14 May 2013

Should we engineer the climate?

Just been to a fascinating talk given by @hughhunt, an Australian academic based in Cambridge, about geo-engineering. Or climate engineering as he prefers to call it, because everyone thinks that geo-engineering is just groundworks by a fancy name. We are not talking groundworks here, but climate control. Specifically the idea that we may be able to mitigate the effects of climate change by tinkering with the atmosphere.

Hugh Hunt's research project involves the feasibility of floating a series of giant, Wembley Stadium, sized balloons 20km up into the stratosphere, each connected to the Earth's surface by a huge hosepipe, through which we would squirt titanium oxide. Why titanium oxide? It's relatively inert and believed to be fairly harmless, it being a key ingredient in white paint and sunscreen.

In fact sunscreen is an apposite metaphor because it would be the equivalent of coating the entire planet with Factor 30. In theory, it would be possible to reduce global surface temperatures by as much as 2°C using this technique. A similar effect is observed when volcanos emit sulphur dioxide as high levels and the sun gets screened out for a while afterwards. We could do it with SO2, but TiO2 is probably preferable.

That's not to say there wouldn't be issues. Hunt identified a few. The release would have to take place around the Equator because the air in the stratosphere spreads out towards the poles from there. There is no telling it would be as effective at the poles as it might be at the Equator. There might be interaction with the oceans, or with the ozone layer. And there might well be many insuperable technical issues to resolve - like how to handle storms, and what happens if the 20km long hosepipe comes loose.

And there is of course the moral hazard of dealing with the symptoms of CO2 build-up, not the root cause. It's nicely dealt with on Wikipedia.

But the really interesting thing about all this is that the preliminary costings suggest that the total cost for a project like this would be in the low billions, much less than building a single nuke, in fact much less than almost any other carbon reducing projects you might care to think of. In fact a similar amount to how much Sheik Mansour is currently investing in Manchester City. Rather than breaking the back of the cash-strapped governments around the world, it's a project which could conceivably be paid for by a few wealthy individuals or even private equity - insurance companies anyone?


  1. Ted LynchMay 16, 2013

    Is there a direct link to Hugh's research on this? The link above is a general one and I can't immediately see the relevant section.

    In general global-scale projects like this make me nervous due to the unknown interactions that have been pointed out and for the material to at least have the potential to impact cloud formation in potentially unexpected ways even when released at this high atomosphere level. You would need a lot of data to placate public concerns and an over excitable press and that will be difficult to create given localised trials will be 'challenging'!

    While I appreciate this is a global problem and needs a global solution. I suspect a drive to adopt 'Cool roof' into building codes would meet with a lot less opposition from the general public and help them to understand why Hugh's approach might be necessary and appropriate in years to come: http://en.wikipedia.org/wiki/Cool_roof

  2. The cool roof or white painted roof was touched on as a possible mitigation strategy. The feeling is that it wouldn't actually make any meaningful difference. There simply aren't enough roofs in the world to make up for loss of ice around the poles.

  3. AnonymousMay 16, 2013

    How about, instead, coming to regard everything that humans make (or do) as an opportunity to actively assist the planet and its plants, 'nature' or whatever you call it, in cleaning up the still-accumulating mess that we humans have made. If we stopped tomorrow it would take the planet 1,000s or 10,000s of years to reprocess everything. We humans won't be able to wait that long - for our survival on this past-tipping-point planet we may just hang on for 100s or 1,000s of years, so nature's normal processes need to be accelerated. Part of deep Permaculture is to not merely slow or even stop the environmental damage, but to actively reverse it.

    But to actively reverse the damage has to mean that we actively support and accelerate nature's natural processes. We should have learned by now to not think of at-a-stroke un-natural techno-fixes, which for sure would just be used as a sticking plaster allowing biz-as-usual to continue.

  4. Ted LynchMay 16, 2013

    @Mark: I realise the limitations of the Cool Roof concept in terms of scale but I see it as an easy solution that works in cities to help reduce the heat island effect, most likely in conjuction with urban tree planting. The advantages are that increasingly people are moving to live in cities and it will have a disproportionate impact if it also reduces Air-Con load by reducing the amibent temperature. It demostrates the use of reflective treatments to reduce global warming and hence has the potential to 'soften-up' Joe Public to Climate Engineering like Hugh's should that prove necessary.

    1. Combating the urban heat island in cities is definitely important for the environment, the way things are going in London we could end up with a vicious circle where increasing use of air con makes the problems worse locally and also impacts globally.

      Sensible environmentally concious design (such as cool roofs, good natural ventilation, sun louvres & growing plants up south facing walls) can all make enough of a difference to make aircon unnecessary (certainly in a place like London, although climate change may mean we never get a summer anyway, so no problems!).

  5. Ted, I realise I didn't answer your original point on where Hugh's research can be viewed in more detail. Short answer is I have no idea, but you can contact Hugh directly to find out. He did set his talk in context of work carried out by the Royal Society which looked at a range of mitigation and sequestration projects which might be undertaken, and made assessments of each in terms of cost and effectiveness.

  6. Tom,

    Your point is well made. But you could argue that we started to mess with the planet when we took up agriculture after the last ice age and that only a return to hunter gathering is consistent with a balanced planet. That's not going to happen (or maybe it will?).

  7. Surely it's impossible to accurately map the effects of tampering so drastically with such an acutely balanced natural process?

    It's impossible to comprehend the complexity of these processes sometimes, I worry it wouldn't be so straight forward...

    1. With measures like this I think everyone would have to accept there would likely be unintended consequences (there usually are) and accept that the risk of doing nothing is greater than the risk of making changes.

      I think it's worth people looking at stuff like this, but I don't know how everyone would agree on it and who would pay for it (unless there was a widespread belief we were facing imminent disaster).

  8. AnonymousMay 18, 2013

    Mark, it's not necessary to return to hunter-gatherer, becvause it's not necessary to reduce the environmental damage we (and all animals) cause, to zero. We only need to reduce it to what the planet can naturally re-process. The planet is a homeostatic system, or organism, as we ourselves are, or as our immune system is. Homeostatic systems have a definite capacity to handle whatever's chucked at them - up to a limit. The problem is that we humans have caused the planet's homeostatic limit to be exceeded - but only since as recently as I think 1986. Obviously some 'environmental services' were well exceeded before then, while other 'environmental services' are even still now within their limit - but broadly, the overall limit was first exceeded quite recently. Until then, the planet had been kinda coping - but now it's losing the plot, and damage is accumulating un-handled, year by year. The accumulation is already huge, increasing exponentially, so whatever problems we're seeing now are nothing compared to what's coming. Just stopping the damage now (as if) isn't enough - we must actively assist the planet's natural damage-repair. If we could do that, to handle the accumulation, then we needn't reduce our environmental damage rate as much as you'd think, in order to stay within the planet's current capacity to repair it.