A couple of weeks ago I was in the Oxfam shop, looking for a science fiction item to buy. I plumped for this one, and I've just finished it.
On the good side, it's a well-written book, with good characters. What happens is that the testing of WMDs (weapons of mass destruction) in space have affected the Van Allen radiation belts around the earth, rendering the human race (and most higher animals) sterile.
So, without children, civilization slowly and inexorably crumbles. England is run, not by a national government, but by regional warlords. A group of old people have established themselves in the village of Sparcot, growing enough food to get by, and avoiding the plague which has decimated the population of the cities. One man, Greybeard, growing tired of the same old way of life, decides he has to leave, to seek his fortune. So off he goes, with this wife, rowing down the Thames.... The book meanders along for a while, telling us what Greybeard does and has done.
Suddenly, about halfway through the book, there is a major gear change, and we find ourselves in the USA, and a completely different storyline ensues. I found this big change rather difficult to swallow, as it's a bit like reading a completely different book!
Eventually the story moves back to England, with the old fogeys and has-beens trying to make the best of things. I found it quite difficult to get into this book, despite it being well-written. It's a bit like watching a mediocre play - not bad, but you are quite relieved when it comes to an end. It's just a bit dull, and I cannot honestly recommend it.