Environmental Engineering Reference
In-Depth Information
Franke and Reinhardt (1998) posit that the production of biodiesel
feedstocks could be quite an intensive land use, often with greater trans-
portation ef orts compared with fossil fuels. Furthermore, commercial
production of these feedstocks could pollute water from leaching of ferti-
lizers, pesticides and herbicides - adversely impacting local and regional
biodiversity. Turley et al. (2002, 2003) state that biodiesel feedstocks
grown in set-asides or on other uncultivated lands could increase trai c
impacts in rural areas, whereas those grown on already cultivated lands by
replacing current crops will have little or no such impact. In addition to
increased trai c impacts, the use or possible use of the set-asides to grow
biodiesel feedstocks could have negative environmental impacts according
to a number of studies (for example, Turley et al., 2002, 2003; Anderson et
al., 2004; Anderson and Ferguson, 2006).
In terms of the impacts of biodiesel on human health, emissions from
biodiesel are reported to pose lower direct or indirect risks compared with
fossil fuel diesel (Poitrat, 1999). However, reports are conl icting on the
impacts of biodiesel feedstock production on human health. Major health
concerns from the production of biodiesel feedstocks, such as oilseed rape,
are the allergies related to these crops - complaints and concerns about
which seem to come mainly from the British public rather than from those
in other oilseed rape growing countries like Canada, France and Germany
(Hemmer, 1998; Turley et al., 2002). As most of these complaints (from
the British public) seem to be from anecdotal rather than scientii cally
proven ill-health impacts, Hemmer (1998, pp. 1327-8) questions if there
is 'prejudice because the expansion of this crop is subsidised by the EU'
or if 'people simply dislike [oilseed rape's] intense smell and l ashy yellow
l owers', concluding that there is 'little evidence to incriminate a versatile
crop of economic importance as a cause of ill health'.
Most studies comparing emissions from biofuel-run vehicles with those
of fossil-fuel-run vehicles conclude that biofuel could be signii cantly less
harmful, implying signii cant environmental benei ts. However, the carbon
neutrality and provision of net energy balance by biodiesel is a contested
issue. Although combustion of biodiesel itself is carbon neutral in that it
releases no more carbon than that sequestered during growth, inputs in
production, transportation and marketing of biodiesel usually increase net
carbon emissions due to the use of fossil fuels in these operations. Thus,
strictly speaking, biodiesel cannot be 100 per cent carbon neutral unless
biofuels themselves are used for the energy component in all parts of the
manufacturing process. It is, however, possible to reduce the net carbon
emissions from biodiesel further by reducing the use of inputs, such as
nitrogen fertilizers, in the production of the feedstocks, the production
of which emits the highest amount of CO
2
among the agricultural inputs
