The following data represent global temperature anomalies that have occurred in the last century. In other words, these measurements represent departures from normal temperatures.
Starting around 1980, global temperatures have been regularly warmer than previously recorded. Since 1990, we have witnessed ten of the highest global temperatures that have ever been recorded. Over the past 100 years, the earth's average surface temperature has increased by about 0.74 °C. For more information about this relatively recent rise in temperature, see the IPCC 2007 report on climate change.