion of biomass (straw, stalks, fallen wood, etc) has to be left in situ to maintain forest or field ecology, and to maintain the condition of the soil, prevent erosion, and provide habitat, for example for beneficial insects and fungi, and to promote biodiversity.
In many potentially productive areas (globally), preserving biodiversity may offer greater environmental and economic benefit than clearing forest to produce energy crops. Hence mechanisms need to be put into place to recognise the value of biodiversity These include the use of payments for ecosystem services, such as Reducing Emissions from Deforestation and Degradation (REDD) and REDD-plus (which places a greater value on biodiversity rather than just the quantity of carbon held in the forest system).
Energy crops and phytoremediation
Cultivation of energy crops can be used for phytoremediation of contaminated or poor soils, while offering the potential of future feedstock production. For example, see Multi-tasking plants for phytoremediation and bioenergy [Source: CABI 2013]. Globally, there is vast potential to grow energy crops on 'contaminated' land and poor soils, which are unsuitable for food crops. Current research is focused on trials of energy crop strains that could offer reasonable production potential. The low nutrient levels and inconsistent soils of marginal land tend to result in lower yields, especially in initial years. However, many plant species have evolved to grow in poorer soils, and may improve soil condition and future yields if cultivation is properly managed to maximise soil carbon and nutrient cycling. See also Second Harvest: Bioenergy from Cover Crop Biomass [Kemp Consulting and NRDC, 2011].
In August 2013, the U.S. EPA announced an update of its RE-Powering Mapping and Screening Tool, which has now identified 66,000 locations where contaminated land, landfill and mine sites could be used for cultivation of energy feedstocks.
Water resources and bioenergy production
"The avilability of freshwater resources is an increasingly important in many parts of the world. A growing population and changing dietary trends mean a steeply rising water demand. Under the impact of climate change the population at risk of water stress could increase substantially by the end of the century. In this context, water demand for bioenergy production might place an additional burden on water availability worldwide and induce increased competition over water resources in an increasing number of regions. However, bioenergy demand also leads to new opportunities to develop strategies to adapt to climate change in agriculture: a number of crops that are suitable for bioenergy production are drought tolerant and relatively water efficient and by adopting such crops farmers may better cope with a change in precipitation patterns and increased rates of evapotranspiration1 (ET) due to higher temperature." [Source: Water demand for global bioenergy production: trends, risks and opportunities; Göran Berndes, WBGU].
In November 2009 the Water Supply and Sanitation Technology Platform WssTP launched a consultation on the review of the WssTP Strategic Research Agenda, (727 Kb PDF), which covers among other topics the use of water by agriculture and industry.
Archive Reports on environmental impact of biofuels
Sustainability Standards for Bioenergy (1.5 Mb PDF) – Uwe R. Fritsche, Katja Hünecke, Andreas Hermann, Falk Schulze and Kirsten Wiegmann with contributions from Michel Adolphe, Öko-Institut e.V., Darmstadt. Published by WWF Germany, Frankfurt am Main, November 2006.
Please note that the material in this report is copyright of WWF Germany, Frankfurt am Main and that any reproduction in full or in part of this publication must mention the title and credit the copyright holder.