The average global temperature has risen by how much in the past 100 years?
A l00 year timeframe is incredibly short, however – Research shows that global temperatures have in fact risen by .6 degrees Celsius (1 degree Farenheit) over the past 100 years and the National Academy of Sciences indicate that the increase is due in large part to human activity. http://www.ncdc.noaa.gov/paleo/ctl/cliihis100.html temperatures have risen by more than 20°C (36°F) since the height of the Ice Age 25,000 years ago. http://www.pbs.org/wgbh/nova/warnings/stories/nojs.
