Medieval warm period, ”MWP”
|Posted by Administrator (admin) on 8th February, 2010|
The Medieval Warm Period (MWP) occurred from about AD 800–1300, during the European Middle Ages. Initial research on the MWP and the following Little Ice Age (LIA) was largely done in Europe, where the phenomenon was most obvious and clearly documented.\
The above graphs are not a “final truth” for temperatures the last millennium, but they do show significant deviations in the data we have for historic temperatures.
Was the Middle ages warmer than present temperatures? IPCC changes opinion on this in 2001 and is now claiming that the middle ages was colder than today. A central part of the IPCC data on this matter is mentioned under ”climategate”.
Mostly peer reviewed data for the above graphic, see: http://wattsupwiththat.com/2009/04/11/making-holocene-spaghetti-sauce-by-proxy/
The notorious hokey stick was made from tree ring temperature proxies (of poor quality). Tree rings might not capture long term temperature changes. Craig Loehle has estimated temperatures of the last 2 millenia by proxies not related to tree rings, and get the following result:
The graph clearly shows the MWP around 800 - 1000, as well as the Little Ice Age around 1500 - 1800.
Still, some scientists argue that MWP has not been finally proven to be global, and if it was global, it hasn't been proven to be significantly warmer than today's temperatures. Well, what does "global temperature" mean? Actually it is not any absolute term, and when we go back in history and use proxies for temperatures, it becomes very difficult to get any scientifically absolute answer to the question wether it was warmer or colder than present. But here are some maps that show what we know about global temperatures during MWP.
Or this one:
Last changed: 16th February, 2010 at 20:44:53Back
|Way more MWP evidence now||By Unknown on 18th December, 2016 at 18:33:45|
|Add this one http://science.sciencemag.org/content/342/6158/617|