The cause was to be found in the migration of a band of heavy tropical rain, which moves in response to phenomena such as El Nino, scientists have argued in an article in Nature.
The effect was to end two golden ages that existed in ignorance of one another on opposite sides of the world.
The scientific team, led by Gerald Haug of Germany’s national geosciences research centre, found a massive movement in tropical rainfall took place in early 900 in both regions.
The scientists discovered that titanium sediment and deposits of magnetic minerals in a lake in southeast China indicated that the period was one of intense climate change that left northern China a desolate waste.
This little snippet in the OZ may have gone through to the keeper but in the current hysteria about AGW I think we should all note that this research suggests to me that the natural variability of the climate is much greater than many of us imagine.The potential for a culture to collapse may be less these days when faced with prolonged drought but the collapse of both the Mayan culture and the Tang Dynasty at the same time certainly suggests that this was a global event.and strangely not a whiff of human agency in the cause of this event…