Climate Change and the Fall of the Roman Empire

Recent advances in paleoclimate research are producing important new data on climate conditions of the entirety of the human past.  What are the most salient recent developments, and what light do they shed on the great question of the end of ancient world and the beginnings of medieval civilization?  What do we need to know better to make even more headway in this and related investigations? What areas are increasingly ripe for investigation, and need creative thinking from teams of historians, archaeologists and climate scientists.