According to Wikipedia (2004) Global warming is a term used to refer to the phenomenon of the increase in global average temperature of Earth's atmosphere and oceans, possibly reaching the level of the warming of the medieval era in the mid-twentieth century, to exceed from then.
Lillian Bird(2011) Affirms that Global warming has caused an increase in average surface temperature of the Earth. Because of the merger of portions of the polar ice, sea level rise suffered a 4-8 inches over the past century, and it is estimated that there will continue to increase. The magnitude and frequency of rainfall has also increased due to increased evaporation of surface water caused by the increasein temperatura.Los Scientists estimate that the average temperature of Earth lasuperficie can reach up to 4.5 º F increase over the next 50 years (2001-2050)
James Trefil (2005) Clarifies that There are many potential effects of global warming that hypothetically affect the environment and human life according to the theories of global warming. The main one is the progressive increase in averagetemperature. From this arises a series of different effects such as rising sea levels, changes in agricultural ecosystems, the spread of tropical diseases, increased intensity of natural phenomena. Some of these phenomena would be producing today, but it is difficult to determine a direct relationship with global warming.
Manuel Vargas Yáñez, (2008) Says that Predicted changes have the potentialto lead to large-scale changes, and probably irreversible changes in climate, resulting in an impact melt global.El range is one of the most important effects and influences affecting now, without adding the effects greenhouse gases which is another important issue that affects global.
Randolph (2000) Accept that Partial loss of ice at the poles can influence the rise in sea levels, a greaterchange in coastline and inundation of low-cost lines also cause effects in river deltas and islands low rise. These changes are believed to happen in a time scale of thousands of years, but rising sea levels it is possible that might happen in a shorter time scale of a few hundred years.
According to the history line-time (see aprendix 1) The author remark some fragment to the history that showsevolutionary processes, such as:
1800-1870 Level of carbon dioxide gas (CO2) in the atmosphere, as later measured in ancient ice, is about 290 ppm (parts per million).
Mean global temperature (1850-1870) is about 13.6°C.
First Industrial Revolution. Coal, railroads, and land clearing speed up greenhouse gas emission, while better agriculture and sanitation speed up population growth.
1985Ramanathan and collaborators announce that global warming may come twice as fast as expected, from rise of methane and other trace greenhouse gases.
Villach Conference declares consensus among experts that some global warming seems inevitable, calls on governments to consider international agreements to restrict emissions.
Antarctic ice cores show that CO2 and temperature went up and downtogether through past ice ages, pointing to powerful biological and geochemical feedbacks.
Broecker speculates that a reorganization of North Atlantic Ocean circulation can bring swift and radical climate change.
1990 First IPCC report says world has been warming and future warming seems likely.
1991 Mt. Pinatubo explodes; Hansen predicts cooling pattern, verifying (by 1995) computer models of...