Last updated on: 10/13/2008 8:51:00 AM PST
Will the Development of Biofuels, Such as Ethanol, Reduce Greenhouse Gas Emissions?
General Reference (not clearly pro or con)
The Food and Agriculture Organization of the United Nations (FAO), wrote the following in its fact sheet "Bioenergy: Environment," published on www.fao.org (accessed July 9, 2008):
"Mitigation of climate change is a policy goal of bioenergy development in many countries. However, life-cycle analyses that measure emissions throughout the bioenergy production chain indicate a wide divergence in carbon balances according to technologies used, locations and production systems - with some even leading to greater emissions than fossil fuels. Key sources of greenhouse gas (GHG) emissions are: land conversion; mechanization; fertilizer and pesticide use at the feedstock production stage and use of non-renewable energy in processing and transport."
July 9, 2008 - Food and Agriculture Organization of the United Nations (FAO)
The US Department of Energy's Office of Energy Efficiency and Renewable Energy published the following information on its website in a section titled "Environmental Benefits of Biofuels" (accessed July 8, 2008):
"Biofuels can provide a number of environmental advantages over conventional fossil fuels—most notably a reduction in greenhouse gas (GHG) emissions. Since the transportation sector accounts for about a third of total U.S. emissions of carbon dioxide (an abundant GHG), cleaner transportation fuels can play an important role in addressing climate change.
The level of GHG emissions associated with a particular biofuel depends on the energy used in growing and harvesting the feedstock, as well as the energy used to produce the fuel (e.g., coal, natural gas, biomass). On a full fuel-cycle basis, corn ethanol has the potential to reduce greenhouse gas emissions by as much as 52% over petroleum-based fuels. Even better, ethanol made from cellulosic feedstocks, such as switchgrass, or agricultural residues such as corn stover, has the potential to reduce greenhouse gas emissions by as much as 86%, compared to gasoline.
Biofuels have the added benefit of providing a 'carbon sink.' As crops grow to produce the feedstocks for making the biofuel, they absorb carbon dioxide from the atmosphere."
July 8, 2008 - United States Department of Energy (DOE)
The National Resources Defense Council (NRDC), wrote in its Dec. 2004 study "Growing Energy: How Biofuels Can Help End America's Oil Dependence," that:
"The United States does not have to rely on oil to drive our economy and quality of life. We can replace much of our oil with biofuels - fuels made from plant materials grown by American farmers. These fuels, especially those known as cellulosic biofuels, can be cost-competitive with gasoline and diesel, and allow us to invest our energy dollars at home. They can also slash global warming emissions, improve air quality, reduce soil erosion, and expand wildlife habitat...
Biofuels could reduce our greenhouse gas emissions by 1.7 billion tons per year - equal to more than 80 percent of transportation-related emissions and 22 percent of total emissions in 2002...
Advanced biofuels technologies that produce both fuel and electricity would be able to displace more than 2 barrels of oil and 1.28 tons of greenhouse gases per dry ton of biomass used."
Dec. 2004 - Natural Resources Defense Council
The Renewable Fuels Association wrote in its fact sheet "Ethanol Facts: Environment," published on its website (accessed Oct. 6, 2008), that:
"Ethanol is a renewable fuel produced from plants, unlike petroleum-based fossil fuels that have a limited supply and are the major contributor of carbon dioxide emissions, a greenhouse gas.
FACT: Using ethanol in place of gasoline helps to reduce carbon dioxide (CO2) emissions by up to 29% given today's technology.
Because ethanol is made from renewable, plant-based feedstocks, the CO2 released during a vehicle's fuel combustion is 'recycled' by the plant as it grows (photosynthesis). New technologies, additional feedstocks, and higher blends of ethanol including E85 all promise greater CO2 reductions. In 2007, ethanol use in the U.S. reduced CO2-equivalent greenhouse gas emissions by approximately 10.1 million tons, equal to removing more than 1.5 million cars from America's roadways."
Oct. 6, 2008 - Renewable Fuels Association
The Intergovernmental Panel on Climate Change (IPCC) wrote in chapter five of its 2007 report titled "Mitigation of Climate Change," published on www.ipcc.ch, that:
"Ethanol from sugar cane, as produced in Brazil, provides significant reductions in GHG emissions compared to gasoline and diesel fuel... These large reductions result from the relatively energy efficient nature of sugar cane production, the use of bagasse (the cellulosic stalks and leaves) as process energy and the highly advanced state of Brazilian sugar farming and processing. Ongoing research over the years has improved crop yields, farming practices and process technologies. In some facilities the bagasse is being used to cogenerate electricity which is sold back to the electricity grid."
2007 - Intergovernmental Panel on Climate Change (IPCC)
Michael Wang, PhD, Vehicle and Fuel Systems Analyst at the Center for Transportation Research at Argone National Laboratory, wrote in his Mar. 7, 2007 report "Life-Cycle Energy and Greenhouse Gas Emission Impacts of Different Corn Ethanol Plant Types," published in Environmental Research Letters:
"For corn ethanol produced in plants fuelled with natural gas, GHG emission reductions vary from 28% to 39%, so natural-gas-fuelled corn ethanol offers distinct GHG emission reduction benefits. Furthermore, if DGS or biomass (such as wood chips) is used as a process fuel, corn ethanol could achieve 39–52% reductions in GHG emissions. However, cellulosic ethanol is—by far—the best option to reduce GHG emissions. When resource supply (corn versus cellulosic biomass) is taken into account, cellulosic ethanol is certainly the ultimate ethanol option, offering GHG reductions of 86%."
Mar. 7, 2007 - Michael Wang, PhD
Jan Suszkiw, Public Affairs Specialist at the USDA Agricultural Research Service, stated in a June 8, 2007 article titled "Biofuel Crops Double as Greenhouse-Gas Reducers," published on the USDA Agricultural Research Service website:
"Corn and soybeans may be the current 'go-to' crops for producing ethanol and biodiesel, respectively. But two other crops—switchgrass and hybrid poplar—could steal the show in the future when it comes to curbing greenhouse gases, according to Agricultural Research Service (ARS) and collaborating scientists.
In a study published in the April issue of Ecological Applications, ARS scientist Paul Adler and colleagues compared the net production of carbon dioxide and two other greenhouse gases associated with producing biofuels from several different bioenergy crops.
In short, it takes energy to produce energy...For example, operating a tractor to plow, plant, fertilize and harvest all require gasoline or diesel fuel. This, in turn, releases carbon dioxide and other greenhouse gases tied to global climate change.
The good news? Bioenergy crops offset their greenhouse-gas contributions in three key ways: by removing carbon dioxide from the air and storing it in crop roots and soil as organic carbon; by producing coproducts like protein for animal feed, which saves on energy to make feed by other means; and by displacement, whereby replacing a fossil fuel with a biobased one 'recycles' rather than adds more carbon dioxide to the atmosphere.
Together with ARS scientist Stephen Del Grosso of Fort Collins, Colo., and William Parton of Colorado State University, Adler predicted a 40 percent reduction of greenhouse gas emissions if ethanol and biodiesel from corn-soybean rotations were used instead of gasoline and diesel. This reduction was about two times greater than using ethanol produced from corn grain alone."
June 8, 2007 - Jan Suszkiw
The UK Renewable Fuels Agency, an official UK government body, in its July 2008 report titled "The Gallagher Review of the Indirect Effects of Biofuels Production," stated that:
"[T]he displacement of existing agricultural production, due to biofuel demand, is accelerating land-use change and, if left unchecked, will reduce biodiversity and may even cause greenhouse gas emissions rather than savings...
Although there are high levels of uncertainty in the data, the science and in the modelling of the indirect effects of biofuels, the balance of evidence shows a significant risk that current policies will lead to net greenhouse gas emissions and loss of biodiversity through habitat destruction. This includes effects arising from the conversion of grassland for cropland."
July 2008 - UK Renewable Fuels Agency
David Biello, Associate Editor at Scientific American, wrote in his Feb. 7, 2008 article "Biofuels Are Bad for Feeding People and Combating Climate Change," that:
"Converting the grasslands of the U.S. to grow corn results in excess greenhouse gas emissions of 134 metric tons of CO2 per hectare - a debt that would take 93 years to repay by replacing gasoline with corn-based ethanol. And converting jungles to palm plantations or tropical rainforest to soy fields would take centuries to pay back their carbon debts...
Ethanol demand in the U.S., for example, has caused some farmers to plant more corn and less soy. This has driven up soy prices causing farmers in Brazil to clear more Amazon rainforest land to plant valuable soy...Because a soy field contains far less carbon than a rainforest, the greenhouse gas benefit of the original ethanol is wiped out."
Feb. 7, 2008 - David Biello
Jack Santa-Barbara, PhD, Director of the Sustainable Scale Project, wrote in a Sep. 2007 report for the International Fourm on Globalization titled "The False Promise of Biofuels," published on www.ifg.org:
"It is true that growing corn sequesters carbon from the atmosphere. However, it is also true that using corn products as combustible fuel releases this carbon back into the air. So there is no net benefit in terms of greenhouse gas emissions. But more significant is that fossil energy used in planting and harvesting the corn, and the industrial processing of the corn into ethanol, are all additional greenhouse gas emissions. Farming activities account for a significant amount of the greenhouse gases created by corn ethanol. In addition, most ethanol plants are powered by coal, which has the highest amount of greenhouse gas emissions of all the fossil fuels. Industrial operations not powered by coal are powered by natural gas, which also emits significant amounts of greenhouse gases. So the outcome is a significant increase in greenhouse gas emissions from corn ethanol regardless of how it is produced...
It must be concluded that corn ethanol's greenhouse gas emissions, as well as emissions from other agrofuels, are not climate friendly, and may be worse than those from petroleum based gasoline. In addition to these high levels of greenhouse gas emissions, corn ethanol produces a range of other pollutants and public health concerns."
Sep. 2007 - Jack Santa-Barbara, PhD
Timothy Searchinger, PhD, Senior Fellow at the Georgetown Environmental Law and Policy Institute, et al., wrote in their Feb. 29, 2008 article "Use of US Croplands for Biofuels Increases Greenhouse Gases Through Emissions from Land-Use Change," published in Science, that:
"Most life-cycle studies have found that replacing gasoline with ethanol modestly reduces greenhouse gases (GHGs) if made from corn and substantially if made from cellulose or sugarcane...
Unfortunately, by excluding emissions from land-use change, most previous accountings were one-sided because they counted the carbon benefits of using land for biofuels but not the carbon costs, the carbon storage and sequestration sacrificed by diverting land from its existing uses. Without biofuels, the extent of cropland reflects the demand for food and fiber. To produce biofuels, farmers can directly plow up more forest or grassland, which releases to the atmosphere much of the carbon previously stored in plants and soils through decomposition or fire. The loss of maturing forests and grasslands also foregoes ongoing carbon sequestration as plants grow each year, and this foregone sequestration is the equivalent of additional emissions...
We calculated that an ethanol increase of 56 billion liters, diverting corn from 12.8 million ha [1 ha = 2.47 acres] of U.S. cropland, would in turn bring 10.8 million ha of additional land into cultivation. Locations would include 2.8 million ha in Brazil, 2.3 million ha in China and India, and 2.2 million ha in the United States...
We calculated that GHG savings from corn ethanol would equalize and therefore 'pay back' carbon emissions from land-use change in 167 years, meaning GHGs increase until the end of that period. Over a 30-year period, counting land-use change, GHG emissions from corn ethanol nearly double those from gasoline for each km driven."
Feb. 29, 2008 - Timothy Searchinger, PhD
George Monbiot, Visiting Professor of Planning at Oxford Brookes University, wrote in his 2007 book Heat: How To Stop The Planet From Burning, that:
"The Environmentalists who support the wider use of biofuels picture the crops they like best. They see nodding heads of sunflowers, or the blue blossoms of the linseed plant. They talk of algae which can be grown in desert ponds, or the use of straw and other wastes to produce ethanol...But what they will not see – in fact what they flatly and repeatedly refuse to understand – is that a global commodity market selects not the most satisfying vision, but the cheapest commodity. And at present and for the foreseeable future that commodity is palm oil...
In Sumatra and Borneo, some 4 million hectares of forest has been converted to palm farms. Now a further 6 million hectares is scheduled for clearance in Malaysia, and 16.5 million in Indonesia...
Before oil palms are planted, vast forest trees, containing a much greater store of carbon than the palm trees will ever accumulate, must be felled and burnt...Having used up the drier lands, the plantations are now moving into the swamp forests, which grow on peat. When they've cut the trees, the planters drain the ground. As the peat dries, it oxidizes releasing even more carbon dioxide than the burning trees produce...
The decision by governments in Europe and North America to pursue the development of biofuels is, in environmental terms, the most damaging they have ever taken. Knowing that the creation of this market will lead to a massive surge in imports of both palm oil from Malaysia and Indonesia and ethanol from rainforest land in Brazil...these imports will accelerate rather than ameliorate climate change."
2007 - George Monbiot