Set in the near future, this book is not a novel, more like a series of futurist articles. The theme is climate change, following a heat wave in India that kills twenty million people, The Ministry for the Future is established to fight climate change. They make slow progress.
Twenty million is a ridiculous number, especially as the temperature given is not that high – India had close to those temperatures last year with a few hundred deaths. The deadliest heat wave, per Wikipedia, was a few years ago in Russia where fifty eight thousand died at much lower temperatures. Since the death toll depends not only on the weather but what the system and infrastructure is built to accommodate. I mention this because KSR specifically talks in the book about the European tendency to assume hear waves are a somewhere else problem. Yet he seems to have done the same.
There are many ideas presented about how to help the world. Some like carbon credits have been extensively talked about already and the EU has already started using them. Others like stabilizing the glaciers seems to be novel. The main thing that the author overlooks is that while some business may be resistant to these changes, there are many others who are interested in combatting climate change and see potential profit in doing so.
The most unrealistic thing is the sci fi trope of the perfect terrorist organization that reaches all its targets, no matter how well protected, and never gets caught. No one ever defects and they are never infiltrated by the police. It is ridiculous and morally dubious. I would prefer to see some of these people fined or jailed, though I understand KSR considers this to be even more unlikely.