Do ya 'spose there are core samples that might provide details of environmental conditions of the year ... oh, say 5016 bce on 01, 01?
How 'bout 10,016 bce? Or have we always enjoyed moderate, accommodating, near perfect environmental conditions?
Ever seen "Logan's Run"? http://www.imdb.com/title/tt0074812/ Possibilities abound. Even though the "biosphere" was an abject failure, it makes for a pretty cool live in green house.
Could just be "our" time is up ... and it's time for a reset.
O.W.