Is the use of biofuels environmentally sound or ethical?

Stephen M. Mudge

The first undergraduate degree course in Environmental Forensics (EF) was started by Stephen Mudge within the School of Ocean Sciences, University of Wales, Bangor. Throughout his career, he has conducted investigations of the environment, usually with the aim of finding out who was responsible for contamination. He took up a lectureship at Bangor in 1991 and almost immediately was quantifying the contribution local sewage discharges made to the coastal zone. He has delivered courses in the biomarker approach to sewage tracking around Europe as part of a Water Framework Directive Masters and at a Chilean University where he is a visiting Professor. In 1997 Dr Mudge won the Enterprise Oil Heriot Watt University Environmental Award for his studies on the use of biodiesel as a solvent for removing oil off contaminated beaches. The formulization of EF into a degree began in 2001 and the curriculum was ratified in early 2003 with three students starting in September of that year. The course has matured since then but retains the core ethos of getting the environmental science basics first and then putting the source identification and legal framework on top. He has published 30 papers since 2001, three book chapters and is editing a new book for 2007 on the diverse methods available to the environmental forensic practitioner. Dr Mudge is married and has two children and lives on the Isle of Anglesey. He has been a Scout leader since 1987 and still enjoys getting out there and doing fieldwork.

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We use a lot of crude oil; these fossil hydrocarbons laid down in the Jurassic Period are extensively used for the generation of electricity, industrial raw materials and fuels. We are currently using in excess of 83 million barrels per day.¹ Estimates suggest we may only have 40 years of these materials left given the current rates of usage and discovery.² Not all the crude oil extracted is of the same quality and some may require extensive processing before they can be used. The chemical nature of crude oil is varied and not all crude oils are able to provide all hydrocarbon components even after treatment. These different crude oils have different prices at different times of the year as they have different uses! Heavier oils are used for heating in winter and are more expensive at that time. Conversely, lighter oils are used for car fuels and are more expensive in summer. This seasonal trend has been masked by the continued rise of the oil price in recent years. In general, however, the lighter oils (e.g. West Texas Intermediate) trade a few dollars more per barrel than Brent crude oil or other heavier oils. Sulfur in the oil is also an issue which may require expensive removal processes.

The most highly publicized aspect of using fossil fuels in recent years has been the generation of CO₂. The atmospheric concentration of this gas has risen from 280 ppm by volume throughout the past millennium to 380 ppm by volume in recent years with a 50 ppm rise in the last 30 years (IPCC report†). Whether this is responsible for global climate change has been widely debated but it is generally agreed that reducing our emissions to 5% below our 1990 level is a good start (Kyoto Protocol‡). As part of this strategy, the UK government has introduced the Renewable Transport Fuel Obligations Order 2007. This requires most suppliers to use 2.6% biofuels in fuels sold at the pumps from April 2008 rising to 3.9% by 2009 and then 5.3% in a subsequent period.§ In the USA, under the Energy Policy Act of 2005, the EPA developed the Renewable Fuel Standard Program in which 7.76% of fuel must be from renewable sources (USEPA).

Part of the rationale for using biofuels is the precept that these materials are carbon neutral; the CO₂ generated from their use is equivalent to the amount of CO₂ taken out of the atmosphere by the plant. However, the validity of this carbon neutral status has recently been questioned.^3,4 Carbon which is stored in the biological compartment and the pedosphere may be released when biofuel crops are grown. In their work, Fargione et al.³ estimate that converting “lowland tropical rainforest in Indonesia and Malaysia to palm biodiesel would result in a biofuel carbon debt of ∼610 tonnes of CO₂ ha⁻¹ that would take 86 years to repay”. Until those ∼86 years have elapsed, less greenhouse gases would have been emitted if a petroleum source had been used instead. This repayment time rises to 423 years if peatland rainforest was cleared for palm production of biodiesel.

If previously uncultivated land, brown field sites or even set-aside land is used for this purpose, there are still environmental costs associated with ploughing, changes to soil structure, burning of biomass, wind blown or surface water runoff of soil and nutrients. All of this pales into insignificance compared to the environmental and social costs of clearing virgin rainforest for the production of palm oil and the conversion of food crop land into non-food crops. There are huge potentials for the loss of biodiversity and carbon sequestration in the complex natural ecosystems which may be turned over to mono-cultures of palms. However, the loss of the ability for the world to feed itself may be more important.

In recent years, there have been droughts in various parts of the world with the consequential crop failures. This, together with the change in land use associated with biofuel production and population increases, has pushed the price of key sources of carbohydrates and fats up dramatically. The price of wheat has more the doubled in the last 12 months and other related crops such as rice have also followed suit. Countries that previously exported grain are now net importers or are holding on to what they have rather than selling them on. The consequences of this can be seen in the recent food related riots in Haiti and Bangladesh. Not all of this can be blamed on the increase in biofuel usage but we are in a dilemma. We need to reduce our CO₂ emissions and biofuels can help with this but we also need to feed the world.

This may challenge our perception of green products whether they are biofuels or washing-up liquid made from palm products. It may be argued that there are shades of green but these hues are changing with time as we become more aware of the secondary effects of their cultivation and usage. Why do we choose green products over others? Everyone wants to do their bit to help reduce our carbon footprint and there are real tangible effects of turning the thermostat down in our heating and laundry both in terms of personal benefits (lower utility bills) and CO₂ emissions from power stations: can the same be said of swapping to a biofuel made from palm oil?

References

1. Z. D. Wang and C. Brown, Chemical Fingerprinting of Petroleum Hydrocarbons, in Methods in Environmental Forensics, ed. S. M. Mudge, Taylor and Francis, 2008.
2. K. S. Dhugga, Maize biomass yield and composition for biofuels, Crop Sci., 2007, 47(6), 2211–2227.
3. J. Fargione, J. Hill, D. Tilman, S. Polasky and P. Hawthorne, Land Clearing and the Biofuel Carbon Debt, Science, 2008, 319(5867), 1235–1238.
4. T. Searchinger, R. Heimlich, R. A. Houghton, F. Dong, A. Elobeid, J. Fabiosa, S. Tokgoz, D. Hayes and T.-H. Yu, Use of U.S. Croplands for Biofuels Increases Greenhouse Gases Through Emissions from Land-Use Change, Science, 2008, 319(5867), 1238–1240.

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Footnotes

† http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-chapter2.pdf

‡ Ministers and other high-level officials from 160 countries reached a legally binding Protocol in Kyoto in 1997 under which industrialized countries will reduce their collective emissions of greenhouse gases by 5.2%. The agreement aims to lower overall emissions from a group of six greenhouse gases by 2008–12, calculated as an average over these five years. Cuts in the three most important gases—carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (N₂0)—will be measured against a base year of 1990. Compared to the emissions levels that would be expected by 2010 without emissions-control measures, the Protocol target represents a 30% cut. It is intended that the Protocol should, therefore, send a powerful signal to business that it needs to accelerate the delivery of climate-friendly products and services.

§ Section 4(4)c of the Renewable Transport Fuel Obligation (http://www.opsi.gov.uk/si/si2007/pdf/uksi_20073072_en.pdf) states:

(i) for the obligation period beginning on 15th April 2008, the specified amount is an amount equal to 2.5641% of that volume;

(ii) for the obligation period beginning on 15th April 2009, the specified amount is an amount equal to 3.8961% of that volume; and

(iii) for each subsequent obligation period, the specified amount is an amount equal to 5.2632% of that volume.

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