From my understanding...the average temperature has risen faster in the last century than during any other time in history.
We can't possibly know that! Any time in history? Say, perhaps, the first century of this planet's existence? Nobody was around to take a measurement. So all we know is that for the time period we have been taking temperatures, we have seen the sharpest rise only recently.

Correlation does not mean causation.

EDIT: This Graph supports a cycle over millenia -- so if we have observed a sharp rise in 100 years, it means virtually nothing in this perspective. That is, if we place our faith in the same scientific speculation that led to both graphs' production.