The Evidence

In 2007 the Intergovernmental Panel on Climate Change, which was run by the United Nations, stated in a report “Scientific evidence for warming of the climate system is unequivocal.” So how did the vast majority of scientists and scientific bodies come to this conclusion? For one temperature has been rising globally since the late 1800’s, the NOAA, CRU, and NASA have backed up this assertion when they reconstructed the Earths global surface temperature. Secondly the major ice reserves all across the globe are decreasing year to year. The Arctic sea ices area in which it inhabits and its overall depth has decreased abruptly in the past several decades (L. Polyak, et. a 2009). Furthermore the World Glacier Monitoring Service has recorded glacial retreat from both coastal and mountain glaciers all across the globe. Another reason is the sea level is rising 17 centimeters in the last 100 years of which the rate is steadily increasing says John Church and Neil White in the 2006 book Geophysical Research Letters. Lastly scientists cite extreme weather events as evidence for global warming. NASA has tracked the number of record high temperature events and number of record low temperature events across the United States and has seen that the prior has been increasing over the last couple of decades while the later has been decreasing. They have also documented the number of severe rainfall events and have shown those to be increasing as well. To sum this all up when they compared all this information with a graph showing the global Co2 concentrations since the 1800’s they found a clear relationship showing that as CO2 concentrations increased so did all these facets (temp, global ice melt, severe weather events, ext.)