The Rough Guides series generally covers topics that are intended to be dipped in and out of, and yet this is a book that should be read like a novel, beginning at chapter 1 and ending some 18 chapters later. The format, to put it lightly, does not suit it. It has boxes of text spotted throughout, which are better suited for people who want to know what's so special about the Colosseum in the guide to Italy - in this book, they break flow and leave you wondering when you should read them. Do you read them after you finish the chapter? Or as you begin a page? Or just ignore them entirely? These are the single worst factor of this book; about a quarter of the content will require consciously deciding when to read it, as they do not comfortably fit into the narrative.
This, combined with the two-column approach, make you wish that Turney had found another publisher who would encourage him to write this in a more straightforward fashion.
On a more positive note, it is well written, and thoroughly researched. Sometimes there is a bias - for example, in the chapter on Population, Turney notes that population was predicted to overtake food supply already, and then goes on to predict that population will overtake food supply in the near future without a hint of irony. The book suffers at times from the breadth of the topic it has taken, and will require frequent thought-breaks (or slower reading) in order to process what Turney is saying. However, generally it is entertaining enough, and it is not the writing itself that is at fault.
If this were written without the 'Rough guide' editorial aspects, it would be a much more successful book. As-is, it leaves something to be desired; though anyone who can force through the enforced Rough Guide style to read it front-to-back will feel like they earned the information they gained from it.