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 February 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'.

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.