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To 1750 – or beyond?

At the current Conference of the Parties in Durban, Libya proposed an ambitious scheme which, it claims, will not only halt, but reverse global warming.   (See

 Effectively, the “Libyan Climate Change Initiative” will turn the Sahara desert, and perhaps the Arabian and other deserts, into a giant wind-farm.  But not your average of wind-farm.  This wind-farm is one which first creates wind out of solar power and then uses it to drive giant wind turbines.  

Whilst reported as a geoengineering project, this massive renewable energy project is not the kind of geoengineering discussed by the Royal Society in its 2009 report, (see  It is not obviously an attempt at removing carbon dioxide from the atmosphere (carbon dioxide removal, or CDR),  nor a method which seeks to hold global temperatures steady regardless of increases in atmospheric GHGs, known as solar radiation management (SRM).  It is mitigation, the reduction of carbon dioxide emissions, but on an almost unimaginably vast scale – planetary engineering, if you like. 

For anyone reading this, I welcome thoughts of whether the project could work technically, all the more because I have no engineering knowledge.  Another complication is that the project will require a huge amount of international co-operation, a resource which is often in short supply.  I also want to raise one question here, a question which has arisen in other debates about geoengineering. 

The Libyan proposal promises “a short-cut back to 1750”, in that atmospheric concentrations carbon dioxide will, by 2080, be at pre-industrial levels.  Exactly how this is achieved is not quite clear to me (I welcome any explanations).  An effective CDR technology would have this potential and so some discussions of geoengineering ask where (and by whom) the “global thermostat” should be set.  Reducing atmospheric concentrations to pre-industrial levels has some appeal, on the grounds that it would “restore” the atmosphere to the point before humanity started emitting GHGs at a prolific rate.  It is tempting to view this point as when the atmosphere was in a natural state.  If by “natural” one means “not changed by human action”, this seems dubious.  There is at least some reason to view the Anthropocene as beginning far before the Industrial Revolution, (e.g. with the development of rice agriculture).   

Perhaps then, we should eschew talk of the natural for talk of the “safe”.   After all, the policy goal in the terms of the UNFCCC, is avoid “dangerous anthropogenic interference” with the climate.  This gives no especially good reason to try return to 1750 levels of atmospheric GHG concentrations, or to aim for global average temperatures of the 1750s.  Somewhere between today’s and the 18th century’s should be sufficient.  But where exactly?  Where should the global thermostat be set?

Some regard the metaphor of the “global thermostat” as misleadingly implying that there is an ideal global temperature.  To me, however, it implies that there is not an ideal global temperature.  Out of most of the couples/housesharers whom I know, one always likes it warmer or cooler than the other(s).  Sometimes this can lead to whole evenings of one person surreptitiously turning it up, for their friend or partner to sneak back over and turn it down.  Perhaps that’s just my friends and family but it seems that choosing a temperature which pleases everyone is going to be near impossible.  I’d be interested to know.  So: is the metaphor of the global thermostat useful or or not?  And if humanity is going to try to fiddle with it further, where should it be set?  To 1750 – or beyond?

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10 Comment on this post

  1. I am not an enginner 🙂
    However, from reading the FT article, what they suggest is to create a renewable energy source that togther with global electricity network will supply enough energy (electricty) that no one will use fossil based energy anymore.
    By that no more emission and allowing the atmosphere to heal itself.

    I doubt it but would love to see them try.

  2. It sounds like they're proposing a <a href="">solar updraft tower</a> or "solar chimney". David MacKay looks at these in <a href="">Sustainable Energy: Without the Hot Air</a> on <a href="">p183</a&gt;, and finds that at least mathematically they are competitive with <a href="">filling deserts</a> with concentrating solar power plants.

  3. Yes, it is a way of generating electricity, basically from sunlight. In principle, they should work. The biggest problem is how to distribute the energy – where are the power lines? How far do they go? How does the generated power get to the users?

  4. The distribution is the issue. You can certainly build the structures to generate the wind and the turbines to capture it and convert to electricity but how do you then get that to Europe, Asia and the America's? Isn't this the exact T Boone Pickens gave up on his mid western wind turbine idea, that the cost, either in dollars or energy would be too expensive to distribute the energy created to the coasts?

  5. A much simpler solution is to circulate brackish water inland and grow salt-tolerant plants and trees (mangroves, marsh grass, etc). Let the plants soak up the CO2, and by the way, you green the desert in the process. Building solar/wind towers in the middle of nowhere is a money pit. It won't work because the consumers for the power are several thousand miles away. Nice try at bagging some dumb government money though.

  6. The Financial Times is asking for payment to access the article…is there a free version somewhere? By a different news source?

  7. Clare wrote: "So: is the metaphor of the global thermostat useful or or not? And if humanity is going to try to fiddle with it further, where should it be set? To 1750 – or beyond?"

    My bet is that pretty much no one would opt for pre-industrial climates, if they really thought about it. My guess is that most people would opt for the climate they remember from their childhood. The only argument I could see for a pre-industrial climate would be based on the cryosphere being pretty stable (but that argument could disappear if current enthusiasm for scary levels of sea-level rise ends up being curtailed by further observation/modelling).
    Ecosystems are an interesting one here – I can't think of a strong reason to privilege pre-industrial ecosystems over modern ones. Species extinction, for instance, strikes me as a pretty weak reason, especially in view of how cavalier we are about the main drivers of species extinction – (a) direct human incursion into ecosystems (b) "ecological imperialism" and its aftermath. It seems lop-sided to get all righteous about species going bust from climate change while ignoring much larger drivers of extinction. Also, are species the right levels at which to be evaluating these things? Why would more species be more valuable, inherently than fewer species? [It's a claim I've often heard that (bio)diversity is inherently good, but I've seldom heard it defended. Anyone care to?]

    So I'd pick the 1970s for my preferred climate. Going all the way back to the pre-industrial era strikes me as unjustified and costly (since much of modern life is acclimatised to modern climates).

  8. In any case there's a difference between atmospheric concentration of CO2 being at pre-industrial levels and having a pre-industrial climate. Anyway it's good that people are thinking creatively about these issues. Climate change tends to be too much about hand-wringing, polemics, denial vs alarmism, and turning off lights. Thinking of it as a spur for innovation seems altogether more promising, provided we don't get carried away by naive enthusiasm.

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