This graph below shows the record of global average temperatures as compiled by the Hadley Centre for Climate Prediction and Research of the UK Meteorological Office.
Lots of data can be found here :
http://www.metoffice.gov.uk/research...tre/index.html
As you would expect, you can see normal variation and fluctuation in temperatures. However, it seems clear that we have moved from "normal variation" to a clear upward trend. 1 degree C sounds quite small, but on a global scale, 1 degree average is statistically incredibly significant.
The saddest part of all is that most models I've seen indicate that we've already passed the point where human activity is the only main driver of warming - feedback has begun. All data modelling is, of course, never going to be a 100% reliable method of prediction and understanding - but they are yet another tool for grappling with issues. I truely hope it's not the case.