Geoengineering trials get under way
14 September 2011 by Michael Marshall
Volcanic ash inspires sunshade (Image: Arctic Images/Corbis)
Editorial: "Give geo- and genetic engineering a fair trial"
07 September 2011
Frontier science must not be feared, but cautiously embraced
IN A city in eastern Brazil, scientists are preparing to release millions of genetically modified mosquitoes into the wild. If the trial works, the people of Juazeiro will have GM technology to thank for keeping them safe from dengue fever (see "Swarm troopers: Mutant armies waging war in the wild").
Meanwhile, in Bristol, UK, scientists are preparing one of the first experiments to figure out how to engineer the climate. If it works, we will be a step closer to developing a last-ditch option to mitigate some of the worst effects of climate change (see "Geoengineering trials get under way").
At first glance these tests have little in common, but dig a little deeper and parallels start to emerge. Both trials reveal our uneasy relationship with our control of nature.
The geoengineering experiment, in itself an innocuous effort to test one proposed system for pumping cooling particles into the atmosphere, has already attracted the ire of the ETC Group, a Canadian NGO that is a leading opponent of geoengineering.
The release of GM mosquitoes into the wild has so far attracted relatively little protest, following encouraging results from a field trial in the Cayman Islands. But if and when similar releases are planned in Europe - perhaps as dengue fever spreads northwards as the climate warms - opponents of GM technology will surely mount bigger campaigns to halt the release on the basis of some ill-defined risk.
These issues should certainly be debated as widely as possible, but demands for bans and moratoriums on trials are not the way forward. It may sound eminently reasonable to sideline tests until we know more, but all too often that is a smokescreen for Luddism. To be in a position to weigh up the risks and benefits of a technology, carefully designed experiments are sacrosanct.
At the same time, the risks have to be constantly reassessed and revised in the light of what experiments tell us. More than three decades ago, top scientists in the emerging field of genetic engineering gathered in Asilomar, California, to thrash out guidelines for regulating their work. These have served science and society very well so far. Last year, Asilomar hosted a similar meeting for geoengineering. It is important that scientists, who hold a diverse range of views, can weigh them in a measured way before the wider debate becomes politicised and polarised into scientists versus pressure groups.
With climate engineering, the benefits of carrying out small trials far outweigh the risks. At the very least, geoengineering experiments will stimulate public debate, perhaps even galvanising support for conventional emissions reductions. At most, they will provide key insights into desperate measures that could be taken in desperate times.
A similar argument applies to the use of GM mosquitoes. Dengue fever sickens some 50 million people every year and kills 40,000. In the face of this toll the risk of releasing millions of GM insects pales into insignificance.
In both experiments, the usual caveats apply - there has to be openness, consultation and appraisal - but the critics must realise that halting an experiment can be risky too. A failure to use technology can effectively harm, maim and kill just as surely as its misuse.
The field test will be conducted at an abandoned airfield in Sculthorpe, UK. Matthew Watson of the University of Bristol, UK, presented details of the project at the British Science Festival in Bradford, UK.
FIELD trials for experiments to engineer the climate have begun. Next month a team of UK researchers will hoist one end of a 1-kilometre-long hose aloft using a balloon, then attempt to pump water up it and spray it into the atmosphere (see diagram).
The water will not affect the climate. Rather, the experiment is a proof of principle to show that we can pump large quantities of material to great heights. If it succeeds, a larger-scale version could one day pump sulphate aerosols into the stratosphere, creating a sunshade that will offset the greenhouse effect.
The trial, led by Matthew Watson of the University of Bristol, UK, is part of a £2 million project called Stratospheric Particle Injection for Climate Engineering (SPICE). Funded by two UK research councils, it also aims to find out the ideal particles to use in an atmospheric sunshade and will attempt to model their effects in greater detail than ever before. The test is not alone: a string of other technologies that could be used to "geoengineer" our environment are being field-tested (see "Coping with emissions").
In his blog, The Reluctant Geoengineer, Watson argues that we need to investigate the effects of sulphate aerosols as a last-resort remedy should the climate start to change rapidly. Researchers contacted by New Scientist agreed with Watson that such research should continue, if only to find out whether the techniques are feasible. "I'd say there's a 50-50 chance we'll end up doing it, because it'll get too warm and people will demand the planet be cooled off," says Wallace Broecker of Columbia University in New York. But there was less enthusiasm for SPICE's approach to the problem.
There are "large gaps" in our understanding of geoengineering, says Thomas Stocker of the University of Bern in Switzerland. Stocker helped to organise an expert meeting on geoengineering in June for the Intergovernmental Panel on Climate Change. It identified key unanswered questions that should be a focus for research. However, it is not clear that field trials like Watson's will provide the answers.
One area of doubt over injecting aerosols into the stratosphere is whether it will change the behaviour of high-altitude clouds. That could in turn affect the climate in ways beyond what was intended - and for now, we don't know how, or how much. Aerosols could also deplete the ozone layer, contribute to air pollution and may alter visibility in the same way as large volcanic eruptions can.
The SPICE test won't answer any of these questions, says David Keith of Harvard University. "I think it's a little reckless." The most interesting result will be how the public reacts, he says.
What's more, Keith adds, in the long run delivering sulphates to the stratosphere with a hose would be a bad idea. Spraying aerosols locally allows the particles to clump together, making them less effective at reflecting sunlight and more likely to be swept down by rain (Environmental Research Letters, DOI: 10.1088/1748-9326/4/4/045108).
Keith's own studies suggest that if we were ever forced to try to screen out some of the sun's rays globally, it would be more effective to spray sulphuric acid from aircraft (Geophysical Research Letters, DOI: 10.1029/2010GL043975).
It would also be cheaper, costing a few billion dollars a year according to a study by Aurora Flight Sciences, an aeronautical firm in Cambridge, Massachusetts. Such figures are tiny compared to the trillions that the consequences of climate change could cost the global economy if emissions continue to rise at current rates.
The point, says Ken Caldeira of the Carnegie Institution for Science in Stanford, California, is that experiments like Watson's, which test relatively simple delivery systems, address the issue of cost. But, since the Aurora study has shown that cost is not a critical factor - a sunshade will be relatively inexpensive - the critical questions relate to potential risks.
More importantly, since a stratospheric sunshade is intended to have a global impact, all countries must agree to such a project and to its precise extent, which is unlikely to happen.
One possibility that may help countries agree is that the sunshade need not be applied evenly across the globe. Caldeira has created, in a climate model, a sunshade with much larger quantities of aerosols above the poles than above the tropics. This produced a temperature distribution much closer to the pre-industrial climate than could be achieved with a uniform sunshade (Environmental Research Letters, DOI: 10.1088/1748-9326/5/3/034009).
Caldeira and others are now toying with the idea of regional geoengineering, or "geoadaptation". Some techniques, such as making clouds over the seas more reflective, should have localised effects, so countries could in theory tinker only with their own climate.
But here too uncertainties need to be resolved. Gavin Schmidt of the NASA Goddard Institute for Space Studies in New York points out that changes in one area will have a knock-on effect on the other side of the planet. "What happens in Vegas does not stay in Vegas," he says. We could perhaps predict these long-range effects, but we cannot eliminate them.
Schmidt says that what we need is not field tests, but better modelling studies. Most simulations of geoengineering are "naive", he says, and cannot model all the possible side effects. "People are not doing the right kinds of experiments to assess these effects," he says.
Coping with emissions
THE pipe-to-the-sky experiment is not the only geoengineering method that is being tested.
In 2009, a team of Russian scientists sprayed a small amount of sulphate aerosols into the atmosphere and found that they blocked between 1 and 10 per cent of incoming solar radiation (Russian Meteorology and Hydrology, DOI: 10.3103/S106837390905001X).
Iceland is testing a less contentious technique to deal with our carbon emissions: turning them into rock. The CarbFix project aims to capture carbon dioxide from a local geothermal power plant, dissolve it in water and inject it into basalt rock, where it will react with magnesium, calcium and iron to form carbonates. If it works, the CO2 should stay put even in an earthquake. It is the safest way of storing CO2, according to project leader Sigurður Reynir Gíslason of the University of Iceland in Reykjavik. The team plans to start the gas injections later this month.
Adding iron to the ocean can trigger plankton blooms that suck up CO2, but a 2009 field test gave mixed results. That's because the test site was unsuitable, says Richard Lampitt of the National Oceanography Centre in Southampton, UK. He and colleagues hope to repeat the trial.
Elsewhere, Ken Caldeira of the Carnegie Institution for Science in Stanford, California, has permission to add sodium hydroxide - an alkali - to a small patch of ocean to see if it can reverse the effects of ocean acidification.
Finally, California-based engineer Armand Neukermans is building a nozzle that will spray seawater into clouds, making them whiter and better able to reflect sunlight into space.
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