Science, Society, Sustainability
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ISIS Report 26/09/11

Skyhook to Save the Climate?

Geoengineering, like banking, can affect the whole world, and again like banking, has no international regulation, which is urgently needed. Prof. Peter Saunders

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Green Energies - 100% Renewables by 2050. A new report by the Institute of Science in Society According to the evidence, measures such as reducing our energy needs and replacing fossil fuels with renewables will be sufficient to mitigate climate change (see for example, [1, 2] Green Energies - 100% Renewable by 2050, Food Futures Now: *Organic *Sustainable *Fossil Fuel Free , ISIS publications). If this assessment is wrong, however, or if we do not have the foresight and the will to do what we know is necessary, then we may have to consider geoengineering, the large scale engineering of the environment. And because geoengineering projects take a long time to develop, if we want to keep that option open, we will have to begin work on them now.

Geoengineering is, however, inherently risky. We do not understand our planet well enough to predict with any confidence the consequences of a major intervention. So it has to be very much a “Plan B”, not a substitute for methods we know are safe and effective. And because implementing or even just testing geoengineering can have an impact on the entire planet, we need international agreement on what sorts of measures are permissible, with an expert group to decide on individual projects. At present, there is nothing beyond an unenforceable call for a moratorium by the Convention on Biological Diversity (CBD) [3, 4].

The SPICE project

One of the main geoengineering strategies is to cool the Earth by reducing the amount of energy it receives from the sun, either by preventing so much getting to us in the first place or by reflecting more of it back into space. To develop this strategy, a grant of £1.8 m was recently awarded by two UK research councils for a project known as Stratospheric Particle Injection for Climate Engineering (SPICE), involving the universities of Cambridge, Bristol and Reading [5]. The aim is to determine the feasibility of creating a cloud of small particles at an altitude of about 20 km. Advocates argue that what it amounts to is reproduce artificially what has often happened naturally through the explosion of large volcanoes.

The work has three parts. One group is to study the properties of candidate particles. In particular, they are going to measure the optical properties: how well they will deflect the sun’s rays. They will also determine how likely the particles are to agglomerate, which will reduce the time they remain in the stratosphere before they fall back to earth.

A second group will use the UK Meteorological Office’s Unified Model (UM) to try to predict the impact of injecting particles into the stratosphere.

It is the third part of the project that has attracted public attention. Most scientists who favour creating a cloud of particles in the stratosphere have assumed that they will be released from aircraft, but the SPICE team are planning to pump them up through a 25 km hose in the sky supported by a helium balloon. At this stage they propose to construct a 1 km hose to see if the idea works. If it does, they will go on to design the full size version, but they do not yet have the funding to build it.

The first phase does not appear to risk large scale or irreversible harm. Most of the experimental work will be carried out in the laboratory. It should be possible to fly a balloon with a 1 km cable hanging from it without much risk, and the group in charge say that they intend to pump only water through it. They point out that if the 1 km pipe is successful, it also has the potential to test some features of whitening low-level clouds to increase their reflectivity. For that they would presumably add salt to the water.

They also say that building the system “will only begin after input from a Public Engagement has taken place,” though this is less reassuring than it sounds when you recall the fate of the UK government’s consultations on genetically modified organisms and nuclear power. Both went the “wrong” way and both were totally ignored. However confident we may be in the good faith of the SPICE group, it should not be up to them to decide whether or not to heed the results of a public consultation.

Why we need an enforceable international agreement

Safe though it appears to be, the project reminds us that there is no international agreement on geoengineering and no international body to authorise projects. There is nothing to stop anyone with enough resources pushing ahead with a scheme that could have disastrous consequences for all of us. That could be through hope of commercial gain, it could be through over-enthusiasm for an idea, it could be through failing to invite other experts to give advice, or for a variety of other reasons. If things do go wrong, what matters will be the consequences, not the motive. The road to Hell is paved with good intentions.

In 2008, for example, the CBD produced proposals for integrating climate change activities within its remit. These included a statement that there should be no experiments on ocean fertilisation until adequate data were available to show that it was safe to go ahead [3].

In 2009, the Alfred Wegner Institute for Polar and Sea Research (AWIPR) sent its research ship, the Polarstern, to spread iron sulphate particles over an area of 400 sq km in the South Atlantic. When it was pointed out that this was contrary to the CBD’s recommendations, the German Ministry of Research announced that it would review the project itself. This was done while the ship continued on its way and by institutions nominated by the AWIPR. To no one’s great surprise, in less than three weeks the German Research Minister announced that she was satisfied there were no scientific or legal objections to the experiment, and allowed it to go ahead (Saving the Climate Dangerously   [6]). (In the event, the outcome was not encouraging [7], in line with what had been found in earlier studies of regions that are naturally iron-rich [8, 9].)

No one should be allowed to proceed with geoengineering experiments outside the laboratory without agreement from an international panel taken in the light of advice from independent experts. If what is being put forward is only the first phase of a project, then the panel should also consider what lies ahead. Clearly the next stages will have to seek approval as well, but there is no point in beginning a project unless it is at least plausible that permission will be granted for the later stages. For example, the current SPICE proposal is to inject only water, but the proposers would be expected to explain why they believe it would also be safe to pump sulphate particles into the sky over our heads.

To conclude

The justification for research into geoengineering is that we can’t wait until we need it because by then it will be too late. But we must not allow it to divert resources from research into energy conservation, the replacement of fossil fuels by renewables and other conventional technologies. We must not use it as an excuse for failing to tackle the problem of climate change by all the means we already have. And we must not run the risk of doing even worse damage to the planet because someone goes ahead with a project without seeking and heeding the best available advice.


1. Ho MW, Cherry B, Burcher S and Saunders PT. Green Energies, 100 % Renewables by 2010, ISIS/TWN, London, Penang, 2009,

2. Ho MW, Burcher S, Lim LC, et al. Food Futures Now, Organic*Sustainable*Fossil Fuel Free, ISIS/TWN, London/Penang, 2008,

3. Tollefson J. Geoengineering faces ban. Nature 2010, 468, 14.

4. United Nations Environment Programme (2010). Convention on Biological Diversity. UNEP/CBD/COP/10/L36. Accessed 21September 2011

5. Cambridge University Engineering Department, 2010. Geoengineering by Solar Radiation Management. Accessed 19 September 2011 

6. Saunders PT. Saving the climate dangerously Science in Society 41, 22-23, 2009.

7. “Setback for Climate Technical Fix.” Richard  Black, BBC News, Accessed 21September 2011,

8. Pollard RT et al. Southern Ocean deep-water carbon export enhanced by natural iron fertilization. Nature 2009, 457, 577-580. doi:10.1038/nature07716

9. Schiermeier O. Ocean fertilization: dead in the water? Nature 2009, 457, 520-521. doi:10.1038/457520b.