The Greenhouse Effect Essay Research Paper 1What — страница 2

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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