OK let me ask this another way - how did all the MWP evidence happen?
If the MWP didn't happen or was a 'regional anomaly' ---
Why were tree lines higher in mountain ranges from the Sierra Nevadas to the Alps?
Why was the US Southwest stricken with drought similar to what is predicted to occur over the next 100 years?
How did crop yields and grazing plants (grasses) grow in increased abundance inside the Arctic Circle?
How did the Vikings farm Iceland and parts of Greenland?
How did the Brits grow the wine grapes grown in Provence today?
How did the Germans grow fig and olive trees?
Why did North Atlantic shipping, despite better ships, decline in the 1200s and 1300s, and why did the people at the time cite dramatic increases in drift ice?
Or if you concede that these things happened because it was warmer, is the Northern Hemisphere what you mean by a regional anomaly?
Answer:
Everyone knows that there have been warming periods in Earth's past.
Which has NOTHING to do with what is happening now. Don't try this in any college class, bubba--the professor will give you an "F." Its called a "straw man" arguement--not relevant and not valid.
The best evidence we have indicates that the MWP was warm, but most of that warmth was confined to the North Atlantic region, and may have been due to changes in the North Atlantic thermohaline circulation system. There is no evidence of excess warmth for the tropics or the southern hemisphere. So globally, the MWP was about as warm as the mid-20th century. But not as warm as today.
Further, much of the evidence shows that periods of peak medieval warmth were not globally simultaneous.
I suggest you read the Wikipedia entry on the MWP, as it answers most of your questions.
Here's the data. 10 different peer reviewed studies, with detailed references so you can examine the original articles. The graph stops in 2004, if it went to 2006 it would be even more impressive.
Things are different this time around.
http://www.globalwarmingart.com/wiki/ima...
EDIT: The graph is a visual cue. To answer your question fully you're going to have to find the references and read them. If you want the truth you're going to need to do some work.
Re the MWP:
http://gristmill.grist.org/story/2006/12...
Re Greenland:
http://gristmill.grist.org/story/2006/12...
Once again, a few paragraphs obviously won't convince you. You're going to have to dig deeper, but the gristmill stuff should start you off.
I don't know if this is a "proxy model" but it models the last 100 years nicely. Once again the graph has a reference to the original peer reviewed articles:
http://www.globalwarmingart.com/wiki/ima...
Could you share your references for your assertions?
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