What is Global Warming?

Global warming is a term used to describe a gradual increase in the earth’s average temperatures across the whole planet. Measurements indicate that the global temperature has increased by about 1 degree Fahrenheit in the past 100 years. This warming trend appeared during a period when human activities were beginning to increase the carbon dioxide (CO2) and other greenhouse gases in the atmosphere. Although most scientists believe that a rise in carbon dioxide emissions will lead to further global warming, uncertainties remain about the timing and severity of resulting climatic change. Nevertheless, many are convinced that human activities are partly responsible for the long-term warming of the past century, and that climatic changes caused by greenhouse gases will be a continuing part of our future. They believe there is enough evidence to demand a sensible approach toward minimizing the potential consequences of global warming. The Intergovernmental Panel on Climate Change, a panel of 1,000 scientists convened by the United Nations’ Environment Program and the World Meteorological Organization, determined that even if we take steps now to reduce our emissions of greenhouse gases, the globe could warm up at a rate faster than it has in the past

The Greenhouse Effect:

Scientists are certain about the greenhouse effect. They know that greenhouse gases make the earth warmer by trapping heat in the atmosphere.

The greenhouse gas occurs when the gas floating in the atmosphere traps heat. When the atmosphere traps heat, it reflects the heat back on the planet. There are a series of gases that are in the atmosphere naturally. However, most gases that are in the atmosphere are a result of the activities of humans on earth. If a fossil fuel is burned, such as oil and natural gas, it will dump carbon dioxide into the atmosphere. Burning trees and other types of wood products causes gas to drift into the atmosphere. Methane is another type of gas that floats in the atmosphere and results in damage to the environment.
 

Climate Change:

Effects of global warming:

With the earth getting warmer, it may lead to changes in rainfall patterns, a rise in sea level, and a wide range of impacts on plants, wildlife, and humans.
Changing weather patterns around the globe seem to indicate that the earth may in fact be in the midst of a global warming cycle. Scientific data shows that the earth's temperature is gradually rising and climate changes are being seen in areas all around the world as a result. We are already seeing moderate rising of sea levels. Storms are becoming more severe. Areas which don't normally receive much rainfall are documenting higher than normal precipitation. Areas which would normally experience good rainfall levels are receiving less and less. The ozone layer over the South Pole is being depleted allowing more radiation from the sun to enter earth's atmosphere raising global temperatures, causing the Antarctic and Arctic ice caps to melt to levels not known in recent history. Glaciers in various locations around the world once thought to be permanent are melting off and receding at alarming rates. The implications to mankind are massive and potentially devastating. Two thirds of the worlds population live in coastal or low lying areas which could be totally eliminated by rising sea levels brought about by the melting of earth's polar ice caps. Society as we know it could be totally devastated. Coastal cities totally wiped out or at the very least made partly or completely uninhabitable. Agriculture severely disrupted. World commerce severely crippled. And the more the earth's temperature rises the faster the effect is amplified. Scientists are predicting that global temperatures could rise by ten to twenty degrees and sea levels rise as much as twenty feet or more by the middle of this century due to accelerated global warming.
Though it is difficult to connect specific weather events to global warming, an increase in global temperatures may in turn cause other changes, including glacial retreat and worldwide sea level rise. Changes in the amount and pattern of precipitation may result in flooding and drought. There may also be changes in the frequency and intensity of extreme weather events. Other effects may include changes in agricultural yields, reduced summer stream flows, species extinctions and increases in the range of diseases.
Some effects on both the natural environment and human life are, at least in part, already being attributed to global warming. A 2001 report by the IPCC suggests that glacier retreat, ice shelf disruption such as the Larsen Ice Shelf, sea level rise, changes in rainfall patterns, increased intensity and frequency of extreme weather events, are being attributed in part to global warming. While changes are expected for overall patterns, frequencies, and intensity, it is difficult to attribute specific events to global warming. Other expected effects include water scarcity in some regions and increased precipitation in others, changes in mountain snow, and adverse health effects from warmer temperatures.
Increasing deaths, displacements, and economic losses projected due to extreme weather attributed to global warming may be exacerbated by growing population densities in affected areas, although temperate regions are projected to experience some minor benefits, such as fewer deaths due to cold exposure. A summary of probable effects and recent understanding can be found in the report made for the IPCC Third Assessment Report by Working Group II. The newer IPCC Fourth Assessment Report summary reports that there is observational evidence for an increase in intense tropical cyclone activity in the North Atlantic Ocean since about 1970, in correlation with the increase in sea surface temperature, but that the detection of long-term trends is complicated by the quality of records prior to satellite observations. The summary also states that there is no clear trend in the annual worldwide number of tropical cyclones.
Additional anticipated effects include sea level rise of 0.36 to 2.5 ft between 1990 and 2100, repercussions to agriculture, possible slowing of the thermohaline circulation, reductions in the ozone layer, increased intensity and frequency of hurricanes and extreme weather events, lowering of ocean pH, and the spread of diseases such as malaria and dengue fever. One study predicts 18% to 35% of a sample of 1,103 animal and plant species would be extinct by 2050, based on future climate projections. Two populations of Bay checker spot butterfly are being threatened by changes in precipitation, though few mechanistic studies have documented extinctions due to recent climate change.
Earth's coral is disappearing at alarming rates. In some parts of the Indian Ocean, mortality is as high as 90 percent. Some corals more than 2000 years old have already died (www.noaa.gov).
The plains may have a lot more fires than expected because of global warming. Global Warming will add extra heat to that region, in addition to the heat they already have there. Some coastal regions will flood more frequently because of all the extra rain. This will cause many inhabitants to leave their homes and cities. Large portions of the Polar Ice Cap might melt making sea level rise 16-20 feet. A rise of 20 feet in the sea level could cover most of the state of Florida. Some forests will dry up and become like deserts by the middle of this new century. Also because of the increase in thunderstorms there could be more forest fires because of the lightning and the dry wood from the trees. The snow covered mountain peaks will probably melt causing floods and very dangerous mudslides.

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