Global warming is a term commonly used in two ways:
1. The phenomenon of an increase in the average temperature of Earth's atmosphere and oceans after the end of the Little Ice Age, which would have heightened dramatically in the last decades of the twentieth century and the first century.
2. A theory that predicts, based on projections based on computer simulations, futuregrowth in global temperatures.
Sometimes the names are used climate change, which means any change in climate or anthropogenic climate change, which consider the influence of human activity. Global warming and greenhouse effect are not synonymous.
History of global warming
The first to express an interest in the matter was Svante Arrhenius, who in 1903 published the Cosmos physical Treaty thatwas for the first time the possibility that the burning of fossil fuels will increase the average temperature of Earth. Among other things, estimated it would take 3000 years for combustion of altering the global climate, under the assumption that the oceans would capture all the CO2 (now known that the oceans have absorbed 48% of anthropogenic CO2 since 1800) Arrhenius estimated the increase inglobal temperature will be doubled when the concentration of carbon dioxide from the atmosphere. Arrhenius eventually calculated this value by 1.6 Celsius without water vapor in the atmosphere and 2.1 ° C with steam present. These results are within the generally accepted parameters in the present. Arrhenius gave a positive assessment to this temperature increase because I imagined it wouldincrease the arable land and the more northern countries would be more productive.
Many organizations are concerned about the effects that global warming may produce are extremely negative, even catastrophic both globally and in specific vulnerable areas. These effects include not only environmental but economic and biological impacts (especially in agriculture which in turn couldaffect the general welfare of mankind. For example, a report by the National Security Center warns U.S.: "In the next 30 or 40 years there will be wars over water, growing instability caused by famine, disease and rising sea levels and waves of refugees. "The resulting chaos is a 'breeding ground' for civil strife, genocide and growth of terrorism "and Javier Solana has suggested:" Climate changealso causes serious political and security risks that directly affect European interests. That is why we need to tackle these together as Europeans. "
Certain phenomena, such as reduction of glaciers, rising sea levels and weather changes are considered consequences of global warming that may influence human activities and ecosystems. Some species may be forced to emigrate from their habitats toavoid extinction due to changing conditions, while other species can spread. Few ecoregions can expect not to be affected.
Another major concern is the rise in sea levels. The sea levels are rising between 1 and 2 inches per decade, while exacerbate extreme weather events, and some Pacific island nations like Tuvalu, are already working on the details of a possible evacuation. Global warming leadsto sea level rise because the water of the oceans expands as it warms, plus there is an increased amount of liquid water from the reduction of mountain glaciers and is feared decrease of the ice caps. In the words of the IPCC TAR:
It is expected that the global mean sea level will rise between 9 and 99 cm between 1990 and 2100. [...] And if all the ice in Antarctica melted, sea level would rise125 m.
The temperature rise does not follow a linear law, but has fluctuations due to natural variability and processes, the most notable of which the phenomenon of El Niño.
Global warming would alter the distribution of fauna and flora of the planet. This would mean the spread of disease from which some of these animals are carriers. Such is the case of malaria, dengue, yellow fever, whose...