Global Warming, (In class Essay)

Global Warming

Global Warming is described as the progressive gradual rise of the earth's surface temperature thought to be caused by the alterations to the greenhouse effect and responsible for changes in global climate patterns.

The greenhouse effect is the absorption of energy radiated from the Earth's surface by carbon dioxide and other gases in the atmosphere, causing the atmosphere to become warmer.

This whole process occurs naturally and has kept the Earth's temperature about 59 degrees Fahrenheit warmer than it would otherwise be. Current life on Earth could not be sustained without the natural greenhouse effect.

The most recent scientific data confirms that the earth's climate is rapidly changing. In the beginning, all climate changes occurred naturally, however, the Industrial Revolution brought about a massive change in the world's atmosphere.

We began altering the climate and environment through agricultural and industrial practices. The cause is a thickening layer of carbon dioxide pollution, mostly from power plants and cars that traps heat in the atmosphere.

Global temperatures increased by about 1 degree Fahrenheit over the course of the last century, and will likely rise even more rapidly in coming years. Natural variations in temperature could be caused by variations in the earth's orbit, or variations in the sun's output (Sunspots), or several other factors including sulfur dioxide emitted by volcanoes.

Human caused warming is by increased concentrations of greenhouse gasses such as carbon dioxide, Methane and a CFC's.

Humans have also emitted sulfur dioxide, which has a cooling effect and has tended to mask the warming effect of rising carbon dioxide for much of the last 100 years until the mid-1970's, when clean air acts became operative.

This planet is losing its forests, 34 million acres each year through burning and cutting. The destruction of tropical forests alone is throwing hundreds of millions of tons of carbon dioxide into the atmosphere each year. The temperate forests that we are cutting down also account for an absorption rate of 2 billion tons of carbon dioxide annually through the process of photosynthesis.

Scientists say that unless global warming emissions are reduced, average U.S. temperatures could rise another 3 to 9 degrees by the end of the century, with far reaching effects. Sea levels will rise, flooding coastal areas.

Heat waves will be more frequent and more intense. Droughts and wildfires will occur more often and species will be pushed to extinction. If carbon dioxide and other greenhouse gases continue to spill into the atmosphere, global temperatures could rise five to 10 degrees(F) by the middle of the next century and possibly new temperature records will be set each year.

Warmer temperatures, average temperatures will rise, as will the frequency of heat waves. Most of the United States has already warmed, in some areas by as much as 4 degrees Fahrenheit.

The last three five-year periods are the three warmest on record. Many places in North America had their hottest seasons or days on record in the late 1990s.

Since 1983, the earth has experienced 19 of its 20 hottest years on record, with 2002 the second hottest ever recorded, and 1998 the hottest. Greater evaporation, particularly during summer and winter, could worsen drought conditions and increase the risk of wildfires.

Warmer temperatures can also increase the probability of drought too. Deadly heat waves and more frequent and more intensive heat waves could result in more heat-related deaths.

Coastal regions, where half the human population lives, will feel the adverse effects of rising sea levels as the ice caps melt under rising ocean temperatures.

If the present melting continues, the sea could rise as much as 6 feet by the middle of the next century. Rising global temperatures will speed the melting of glaciers, and ice caps, and cause early ice thaw on rivers and lakes.

The area of the Arctic covered by sea ice declined by about 6 percent between 1978 and 1995. Arctic ice thickness has also decreased since the 1960s. Consequences of the sea levels rising include loss of coastal wetlands and barrier islands, and a greater risk of flooding in coastal communities.

The current pace of sea-level rise is three times the historical rate and appears to be accelerating. Global sea level has already risen by four to eight inches in the past century. Scientists' best estimate is that sea level will rise by an additional 19 inches by 2100, and perhaps by as much as 37 inches.

Ecosystem disruption, warmer temperatures may cause some ecosystems to disappear. The increase in global temperatures is expected to result in loss of species diversity, as some species that cannot adapt die off. A recent study found that at least 279 species of plants and animals are already responding to global warming.

We know that the primary sources of pollution including automobiles, public waste (garbage and sewage), agriculture pesticides, air pollution resulting from the absence of forest trees, industrial processes, the burning of gasoline, oil, coal, and natural gas, add more carbon dioxide to the atmosphere.

The concern is that if we do not fix these problems, then our future generations will live in a horrible place that will not allow them to play outside without high level sunscreen.