Prior to Mann's work, it was generally accepted that there was a Medieval Warm Period
or "Medieval Maximum," when temperatures were several degrees warmer, on average, than in the preceding half a millennium or so.
Perhaps they can explain the following: From about years 800 to 1300, we had the Medieval Warm Period
in which Earth was as hot or hotter than it is today.
Why, then, are our children to be shown an alarmist video incorporating such errors as the discredited "hockey stick" graph, which ignores both the medieval warm period
and the Little Ice Age, and which will apparently be withdrawn from the next Intergovernmental Panel on Climate Change report?
There have been occasional blips in the climate regime since then, such as the Medieval Warm Period
about a thousand years ago, when the Norse established settlements in Greenland--only to abandon them a few generations later when a cooler climate returned.
The book is divided into four parts: The Medieval Warm Period
Average temperatures are now approaching those at the height of the Medieval Warm Period
, near the end of the 12th century.
He finds that population growth accelerated during the warm period between 5000-1000 BC, increased very slightly during the Medieval warm period
of 800 to 1200 AD, and fell during two cooling periods, the years between 500 and 600 AD and the "Mini Ice Age" between 1300 and 1800 AD.
One author titled a paper: "Was there a Medieval Warm Period
, and if so when and where?
The climate is always changing: It is not what it was during the Medieval Warm Period
(ninth to 13th centuries) or the Little Ice Age (about 1500-1850).
These are the Medieval Warm Period
, which is well known, but also a period during the toga-wearing Roman times when temperatures were apparently 1 deg C warmer than now.
It is this kind of manipulation which caused the IPCC to ignore the medieval warm period
because it did not suit their discredited "hockey stick" graph which supported their scare tactics about global warming.
The now thoroughly discredited "'hockey stick," which was a big component of Al Gore's Nobel Prize-winning documentary, An Inconvenient Truth, attempted to wipe the Medieval Warm Period
, one of the most solidly established periods of climate history, from the historical record.