My answer is I don't know what you are talking about. I don't know what presentation of the data you are looking at, but the sudden and unprecedented increase in temp is a more recent phenomenon than 700 years ago. The only thing I can figure is you are trying to include the Medieval Warm Period in this. WEll, that phenomenon was slower and more minor increase that fits perfectly within normal fluctuations seen over the previous 650,000 years, perhaps slighly larger due to the increased deforestation due to increased European population. THe Medieval Warm Period is not really part of the carbon dioxide induced phenomenon since the two a.) have a completely different dynamic and b.) are separated by the "little ice age" (a cold period whose dynamics also fit the pattern of normal fluctuations over the past 650,000 years).

The current trend, popularly called "the hockey stick," looks NOTHING like any of the natural fluctuations in the past 650,000 years. The rate of increase is much faster (and matches the rate of increase seen in carbon dioxide, which is also unlike anything seen in the last 650,000 years) and much higher. The carbon dioxide levels are far higher than they have been in the past 650,000 years and the temperature is the highest it has been in the past 650,000 years. If you look at the past 650,000 years you see relatively gradual fluctuations that peak within a certain range. If you look since 1800, you see a change in carbon dioxide AND temperature with a biphasic character: about 150 years where the rate of change looks maybe higher than normal, but maybe not (possibly a natural phenomenon with a minor human caused componant) followed by 50 years where the rate of change is unprecedented in the past 650,000 years.

So, please familiarize yourself with the full data, not just the tiny bit Rush Limbaugh tells you about. Remember, he used to blame global warming on Mt. Pinatubo...based on numbers he KNEW were wrong.