The Earth Is Heating Up

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 through exhaling return carbon dioxide in atmosphere, completing the cycle .Greenhouse effect is a natural process which made life on Earth feasible.
The temperature of Earth's atmosphere is regulated by a process in which the quantity of energy Earth gets from the Sun is poised by the amount returned back into space. Greenhouse gases in atmosphere let the energy in and prevent it from escaping, directing it back to Earth's surface .
By the greenhouse effect, in the discussions of the global warming and other environmental problems, people mean "the enhanced effect which is caused by the increase of greenhouse gases from human sources” .
Science brings different theories about the primary causes of the global warming of atmosphere. Eventually, the processes that happen in the environment are so complex even on local scale, that analyzing causes and effects of global processes leads scientists to controversial conclusions. Most scientists agree on certain facts. Arguments start upon interpretation of these facts. Concentration of atmospheric carbon dioxide, which the scientists agree determines the temperature of Earth, has increased from a value of about 275 parts per million before the Industrial Revolution to about 360 parts per million in 1996. The rate of increase has also been