Saturday, May 22, 2010
7:14 PM | Posted by Gregory Maxwell | |
In recent years the commercial aviation industry has been buffeted by severe turbulence left in the wake of the Global Warming movement. Aviation in all its forms has become the poster child for environmentalist and is being used as a symbol of the unnecessary excess in today’s society which is supposedly driving our planet to the brink of an irreversible slide towards extinction. Despite popular belief, anthropogenic global warming is not a fact but rather a scientific theory which is based on extrapolations of historical global climatic data that is fed into computer models, producing nothing more than probability distributions which attempt to predict the likelihood of possible scenarios. But absent a time machine there is no way to validate any particular model’s accuracy with any degree of certainty as it is impossible for us to know what the earth’s climate will look like in 50 or 100 years.
For its part the industry as a whole has failed miserably in its response to the threat the Global Warming movement poses to its continued viability. In response to the public assault airlines have been very open about their plans to reduce carbon emissions and be better environmental stewards. One of the most popular demonstrations of this commitment has been biofuel test flights. Every month it seems that another airline is conducting a biofuel trial and touting the benefits of a particular exotic blend which it promises when put into large scale use will greatly reduce the airlines carbon footprint. But once you peel away the sexy packaging and trendy marketing do biofuels really live up to the hype? Are they the future fuel source that will power the next generation of jetliners?
Before you answer these questions consider this: Biofuels can be derived from a variety of food and feed stocks, but the most productive in terms of maximizing carbon storage and therefore reducing carbon emissions, are primarily grown in the tropic regions of the world in countries like Malaysia, Indonesia and Brazil. These tropical ecosystems are dominated by extremely productive forest lands, which collectively store an enormous 340 billion tons of carbon, this is equivalent to more than 40 times the total annual anthropogenic emissions from fossil fuels combustion (Gibbs et al 2007). When forests and grasslands are cleared, burned and then converted into farmland the carbon stored in the soil is released into the atmosphere. Scientists estimate that approximately 1.5 billion tons of carbon leach into the atmosphere every year due to tropical deforestation in the name of agricultural expansion. This accounts for approximately 20% of annual global CO2 emissions (IPCC 2007). To be fair this is not a new phenomenon caused by the expanding market for biofuels, but traditionally has been linked to an increased worldwide demand for both food and feed stocks caused by population increases and rising dietary affluence. However, there is no doubt that the increased popularity of biofuels is leading to more deforestation as the biofuel crops are forced to compete for land with food and feed crops.
In fact, concern is mounting in the scientific community that crop-based biofuels may actually increase net greenhouse gas emissions. It is estimated that biofuel crop expansion into natural areas and the resulting deforestation could release 17-420 times more CO2 than the annual potential savings realized by replacing fossil fuels (Fargione et al 2008). The reason is rooted in the decades and is some cases centuries it takes for biofuel crop production to overcome the initial carbon debt caused by deforestation. For example the production of biofuel crops like maize and soybeans on deforested tropical forest land requires approximately 300-1500 years of biofuel carbon savings to compensate for the initial lose of carbon stored in the soils of the mature forests (Gibbs et al 2008).
Even so called second generation biofuel crops, which can be grown in more arid climates on less productive soils, therefore not competing with food and feed crops are not the answer. Jatropha which was flight tested by both Continental Airlines and Air New Zealand and was once touted as the second generation crop that would revolutionize the biofuel industry, as the plant produces seeds which yield a very high oil content, around 35% on average. To validate Jatropha’s potential in 2007, British Petroleum partnered with British biofuels company D1 Oils on a five-year, 100 million project to grow the plant in India, Southeast Asia, and Southern Africa. Together the two companies planted more than 200,000 hectares, or 25% of the worldwide crop. What BP learned which was validated by Researchers from the University of Twente, in the Netherlands, and report in a recent issue of the Proceedings of the National Academy of Sciences is that Jatropha requires five times as much water per unit of energy as sugarcane and corn, and nearly ten times as much as sugar beet--the most water-efficient biofuel crop. In fact if the 13 biofuel crops whose water footprint were studied researchers calculated that Jatropha was the least efficient, requiring an average of 5,283 gallons of water to produce .26 gallons of biodiesel in India, Indonesia, Nicaragua, Brazil, and Guatemala--the only countries for which Jatropha production figures were available. Soybeans and rapeseed were the second and third least efficient crops requiring on average 3,698 gallons of water to produce the same .26 gallons of biodiesel. It was further discovered that when Jatropha was grown in arid climates in less productive soils its oil yield became marginal.
Environmental conservation, and finding ways to minimize our impact on the earth is very important. Biofuels are an important step in developing the next generation of fuels that will power the global economy. But if the goal is to reduce the carbon footprint of the aviation industry how can the airlines endorse fuel sources that increase carbon emissions, expand deforestation and in general are less energy efficient than fossil fuels to produce. Biofuels may be a popular trend but when the payback to replace the initial carbon release is measured in hundreds of years how can this be a viable solution when environmentalists say that we have possibly only a decade to reverse the otherwise inevitable fate of our planet as a result of global warming.
The current generation of biofuels simply are not the solution for the airlines or other transportation modes. The industry should abandon its fashionable affair with biofuels and instead should focus on more realistic incremental improvements in fuel efficiency and emissions reductions using proven technology paths. Biofuels in their current form are not close to being carbon neutral. Instead of decreasing emissions they actually produce a net increase in carbon emissions which take centuries to overcome. More research and experimentation in this field is needed before plant sources can be considered a viable alternative to fossil fuels for the commercial airline industry. It is irresponsible for the industry to continue to funnel millions of dollars into an unsustainable fuel source in the name of environmental activism.
The author is an independent aviaion consultant with 7 years of industry experience and holds a Masters Degree in Aviation Safety from Embry-Riddle Aeronautical University