Last week a study was released in Science by researchers from the Nature Conservancy and the University of Minnesota on the adverse effects of increased use of biofuels. To me, this has always been the elephant in the room for renewable energy. Pushing biofuels doesn’t necessarily solve the problem of our energy needs or climate change, but only spreads the problem to other areas.
The study highlights the fact that land use is seldom accounted for when considering the benefits of switching to biofuels (such as more autonomous energy dependence, ‘cleaner’ CO2, and economic incentives for farming). For example, if you consider the net carbon impact of converting native habitats to farm-based ecosystems, there is actually a net increase in the amount of CO2 emitted into the atmosphere, not to mention the countless ways in which such practices would destroy native ecosystems.
Another resource that seems to get far less attention is freshwater. Imagine how much water will be required to produce all of these biofuels. The potential conflict between water consumption and biofuel production is so important, the National Academies released a report late last year (PDF ) highlighting the urgency of this issue.
I was always confused as to why many advocates of renewable energy continue to press upon legislators the use of biofuels when they do very little to solve the issue of carbon emissions (of course, this is not the case if biofuels are made from waste products). As this and similar studies get increased media attention (NY Times ), it will be interesting to see if efforts to lobby government officials in the near future begin to push towards more traditional renewable energies such as wind and solar (of course, my last post was about the life-cycle energy use of photovoltaics) that are ‘less’ intrusive on nature than biofuel production.
Full reference:
J. Fargione et al. (2008) Land clearing and the biofuel carbon debt. Science DOI: 10.1126/science.1152747
It is an interesting paper indeed. Land use and land use change should be more emphasized in impact assessment tools of product or systems. A tool like Life-cycle impact assessment (LCA) still struggles on how these initial emissions should be allocated to a certain product or function.
I certainly support the fresh water concern as well. Apart from the greenhouse gas (GHG) emissions caused by human induced land use and land use change we should also consider impacts on soil, water and biodiversity of product production triggering land use change.
The authors also state that perennial crops grown on degraded or abandoned grounds could offer immediate and sustained GHG advantages. Jatropha curcas could be such perennial that could be grown on degraded or abandoned lands, but it is not clear how this crop, as it is an exotic species in most places, will affect local and regional biodiversity, or how it has an off-site impact on water availability… And, besides the environmental sustainability dimension there are still the social and economic side of the story. Certainly in developing countries.
I think there is clear need for certification. But where to draw the lines? Which initial GHG emission, biodiversity, soil-erosion, etc. investments are acceptable?