I thought it was a good book too, read it some time ago...but nothing about peak oil though!
Another aspect of the book that is a little outdated is on the subject of climate variation...recent scientific advances - such as ice core analysis, and plant pollen deposits in sedimentary layers - have made it possible to reconstruct past climate variations in different regions. It is then possible to compare this data with the historical record, and interpolate the impact on human societies.
Clive Ponting tends to see the climate as pretty stable, but there are many things that make more sense against a backdrop of continuous climate variations.
For anyone interested in this kind of thing there is an excellent book on the subject by Robert Fagan called
The Long Summer (2004)