Middle Ages climate (letter)by C. RuleNews Weekly
, August 11, 2001
I refer to the article "How the sun causes global warming" (News Weekly
, June 16). In that article, Dr Sallie Baliunas says "With records going back 1000 years of solar magnetism, and the warm period certainly was in effect from about the years 1000 to 1200, maybe 1300 was about the edge of it ...".
Corroboration (if any is needed) of a period of warming, in the latter part of the first millenium AD and the early part of the second millenium AD, is provided by English historian Emma Mason in the May 2000 edition of the magazine History Today
In her article, "Britain 1200", Mason states:
"In the year 1200 Britain was in the middle of a spell of warm weather that had begun c.AD 900 and lasted to c.1300."
One of the benefits of this warming was that it "made possible the cultivation of land on higher ground beyond the margins of previous habitation" which assisted in feeding an increasing population.
We are often told that the current period of global warming is causing extremes of weather. Mason's article does not mention this having happened during the earlier period of warming.
In an article in the June 2000 edition of the same magazine, historian Bruce Campbell, in an article entitled "Britain 1300", states:
"From the late thirteenth century the climate became cooler and more prone to extremes ...".
Both Mason's and Campbell's articles also indicate that unlike what we hear about the current period of global warming, i.e. that global warming causes higher sea levels, the opposite would appear to have been the case during the period 900 -1300 AD.
Both articles indicate that land reclamation was able to be undertaken along the coast, e.g. along the Lincolnshire coast (Mason, p. 39 of May 2000 edition); and that with the cooling of the climate "heightened storm surges in the North sea threatened reclaimed coastal marshlands ...". (Campbell, p. 11 of June 2000 edition).C. Rule,