It was discovered by Joseph Fourier in 1824 and studied in further depth by Svante Arrhenius in 1896. The greenhouse effect is necessary for human survival. Natural gases from the earth have a warming effect, without which the earth would be uninhabitable. However, it is the strength of this effect that concerns scientists. The main greenhouse gases are water vapor, carbon dioxide, methane, ozone, and nitrous oxide. There is evidence that atmospheric concentrations of carbon dioxide and methane have increased significantly since the pre-industrial levels of 1750. In fact, current levels are higher than at any other time within the last 650,000 years, according to data extracted from ice cores. Some of these gases occur naturally. Others, like carbon dioxide, are caused by human activity, such as the burning of fossil fuels. Other possible causes of global warming are changes in the earth 's orbit or increased solar activity. Slight variations in the earth 's orbit over time may cause increases or decreases in global temperature. It is possible that the path of the earth 's orbit has brought us closer to the sun, thus raising the temperature. Some scientists believe that increased solar activity has more to do with global warming than do changes in the earth 's orbit. In fact, many believe that up …show more content…
Economically, global warming could be good because it could extend the growing season and produce more food in a given season. It could spur development in new industries designed to reduce greenhouse gases and keep warming to a minimum. Automobile emissions standards are getting tighter and tighter in order to reduce human consumption of fossil fuels. In turn, hybrid cars have become quite popular, a technology that perhaps wouldn 't have been brought to market as quickly as it has. On the other hand, warming could cause bad weather as well as increase intensity. These effects could make production of food harder, thus reducing agricultural economic output. Transportation would slow, causing distribution to