If you are a Sci-Fi or alternative history fan then I would recommend you read The Second Sleep.
There are enough interesting ideas here to keep you engaged, even if the plot line let's the reader (and the author) down at the end.
The descriptions of slight changes to climate and fauna are convincing. The suggestion of a 'Northern Caliphate' interesting but not terribly helpful to the here and now.
Fans of this genre would be better served by reading John Wyndham's The Chrysalids or Russell Hoban's Riddley Walker.
