Let me start, dear reader, in exactly the same way as Oliver Morton himself does, by asking you two questions:

Do you believe the risks of climate change merit serious action aimed at lessening them?

Do you think that reducing an industrial economy’s carbon dioxide emissions to near zero is very hard?

I would be very surprised if anybody reading a review in this magazine gave any other answers than yes and yes. Those are also Morton’s own answers – but that is not his expectation of how most people concerned about climate change are likely to have answered them:

To judge by what they say, and what policies they support, most people in favour of action on climate change are in the Yes/No camp: they want to act on the risks; they don’t think that getting off fossil fuels is a terribly hard problem. Their way forward is to argue ever more strongly for emissions reductions; they believe these would be quite easily achieved were it not for a lack of political leadership willing to take on the vested interests of emitters.

I’ve rarely heard such twaddle! I know almost nobody who thinks it’s going to be “quite easily achieved”; indeed, the prevailing rhetoric (along the lines of ‘the greatest single challenge that humankind has ever faced’) is seen by many sceptics as exaggeratedly gloomy.

Would that Morton had gone on to ask a third question, in two parts:

Given just how hard such a transition is going to be, do you believe that geoengineering is either (a) a potential solution to be included in the mix, or (b) the only solution?

That’s where it gets complicated – morally, scientifically, technologically, philosophically. And that’s what makes The Planet Remade such a good read – despite the above – whatever your own answers may be to a third question of that kind.

First and foremost, Morton is a great companion. The sweep of his enquiry is extraordinary, the clarity and accessibility of his writing are exemplary, and the depth of his knowledge is everything you might hope of such a seasoned polymath. If you don’t enjoy The Planet Remade (as in end up much better informed and appropriately challenged to rethink your own, possibly untested, assumptions about geoengineering), I’ll be very surprised.

In part, this is owing to the deliberately discursive approach that Morton adopts. Most of his protracted excursions (into the history of climate science and climate politics, or around other existential risks to humankind such as asteroid impact or the possibility of a nuclear winter) are highly entertaining and insightful. The best chapter in the book, for me, is actually about the nitrogen cycle, which he uses to demonstrate very convincingly that we’re already into some pretty comprehensive geoengineering!

At the end of the day, Morton’s book provides top-notch advocacy for one particular kind of climate-related geoengineering: stratospheric “veil making” – creating a thin veil of sulphate (or other) aerosols in the stratosphere to reflect back a certain percentage of incoming solar radiation “to help cool the world”. He believes we should start doing this as soon as possible to create some “breathing space to slow the rate of warming for five decades or so” – having rejected the alternative ‘use-only-in-case-of-emergency’ idea on the grounds that by the time the emergency had revealed itself it would already be too late.

By plumping for one geoengineering option, Morton inevitably ends up rejecting the rest, including direct air capture, ocean fertilisation, and so on. Irritatingly, his accounts of these are scattered somewhat randomly through the book, making it unnecessarily difficult to do any kind of comparative analysis.

But he’s careful not to be too gung-ho in his advocacy; he dutifully expresses regret that such an option is, in his view, already absolutely necessary (given our continuing failure to clamp down on emissions of greenhouse gases), sees it more in terms of taking care, not taking control of planetary systems, and purports to understand why so many people are either afraid of or hostile to climate geoengineering – and indeed the somewhat murky ‘geoclique’ of philanthropists and corporate interests that promote it so vehemently.

For all that, however, it’s his failure to ask himself that critical third question, and to pursue far more rigorously what those alternatives to geoengineering might be, that ultimately undermines the case he seeks to make. In two areas, in particular.

First, his treatment of what is already being done to decarbonise our energy systems across the world, let alone of the prospects for accelerated decarbonisation over the next couple of decades, is embarrassingly inadequate. He spends a couple of pages doing the usual hand-wringing about what he sees as the notional limitations of renewable energy (intermittency, the requirement for huge amounts of land, its cost, and so on) before dismissing its total contribution as nugatory. Even BP no longer takes that stance, let alone the International Energy Agency (not so long ago the compliant mouthpiece of the fossil-fuel industries), whose latest World Energy Outlook provides a far more realistic – but still very conservative – view of the role of renewables. And Morton’s understanding of the total decarbonisation story (embracing energy efficiency, demand management, grid balancing, storage, and so on) is even more inadequate.

Second, his treatment of land-based alternatives to stratospheric veilmaking is equally cursory. He rapidly dismisses afforestation as irrelevant, and he clearly has no inkling of the increasingly lively debate about building up carbon in the soil – radically transforming current agronomic practices to help sequester billions of tonnes of carbon along the way.

For me, these blind spots are inexcusable. He’s a good scientist, and a great writer, and his readers deserve a whole lot more on both fronts. I interpret this as a kind of studied ignorance: ‘I really haven’t got time to find out what’s actually happening here, for fear that I might not get to ride my favourite hobby-horse for very much longer.’

That said, Morton may still be right. We may indeed not have enough shots in the decarbonisation locker to get the job done. At some point in the future, runaway climate change may still loom as an existential threat to the prospects for humankind – without the kind of geoengineering he so eloquently espouses. In that regard, The Climate Remade is definitely the best of its kind in helping us to contemplate what we may one day be forced to embrace.

Jonathon Porritt is Founder Director of Forum for the Future. www.forumforthefuture.org