Global warming is commonly referred to as an increase in the temperature of the lowest layers of Earth's atmosphere. Global warming has occurred in the distant past as the result of natural influences, but the term is most often used to refer to the warming predicted to occur as a result of increased emissions of greenhouse gases. Primary greenhouse gases include water vapor, carbon dioxide, methane, nitrous oxide, and ozone . Carbon dioxide, as well as other greenhouse gases, is a very important factor in the vital cycles which sustain life on this planet, plants use carbon dioxide in photosynthesis and release oxygen necessary to maintain the lives of animal species, who ...view middle of the document...
The rate of increase has also been accelerating in this period of time . The researches made by different groups of scientists came nearly with the same results on the rise of the near surface atmospheric temperature. The Intergovernmental Panel on Climate Change officially concluded that it has increased by somewhere in between 0.5 to 1.1 degrees Fahrenheit since the last century. The sea level has risen four to ten inches during the same period of time . The main issue which troubles not only scientific, but also political arguments is mankind’s contribution to the current warming of atmosphere.
In 1924 M. Milankovitch, a Serbian mathematician, worked out a theory about the causes of changes in the Earth's ice cover . Milankovitch supposed that small variations in earth's orbit can lead to the "extreme" changes in climate. In the period of about forty one thousand years the axis' of rotation angle changes between 22 and 24.5 degrees resulting in melting or expanding of the glacier ice sheets in the Northern Hemisphere and, consequently, in the warming or cooling of climate . Recent techniques let scientists see that for the last several million years, glaciers have varied accordingly to variation of Earth's orbit. This have been causing so called ice ages. The last one lasted from one hundred thousand years ago to 10,000 B.C.
A large quantity of carbon dioxide is dissolved in the ocean water. The quantity of it always comes to equilibrium with the amount of it in atmosphere. Based on the very detailed statistical study of the correlation of the ocean's temperature and the concentration of carbon dioxide in the air, held by the Bell Telephone Laboratories in the period of 1958 - 1988, some scientists conclude that it may not necessarily be the increase of the concentration of the atmospheric carbon dioxide that causes the warming of atmosphere. The study showed that a rise in ocean temperature actually preceded the rise of carbon dioxide concentration in atmosphere .
Other theory states that the primary cause of the global increase of the temperature is the consequence of the sun activity. Sunspot cycles, which range between nine to thirteen years, are determining the amount of the sun radiation which is released in space and received by Earth in particular . "Changes in this cycle on the order of 0.1 percent are equivalent to atmospheric effects on the climate during the time period” .
A large group of people see the cause of the current temperature change due to human activities such as burning of fossil fuels in the course of the past two centuries since the beginning of the industrial revolution and active deforestation of the planet's surface.
Oil, coal and natural gas are fossil fuels formed in Earth from the remains of plants and animals. They are rich in carbon and, when burned, produce carbon dioxide. Fossil fuels have been largely used by humanity since eighteenth century to produce heat. At present they are mostly used...