Your proof?http://www.skepticalscience.co m/medieval-warm-period.htm
takes care of this standard denier question: How does the Medieval Warm Period compare to current global temperatures?
The conclusions are:
a) Globally temperatures are warmer than they have been during the last 2000 years, and
b) the causes of Medieval warming are not the same as those causing late 20th century warming.
What caused warming during that period?
How has it been ruled out now?