This is a really interesting post at WUWT by J. Storrs Hall. It reminds me of one of those powers of ten films. He looks at data from a Greenland ice core (archived at NOAA here) going back over 50,000 years. He begins looking at the last few hundred years, and then pulls back the view on larger and large time scales. Highly recommended.
Note: Box, et al in 2009 claim to have found from 1-1.5C of warming since around 1900 when this chart leaves off. It is very, very , very dangerous to splice data sets together, but one probably has to add a degree or so to the tail of the chart to bring it up to date, putting current warming about at the Medieval level but below earlier Holocene temperatures.