A climate in change
â€The average temperature on earth could increase with 4 degrees within this century.â€ This could have been a headline in any Swedish newspaper during the last 10 years. It is a headline that easily could have been accepted as by the public as actual facts without any further thoughts. Even if this statement does not necessarily have to be inaccurate, it does not fable the entire truth.
With this in mind, I decided I would try to give both my self and the reader a more distinct picture of the climate issue. As the change of climate is a subject field too vast for me to immerse in, I will narrow my research by choosing two eminent ...view middle of the document...
Earlier observations from the 20th century showed a decline in global temperature, which resulted in speculations about a new incoming ice age. People who criticized this, one of the Swedish professor Bert Bolin, and claimed the resources of the earth would lead to a global warming, became a laughing stock in the media.
To explain all the different climate theories, a compilation of the research and knowledge available is needed. Our climate is depending on several diverse factors and here they will be displayed and explained.
Without the sun, no life on earth would be able to exist. But the relationship is more complicated than solar energy transforming into heat. The sun sends out infrared rays and some of these will be absorbed by the land surface and contributes to the warming of earth while others reflects against the surface and radiates into space again. The latter, however, will encounter a layer of so called greenhouse gases in the atmosphere, which will reflect the radiation against earth once more. This tropospheric layer also functions as a mirror for some of the incoming infrared rays.
The solar activity constantly changes, something that means that the surface temperature on earth can shift merely with the activity level of the sun. There are miscellaneous cycles concerning the solar activity, one of them the sunspot cycle, which lasts 11 years. Sunspots are dark areas on the surface of the sun that depends on differences in temperature. They arise as a result from disturbances in the sunâ€™s magnetic field. Studies from GISS (Goddard Institute for Space Studies), a part of NASA, indicate on a correlation between earthâ€™s temperature and the number of sunspots.
An additional cycle worth mentioning lasts 100 000 years and even though it only changes earthâ€™s solar energy by a couple of parts per thousand, it can be the difference between ice age and heat period.
Earth and Sea
The orbit of the earth is elliptical and since the earth itself is not entirely round, variations occur over thousands of years. The weight distribution over the globe is uneven which also contributes to the variations. Combined, these factors creates a cycle of 21 000 years that affects the climate. In 41 000 year, the temperature therefore varies with +/- 1.5Â° degrees.
The earth has a number of ways to distribute the temperature over the globe. Ocean currents are the most important part of this process. Since the density of the water is the highest at 4Â°, water move from colder to warmer places and vice versa. The ocean works as a temperature equalizer as it takes longer time for water than soil to warm up.
As a result of the ocean being so involved in the temperature on earth, a change in the underwater system could have disastrous consequences. Earth also has something called albedo, which is its reactivity on changes in the climate. This can be found in observations of the ice masses. Since ice reflects a great deal of...