a. The Medieval Warm Period (MWP) temperature is warmer than the Modern Warm Period proxy temperature – at no time do the modern proxies exceed the MWP proxies.
b. The recent instrumental temperature is warmer than the Medieval Warm Period temperature.
c. The MWP is obviously preindustrial and it would be logical to use the MWP temperature as preindustrial temperature instead of the Little Ice Age (LIA) favoured by the climate establishment.
The Little Ice Age (LIA) was a period of cooling that occurred after the Medieval Warm Period. It has been conventionally defined as a period extending from the 16th to the 19th centuries, but some experts prefer an alternative timespan from about 1300 to about 1850. Climatologists and historians working with local records no longer expect to agree on either the start or end dates of the period, which varied according to local conditions.
There is no consensus regarding the time when the Little Ice Age began, but a series of events before the known climatic minima has often been referenced. In the 13th century, pack ice began advancing southwards in the North Atlantic, as did glaciers in Greenland. Anecdotal evidence suggests expanding glaciers almost worldwide. Based on radiocarbon dating of roughly 150 samples of dead plant material with roots intact, collected from beneath ice caps on Baffin Island and Iceland, Miller et al. (2012) state that cold summers and ice growth began abruptly between 1275 and 1300, followed by "a substantial intensification" from 1430 to 1455.
In contrast, a climate reconstruction based on glacial length shows no great variation from 1600 to 1850 but strong retreat thereafter.