Spotted this book in the January Book Releases list, and was interested due to it being another in the recent trend of dystopias about boundaries (most of which are caused by climate change). But then the BBC abridged it and stuck it on the radio, and since I've already got a couple of books I'm working on, it seemed a good idea to cheat and listen to it instead.
Kavanagh is a new Defender of the Wall, a massive concrete structure that runs all around the coast of Britain. At some point before he was born, the world went through the Change, characterised as a single catastrophic event, but really the slow inevitable destruction of the world as global warming takes hold and overruns farming land. Britain has been relatively lightly hit, with the death of the Gulf Stream resulting in it becoming much chillier, but other parts of the world have seen significant desertification, leading to huge migration.
So Britain is worried that the refugees are coming. And the Wall is intended to keep them out.
I say refugees. In this, they're "The Others". Everything in this is named as if it's a first draft. You've got the Wall, the Defenders, the Flight, the Guard, the Captain among others. It's presumably intended to act as an indicator of the brutal minimalism of the world, without the spare energy available for beauty or description, but it mostly feels like someone had planned on doing a find and replace with some actual names.
It also feels like someone needs to do a find and replace with some plot.
There are occasionally nice bits of world-building sneaked in, with some suggestions of modern slavery ("The Help"), and the rebellion in Britain of people who are helping the refugees, but the main storyline is a plod through "oh no, isn't it bad that Britain got all isolationist". There's lots of lingering considerations of boredom, or the fact that all the young people hate the older generation who screwed up the environment, but not much by way of a personal arc.
Kavanagh goes through a few trials, but it's much along the lines of "and then this happened, and then this happened, and then this happened", with no overall theme.
Like a lot of dystopias, it's trying to tell an interesting story while also holding a mirror (air quotes) to our current situation, in such a way that we think "huh, perhaps not all migrants are bad". But the lack of subtlety of the message makes that more of an eye-roll than a revelation. It might be that I've simply read too many stories recently that tell the same tale, and do it better (eg, America City, which combined environmental disaster with "fake news") to appreciate this one.
I'd say skip it.