While 97% of climate scientists are trying to figure out if they are part of the 97%, the not the climate scientists are laughing their asses off. Why?
The mean value lines are included for easy comparison. With the exception of the 64N reconstruction, today is pretty close to average. With the Arctic warming, it is approaching "average" for the past 2000 years. Average is generally not "unprecedented".
Now if I picked say 900 to 1300 AD for the baseline period, I would come up with something like this from Wikipedia.
With thousands of paleo reconstructions available I would of course be accused of being part of the 3% even though as not a climate scientist I not allowed in the club anyway, because I picked three reconstructions which obviously were cherry picked after consultation with some big oil or big tobacco firm. I actually picked these three because I like to follow the energy. The IPWP would be a good indication of the total energy of the global oceans and the comparison of the 57N and 66N should provide a fair indication of the Thermohaline Current and Arctic sea ice conditions. In order for there to be moisture available to build the ice sheets that are required if you are going to have a respectable ice age, there should be more energy aka heat in the northern Atlantic. For that to happen, the IPWP would likely have to give up or redistribute some of its energy/heat to start the ball rolling. Right around 1600 AD there is a bit of a divergence between the IPWP and the Sub-Polar North Atlantic. That would be a perturbation.
Whatever the cause of the perturbation, it seems to have had some relationship with the little ice age. Nothing "unprecedented" enough to rewrite history over, just a minor shift in climate that got a lot of press in Europe and northern Asia. Without modern farm equipment, the little ice age caused more problems than it would today, but we have Climate Scientists and mass media to make up for the lack of real hardships.
Now Climate Scientists are impaled on the horns of a dilemma. They have created a larger problem than existed by over analyzing a situation and clinging to a theory that had already been revised and recalculated, Arrhenius' Greenhouse Effect.
Originally, Arrhenius estimated that CO2 from burning fossil fuels would be enough to save the world from what he imagined was the new real Ice Age. Arrhenius' peers noted that he appeared to have overestimated his Greenhouse Effect so in 1906 Arrhenius unceremoniously revised his estimate downward. In 1938 Guy Callendar renewed Arrhenius' work and came up with about the same revised or lower estimate. A number of others afterwards also found that there was a Greenhouse effect and that it would have a small and mostly beneficial impact. It took real geniuses of Climate Science to disregard the Arrhenius take two, Callander and the others to produce a crisis of atheistic proportions. Now the "believers" have to confirm that the 97% consensus exists so they can hide in the masses in order to cover their pseudo-scientific asses.
While the 97% creators still try to promote the crisis of atheistic proportions, there are some of the not technically climate scientist that are having fun showing how the old masters kicked butt compared with their drug culture replacements.
This situation is bound to get even more entertaining in the next few months. The data used is available at NOAA Paleo and a description of the slice to Oppo 2009 is available here.