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The Greenhouse Effect Essay, Research Paper
1.What are the Greenhouse Gases?
Carbon dioxide (CO2) is responsible for more than half the human contribution to the greenhouse effect, and concentrations have climbed steadily from around 280 parts per million at the dawn of the industrial revolution meaning 0.028 percent of the air s volume is taken up by the gas to around 355 ppm today. As people burn oil, coal and natural gas, they release carbon that ancient plants in past geological ages absorbed and stored.6 As cement workers process limestone, carbon absorbed over millions of years by prehistoric marine organisms enters today s atmosphere as carbon dioxide. Each year human beings shift 6 billion metric tons of this fossil carbon from the earth to the air in the form of 22 billion tons of carbon dioxide. The destruction of forests and the degradation of soils adds an estimated 5.9 billion tons of CO2 to the atmosphere, although this estimate may be off in either direction by as much as 3.7 billion tons.7
About half of the CO2 released by human activities is quickly reabsorbed by the oceans and by immature trees, which store carbon in their expanding trunks and branches. But human-caused CO2 emissions exceed what the oceans and lands assimilate. Half the global emission total remains in the atmosphere indefinitely, contributing to the greenhouse effect. The annual human contribution of carbon dioxide seems small in comparison to the 2.75 trillion metric tons of the gas already in the air. The carbon cycle is so closely balanced under natural conditions, however, that the 11 billion tons of carbon dioxide we add each year produces a continuous growth in the gas s atmospheric concentration of about 0.5 percent annually.
Methane (CH4) is released as a result of the combustion of carbon and microbial decay in the absence of oxygen. This occurs in the cultivation of wetland rice, the burning of plant material (biomass), landfills and the digestive systems of livestock and termites. Methane also emanates from coal mines and the production and distribution networks of natural gas. Molecule for molecule, methane is 50 times more powerful in trapping heat than carbon dioxide, but there is less than one 200th as much of it in the atmosphere. Human activities have more than doubled its concentrations from 0.7 parts per million in pre-industrial times to more than 1.7 ppm today.
Methane accounts for 15 percent or more of the human intensification of the greenhouse effect. Because it is removed from the atmosphere relatively rapidly by chemical reactions in the air, emissions reductions of only about 15 to 20 percent would be required to stabilize methane at its current high concentrations. In recent years the rise of methane concentrations has slowed noticeably, perhaps largely as a result of reduced leakage from the natural gas pipeline network in Russia.8
Nitrous oxide (N20) is produced by a variety of biological processes in soils and water. Although its concentration increase of 8 percent since preindustrial times (from 288 to 310 parts per billion) is ascribed to human influence, its human sources are not well understood. Soil cultivation, biomass burning, and fossil fuel combustion all play some role in nitrous oxide production. Bringing new land into cultivation may be the largest source of the gas. Two recently identified major sources are the production of nylon and nitrogen fertilizer. The uncertainty about this gas is especially troubling since the scientists advising the Intergovernmental Panel on Climate Change (IPCC) estimated that a 70 to 80 percent reduction in human emissions of nitrous oxide would be needed in order to stabilize concentrations at their present high level.9
Ozone (O3) is a powerful greenhouse gas with a split personality. In the upper atmosphere ozone protects living things from the sun s potentially harmful ultraviolet-B radiation. Near the earth s surface, however, ozone is a human-made pollutant produced by the interaction of sunlight and industrial and vehicle waste gases that damages lung tissue and some plants. Although difficult to measure, concentrations of this lower-atmosphere ozone are presumed to be increasing as the burning of fossil fuels and biomass increases. Miles above the earth s surface in the stratosphere, however, naturally occurring ozone is subject to depletion by chlorofluorocarbons and similar human-made compounds. Scientists are unsure whether these changes in the atmosphere s ozone concentrations are, on balance, increasing or decreasing the strength of the greenhouse effect.
Industrial gases known as chlorofluorocarbons (CFCs) are powerful heat-trappers. But the net impact of CFCs on climate change may be neutral, because they also contribute to the depletion of the upper atmosphere s ozone layer.10 Production of CFCs is being gradually phased out under the Montreal Protocol, but they are still abundant in the atmosphere and environment. Some of the compounds being developed to replace them are also greenhouse gases.
Water (H30) vapor is the most abundant greenhouse gas. Its concentrations are regulated by overall atmospheric temperature and pressure, not human emissions. However, water vapor plays a major role in human-induced climate change through what is called a feedback loop: If increasing concentrations of carbon dioxide and other gases raise global temperatures, that will draw more water vapor into the atmosphere, amplifying the warming.
2.Why is the Global Warming effect now a problem?
The Global warming effect is now a problem as the earth temperature is now rising, this could lead to widespread extinctions of animals as the temperature raises in places that would normally be cold, and become a tropical climate, for example certain sorts of fish would be unable to survive in the waters around Ireland if the water heated.
Another possiblilty from the earths warming is that the ice caps could melt, if this would happen it would be disasterous for the worlds populations, and anywhere near the sea could go under water by a foot or more, countries like Ireland would nearly entirely disappear underwater, an with this obviously millions would die.
3. Wheat evidence is there that the earth`s atmosphere has warmed
Worldwide thermometer readings go back to around 1860. But how does the warming this century fit a longer-term picture? A recent National Science Foundation (NSF) study reconstructs a 600-year temperature history using natural records such as tree rings, ice-cores and corals. The study finds that 1990, 1995, and 1997 were hotter than any other year back to 1400… (at) roughly a 99.7% level of certainty.
A primary argument of those skeptical that global warming is underway has been that, while surface-based and balloon-borne instruments show clear warming trends, satellite readings with better global coverage contradict them, showing instead slight cooling from 1979 to 1995 at about 5.5 miles in altitude. Satellite experts corrected a critical discrepancy in 1998, however. They found that drag from the atmosphere has caused satellites to drop into lower orbits since they were launched in 1979, distorting their readings. When corrected, the satellite data actually show a warming trend of .13 deg F per decade, which is consistent with surface-based measurements.
Deep in the ocean, there is also ominous evidence that suggests that excess heat may be filling the deep ocean, which will continue to warm the atmosphere for decades or centuries after greenhouse gas levels stabilize. Measurements taken in 1957, 1981 and 1992 on trans-Atlantic voyages along 24 degrees N latitude show the waters between 800 and 2,500 meters in depth have consistently warmed over the past 35 years and…(the warming) is remarkably uniform across the east-west extent of the North Atlantic.
Another way that the earth has been proved to be warming is the largest glacier on Africa s Mount Kenya lost 92 percent of its mass in the last century and Mount Kilimanjaro glaciers have shrunk by 73 percent in that time period. Spain had 27 glaciers in 1980. That number has dropped to 13.
The retreat of mountain ice in tropical and subtropical latitudes is proceeding at a phenomenal rate, confirm scientists at Ohio State University s Byrd Polar Research Center, providing some of the most compelling evidence yet for recent global warming. For example, the Qori Kalis glacier in the Peruvian Andes retreated 13 feet each year between 1963 and 1978. By 1995, the annual rate of retreat was 99 feet.27 Since 1970 the freezing level in the Earth s atmosphere has been rising nearly 15 feet each year.28
4. What are the climate predictions for 2050?
Among researchers predictions: Average increases in the annual temperature
well above anything wrought by the Pacific-driven weather phenomenon of El
Nino, water shortages, diminished snow pack, wetter winters, decreased forest
productivity, increased wildfires, and ever-more-threatened salmon runs.
While global climate models predict an average temperature increase of 2 to 6
degrees Fahrenheit, seven climate simulations run by area researchers said the
Northwest can expect a warming of about 2 degrees by the 2020s and 4
degrees by the 2050s.
5. Is there a way to help the evironment?
Abatement: To abate means to slow or stop. Abatement strategies aim to reduce the emissions of carbon dioxide and other gases that can cause climate change. They include improving energy efficiency, so that we burn less fuel, and using sources of energy that emit no greenhouse gases, such as solar or nuclear power.
Adaptation: Under this strategy people find ways to live successfully with the changed climate. For example, land use may change. Aqueducts can be built to bring water into newly dry areas. Coastal populations can be protected from rising sea level by building dikes and sea walls, by relocating populations inland, and by protecting fresh-water supplies from salt-water intrusion.
Geo-Engineering: Geo means earth, so geo-engineering means to engineer the earth’s atmosphere and oceans to reduce the amount of climate change. For example, the amount of sunlight that strikes the earth might be reduced by putting more small particles into the high atmosphere. The idea is to off-set the warming effect of more greenhouse gas by reflecting more sunlight back into space. Many people oppose geo-engineering because they think there might be unintended side effects. However, if rapid and severe climate change occurs, some are likely to press for geo-engineering because it may be relatively inexpensive
Things that an individual can do to reduce the chance of climate change:
Most effective actions.
Since most of our energy comes from oil, coal and gas, actions that reduce energy use will reduce the emissions of carbon dioxide. For example:
+ When you buy a car, choose one that gets good mileage.
+ Insulate and weatherize your home or apartment.
+ Carpool or drive less.
+ Replace old, worn-out appliances (e.g., refrigerators, heat pumps) with the most efficient new models. If the average U.S. citizen undertakes all of these actions, they can reduce their carbon dioxide emissions by about 25%, which equals about 5 tons of carbon dioxide per year.
Less effective, but helpful, actions.
+ Turn off lights and appliances when not needed.
+ Plant trees.
+ Set the thermostat lower in winter and higher in summer.
If the average citizen undertakes all of these actions, they can reduce their carbon dioxide emissions by about 3%, which equals just over half a ton of carbon dioxide per year.
Using aerosol spray cans does not cause climate change. In the U.S., they no longer contain CFCs.
Individual actions that influence others. Become informed and help your family and friends to learn about climate change. Actively support the government policies you decide are most appropriate.
What might nations do?
Improve energy efficiency: More efficient cars, appliances, and industrial systems use less energy, which means that less fuel is burned and less carbon dioxide is emitted. Substantial energy efficiency improvements can be obtained by replacing individual devices. In the longer run, even larger savings may be possible through structural changes, such as being able to work closer to home or redesigning the way houses and cities are built.
Develop and use energy sources that emit little or no carbon dioxide: Hydro power, solar power and windmills, as well as other “renewable energy” sources, emit no carbon dioxide. Neither does nuclear power. Burning natural gas emits less carbon dioxide than burning coal or oil. In the future, hydrogen, which emits no carbon dioxide when it is burned, may become a practical fuel. Ways of capturing and storing carbon dioxide might also be developed.
Improve forest and agricultural management practices: Trees remove carbon dioxide from the atmosphere and store it in wood. Methane produced by some agricultural activities, such as raising cattle and rice farming, can be reduced.
Reduce the impacts of climate change: New varieties of crops can be developed to grow in changed climates. Aqueducts can carry water to regions affected by drought. Coastal settlements and water supplies can be protected from rising sea level with dikes and sea walls. Coastal ecosystems, especially wetlands, are harder to protect.
How might government help do these things?
Government regulation: Government can require desired behaviors (e.g., force auto companies to build more efficient cars). An advantage of regulation is that it specifies the desired outcomes and can force action. However, regulation can be inflexible and discourage innovation.
Prices and markets: Higher prices for fossil fuels encourage people to save energy by promoting energy efficient devices and behavior (e.g., expensive gas prompts companies to make and people to buy more fuel efficient cars). Government subsidies and taxes can also influence behavior. An advantage of using prices is that they present a constant incentive to innovate. However, using prices can have undesirable side effects, such as imposing a relatively larger burden on the poor.
Information and education: People often do not know how to improve efficiency or reduce emissions. Government can provide them with the information they need to make better choices.
Research and development: Government and industry can support research to demonstrate and improve existing technology, and to develop new technologies that use less energy or emit no carbon dioxide (e.g., refrigerators that use less electricity, cheap practical solar water heaters, and inexpensive solar/hydrogen technology).
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