Global Warming - an Average Increase in Temperature

Throughout the world the issue of global warming has become an increasingly important issue. Global warming has been an issue that has been heatedly debated for many years. Scientists all over the world have been debating weather global warming actually exists. If it exists some scientists believe it is natural. While others believe it is caused by humans.

Global warming is defined as an average increase in temperature in the atmosphere near the earths surface and in the troposphere. Which can contribute to changes in global climate patterns. In relativity the thickness of a coat of varnish on a globe is the thickness of the atmosphere compared to the world it self. Thin enough that we are capable enough to change its composition.

Over the past two hundred years the burning of fossil fuels such as, coal and oil, and deforestation have caused the concentrations of green house gases to increase. Which in turn causes the atmosphere to thicken. This prevents heat from escaping the earth for example like panels in a green house.

The suns radiation comes to earth in the form of light waves. Most of this is absorbed by the earth and heats it. The earth sends some of this energy back to space in the form of infrared waves. Again some of this is trapped by the earth. This is important because this keeps the temperature on the earth livable.

This can also be a bad thing because of the green house gases that thicken the atmosphere. More and more of the suns heat gets trapped and cause the earths temperature to rise. Over the last century the average temperature has climbed one degree Fahrenheit, about sixty percent of a degree Celsius. The United Nations Intergovernmental Panel on Climate Change has predicted the global temperature will rise an additional 3 to 10 degrees by the end of the century. So there should little doubt that the earth is warming.

The 1990's was the hottest decade since the mid 1800's when record keeping began. The hottest years were 1997-1998and 2001-2003. The rising temperatures have had a major impact on the artic ice. This ice serves as a air conditioner for the earth.

Since 1978 the artic sea ice are has shrunken 9%.

Since 1970 nuclear submarines have kept track of the thickness of the arctic ice shelf. It has diminished 40% in forty years. Scientists predict in the next fifty to seventy years it will have completely melted. These ice caps are important because 90% of the suns rays are reflected back to space, but if the suns rays hit the open ocean 90% of the suns energy is absorbed thus raising the earths surface temperature.

This continuous melting of glaciers and ice caps are a real big problem. Especially in the Himalayas, 40% of all the people in the world get there drinking water from rivers and streams fed from this glaciers seasonal melt. Within the next fifty years these people are going to have an extreme shortage of water. In 2002 the worlds largest ice shelf cracked in half(Ward Hunt ice shelf). Starting January 31, 2002 scientists began looking at the Larsen B ice shelf. Within thirty five days of studying it, it had completely broken off. Scientists assumed pools of water on the ice shelf would refreeze but instead burrowed deep into it creating mulins. Which caused the ice to break up. Not only did the sea based ice break up but the land based ice to. All because the sea based ice held it back. Since 1999 several ice shelves the size of Rhode Island have broke up and melted. Due to this many pacific nations had to be evacuated to New Zealand because of excessive flooding.

If this continues the earth sea level will continue to rise. If a shelf the size of Greenland or Greenland itself broke up the earths sea level will rise twenty feet and submerge many low lying countries causing millions of deaths.

Scientists that study ice cores can tell the carbon dioxide levels each year and how

hot it was. Since congress passed the clean air act there is visible change in the ice cores. The carbon dioxide levels have never gone over 300 parts per million until this last decade. They will continue to rise extremely. Which will cause an increase in the

earths temperature.

This is very bad because the earth redistributes heat through ocean

and wind currents. The earths currents are all connected in one giant conveyer. The one part of the current that affects this part of our world is the north Atlantic current. The currents are formed by cold dense salt water that cause the hot water to sink. The melting of ice causes this cold water to dilute and slows the current. If the north Atlantic current was to stop the whole