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How are total annual greenhouse gas emissions estimated?
The greenhouse gas estimates presented here are full fuel-cycle estimates, combining the three major greenhouse gases emitted by motor vehicles:
Carbon dioxide (CO2) Nitrous oxide (N methane . Full fuel-cycle estimates include all steps in the use of a fuel, from production and refining to distribution and final use. This gives a more complete picture of the climate change impacts of using a particular fuel.
Some greenhouse gases have greater impacts on climate than others. Scientists have developed relative global warming potential numbers for each gas that gives its impact on global climate realtive to that of carbon dioxide. We use the global warming potentials developed by the Intergovernmental Panel on Climate Change to combine the three gases into tons of carbon dioxide equivalent. We believe this gives the most compete and accurate reflection of the impact of each vehicle's energy use on the global climate.
Numerous assumptions and calculations are necessary to estimate full fuel-cycle greenhouse gas emissions in carbon dioxide equivalents. So, estimates from different sources will vary estimates are taken from the U.S. Department of Energy's GREET model (Version 1.5) developed by Argonne National Laboratory.
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What is Biofuels such as Biodiesel,and Ethanol
Earth Biofuels is in the business of providing balanced energy solutions. By this, we mean that biofuels such as biodiesel and ethanol provide real solutions to the myriad challenges facing America with regard to our current and future energy needs. Further, biofuels are integral to restoring balance to the nation’s economy and air quality. Biofuels can provide a measurable reduction in America’s dependence on foreign oil by displacing petroleum-based fuels with their agricultural counterparts. Derived from crops such as corn, soybeans, canola, and sugar, biofuels can be produced domestically in significant quantities, thereby reducing oil imports by comparable volumes and relieving pressure from the nation’s already strained oil refineries. According to the Energy Information Administration, the U.S. produced over 3.9 billion gallons of ethanol in 2005, or approximately 3% of all gasoline consumed. Though biodiesel and ethanol are collectively referred to as biofuels, they are quite distinct in how they are produced and utilized.
Biodiesel can be refined from a variety of vegetable oils and animal fats to be burned in most any diesel engine. Production of biodiesel consists of a simple and efficient chemical process, whereby vegetable oil reacts with methanol in the presence of a catalyst to yield methyl esters (biodiesel) and glycerin, a co-product that can be used for pharmaceuticals, soaps, and other products. Following the refining process, the fuel is immediately ready for distribution as a substitute or additive to petrodiesel. The process yields a net energy gain of approximately 93%, according to a University of Minnesota study. (Jason Hill, Erik Nelson, David Tilman, Stephen Polasky, and Douglas Tiffany, „Environmental, economic, and energetic costs and benefits of biodiesel and ethanol biofuels,“ PNAS, Departments of "ecology, Evolution, and Behavior and Applied Economics, University of Minnesota, St. Paul, MN and Department of Biology, St. Olaf College, Northfield, MN, June 2, 2006.)
In the United States, ethanol is produced almost entirely from the fermentation of a corn/water mash. The ethanol is separated, distilled, and dehydrated before being blended with gasoline. Only 17% of the energy used to produce ethanol comes from liquid fuels such as gasoline and diesel, according to the Renewable Fuels Association. The remainder comes from domestic sources such as natural gas. The net energy gain is estimated at 25% by the aforementioned University of Minnesota study.
Biofuels are a balanced energy solution.
Balanced Air Quality Petroleum diesel exhaust contains hundreds of constituent chemicals, including many that are human toxins, carcinogens, or present reproductive hazards. In addition, petroleum diesel is a major contributor to ozone air pollution, which is generated by nitrogen oxide and hydrocarbons from fuel combustion. According to the National Biodiesel Board, when biodiesel is blended at a ratio of just 20% with petroleum diesel (B20), harmful emissions and particulates are reduced by as much as 20%; while carbon monoxide, a prime contributor to global warming, is reduced by 12%. Likewise, ethanol reduces overall toxic emissions by as much as 30% and carbon monoxide greenhouse gases over 24% compared to gasoline, according to the American Coalition for Ethanol.
Biofuels are a balanced air quality solution