Volume 11, Number 12: 19 March 2008
In our Editorials of 26 Sep 2007, 10 Oct 2007 and 24 Oct 2007, we describe a number of reasons why IPCC apologist Sir John Houghton's Creation Care Crusade is way off base when he preaches the large-scale production of biomass (as in biofuel) as our second-best substitute (after solar energy) for fossil-fuel energy. Among other things, we note how the implementation of his proposal would create intense competition for land between man and nature, driving innumerable plants and animals to extinction (26 Sep 2007), result in even higher net CO2 emissions to the atmosphere, since the emissions costs of liquid biofuels often exceed those of fossil fuels (10 Oct 2007), and contribute as much -- or more -- to global warming by ancillary N2O emissions than cooling by fossil fuel savings (24 Oct 2007). These several points have subsequently been further discussed by Laurance (2007) and Scharlemann and Laurance (2008); while yet another problem associated with Sir John's view of the issue has been described by Lal (2007).
Lal begins his critique of the biofuel craze with some important background information. Singing the praises of soil organic carbon, he notes that it "improves soil structure and tilth, reduces soil erosion, increases plant available water capacity, stores plant nutrients, provides energy for soil fauna, purifies water, denatures pollutants, increases soil biodiversity, improves crop/biomass yields, and moderates climate," as well as being "essential to ending global hunger and malnutrition." On a negative note, however, he reports that most agricultural soils have lost 25-75% of their antecedent pools of soil organic carbon, and that we can't afford to lose any more. Unfortunately, this is precisely the juncture where the lust for biofuels rears its ugly head.
Because of all the problems associated with biofuel production that we discussed in our first three editorials on the subject, some people are suggesting that we produce biofuels from crop residues, since this approach would not involve the use of additional land and it would focus on an agricultural "waste product." However, as Lal points out, crop residues are not exactly unwanted by-products of farming, as they perform many vital functions. He reports, for example, that "there are severe adverse impacts of residue removal on soil and environmental degradation, and negative carbon sequestration as is documented by the dwindling soil organic carbon reserves." And he further notes that "the severe and widespread problem of soil degradation, and the attendant agrarian stagnation/deceleration, are caused by indiscriminate removal of crop residues."
Clearly, as Lal continues, "short-term economic gains from using crop residues for biofuel must be objectively assessed in relation to adverse changes in soil quality, negative nutrients and carbon budget, accelerated erosion, increase in non-point source pollution, reduction in agronomic production, and decline in biodiversity." And when all the many benefits of soil organic carbon are tallied, he concludes that "the depleted soil organic carbon pool must be restored, come what may."
We totally agree. We cannot afford to destroy the productive potential of the soil that sustains all of humanity and nature as well (by enabling us to grow most of our own food and thereby not take what the rest of the biosphere needs in terms of land and water to sustain itself). Truly, Scharlemann and Laurance have appropriately labeled multibillion-dollar U.S. subsidies for certain biofuel enterprises a "perverse incentive" that will only add to mankind's and nature's many overwhelming problems.
Sherwood, Keith and Craig Idso
References
Lal, R. 2007. Farming carbon. Soil & Tillage Research 96: 1-5.
Laurance, W.F. 2007. Switch to corn promotes Amazon deforestation. Science 318: 1721.
Scharlemann, J.P.W. and Laurance, W.F. 2008. How green are biofuels? Science 319: 43-44.