This book is not a serious review of the science of different approaches but a diatribe on why these are all flawed. The author, while a Dean at a reputable university, has no science or engineering background after grade 12, being a philosopher and ethicist. He is is simply enamored with the argument that complexity prevents humans from taking any action and that the only approach is to live in a "natural" world (whatever that is).
In essence, the author opposes climate engineering based upon two "scientific or technological" arguments. The first argument is that massive scale efforts will be needed for some approaches and this will take a lot of effort. This is not surprising since addition of CO2 to the atmosphere is due to a massive worldwide industrialization! The author is incredibly naive about industrial scale electrical generation and fuel discovery and refining necessary to support billions of people. He needs to read "Energy w/o the Hot Air", although that might be very difficult because he has absolutely no science background to understand any scientific arguments. The second argument is that solar radiation reduction (which amazingly requires little effort) is too easy to turn off and is thus subject to political whims.
The author doesn't see any contradiction in these statements, neither of which make sense, because the author really opposes climate engineering based upon a philosophical, not scientific or technical, argument, i.e., humans don't know a lot about the ramifications of each approach because the earth's ecological system is very complex. This may be true but is not a reason for inaction given the looming crisis.
Let me use a medical analogy to illustrate the author's arguments. An overweight man arrive in hospital with chest pains and the doctor says "You are having a heart attack. The treatments are all invasive and dangerous and could kill you, so I don't want to try." Everyone recognizes that is crazy, of course, as the doctor has to try and help the patient now. But, the doctor then continues with "If you had lost weight and started exercising 20 years ago, you wouldn't be in this condition." That is immaterial. The doctor must treat the patient's condition not chastise him.
In essence, the real intent of this book is to chastise humans for not taking actions to mitigate CO2 pollution 20 years ago. One doesn't need to read over 200 pages or pay $18 to learn this. Indeed, there is nearly unanimous agreement from scientists of all walks that mitigation would have been the better choice. But, human political systems have not done that. So, the question is how to prevent the upcoming climate disaster. Unfortunately, this book doesn't address that question in all its complexity.
BTW: before people start accusing me of lots of things, let me be clear that there is a great crisis coming. It is not just global warming but also, and IMHO more critically, acidification of the ocean. The latter fact strongly suggests that solar radiation management is not the appropriate climate engineering approach, but one would never know this from Dr. Hamilton's book. IMHO, humans may simply be taking an evolutionary route to extinction, which has happened many times to the dominant species in the history of the earth.