Necessity's inventions

Can the new science of geo-engineering save the planet? Tim Radford weighs the probabilities

Tim Radford
guardian.co.uk,
Friday September 05 2008 00:01 BST

Cooling towers at Eggborough Power Station. Photograph: John Giles/PA
The infant science of geo-engineering – one that so many would gladly see strangled in its cradle – could grow into the best job creation scheme for universities ever invented. Every one of the contributors to the Royal Society's Philosophical Transactions special on how to confront global warming with gee-whizz technology warns that the engineering is difficult, the outcome unpredictable, the side-effects possibly perilous and the expense prodigious. And that before any of it gets attempted, more research will be necessary.
For those who have been asleep in the back of the class: a tiny rehearsal. Geo-engineering is one of the get-out-of-jail-free cards routinely played by the climate change sceptics when it begins to look, even to them, as though global warming might after all be a reality and that profligacy with human resources might – just might – have played some marginal role. Well, they say: why give up our cars, our technology, our cheap air travel and our patio heaters? Human ingenuity will surely find a way out of the situation. What's wrong with uncontrolled growth? Surely more wealth means more technological potential, higher population levels mean an even bigger crop of really clever people to find future solutions. And, they point out, so many doomsayers have been wrong in the past, who says the current bunch will be right now?
So according to this argument, geo-engineering could be the perfect technological response to a problem fuelled in the first place by profligate technological invention. Why not place a tier of sunshades a million miles from Earth, at a strategic point between the planet and the sun to deflect or absorb a proportion of the solar radiation? Why not erect thousands of vast structures to absorb surplus carbon dioxide and bury it, the way trees soak up the stuff and turn it into wood? Why not darken the clouds with sulphur particles, and recreate the murk of acid rain, but at least stop the poles from melting?
Why not cruise across the oceans in robot wind-powered sailing vessels spraying fine particles of brine toward the clouds, to seed condensation and make them whiter and more reflective? Why not dust the oceans with iron filings and trigger carbon-consuming plankton blooms, or achieve the same effect by mixing deep and surface ocean waters, with an array of vast floating funnels? Some or all these things would bring the planetary thermometer tumbling to comfortable levels, and then we could go on as before.
And this is the point at which the scientists published by the Royal Society become embarrassed cheerleaders for the technological fix. It would be so much better, they all agree, if the world changed its ways, reduced its dependence on fossil fuels, and tried to live sustainably.
But since almost nobody shows any real signs of wishing to adopt the sustainable answer – and that includes most of the nations that have signed up to the Kyoto protocol, never mind the ones that have no intention of doing so – then we had better think about some other options now, they argue, because a decade down the line it will be too late. It may seem daft to mitigate the challenge of energy profligacy by expending even more energy, of responding to uncontrolled economic growth by spending even more money on even more ambitious projects, but – they argue – tough. What else should we do? Let us at least look at the technological challenges.
So in each paper, in the preface and in the critiques, the ideas come with explicit or implied intellectual health warnings. The stratagems may not work at all, or they may work too well and threaten to tip the world into an ice age, or they may seem to work for a while but just trigger some other, unforeseen chain reaction in the great climate machine, and so make things worse, or they may alleviate global warming in one of the few areas of the planet where people would welcome it but make things even worse for rival or partner nations across the sea or on the other side of the mountain range. The ideas might be sound, but the proposed technologies might not be up to the challenge, and require rethinking. The energy costs might be too high (although hardly as high as the cost of doing nothing and letting global warming run away) or the scientific understanding behind the logic of temperature manipulation on a planetary scale might turn out to be incomplete.
That's where the academic job creation programme begins. Climate modellers think they understand the climate machine well enough to make a set of predictions about the future. But it is one thing to make detailed predictions about temperatures and sea levels in 2100, after not just you but your grandchildren are dead; quite another to devise a set of actions that could take charge of global thermometer in the next decade, and on your watch. To do that, researchers would have to understand the behaviour of the planet in the finest detail: the role of sea-spray in the condensation of clouds, the intricate pattern of the winds all the way up to the stratosphere and beyond, the chemistry of clouds, the significance of dust storms in the Sahara and central Asia, the enigmatic interplay between ocean temperatures and continental weather systems, the importance of forests and grasslands and the knock-on effects of precise human behaviour. A series of geo-engineering studies would make researchers ask themselves questions, and test hypotheses, and begin to understand the planet in an entirely new way.
It would be money well spent. This is the only home we have: the more we appreciate it, the better. It would be money even better spent if – while university departments were working on space mirrors, chemical sunshades and the greening of the oceans – governments and peoples took the hint and found effective ways to reduce carbon dioxide emissions, restore the rainforests and protect the oceans. That way, we'd all win: we'd save the planet and at the same time understand more about the planet we had just saved; we'd save money on fuel and we wouldn't even have to build the expensive planet-saving machinery the research was designed to test.
The only flaw is that the British may not have the maths, physics, geochemistry or geophysics or engineering graduates to even begin the job, let alone finish it, but that's a different problem.