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|Biofuels - Summary Update from CO2 Science|
|Written by Staff|
|Friday, 15 August 2008 14:01|
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Biofuels – Summary Update
In a world where food is fast becoming scarce in many places, it seems strange indeed to use the planet's land and water resources for growing anything else, as we note in our critique of Sir John Houghton's Creation Care Crusade, which is described by Feder (2007). In this regard, for example, Johansson and Azar (2007) analyzed what they call the "food-fuel competition for bio-productive land" by developing "a long-term economic optimization model of the U.S. agricultural and energy system," wherein they find that the competition for land to grow crops for both food and fuel production leads to a situation where "prices for all crops as well as animal products increase substantially." In fact, in the May/June 2007 issue of Foreign Affairs, Runge and Senauer (2007) report that corn-based ethanol in the United States already "takes so much supply to keep ethanol production going that the price of corn -- and those of other food staples -- is shooting up around the world." And to put the situation in a perspective all can readily appreciate, they write that "filling the 25-gallon tank of an SUV with pure ethanol requires over 450 pounds of corn -- which contains enough calories to feed one person for a year."
What makes this situation even more disturbing is that not only do people (and especially poor people) suffer the adverse consequences of this perverse policy, so too does what we could call "wild nature" suffer, as it loses ever more habitat and freshwater resources to the great anthropogenic land-and-water grab needed to sustain the biofuels craze. In fact, even without the biofuels problem, Raven (2002) has indicated that "species-area relationships, taken worldwide in relation to habitat destruction, lead to projections of the loss of fully two-thirds of all species on earth by the end of this century."
Also concerned about the world of nature were Tilman et al. (2001), who noted that at the end of the 20th century mankind was already appropriating "more than a third of the production of terrestrial ecosystems and about half of usable freshwaters." Consequently, in order to meet the doubled global food demand they predict for the year 2050, mankind could well be appropriating more than two thirds of terrestrial ecosystem production, as well as all of earth's remaining usable freshwater, as has also been discussed by Wallace (2000). What is more, Tilman et al. conclude that "even the best available technologies, fully deployed, cannot prevent many of the forecasted problems," and the world's climate alarmists would make the problem even worse with their misguided biofuels program.
Additional light on this aspect of the subject has been provided by Righelato and Spracklen (2007), who also find that the use of biofuels for transport, particularly ethanol from the fermentation of carbohydrate crops as a substitute for petrol, and vegetable oils in place of diesel fuel, "would require very large areas of land in order to make a significant contribution to mitigation of fossil fuel emissions and would, directly or indirectly, put further pressure on natural forests and grasslands." As an example of this phenomenon, the two UK researchers calculate that a 10% substitution of petrol and diesel fuel would require "43% and 38% of current cropland area in the United States and Europe, respectively," and that "even this low substitution level cannot be met from existing arable land," so that "forests and grasslands would need to be cleared to enable production of the energy crops."
Adding insult to injury, Righelato and Spracklen hasten to add that the required land clearance would result in "the rapid oxidation of carbon stores in the vegetation and soil, creating a large up-front emissions cost that would, in all cases examined [our italics], out-weigh the avoided emissions." Furthermore, even without the large up-front carbon emissions, they report that individual life-cycle analyses of the conversion of sugar cane, of sugar beet, and of wheat and corn to ethanol, as well as the conversion of rapeseed and woody biomass to diesel, indicate that "forestation of an equivalent area of land would sequester two to nine times more carbon [our italics and boldface] over a 30-year period than the emissions avoided by the use of the biofuel." As a result, they rightly conclude that "the emissions cost of liquid biofuels exceeds that of fossil fuels."
Coming to much the same conclusion in a News & Views article in Nature was Laurance (2007), who discussed the ability of forests to reduce catastrophic flooding. In addition to this important virtue, he writes that "tropical forests, in particular, are crucial for combating global warming, because of their high capacity to store carbon and their ability to promote sunlight-reflecting clouds via large-scale evapotranspiration," noting that "such features are key reasons why preserving and restoring tropical forests could be a better strategy for mitigating the effects of carbon dioxide than dramatically expanding global biofuel production."
Another analysis of this aspect of the subject was provided by Bradshaw et al. (2007), who studied the effects of the presence and absence of forests on the propensity for flooding, using data collected from 56 developing countries for the period 1990-2000. Employing generalized linear and mixed-effects models, they demonstrated that "flood frequency is negatively correlated with the amount of remaining natural forest and positively correlated with natural forest area loss." Based on an arbitrary decrease in natural forest area of 10%, for example, they report that "the model-averaged prediction of flood frequency increased between 4% and 28% among the countries modeled," additionally noting that the "unabated loss of forests may increase or exacerbate the number of flood-related disasters, negatively impact millions of poor people, and inflict trillions of dollars in damage in disadvantaged economies over the coming decades."
So that is what the world will ultimately experience if the biofuels craze continues. But if biofuels are not promoted, and if the air's CO2 content is allowed to continue to rise, we should see just the opposite trend; for not only would we not experience the increase in floods caused by forest area loss to biofuel production, we would experience the decrease in floods caused by forest area increase due to rising atmospheric CO2 concentrations, as described in our many reviews of pertinent scientific papers that we have archived under the headings of Long-Term Studies (Woody Plants) and Range Expansion (Woody Plants) in our Subject Index.
In an important paper published on 1 August 2007 in Atmospheric Chemistry and Physics Discussions, Crutzen et al. (2007) examine the subject of biofuels from an entirely different perspective, calculating the amount of nitrous oxide (N2O) that would be released to the atmosphere as a result of using nitrogen fertilizer to produce the crops used for biofuels, which analysis, in their words, "only considers the conversion of biomass to biofuel" and "does not take into account the use of fossil fuel on ... farms and for fertilizer and pesticide production." As they describe it, this work revealed that "all past studies have severely underestimated the release rates of N2O to the atmosphere, with great potential impact on climate warming." And why would greater N2O emission rates have a tendency to cause the climate to warm? Because, as they describe it, N2O "is a 'greenhouse gas' with a 100-year average global warming potential 296 times larger than an equal mass of CO2."
The ultimate consequence of this phenomenon, as best the four researchers could evaluate it, is that "when the extra N2O emission from biofuel production is calculated in 'CO2-equivalent' global warming terms, and compared with the quasi-cooling effect of 'saving' emissions of fossil fuel derived CO2, the outcome is that the production of commonly used biofuels, such as biodiesel from rapeseed and bioethanol from corn (maize), can contribute as much or more to global warming by N2O emissions than cooling by fossil fuel savings."
As a result of these observations, Crutzen et al. conclude that "on a globally averaged basis the use of agricultural crops for energy production can readily be detrimental for climate due to the accompanying N2O emissions." In addition, they note that "increased emissions of N2O will also lead to enhanced NOX concentrations and ozone loss in the stratosphere." Taken together, they thus conclude that the relatively large emission of N2O associated with biofuel production "exacerbates [our italics] the already huge challenge of getting global warming under control."
As if all of these problems associated with the biofuels craze were not enough, Lal (2007) describes yet another one. 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 have discussed above, 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 of 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 taking what the rest of the biosphere needs in terms of land and water to sustain itself). Truly, Scharlemann and Laurance (2008) 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.
In a lengthy discourse entitled "Energy, Food, and Land -- The Ecological Traps of Humankind," Haber (2007) enlarges on these concepts by noting that energy, food and land are the principal resources required by contemporary human societies, but that "the absolutely decisive resource in question is land, whose increasing scarcity is totally underrated."
Expanding on this theme, Haber writes that the energy trap is "formed by a quasi-return to renewable energy suppliers for which we need very vast, hardly available tracts of land," that the food trap is "formed by increased use and demand of arable and pasture land with suitable soils," and that the land trap is "formed by the need of land for urban-industrial uses, transport, material extraction, refuse deposition, but also for leisure, recreation, and nature conservation." All of these needs, as he continues, "compete for land," and good soils, as he adds, are becoming "scarcer than ever ... scarcer than coal, oil and uranium."
Haber also notes that "we are preoccupied with fighting climate change and loss of biodiversity," and he says that "these are minor problems we could adapt to, albeit painfully." In fact, he states that "their solution will fail [our italics] if we are caught in the interrelated traps of energy, food, and land scarcity," which are looming menacingly before us just a few short decades down the road.
"Land and soil," as Haber continues, "have to be conserved, maintained, cared for, [and] properly used, based on reliable ecological information and monitoring, planning and design." We agree; and we have reported, in this regard, that a switch to biofuels to help meet our energy needs will result in our taking unconscionable amounts of land and freshwater resources from nature to produce them, and that the simple task of growing enough crops to meet the food needs of the world's population in the year 2050 will require our using so much more land than we do now, that the resulting loss of habitat will drive unnumbered species of plants and animals to extinction.
So what's the solution? As we have noted in many of our other writings on this question, it is to let the air's CO2 content continue to climb as the world's scientists and engineers devise ways of meeting mankind's growing energy needs without usurping the remaining habitat of "wild nature." We say this because of two things. First, some of the world's most prominent ecologists have concluded that even with all agricultural advancements they can anticipate over the next few decades, we may still not be able to grow sufficient food to sustain the planet's human population without appropriating for this purpose vast amounts of land and water that are currently needed to support the other species with which we share the earth. Second, we have calculated (Idso and Idso, 2000) that the crop yield enhancements and water-use efficiency increases that should be caused by the expected increase in the atmosphere's CO2 concentration between now and the year 2050 should be sufficient, but only barely, to enable us to grow the crops we will need at that time on the lands and with the water that we currently use for this purpose. If we are to prevent the extinctions of innumerable species of plants and animals that many see occurring only half a human lifespan from now, we must pursue a course of action that is congruent with the one we outline here.
In bringing this Summary to a close, we feel it important to recount some of the thoughts of Norman Borlaug, which were eloquently expressed in a recent Science editorial (Borlaug, 2007), wherein he begins his mini-treatise on "feeding a hungry world" by noting that "some 800 million people still experience chronic and transitory hunger each year," and that "over the next 50 years, we face the daunting job of feeding 3.5 billion additional people, most of whom will begin life in poverty."
Discussing a bit of history, the father of the Green Revolution recounts how "over a 40-year period, the proportion of hungry people in the world declined from about 60% in 1960 to 17% in 2000," primarily because of the effectiveness of the movement he was instrumental in initiating. Had that movement failed, he says that environmentally fragile land would have been needed to be brought into agricultural production, and the resulting "soil erosion, loss of forests and grasslands, reduction in biodiversity, and extinction of wildlife species would have been disastrous." And that same result is what awaits the world of tomorrow if the biofuels scheme of the world's climate alarmists is ever implemented to a significant degree.
Borlaug notes, for example, that "for the foreseeable future, plants -- especially the cereals -- will continue to supply much of our increased food demand, both for direct human consumption and as livestock feed to satisfy the rapidly growing demand for meat in the newly industrializing countries." In fact, he states that "the demand for cereals will probably grow by 50% over the next 20 years [our italics], and even larger harvests will be needed if more grain is diverted to produce biofuels."
Noting that most food increases of the future "will have to come from lands already in production [our italics]," and that "70% of global water withdrawals are for irrigating agricultural lands," Borlaug's facts suggest that crop water use efficiency (biomass produced per unit of water used) will have to be increased dramatically if we are to meet humanity's food needs of the future without creating the disastrous consequences he outlines above; and it should be evident to all but those most blinded to the truth that this requirement can only be met if biofuels are not a part of the picture, while the aerial fertilization and anti-transpiration effects of atmospheric CO2 enrichment are.
Although Borlaug notes that conventional plant breeding, improvements in crop management, tillage, fertilization, and weed and pest control, as well as genetic engineering, will help significantly in this regard, we will in all likelihood need the beneficial biological byproducts of concomitant increases in the atmosphere's CO2 concentration in addition. Without them, to borrow a chilling phrase from Borlaug, "efforts to halt global poverty will grind to a halt," and, we might add, much of the world of nature will be no longer.
Borlaug, N. 2007. Feeding a hungry world. Science 318: 359.
Bradshaw, C.J.A., Sodhi, N.S., Peh, K.S.-H. and Brook, B.W. 2007. Global evidence that deforestation amplifies flood risk and severity in the developing world. Global Change Biology 13: 2379-2395.
Crutzen, P.J., Mosier, A.R., Smith, K.A. and Winiwarter, W. 2007. N2O release from agro-biofuel production negates global warming reduction by replacing fossil fuels. Atmospheric Chemistry and Physics Discussions 7: 11,191-11,205.
Feder, T. 2007. A physicist proselytizes about countering global warming. Physics Today 60 (9): 30-32.
Haber, W. 2007. Energy, food, and land -- the ecological traps of humankind. Environmental Science and Pollution Research 14: 359-365.
Idso, C.D. and Idso, K.E. 2000. Forecasting world food supplies: The impact of the rising atmospheric CO2 concentration. Technology 7S: 33-55.
Johansson, D.J.A. and Azar, C. 2007. A scenario based analysis of land competition between food and bioenergy production in the US. Climatic Change 82: 267-291.
Lal, R. 2007. Farming carbon. Soil & Tillage Research 96: 1-5.
Laurance, W.F. 2007. Forests and floods. Nature 449: 409-410.
Raven, P.H. 2002. Science, sustainability, and the human prospect. Science 297: 954-959.
Righelato, R. and Spracklen, D.V. 2007. Carbon mitigation by biofuels or by saving and restoring forests? Science 317: 902.
Runge, C.F. and Senauer, B. 2007. How biofuels could starve the poor. Foreign Affairs 86.
Scharlemann, J.P.W. and Laurance, W.F. 2008. How green are biofuels? Science 319: 43-44.
Tilman, D., Fargione, J., Wolff, B., D'Antonio, C., Dobson, A., Howarth, R., Schindler, D., Schlesinger, W.H., Simberloff, D. and Swackhamer, D. 2001. Forecasting agriculturally driven global environmental change. Science 292: 281-284.
Wallace, J.S. 2000. Increasing agricultural water use efficiency to meet future food production. Agriculture, Ecosystems & Environment 82: 105-119.
|Last Updated on Friday, 15 August 2008 14:06|