Humankind is currently faced with the huge challenge of securing a sustainable energy supply and biofuels constitute one of the major options. However, the commercially traded edible crops are barely sufficient to meet food demand of the present world population. Certain regions, for example EU-27, do not even have a sufficient indigenous crop production. Of this follows that motor biofuels based on edible crops should be avoided. To replace more than some percent of the fossil motor fuels, non-edible biomass—rest products and wastes—should instead be considered for conversion to biofuels. In this way, about 10% of the current fossil fuels can be replaced. Feeding a world population expected to grow by some 50% during the next 50 years will be a major challenge. For environmental reasons it seems that agricultural land cannot be expanded very much, maybe not at all. The solution to the increasing food demand seems therefore to be using the present crop production more efficiently and increasing output from present agricultural land, maintaining biodiversity and climate stability within reasonable limits. In the future, agriculture will need more energy and more water irrigation. Food production is, however, already very energy demanding, requiring several times more externally provided energy than the energy content of the food itself. A sufficient energy supply will be a key issue for the future farming!
KeywordsAgriculture Food Biofuel Cropland Residues Energy
Discussions on the manuscript with Lars Ohlander and Kersti Johansson are gratefully acknowledged.
- AEBIOM Newsletter. 2007. http://www.google.com/search?sourceid=navclient&ie=UTF-8&rlz=1T4SUNA_enSE299SE300&q=AEBIOM++0%2e16.
- Aranda, D. 2007. On Brazilian biofuel. Private communication.Google Scholar
- Bringezu, S., H. Schütz, M. O′Brien, L. Kauppi, and R.W. Howarth. 2009. Towards sustainable production and use of resources: assessing biofuels. UNEP report. http://www.unep.fr/scp/rpanel/pdf/Assessing_Biofuels_Full_Report.pdf.
- FAO. 2002. World agriculture towards 2015/30. Summary report. Rome: FAO. ISBN: 9251047618.Google Scholar
- Foley, J.A., C. Monfreda, N. Ramankutty, and D. Zaks. 2007. Our share of the planetary pie. Proceedings of the National Academy of Sciences of the United States of America 104(31): 12585–12586. http://test-globalchange.mit.edu/files/document/MITJPSPGC_Rpt18.pdf.
- Fredga, K., K. Danell, H. Frank, D. Hedberg, and S. Kullander. 2008. Bioenergy—opportunities and constraints. http://www.kva.se/Documents/Vetenskap_samhallet/Energi/Utskottet/rapport_energi_bio_eng_2008.pdf.
- Heinberg, R., and M. Bomford. 2009. The food and farming transition: toward a post-carbon food system. http://pc-ds.webvanta.com/files/PCI-food-and-farming-transition.pdf.
- International Energy Agency. 2007. Potential contribution of bioenergy to the world’s future energy demand. IEA Bioenergy, ExCo 2007:02. http://www.idahoforests.org/img/pdf/PotentialContribution.pdf.
- Johansson, K., K. Liljequist. 2009. Can agriculture provide us with both food and fuel?—a survey of present agricultural production. http://www.tsl.uu.se/uhdsg/publications/agriculture.pdf.
- Krause, M., H. Lotze-Campen, and A. Popp. 2009. Spatially-explicit scenarios on global cropland expansion and available forest land in an integrating modeling framework. International Association of Agricultural Economists Conference, Beijing, China. http://ageconsearch.umn.edu/bitstream/51751/2/Krause_%20et_al_iaae_090630_final.pdf.
- Kullander, S. 2009. Energy from biomass. The European Physical Journal 176: 115–125.Google Scholar
- McLaughlin, S.J. 1999. Developing switchgrass as a bioenergy crop. In Perspectives on new crops and new uses, ed. J. Janick, et al., 282–299. Alexandria: ASHS Press.Google Scholar
- Pfeiffer, D.A. 2004. Eating fossil fuels. http://www.fromthewilderness.com/free/ww3/100303_eating_oil.html.
- Pimentel, D., and T.W. Patzek. 2005. Ethanol production using corn, switchgrass, and wood. Biodiesel production using soybean and sunflower. Natural Resources Research 14(1). doi: 10.1007/s11053-005-4679-8.
- Ulgiati, S. 2001. A comprehensive and economic assessment of biofuels. Critical Reviews in Plant Sciences 20(1): 71–106.Google Scholar
- Xiao, X., et al. 1998. Transient climate change and potential croplands of the world in the 21st century. Report 18, Joint Program on the Science and Policy of Global Change, MIT.Google Scholar