Are biofuels a sustainable alternative for fossil fuels? In a recent publication, Prof. Lucas Reijnders of the Institute for Biodiversity and Ecosystem Dynamics (IBED) of the University of Amsterdam (UvA) and co-authors critically examined the impact of biofuel production in Southeast Asia on biodiversity and CO2 reduction. They concluded that when biodiversity loss and CO2 release associated with land use change are entered in the equation, biofuels are often unsustainable.
With his co-workers Prof. Reijnders examined the conversion of different land types to oil palm plantations for biofuel production in Indonesia and Malaysia. They focused particularly on the impacts on local biodiversity and on climate change, i.e. net CO2 production/storage.
Prof. Reijnders: "Within the Southeast Asian setting a conversion of existing tropical forest to oil palm plantation, as is common practice, results in a great loss of biodiversity, with specialist species with a high biodiversity value being replaced by generic ones with low conservation concern. In addition, owing to a large initial production of CO2 as a result of the conversion of vegetation types, it takes almost a century before the use of biofuels produced by the plantation result in a net reduction of CO2 emissions compared to the use of conventional fuels."
The picture is more positive if, instead of tropical forest, degraded grasslands are converted to biofuel plantations: the impact on biodiversity is much lower and the time needed before a net CO2 reduction is established is reduced to a decade.
Studies like the one in Southeas Asia yield very valuable scientific information on the impact of local biofuel production on biodiversity and carbon storage. However, to develop a sustainable policy on the use of biofuels as alternative source of energy, the results must be interpreted within a global context. This entails not only combining the results of various case studies to obtain a global picture, but also translating scientific results to a non-specialists public consisting of policy makers and the general public as a whole. The conviction that such an interpretation and dissemination of results beyond the direct scientific community is one of its explicit responsibilities, prompted IBED to formulate its ‘Science for Society' initiative. As part of this initiative we asked the two UvA experts Prof. dr. Lucas Reijnders and Prof. dr. Louise Fresco to interpret the results of the biofuel study from Southeast Asia within the context of a global discussion of the merits and drawbacks of biofuel production and use as a large scale sustainable energy source, mainly for mobility.
Prof. Fresco agrees that a conversion of existing tropical forest to biofuel plantation is never a good idea. A limited net reduction of CO2 compared to fossil fuels is no compensation for the immediate loss of unique and irreplaceable biodiversity, she argues. Moreover, the calculation of the impact on net CO2 production and climate changes is mostly based on model studies that need more experimental validation. The fact that conversion of tropical forest to biofuel plantation is applied in several areas around the world lies in the scarcity of the main commodity needed for biofuel production: land. Fresco: "To produce biofuels, land is needed on which biofuel crops will grow, preferably in a manner that is as productive as possible. However, this is precisely the land that is either already used to grow food crops, or is part of valuable natural ecosystems such as rainforests. This results in a serious risk that without a strict and coherent policy on energy, agriculture and environment, biofuel production will take place at the expense of food production, nature or both."
Unfortunately, as Fresco points out, it is precisely in the developing countries where most of the biofuel production takes place that such a coherent policy is often lacking as, within the context of the present study, is the case in Indonesia. Even less desirable is the situation where food crops such as maize are used for biofuel production. The global market for a crop like maize is quite rigid according to Reijnders: "A higher demand due to biofuel production leads to a higher market prices, immediately affecting the poorest people in the world who depend on the crop in question for food."
The question then is if there are more sustainable alternatives for biofuel production than the conversion of tropical forest to biofuel crop plantations or the use of food crops for biofuel production. Fresco mentions the large scale production of bioethanol from sugar cane in the Brazilian Cerrado savannah as an example of such sustainable production, but Reijnders only agrees to some extent: "Unlike a conversion of tropical forest, the Brazilian sugar cane plantations indeed create a net CO2 sink. However, there is also a serious loss of biodiversity in the Cerrado".
He would prefer degraded grasslands as investigated in the Southeastern study, or equivalent areas in other regions around the globe, as the most sustainable areas for biofuel production, i.e. the best combination of net CO2 storage and limited loss of biodiversity. But even here he has some general reservations: "One can question if biofuels are the best way to use even these lands. Considering the conversion of solar power to fuel through photosynthesis, with an efficiency of just 0.16% sugar cane is the most efficient crop available to date. In comparison, modern solar cells convert solar power to energy with an efficiency of 12%. Therefore, it may be more efficient in terms of land use to build solar panels in degraded areas than to grow biofuel crops".
Nevertheless, when focusing on biofuels, Fresco and Reijnders agree that in addition to using other areas than tropical forests, improvement of the yields of biofuel crops is an important way to make biofuel production more sustainable. Fresco: "For instance, when considering the oil palm as biofuel crop, currently only the oil is used to produce biofuels. If we were able to convert cellulose to biofuels, a much large proportion of the plant in question could be used. In addition, this would mean that harvest residues of other crops, e.g. food crops like maize, could be used to generate biofuels, thereby eliminating the competition with food crops for space".
However, she emphasizes that not all of the residue can be used in this way as some is needed to sustain the organic carbon content of the soil. Reijnders estimates that roughly 10-20% of crop residue can be used without soil organic carbon loss, provided that a no-tillage system is used as is common practice in the Unites States, but not for instance in Europe.
Neither Prof. Reijnders nor Prof. Fresco sees biofuels as the single cure-all large scale sustainable energy source for mobility. Reijnders: "Foregoing any discussion about sustainability, from a purely technical point of view biofuels are only a realistic energy source for use in road transport. In airplanes, which also form a major global source of CO2 emissions, biofuel use is limited to the addition of at most a few percent to conventional kerosene. Adding more would cause the fuel to freeze up as a result of the cold outside temperatures endured during the flight. Alternatively one may crack bio-oil to generate a hydrocarbon, but this leads to a much lowered solar energy to fuel efficiency".
In addition, both Reijnders and Fresco see the competition with food production and natural ecosystems as a complicating factor as previously explained.
Prof. Reijnders feels that these problems are so great that, if possible at all, at least several decades to a century will be needed to develop sustainable biofuel production at a scale needed to seriously reduce the need for fossil fuels. This leads him to a quite pessimistic conclusion about large scale biomarker use: "Given the current rapid development in the automotive industry with respect to alternative energy sources, such as electricity and hydrogen, I expects that within the same time period needed to develop sustainable biofuel production, the need for carbohydrate fuels to power road transport will have disappeared. As a result, I seriously wonder whether the concept of biofuels as a sustainable energy source has not already become obsolete."
Prof. Fresco is bit more optimistic with respect to a large scale role for biofuels as sustainable automotive energy source. She emphasizes the earlier mentioned success of large scale production in countries such as Brazil, and the technical possibilities of increasing biofuel production yields by using crop residues and more efficient use of existing biofuel crops.
Independent from the discussion about biofuels as large scale sustainable energy source, both Prof. Reijnders and Prof. Fresco do see possibilities for the smaller scale production and use of biofuels in specific areas. Fresco: "We see for instance that small scale production and use of biofuels in developing countries like Tanzania or Mali makes them less dependent on expensive imports of fossil fuels, liberating funds for the development of their country and the alleviation of poverty".
Prof. Reijnders adds that when small scale biofuel production on marginal soils by the local population is used to replace fire wood for cooking and heating, this would lead to an important reduction in net CO2 emissions. Not only is burning of biofuels much more efficient than burning of fire wood, he argues, it would also prevent the deforestation associated with fire wood collection. The only caveat he makes is that the biofuel production must remain small scale lest it lead to large scale clearing of forest itself.
Regardless of whether one sees biofuels as a realistic large scale energy source or not, both Prof. Reijnders and Prof. Fresco agree that there is an urgent need for the development and implementation of a coherent, combined global policy in the areas of agriculture, energy and environment to regulate its production. In this context, both see an important responsibility for the developed countries as important users of (bio)fuels produced in developing countries. On the one hand, as customers they should insist on buying only biofuels produced in the most sustainable way, while using an independently controlled certification system. On the other hand, developed countries should help developing countries in setting up and implementing local regulation leading to sustainable production of biofuels, while safeguarding food production and the environment. The latter can be seen as part of development aid, and warrants an intimate cooperation between governments, energy companies and NGOs.
Prof. Lucas Reijnders is Chair of Environmental Sciences at the Institute for Biodiversity and Ecosystem Dynamics (IBED) of the University of Amsterdam. He is a well-known international expert on issues of sustainability and the environment who has published a score of scientific articles as well as popular publications on the sustainable use of natural resources. One of the recent foci of his research is on the use of biofuels as a sustainable alternative for fossil fuels within the context of biodiversity conservation and climate change.
Prof. Louise Fresco is University Professor at the University of Amsterdam. She has a scientific background in Tropical Agronomy and fulfilled several high-impact societal positions in the area of sustainable agriculture and food production, amongst others as Assistant Director-General of the Agriculture Department (FAO) of the United Nations. As a result Prof. Fresco is an international authority on combining issues of food, nutrition, environment and economy. In 2006 she delivered the ‘Duisenberg Lecture' at the Annual Meeting of the International Monetary Fund, resulting in the widely noted publication ‘Food or Fuel, is there a dilemma?'.
F. Danielsen, H. Beukema, N.D. Burgess, F. Parish, C.A. Brühl, P.F. Donald, D. Murdiyarso, B. Phalan, L. Reijnders, M. Struebig, and E.B. Fitzherbert, (2009), Biofuel Plantations on Forested Lands: Double Jeopardy for Biodiversity and Climate, Conservation Biology, 23: 348-358.
Prof. Fresco and Reijnders were interviewed by Dr. Boris Jansen of IBED in 2009