For many years now, the subject of global warming has been the cause of heated debates throughout the world. The theory is based on the idea that greenhouse gasses are accumulating in Earth's atmosphere as a result of human activities, causing surface air temperatures and subsurface ocean temperatures to rise. Debates have covered its causes and effects, and whether or not it actually exists and is a true threat to the planet. I, for one, do not believe that global warming is a real issue, but one created by environmentalists and scientists with a need for funding for additional and continuing research. I believe that research shows while there may be cyclical changes in temperature and weather on our planet, they occur naturally and not affected by man in any real way.
One of the most popular theories being debated is the "greenhouse effect- which is caused by greenhouse gasses - naturally occurring gasses such as water vapor, methane, oxygen and carbon dioxide. As the Earth is a living planet, it is constantly undergoing change. Plate tectonics continue to change the face of the planet. The sea floor is still spreading, and we still have earthquakes and volcanoes. Convection currents created by the tremendous heat and pressure at the core of the Earth move the plates. These processes release tremendous amounts of carbon dioxide and water vapor (greenhouse gasses). We know that these processes have been taking place since the beginning of time and, according to the geologic record, there have been numerous greenhouse and icehouse ages. Additionally, we know that the motion of the Earth, known as the Milankovitch cycles, also affect the Earth's atmosphere. These cycles - the Earth's elliptical orbit, the tilt of the Earth's axis, and the procession of the equinoxes - all have an effect on the Earth in various ways. The Earth's orbit brings the planet closer to the Sun at one point in its 100,000 year trip.