The environmental impacts of fossil fuels and nuclear power
Introduction
Coal, Oil and Gas are called "fossil fuels" because they have been formed from the fossilised remains of prehistoric plants and animals. They provide about 85% of all commercial energy in the world (see below), which is more than ten times the amount we use biomass fuels (wood, peat, charcoal, and manure) and other renewable resources, such as wind, geothermal, hydroelectricity and solar combined
Source:Internet
Although oil and coal still dominate, their market fraction began declining decades ago.Meanwhile, nat 19319u2017t ural gas and nuclear power have steadily increased their share and should continue to do so. Contrary to the assertions of antinuclear organizations, nuclear power is neither dead nor dying.
Nuclear power is generated using Uranium, which is a metal mined in various parts of the world, in a process called fission. Nuclear power produces around 11% of the world's energy needs, and produces huge amounts of energy from small amounts of fuel, without the pollution that you would get from burning fossil fuels. France generates 79 percent of its electricity with nuclear power, Belgium 60 percent, Sweden 42 percent, Switzerland 39 percent, Spain 37 percent, Japan 34 percent, United Kindom 21 percent, and the United States (the larget producer of nuclear energy in the world) 20 percent.
Source:" The need for nuclear power", Rhodes, Richards- Foreign Affairs Vol.9, no.1, 2000,pag. 34
Meeting our worldwide energy demands currently requires the burning of fossil fuels (mainly) or generating nuclear energy. Burning fossil fuels contributes to climate change and not only. Renewable resources offer some of the best environmental options, but these technologies need to be developed further.
Environmental impacts
The very resources that the world relies upon for energy are also helping to destroy the world. So fossil fuels, such as petroleum, coal, and natural gas, all include some very serious environmental concerns with their essential energy usage abilities. All stages of fossil fuel use have a severe impact upon the environment, from recovery to storage and end use. Thankfully, important legislation has been put together to help to reduce and control the havoc caused by fossil fuels on the environment. But, with the enormous need for fossil fuels, it is impossible to prevent all environmental problems, especially when they are a part of each stage of usage. These environmental impacts include global warming, air quality deterioration, oil spills, acid rain, health problems etc.
Environmental impacts arise at all stages in the life-cycle of energy sources:
The environmental burdens associated with these activities are many and varied, including:
Global Warming
Among the gases emitted when fossil fuels are burned, one of the most significant is carbon dioxide, a gas that traps heat in the earth's atmosphere. Over the last 150 years, burning fossil fuels has resulted in more than a 25 percent increase in the amount of carbon dioxide in our atmosphere. Fossil fuels are also implicated in increased levels of atmospheric methane and nitrous oxide, although they are not the major source of these gases.
Since reliable records began in the late 1800s, the global average surface temperature has risen 0.5-1.1 degrees Fahrenheit (0.3-0.6 degrees Celsius). Scientists with the Intergovernmental Panel on Climate Change concluded in a 1995 report that the observed increase in global average temperature over the last century "is unlikely to be entirely natural in origin" and that "the balance of evidence suggests that there is a discernible human influence on global climate."
Climate scientists predict that if carbon dioxide levels continue to increase, the planet will become warmer in the next century. Projected temperature increases will most likely result in a variety of impacts. In coastal areas, sea-level rise due to the warming of the oceans and the melting of glaciers may lead to the inundation of wetlands, river deltas, and even populated areas. Altered weather patterns may result in more extreme weather events. And inland agricultural zones could suffer an increase in the frequency of droughts
Air Pollution
Clean air is essential to life and good health. Several important pollutants are produced by fossil fuel combustion: carbon monoxide, nitrogen oxides, sulfur oxides, and hydrocarbons. In addition, total suspended particulates contribute to air pollution, and nitrogen oxides and hydrocarbons can combine in the atmosphere to form tropospheric ozone, the major constituent of smog.
Carbon monoxide is a gas formed as a by-product during the incomplete combustion of all fossil fuels. Exposure to carbon monoxide can cause headaches and place additional stress on people with heart disease. Cars and trucks are the primary source of carbon monoxide emissions.
Two oxides of nitrogen--nitrogen dioxide and nitric oxide--are formed in combustion. Nitrogen oxides appear as yellowish-brown clouds over many city skylines. They can irritate the lungs, cause bronchitis and pneumonia, and decrease resistance to respiratory infections. They also lead to the formation of smog. The transportation sector is responsible for close to half of the US emissions of nitrogen oxides; power plants produce most of the rest.
Sulfur oxides are produced by the oxidization of the available sulfur in a fuel. Utilities that use coal to generate electricity produce two-thirds of the nation's sulfur dioxide emissions. Nitrogen oxides and sulfur oxides are important constituents of acid rain. These gases combine with water vapor in clouds to form sulfuric and nitric acids, which become part of rain and snow. As the acids accumulate, lakes and rivers become too acidic for plant and animal life. Acid rain also affects crops and buildings.
Hydrocarbons are a broad class of pollutants made up of hundreds of specific compounds containing carbon and hydrogen. The simplest hydrocarbon, methane, does not readily react with nitrogen oxides to form smog, but most other hydrocarbons do. Hydrocarbons are emitted from human-made sources such as auto and truck exhaust, evaporation of gasoline and solvents, and petroleum refining.
The white haze that can be seen over many cities is tropospheric ozone, or smog. This gas is not emitted directly into the air; rather, it is formed when ozone precursors mainly nonmethane hydrocarbons and nitrogen oxides react in the presence of heat and sunlight. Human exposure to ozone can produce shortness of breath and, over time, permanent lung damage. Research shows that ozone may be harmful at levels even lower than the current federal air standard. In addition, it can reduce crop yields.
While nuclear energy avoids many of the pollution drawbacks associated with the increased burning of fossil fuels, there are many risks associated with the use of nuclear fuels for energy. Environmental dangers exist in reference to obtaining, using, and storing the wastes from these fuels. Many of the waste products of used nuclear fuel stay in the environment for thousands of years and release radiation which is harmful to humans or other living things.
Finally, fossil fuel use also produces particulates, including dust, soot, smoke, and other suspended matter, which are respiratory irritants. In addition, particulates may contribute to acid rain formation.
Water and Land Pollution
Production, transportation, and use of oil can cause water pollution. Oil spills, for example, leave waterways and their surrounding shores uninhabitable for some time. Such spills often result in the loss of plant and animal life. Coal mining also contributes to water pollution. Coal contains pyrite, a sulfur compound; as water washes through mines, this compound forms a dilute acid, which is then washed into nearby rivers and streams.
Coal mining, especially strip mining, affects the area that is being mined. Characteristically, the material closest to the coal is acidic. After the mining is completed, the land will remain barren unless special precautions are taken to ensure that proper topsoil is used when the area is replanted. Materials other than coal are also brought to the surface in the coal mining process, and these are left as solid wastes. As the coal itself is washed, more waste material is left. Finally, as the coal is burned, the remaining ash is left as a waste product.
Health problems
Burning fossil fuels for electricity generation produces many important pollutants including nitrogen oxides, sulfur oxides, hydrocarbons, dust, soot, smoke, and other suspended matter. These pollutants can cause serious health problems including asthma, irritation of the lungs, bronchitis, pneumonia, decreased resistance to respiratory infections, and early death. Nitrogen oxides and hydrocarbons combine in the atmosphere to form ground-level ozone, the major constituent of smog. Human exposure to ozone can produce shortness of breath and, over time, permanent lung damage.
Nuclear power plants, through normal operation, generate high-level radioactive wastes that will remain dangerously radioactive for 10,000-250,000 years. Nuclear wastes present a serious storage problem, and human exposure results in severe radiation sickness and death.
Advantages and disadvantages
Fossil Fuels
Very large amounts of electricity can be generated in one place using coal, fairly cheaply.
Transporting oil and gas to the power stations is easy.
Gas-fired power stations are very efficient.
A fossil-fuelled power station can be built almost anywhere, so long as you can get large quantities of fuel to it. Didcot power station, in Oxfordshire, has it's own rail link to supply it's coal.
Coal-fired power
stations need huge amounts of fuel, which means train-loads of coal almost
constantly. In order to cope with changing demands for power, the station needs
reserves.
This means covering a large area of countryside next to the power station with
piles of coal
Fossil fuels are not a renewable energy resource Once we have burned them all, there is not any more, and our consumption of fossil fuels has nearly doubled every 20 years since 1900.
Nuclear Power
Nuclear energy from Uranium is not renewable.
Once we have dug up all the Earth's
uranium and used it, there is not any more.
Beyond fossil fuels and nuclear power
Even if there were no greenhouse effect, all of the fossil fuels will be depleted within a few hundred years. If humankind is going to have a future on this planet, at least a high-technology future, with a significant population of several billions of humans continuing to inhabit the Earth, it is absolutely inevitable that we will have to find another energy source. The nuclear power issue has been a very contentious issue in the United States and in other parts of the world. Since the Three Mile Island and Chernobyl nuclear accidents, no nuclear power plants have been built, and there are many, many sets of issues having to do with the disposal of radioactive materials and the proliferation of weapons-grade material and so forth.
The first alternative, of course, is renewables, which include solar energy in its various forms, biomass energy, wind power.
Well, in contrast to renewable energy, nuclear power is a very high-density source of energy. Biomass energy per unit area can produce a few watts per square meter. By contrast, the boiler of a nuclear power plant, where the nuclear energy is being converted into steam, produces tens or hundreds of thousands of watts per square meter.
It is vitally important to confront the real issue, which is the urgent need for a transition to a non-fossil fuel source of energy for our civilization. If we do not do it, we will be faced with the alternative of possibly transforming our planet dramatically, changing the climate to one that we have not seen for perhaps 100 million years. To make the transition, it will be necessary to recognize the magnitude of the problem and to develop a policy that addresses it.
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