Biofuels have long been viewed as a means to reduce greenhouse gas emissions from vehicles. However recent research indicates that extracting this fuel from plants has the potential to release more greenhouse gas (GHG) emissions than the burning of fossil fuels. This is just one of many problems facing biofuels as it seeks to find a place in the renewable energy landscape.
Currently the biofuel industry is booming. According to Frost & Sullivan, market research analysts, the global biofuel market is expected to grow at a rate of 20% per annum for the next few years.
Both the United States and the European Union have put in place plans to significantly increase biofuel use in the coming decade, leaving little doubt that this form of renewable energy will be here for the long haul.
The United States requires that all vehicles must use a 15% ethanol blended fuel by 2020. This would equate to approximately 136 billion litres per year of biofuel. The European Union has set a target for member countries of 10% biofuel for transportation by 2020.
Both plans aim to significantly reduce the greenhouse gases being produced from vehicles by utilizing ethanol.
Biofuels have long been viewed as ‘greener’ than fossil fuels because they originate from renewable agricultural sources. Ethanol also burns cleaner than fossil fuels and emissions from its combustion are offset in theory by plant growth.
Two independent studies released in January suggest otherwise. Both studies indicate that biofuels, in a life-cycle analysis, may generate more greenhouse gas emissions than the simple use of fossil fuels.
The argument is essentially as follows: Increased demand for biofuel crops means more land is cleared as farmers - particularly in developing countries - try to earn more money from growing crops for fuel. Crops from old plantations are being sent to Europe for use as biofuels, while new land is cleared to feed people at home. The conversion of farm land not only puts stress on food supplies, it also creates huge volumes of GHG emissions.
The studies found that:
- Converting rainforests, peatlands, savannas, or grasslands to produce biofuels in Brazil, Southeast Asia, and the United States creates a ‘biofuel carbon debt’ by releasing 17 to 420 times more carbon dioxide than the fossil fuels they replace.
- For U.S. Central grassland or farmland that has been enrolled in the United States Conservation Reserve Program for 15 years, converting it to corn ethanol production creates a biofuel carbon debt that would take approximately 48 years to repay.
- The analyses suggest that biofuels produced on converted lands could, for long periods of time, be greater net emitters of greenhouse gasses than the fossil fuels they typically displace.
- For current or developing biofuel technologies, any strategy to reduce greenhouse gas emissions that causes land conversion from native ecosystems to cropland is likely to be counterproductive.
'When you take this into account, most of the biofuel that people are using or planning to use would probably increase greenhouse gasses substantially,' said Timothy Searchinger, lead author of one of the studies and a researcher in environment and economics at Princeton University. 'Previously there’s been an accounting error: land use change has been left out of prior analysis.'
The clearance of grassland releases 93 times the amount of greenhouse gas that would be saved by the fuel made annually on that land, said Joseph Fargione, lead author of the second paper, and a scientist at the Nature Conservancy.
International environmental groups, including the United Nations, responded cautiously to the studies, saying that biofuels could still be useful. 'We don’t want a total public backlash that would prevent us from getting the potential benefits,' said Nicholas Nuttall, spokesman for the United States National Energy Program, who said the United Nations had recently created a new panel to study the evidence.
'There was an unfortunate effort to dress up biofuels as the silver bullet of climate change,' Nuttall said. 'We fully believe that if biofuels are to be part of the solution rather than part of the problem, there urgently needs to be better sustainability criterion.'
The studies do not condemn the use of biofuels, but instead shine light on the issue that there are two sides to the renewable energy coin. Although renewable energy is emerging as a staple in the future energy landscape, renewable energy projects still require due care, research and proper management.
In the case of biofuels, land management and crop choice can help to significantly alleviate some of the problems brought out by the studies.
The European Union and a number of European countries have recently tried to address the land use issue with proposals stipulating that imported biofuels cannot come from land that was previously rain forest.
In the United States the primary source of bioethanol is corn. The energy obtained from corn-based ethanol is only marginally higher than the energy used to produce it. Corn yields are also heavily reliant on fertilizers and pesticides.
The low energy efficiency of corn requires a large area of farmland which has caused indirect land use changes. For example, Midwestern US farmers previously alternated corn with soy in their fields, one year to the next. Now many grow only corn, meaning that soy has to be grown elsewhere.
Corn is not the only crop capable of producing ethanol, and both the United States and Europe are exploring other options.
Sugar cane, the primary source of ethanol in Brazil, produces greater energy yields than corn. However, sugar cane requires a hot climate and there are concerns that displacing Brazilian subsistence farmers to grow sugar cane will push them into slashing and burning virgin rainforest for cropland.
The most promising crop choice for the US and Europe may be switchgrass, which, according to a recent study conducted by the National Academy of Sciences, can produce five times more energy than that which is required to grow it.
Switchgrass is a native prairie grass that is known for its hardiness and rapid growth. This perennial grows during the warm season of the year and grows 2 to 6 feet tall. Switchgrass can be grown in most parts of the United States, including swamplands, plains, streams, and along the shores. It is resistant to many diseases and pests and can produce high yields with low applications of fertilizer and other chemicals.
As good as switch grass seems, it brings about its own problems. The average switchgrass yield is only three tonnes per acre while the average feedstock yield is ten tonnes per acre. Switchgrass also carries the problem of being highly flammable and may not be suited to dry environments.
Critics of biofuels also suggest that replacing agriculture land to make fuel instead of food is putting additional pressure on global foodstocks while a global food shortage looms in the future. Replacing crops with ethanol sources that are inedible such as switchgrass may prove very shortsighted in the long run.
The issues brought up by biofuels demonstrates that there may not be one ‘miracle solution’ to climate change and the success of alternative and renewable energy is dependent on a complete life-cycle understanding of technology impacts. Anything less could result in unforeseen consequences which may undermine the potential benefits offered by the renewable energy.
Renewable energy, climate change and future energy alternatives will be discussed by leading experts at GLOBE 2008, a premier conference and trade show about the business of the environment. Auto FutureTech is a new feature at GLOBE which will bring together representatives of the automotive and fuel sector’s major stakeholders to discuss the future of the automotive industry.
Auto FutureTech is an integral part of the GLOBE Conference to be held in Vancouver March 12 to 14, 2008.