Global Warming And Its Causes Essay Research

Global Warming And Its Causes Essay, Research Paper

Global Warming

Global warming is the warming near the earth’s surface that results when the earth’s atmosphere traps the sun’s heat. The earth is getting warmer. The changes are small, so far, but they are expected to grow and speed up. Within the next fifty to one hundred years, the earth may be hotter than it has been in the past million years. As oceans warm and glaciers melt, land and cities along coasts may be flooded. Heat and drought may cause forests to die and food crops to fail. Global warming will affect weather everywhere, plants and animals everywhere, people everywhere; humans are warming the earth’s atmosphere by burning fuels, cutting down forest, and by taking part in other activities that release certain heat trapping gases into the air.

One major cause of global warming is the use of fossil fuels. Fossil fuels like coal, oil, and natural gas that were formed from the remains of plant material deposited during the earth’s carboniferous period. We have known for only a few thousand years that coal, oil, and natural gas can be burned to provide energy. It was not until the mid-1800’s, however, that we began to burn very large quantities of these fossil fuels. It has been estimated that between 1850 and 1950, approximately sixty billion tons of fossil fuel were burned, mostly in the form of coal. More recently, the worldwide consumption of fossil fuel has increased dramatically. The world now burns at least five billion tons of fossil fuel each year. This means that we are adding between fifteen and twenty billion tons of carbon dioxide to the air every twelve months! As this carbon dioxide from burning fossil fuels enters the atmosphere, some of it is take up by photosynthesizing plants, and the oceans absorb some. But because we are burning so much fossil fuel at such a rapid rate, we are putting carbon dioxide into the atmosphere much faster than these natural processes are taking it out. There is no longer a balance between the amount of carbon dioxide being added to the air and the amount of carbon dioxide being removed. As a result, the concentration of carbon dioxide in the air is steadily increasing.

Unfortunately, burning fossil fuels is not the only thing that we humans are doing to increase the amount of carbon dioxide in the atmosphere. In many parts of the world today, forests are being destroyed at an alarming rate. Enormous numbers of trees are being cut down, both to provide timber and to clear the land for farming or ranching. This destructive process is called deforestation. In order to clear forests for agriculture, people cut down and burn all the trees in area. When the flames die down, nothing is left but acres of blackened, lifeless countryside. The fire destroys all the plants and kills or drives off the animals. Because there has been little attempt to replant trees in deforested areas, the world’s forests are disappearing very quickly. In fact some experts predict that if deforestation continues at its current rate, all the world’s rain forest could vanish within only a few decades.

Deforestation makes the problem of the greenhouse effect worse in two ways. When trees are burned, carbon dioxide is released into the air. Some researchers think that the large-scale burning of forests around the world adds at least one billion tons of carbon dioxide to the atmosphere each year. But deforestation does more than just add carbon dioxide into the air. To also eliminates countless numbers of carbon dioxide-absorbing trees from the environment. As fewer and fewer trees are left to take up carbon dioxide, the concentration of carbon dioxide in the atmosphere increases faster and faster.

Much evidence exists showing that the climate changes in response to the greenhouse effect. The degree of change depends on the degree of global warming. Even the lowest projected temperature increases for the coming decades, however, are expected to cause considerable climatic changes. The greater the increase, the more dramatic the changes. Some parts of the earth will warm more than other parts. Some parts may even become cooler. Global circulation models have shown that warming will be faster near the poles than near the equator. Such changes will have a significant effect on weather patterns. There will be changes in precipitation, storms, and wind directions and so on. Rising temperatures are expected to increase tropical storm activity. The hurricane season in the Atlantic and Caribbean is expected to start earlier and last longer. Storms will be more severe. Changing wind patterns will mean that the paths of the storms will be changed, too, making some regions more vulnerable to damage than they are today.

Another major effect of global warming is the rising of seas. As the earth gets warmer, there will be a rise in the average water level of the oceans. Two factors will cause this rise: thermal expansion and melting polar ice caps. As water is heated, it expands, or increases in volume. According to theory, global warming could cause thermal expansion of the ocean waters, which in turn would cause sea levels to rise. Thermal expansion is expected to account for as much as half of the increase in sea level over the next century. The rest will come from the melting of glaciers.

Glaciers are large, thick masses of slow-moving ice that persist from year t