Global Warming Question 3 - How much warmer has it been?

Question

Relative to currrent temperatures, how much hotter have past global maximums been?

As always, answeres must be supported by scientific data sources. Al Gore, other politicians, Hollywood celebrities and Wikipedia are not scientific sources. Non-responsive replys will get negative ratings.

Answer 1

I do not have a specific source but if you look in any world history textbook you could see that at one point it was so warm the vikings were farming large tracts of land in Greenland. Evidence that at one time in recorded history Greenland was not as completely ice covered as it is now. From this we can extrapolate that it was warmer at least in Greenland then.