• Energy Research

Abstract Biofuels have been promoted as a sustainable energy carrier, able to supply fuels while reducing Greenhouse Gas emissions (GHGs) within the energy sector. It is also believed that biofuels will offer new income opportunities to farmers and create new jobs in rural areas. I argue that this may be a far too optimistic picture. Biofuels have poor energy performance (in actual fact, their use requires a high volume of subsidies), are potentially in conflict with food production and have high environmental impacts, especially on soil, forests and natural resources. Large scale biofuels production may cause detrimental effects on those key ecosystem services that we should strive to preserve, in particular when considering soil health. Assessing the sustainability of energy carriers requires a comprehensive assessment able to address multiple issues at the same time. It is necessary to rethink biofuels policy in view of preserving soil heath and key ecosystem services. Agricultural policies would better focus on supporting farmers in the adoption of more sustainable farming practices. Policies aiming at preserving forests are also necessary. Subsidies could be used to explore different renewable energy sources, with a lower impact on our support systems, and more sustainable agricultural practices. Eventually, rethinking our development patterns may become necessary in order to cope with the Earth’s limited resources and reduce the alarming trends associated with the environmental impact of human global societal metabolism.

Soil health, along with water supply, is the most valuable resource for humans, as human life depends on the soil’s generosity. Soil degradation, therefore, poses a threat to food security, as it reduces yield, forces farmers to use more inputs, and may eventually lead to soil abandonment. Unfortunately, the importance of preserving soil health appears to be overlooked by policy makers. In this paper, I first briefly introduce the present situation concerning agricultural production, natural resources, soil degradation, land use and the challenge ahead, to show how these issues are strictly interwoven. Then, I define soil degradation and present a review of its typologies and estimates at a global level. I discuss the importance of preserving soil capital, and its relationship to human civilization and food security. Trends concerning the availability of arable agricultural land, different scenarios, and their limitations, are analyzed and discussed. The possible relation between an increase in a country’s GNP, population and future availability of arable land is also analyzed, using the World Bank’s database. I argue that because of the many sources of uncertainty in the data, and the high risks at stake, a precautionary approach should be adopted when drawing scenarios. The paper ends with a discussion on the key role of preserving soil organic matter, and the need to adopt more sustainable agricultural practices. I also argue that both our relation with nature and natural resources and our lifestyle need to be reconsidered.

The wide-ranging literature on food systems provides multiple perspectives and world views. Various stakeholders define food and food systems in non-equivalent ways. The perception of the performance of food systems is determined by these specific perspectives, and a wide variety of policies responding to different aims are proposed and implemented accordingly. This paper sets out to demonstrate that the pre-analytical adoption of different narratives about the food system leads to non-equivalent assessments of the performance of food supply chains. In order to do so, we (i) identify a set of relevant narratives on food supply chains in Spanish and Catalan contexts; (ii) identify the pertinent attributes needed to describe and represent food supply chains within the different perspectives or narratives; and (iii) carry out an integrated assessment of three organic tomato supply chains from the different perspectives. In doing so, the paper proposes an analysis of narratives to enable the analyst to characterize the performance of food supply chains from different perspectives and to identify the expected trade-offs of integrated assessment, associating them with the legitimate-but-contrasting views found among the social actors involved.

In this paper, I analyze the constraints that limit biomass from becoming an alternative, sustainable and efficient energy source, at least in relation to the current metabolism of developed countries. In order to be termed sustainable, the use of an energy source should be technically feasible, economically affordable and environmentally and socially viable, considering society as a whole. Above all, it should meet society’s “metabolic needs,” a fundamental issue that is overlooked in the mainstream biofuels narrative. The EROI (Energy Return on Investment) of biofuels reaches a few units, while the EROI of fossil fuels is 20–30 or higher and has a power density (W/m2) thousands of times higher than the best biofuels, such as sugarcane in Brazil. When metabolic approaches are used it becomes clear that biomass cannot represent an energy carrier able to meet the metabolism of industrialized societies. For our industrial society to rely on “sustainable biofuels” for an important fraction of its energy, most of the agricultural and non-agricultural land would need to be used for crops, and at the same time a radical cut to our pattern of energy consumption would need to be implemented, whilst also achieving a significant population reduction.