If the continued exploitation of carbon-based fuel sources do indeed pose a consid­erable threat to the earth via anthropogenic climate change, it will be necessary to consider the optimal use of an energy source that, in a way, could prolong the adop­tion of truly carbon-free technologies. The role of biofuels in transitioning human­ity away from carbon-based energy sources needs to be considered dispassionately and beyond the influence of short-term political manipulation. Biofuels will clearly be an important component in any future energy mix, though the extent to which they will be used remains a subject for debate (Charles et al. 2011). Eggert et al. (2011) emphasize this level of uncertainty and forcefully argue that the view that first-generation biofuels should be supported by policymakers so as to pave the way for second-generation biofuels is inherently faulty—and indeed counter-productive to promoting the market entry of more environmentally friendly biofuels, espe­cially since the feedstocks and production techniques are so very dissimilar. Their argument that investment subsidies for first-generation biofuels should be removed immediately so as to allow a ‘learning by doing’ approach to improve the economic efficiency of immature second-generation technologies has much to recommend it.

Whatever the case, it appears highly unlikely that biofuels will ever be able to replace petroleum-derived products on a one-for-one basis (Di-Lucia and Nilsson 2007), especially if current growth in the transport sector continues unabated. Indeed, the IEA (2012) reported a continued increase in CO2 emissions, particularly in developing countries such as China and India, owing to growth in the consump­tion of fossil fuels. As mentioned previously, biofuels have a clear advantage over other emerging transport energy solutions, such as those relying on stored electric­ity, electricity produced from chemical reactions (e. g. in fuel cells), or hydrogen, in either gaseous or liquid form. This is because they are able to be deployed and con­sumed, in blended form, by existing infrastructural systems—and the internal com­bustion engine in particular—without major technological modifications.[18] Indeed, most existing vehicles can operate with a small proportion of biofuel (usually cited as 10 %) without the need for any modification. In Brazil, the majority of vehicles (around 90 %) sold are able to run on pure bioethanol in its hydrated form (E100) if required to do so thanks to FlexFuel technology, though E20 or E25 is much more commonly used (Eggert et al. 2011). Switching costs are therefore dramatically reduced (Charles et al. 2009). A danger, here, is that reliance on biofuels might pro­long our existing lock-in to technologies that are manifestly dangerous to the envi­ronment, such as the internal combustion engine or the gas turbine. When looking at possibilities associated with new technologies, the network externalities that these technologies are likely to face must be considered, more so in light of the ‘lock-in’ effect of existing technologies (Katz and Shapiro 1986).

There also remains the possibility that biofuels, together with the engines that they have the ability to power, will be made largely redundant, in time, by other mobile energy technologies. In some respects, this would be the optimum outcome, since the preferred transport energy paradigm would clearly be almost completely, if not entirely, de-carbonized—something which can obviously never be achieved with the combustion of biofuels, no matter how de-carbonized their production becomes. Some of these potential contributors to reducing global GHG emissions across all sectors could include nuclear energy (particular if problems associated with the disposal of contaminated waste products are resolved, how­ever unlikely that may seem at present), cleaner second-generation (and third — and fourth-generation) biofuel production processes, the development of a hydrogen economy (predicated on the availability of clean, renewable energy, with potential links to nuclear energy) and other energy paradigms, e. g. geothermal, hydroelec­tric, photovoltaic and wind, all of which could contribute either directly or indi­rectly to de-carbonized mobility (Charles et al. 2011).

Of course, up until the point that other technologies become more cost effective, biofuels would have an important place in alleviating the existing reliance on carbon — based forms of transport energy. A balance must therefore be reached between (1) biofuels taking over from traditional petroleum-based transport energy fuels (which seems highly problematic, at least with existing technologies) and (2) the emergence of the environmentally optimum outcome of a completely de-carbonized transport sector throughout the world. In effect, the transition from liquid carbon-based energy transportation, based on a combination of fossil fuels and biofuels, to a more gen­uinely sustainable paradigm will need to be governed carefully, while the ongoing suitability of biofuels as part of this transition will need to be monitored closely. As Sharpe and Hodgson (2006, p. 6) have observed, there is “a significant danger that, by wringing more capability out of our existing systems, we may fail to tackle more fundamental issues”. In this respect, biofuels of whatever type must not be allowed to impede the bringing to market of more long-term transport energy technologies.

Given the current inability of second-generation biofuels to find their way to mar­ket, it is likely that substantial political support, with attendant policy mechanisms, will be required. Yet, as Eggert et al. (2011) point out, it will be necessary to avoid any political or technological lock-into biofuels of any sort. Governments clearly must balance support for second-generation biofuels with support for other alterna­tive mobile energy sources. As a consequence, they argue that policies that promote even second-generation biofuels will need to be flexible, while support programs should be able to be terminated at short notice if it becomes clear that alternative technologies are more desirable in the long run. In effect, and as Eggert et al. (2011, p. 9) aptly put it, “policies for promoting R&D for cellulosic ethanol should only have as their aim to uncover the technology’s true potential (which is so far not clear), and not operate with ambitious goals for the technology’s future market penetration”.

To demonstrate this point, one need only think of existing political commitment to first-generation biofuels, which has proved difficult to withdraw, even though these fuels have not shown the environmental potential once commonly ascribed to them. The same must not occur with respect to second-generation biofuels if other technol­ogies emerge as offering greater long-term potential. A particular threat is that first — generation technologies will continue to be supported by politicians and stakeholder interest groups, particularly in agrarian-based societies, because second-generation production, together with third — and fourth-generation, will typically be far more cap­ital intensive and less labour intensive, and therefore may have more limited immedi­ate economic impacts on the local area as a result of reduced employment prospects in the local community (Larson 2008). This issue is gaining increasing attention in the biofuel policy space as existing multilateral arrangements continue to focus on promoting international trade rather than overall global sustainability (Lima 2009).

5 Concluding Remarks

There is clearly a need for producers of biofuels to look carefully at their biomass sources so as to ensure that they are not creating a market for unsustainable agri­cultural practices. Indeed, without sufficient scrutiny from these purchasers of bio­mass, agricultural producers may be prompted to cultivate the requisite biomass in a highly unsustainable fashion (Mathews 2008). Advances in biotechnology, and the increasing possibility of replacing fossil fuels with second — and probably third — and fourth-generation biofuels, could potentially address many challenges related to both energy and food security in a relatively sustainable manner. However, there is a need to (1) further investigate the environmental impacts of advanced biofu­els through more comprehensive analysis in individual circumstances to ensure that they are truly reducing the global carbon footprint without affecting exist­ing ecology and (2) create effective governance and institutional arrangements across national boundaries to ensure that the biofuel industry looks beyond the visible horizon and does not advantage some regions at the cost of others. While biofuel technology is likely to evolve over time, thereby making the production processes more sustainable from an environmental, social and economic perspec­tive, the developed world will undoubtedly need to play a strong leadership role. This could be achieved by supporting the commercialization of cutting-edge bio­fuel production processes instead of protecting their respective local economies by subsidizing biofuel crops that are not particularly friendly to the environment. A greater focus must be placed on non-edible biocrops (including algae) and com­mercializing advanced biomass-processing techniques that will emit less GHGs, consume less land and yield high-energy outputs. In short, moral and ethical con­siderations must prevail over the arguably short-term political and economic out­comes currently associated with the global biofuel industry.