The following sections provide a brief discussion of other environmental impacts that in addition to global warming are associated with biofuel systems:

Biodiversity

Agriculture and forestry have been the main drivers for biodiversity loss globally. For example, more land was converted to cropland over 30 years between 1950 and 1980 than over 150 years between 1700 and 1850 (MEA, 2005). Therefore, there is also a potential for biofuel crops to alter local habitats and resources in a way that will affect native species. These effects will depend on the crop, its density, duration and distribution on the landscape and any regular inputs, including water and chemicals (The Royal Society, 2008). Biodiversity loss can also occur due to direct effects of land-use change. For example, if set-aside land in Europe is used to grow biofuel crops, impacts on biodiversity will need to be evaluated because some of these areas are more biodiverse than farmlands (Critchley and Fowbert, 2000). Intensified cultivation of biofuel crops could also lead to new pests and diseases which could in turn lead to increased use of pesticides/herbicides, causing further environmental damage.

Introducing new, particularly more invasive, species into an area could lead to the displacement of local biodiversity. Eucalyptus, some Miscanthus species and switchgrass all exhibit some features of invasiveness (The Royal Society, 2008).

However, there is also some evidence that under certain circumstances biodiversity could increase. For example, large-scale short rotation coppice (SRC) such as willow can provide benefits for some bird species, butterflies and flowering plants (Anderson and Fergusson, 2006).

Therefore, it is important that the overall risks and benefits for biodiversity be evaluated appropriately for bioenergy feedstocks. The Royal Society (2008) recommends using a risk assessment framework that covers the following:

• the full life cycle of biofuel production;

• the invasiveness potential of the crop;

• potential interactive effects of the biofuel crop with other pressures in the area (e. g. drought stress);

• the impacts on ecosystems; and

• changes in these risks under a future climate.

However, the lack of data represent a significant barrier in addressing biodiversity on a life cycle basis as biofuel crops have not yet been assessed for their impacts on biodiversity. Furthermore, currently there is no agreed methodology on estimating the impacts on biodiversity in LCA.

Water use

Water is used throughout the life cycle of biofuels, from feedstock to biofuel production. However, water use is usually not included in LCA or other evaluations of environmental sustainability of biofuels. The main reasons are the lack of data and an agreed methodology for estimating the water footprint. Although there are some data available on water use for crops, water requirements through the rest of the supply chain are not available. This is not an issue specific to biofuels only but also to other systems — as water has started to become a global issue only relatively recently, the need for information on water consumption in different productive systems has only come to light recently. Consequently, no current LCA databases contain reliable data on water consumption so that it is not possible to provide reliable estimates of water usage on a life cycle basis.