Great post. Never heard about the weather in Constantinople, I am curious about that...gonna track it down. Have read about the deforestation of the Greek isles. Anyone who has ever travelled through there would be suprised that these barren islands were once completely forrested. Likewise, at the time of Alexander the Great, there were still lions in Macedonia. The wild boar in Europe is well known and written about.
Regarding the weather in Constantinople, I think this event was also reported by Cassiodorus (Google this) who complained about abnormal cold, a blue dimness to the atmosphere, and crop failures. His descriptions made it sound like a possible major volcanic or boloid event. Interestingly, a similar blueish atmosphere occurred in Europe after the eruption of the Laki Fissure in Iceland in 1783. Benjamin Franklin, who was in France at the time suspected it was caused by volcanic activity in Iceland. He was right, and subsequent bad weather and crop failures may have helped percipitate the Franch Revolution.
Regarding the deforestaton of the Greek isles and the failure of the Indus Valley civilizations, cutting of trees by people for firewood and pottery and matalurgical uses was probably responsible. Furthermore, in many areas, and probably in the Indus Valley, once the trees were gone and irrigation was engaged in it probably led to salt poisoning of the earth. Thus, whether we belief in global warming or not, the message is quite clear that we have to treat the earth’s resources with care and good sense.
Decided to check out Cassiodorus strange weather on Google. There were a number of links. Here are two. One refers to an 11 year climate disruption.
http://books.google.com/books?id=UQWG2YKW6iwC&pg=PA179&lpg=PA179&dq=cassiodorus+on+strange+weather&source=bl&ots=ztS4G98b9F&sig=MRgIEHElVWzkUFlVBYENyzhlX9M&hl=en&ei=evkISsrtM5Gktwe5n-XpCw&sa=X&oi=book_result&ct=result&resnum=3#PPA179,M1, See pages 180 and 181. Or maybe 179 and 180. Darn these senior moments.
http://dml.cmnh.org/2004Feb/msg00235.html