Marine oil spills such as the Exxon Valdez Spill in Alaska in 1989-cause considerable environmental damage. Acute oil spills such as the Valdez spill can damage individual organisms and wipe out entire populations of marine and coastal species. They also require large-scale, costly clean-up operations. Even more alarming, however, is that marine oil spills such as the Valdez spill are not nearly as damaging to the environment as the thousands of smaller spills that are reported annually. Pipeline spills reported to the U.S. Department of Transportation average 12 million gallons of petroleum products per year. The Exxon Valdez Spill, by comparison, spewed out 11 million gallons. According to the U.S. General Accounting Office, an average of 16,000 small oil spills seep into waterways each year and estimates that in recent years more than 46 million gallons have spilled per year.
Another source of water pollution from gasoline is groundwater pollution. According to the U.S. Environmental Protection Agency, more than a quarter of the nation's one million underground gasoline and oil tanks leak, causing considerable groundwater contamination. Besides direct oil spills and leakage, secondary water pollution from petroleum is also a problem. Oil and gas leakage from cars and trucks is collected on pavement and is carried to streams and lakes whenever the pavement is wet and water drains across it, causing environmental damage to aquatic plant and animal life.
Ethanol can replace the most toxic parts of gasoline with a fuel that quickly biodegrades in water, reducing the threat that gasoline poses to waterways and groundwater. Ethanol spills or leaks are not an environmental hazard.
Bio diesel is also biodegradable in water and is becoming an attractive alternative to using petroleum diesel for boating to protect and improve water quality.
Global Climate Change
The U.S. transportation sector is responsible for one third of our country's carbon dioxide (CO2) emissions. CO2 is considered to be a greenhouse gas, the build-up of which may lead to global climate change. These emissions result from combusting fossil fuels, which releases the carbon content of the fuels into the atmosphere.
Producing and using bio fuels for transportation can help reduce CO2 build up in two important ways: by displacing the use of fossil fuels, and by recycling the CO2 that is released when it is combusted as fuel. By using bio fuels instead of fossil fuels, the emissions resulting from fossil fuel use are avoided, and CO2 content of fossil fuels is allowed to remain in storage. Further CO2 reductions occur because the plants and trees that serve as feedstocks for bio fuels require CO2 to grow, and they absorb what they need from the atmosphere. Thus, much or all of the CO2 released when biomass is converted into a bio fuel and burned in automobile engines is recaptured when new biomass is grown to produce more bio fuels.
Waste disposal
Almost half the existing landfills in the U.S. are close to capacity and are expected to close in the near future, and the rate at which we produce waste continues to increase. Disposal costs are increasing as available landfill space decreases. This is especially problematic for some segments of the agricultural and forest products industries, which produce huge amounts of waste each year.
A sound solution to many of these waste problems is to convert the waste into ethanol. The National Bio fuels Program is working to decrease the cost of the technology to convert waste to ethanol so that it can be commercialised. Then private industry will lead this effort to solve some of our waste problems. One U.S. Company has taken strides toward this. Masada, Incorporated, has plans to build an ethanol plant in Middletown, New York, that will convert the celluloid materials in municipal solid waste to ethanol.
Ozone Formation
Tropospheric Ozone Formation
Smog is made up, in large part, of ozone gas. When most people think of ozone, they think of the protective layer of ozone in the earth's upper atmosphere that protects us from harmful ultraviolet rays. At the ground level, however, ozone is a toxic gas and a powerful oxidizing agent. While "ground-level ozone" does occur naturally, it only does so in small quantities.
When fossil fuels are burned, a variety of pollutants are emitted into the earth's troposphere, or the region of the atmosphere where humans live. Among these pollutants, hydrocarbons, nitrogen oxides, and carbon monoxide are all ozone precursors. A variety of complex chemical reactions occur between these, some resulting in the formation of nitrogen dioxide, which gives the distinctive brown haze to our air, which we know as smog. Nitrogen dioxide also can react photo chemically to form ozone, which is a known health hazard.
Bio fuels help combat ground-level ozone formation because they emit fewer of the ozone-forming pollutants than petroleum fuels.
Acid Rain
Fossil fuels contain sulphur, and depending on the blending process, different blends of gasoline and diesel contain varying amounts of sulphur. When these fuels are combusted the sulphur in the fuel is emitted into the atmosphere as sulphur dioxide (SO2). In the atmosphere, SO2 is oxidized into an aerosol of sulphuric acid that is deposited in tiny droplets on the earth's surface when it rains. This type of rainfall is commonly known as acid rain. When the SO2 concentrations are very high in rainfall, they can cause severe respiratory damage to humans and substantial damage to buildings.
Fortunately for humans, most of the sulphur sprayed back onto the earth falls in unpopulated regions. When that happens, our agricultural crops, forests and lakes suffer tremendous damage. Acidic rain damages an estimated $2 to $3 billion annually of agricultural crops in the United States each year. Natural forests die from the acid rain, along with their biological diversity of species. Metal deposits in soil from acidic rain are later released back into lakes and streams and are toxic to fish. Thousands of lakes in the U.S. and Canada have suffered serious losses of aquatic life due to acidic rain.
Replacing petroleum fuels with bio fuels can dramatically reduce the amount of sulphur dioxide emissions from the transportation sector. Using any amount of ethanol or bio diesel in blends displaces the corresponding amount of sulphur in petroleum, thereby decreasing sulphur emissions. .
