Many green organisations don't like geoengineering, because they see it as more of the same - humans interfering with the environment which they should leave alone - but if you take a logical, rather than emotional approach, then some form of geoengineering will almost certainly be necessary.
Oliver Morton makes a persuasive case for this in an odd book, which meanders between the factual and unnecessarily poetic in a way that readers will either love or hate. Considering the content, the book is far too long - padded out with an awful lot of prose that doesn't do much, often making tangential references to some kind of geoengineering activity. So, for instance, on the last page we get this paragraph:
Up above and far away, too far for any eye but the mind's, a future lifted on long, strong wings starts a graceful, cautious turn. It seems almost beyond the bonds of Earth, but it does not fly in freedom; there are things it cannot do and must not do - many ways for it to slip and fall. The future is hemmed in on one hand by its design, on the other by the unforgiving laws of nature. But its heading and height can, with skill, be changed.What? Really? Haven't a clue, and that's 30 seconds of my life I won't get back. There is far too much of this meandering waffle, and were it not for the power of the argument when he does stay on topic, I would only give this book three stars. But, the fact is that when Morton does focus we get lots of great material on geoengineering. He spends a lot of time on modifying what he calls the 'earthsystem' by 'veilmaking' (as you may gather, he likes making up words, or using these neologisms if someone else dreamed them up) i.e. spraying material up in the stratosphere which will reduce incoming energy from the Sun and hence reduce warming.
There is also a fair amount - probably the most interesting part of the book - on cloud science and manipulation of clouds and their impact on warming or cooling. By comparison, most of the methods of taking carbon out of the atmosphere get short shrift. Carbon capture and storage is, probably correctly, dismissed as simply not doing enough, and most of the mechanisms for taking carbon from the air at large are simply too expensive in money and/or land usage to be meaningfully deployed.
I came out of the other end of the experience of reading this book convinced we ought to be doing more on geoengineering, but without a clear picture of the way forward, in part because of the obscurity of the writing. I think this book will delight someone who wants to get all touchy feely about the concept, but it left me wanting more. Even so, it is doing something that no one else has, and so is worth a try.
Review by Brian Clegg