The Medieval Warm Period is a big headache for Canutists and Environazis. They would prefer it if it would just go away. After all, how can they claim that global warming is caused by the emissions caused by man if there is historical evidence that there have been significant warm periods before man started chucking out all this CO2.
Mostly they try and get around this by saying that the MWP only affected the northern hemisphere and therefore does not constitute "global" warming. They say this even though there is an increasing amount of evidence from South America, Australasia and Antarctica that indicates the MWP was indeed global - and warm.
The latest edition of CO2 Science features a temperature record from South Africa - which is also in the southern hemisphere. This study demonstrates that the MWP was apparent in South Africa and was as much as 2.5 C warmer than the current warm period.
The study has been published in a peer reviewed scientific journal - as has all the other evidence that climate change is not man made - but unlike the "evidence" that is is anthropogenic it doesn't get high profile, wall to wall coverage on the BBC or in The Grauniad and The Independent.
Scientific consensus, my arse.