Making the Case for Geo-engineering

Making the Case for Geo-engineering
by Caspar Hewett
September 2012

In August 2009, The Institution of Mechanical Engineers in the UK produced a report entitled Geo-Engineering: Giving us the time to act?. The report, which desribed geo-engineering as "another potential component in our approach to climate change that could provide the world with extra time to decarbonise the global economy," focused on practical geo-engineering solutions that are either available now, or soon will be^[1]. The study included detailed assessment of three case studies which the authors considered the most promising: two CDR methods - carbon dioxide storage by artificial trees and carbon absorption by algae on buildings; and one SRM technique - reflective buildings.

One thing to note about this report, apart from its discusssion of just three of the potential technologies on the table, is that the authors chose to focus on what they described as "key practical issues to be addressed from an engineering perspective." They were to ensure "that geo-engineering implementations:

are low-carbon solutions
build on existing engineering knowledge and are relatively easy to design, deploy and operate (to avoid distraction of significant engineering resources from mitigation activity)
can be achieved at low cost within a government low carbon policy framework"

These criteria should not be taken at face value when you consider that some geo-engineering technologies have the potential to have a much greater effect than any 'mitigation acitivity' at much lower cost, and is sadly indicative of narrow expectations and ambitions which run through all the discussions of geo-engineering.

The conclusion of the report was that, against the above criteria, artificial trees showed the most potential of the three case studies. However, the main conclusion was that

"There is currently insufficient information to adequately support an informed debate on this topic, for formation of robust Government policy, or the laying out of a detailed roadmap. The Institution urges Government to empower the scientific and social sciences community to undertake a thorough, collaborative and rigorous research activity to provide guidance as to which approaches offer the most potential at lowest risk to the Earth system."

This was essentially a call for more research funding. Elsewhere they estimated that a publicly funded national and international programme of research was needed to assess the feasibility of geo-engineering schemes "so that the global community is technically informed of the real practical potential of geo-engineering" and proposed a "£10-20 million UK contribution to such a programme, carried out internationally for about £100 million." This was the first major call for serious expenditure on geo-engineering research but actually is a remarkably small sum for such an important topic, especially when compared to, say the $17 billion for construction alone of the proposed ITER (International Thermonuclear Experimental Reactor) nuclear fusion reactor in France.

In September 2009, The Royal Academy published a report Geoengineering the climate: Science, governance and uncertainty^[2]. I was quite excited and encouraged to hear that Royal Academy were producing this report, but was to be sorely disappointed. On its publication Professor John Shepherd, who chaired the panel of experts, made a statement saying:

"We are not advocates of geoengineering ... But unless the world community can do better we fear that it is likely that we will need to use additional techniques such as geo-engineering to avoid really very dangerous climate change in the future.

"It is proposed as a response to reduce the risk we would otherwise incur due to climate change. An insurance policy or a backup."

Shepherd went on to say that the research showed that many of the techniques were deeply flawed and could have serious unintended and detrimental effects on many people and ecosystems. "None of the geoengineering technologies so far suggested is a magic bullet, and all have risks and uncertainties associated with them," he said, adding "It is essential that we strive to cut emissions now, but we must also face the very real possibility that we will fail. If plan B is to be an option in the future, considerable research and development of the different methods, their environmental impacts and governance issues, must be undertaken now."

In June 2011 the UN held a meeting to discuss geoengineering in Peru. In advance of the meeting a number of green groups jointly issued the following statement which reflects the tone of their reaction more broadly to these techniques: ^[3]

"Geoengineering ... is one of the most serious issues the international community will face in the decades ahead. The prospects of artificially changing the chemistry of our oceans to absorb more CO₂, modifying the Earth's radiative balance, devising new carbon sinks in fragile ecosystems, redirecting hurricanes and other extreme weather events are alarming. The potential for accidents, dangerous experiments, inadequate risk assessment, unexpected impacts, unilateralism, private profiteering, disruption of agriculture, inter-state conflict, illegitimate political goals and negative consequences for the global South is high. The likelihood that geoengineering will provide a safe, lasting, democratic and peaceful solution to the climate crisis is non-existent."

There are two striking things about this statement. The first is that it was a response to a meeting that had not even happened. The second is that, unfortunately, it falsely represents the tone of the meeting itself, which was hardly upbeat. A statement released in advance of the meeting^[4] said:

"Geoengineering ... is increasingly being discussed as a potential strategy to counteract anthropogenic climate change. Prevailing uncertainty in the sensitivity of the climate system to anthropogenic forcing, inertia in both the coupled climate-carbon cycle and social systems, and the potential for irreversibilities and abrupt, nonlinear changes in the Earth system with possible significant impacts on human and natural systems suggest that research is needed into geoengineering options as a possible complement to climate change mitigation efforts."

A reasonable start, but it then goes on:

"Current discussions that suggest geoengineering as an option to support climate mitigation efforts ... lack comprehensive risk assessments that take into account possible adverse impacts over short and longer time frames. Major uncertainties exist regarding the effects of these techniques on the physical climate system and on biogeochemical cycles, their possible impacts on human and natural systems, and their effectiveness and costs. Unilateral action may have environmental side effects on other countries and regions, and may not appropriately address the global scale of the issue."

This is not a confident promotion of geoengineering by scientists. Rather, it is extremely cautious and emphasises the same concerns as those raised by the environmental pressure groups. In addition, considering that this statement was also released before the meeting, it sounds suspiciously as if they had already made up their minds on what to conclude - this was not to be a call for major investment in research into geoengineering but rather was to be another assessment of what is already known in order to say it is too risky to try! The statement goes on to say:

"The understanding of the physical science basis of geoengineering is still limited and IPCC will, for the first time, assess this ... Improved scientific understanding of the impacts of geoengineering proposals on human and natural systems will be assessed ..."

In addition to this typical cautiousness and a general lack of willingness to actively promote geo-engineering, there have been major moves to hold back experiments. For example, in Autumn 2011 a planned field test of a balloon-and-hosepipe device to pump water into the atmosphere generated controversy. The British government-funded project - Stratospheric Particle Injection for Climate Engineering (SPICE) - was cancelled after an outcry by global NGOs, who described SPICE as a "Trojan Hose" that would open the door to full-scale deployment of the technology.

More recently in July 2012, two Harvard engineers announced an SRM experiment in which they plan to use a balloon flying 80,000 feet over Fort Sumner, New Mexico to spray sun-reflecting chemical particles into the atmosphere^[5]. The field experiment is investigating the viability of replicating the volcano effect outined above by introducing sulphates into the stratosphere. David Keith, one of the investigators, argues that such techniques could be a simple, cheap method to reduce global warming. This admirably bold proposed experiment will probably take place within a year - it will involve the release of tens or hundreds of kilograms of particles to measure the impacts on ozone chemistry, and test ways to make sulphate aerosols the right size.

It needs to be stated categorically here that there is good reason to do a large-scale experiment like this because the complexity of the stratosphere simply cannot be simulated in a laboratory let alone in a mathematical model. Only through such research can we collect the data required to generate decent models of how larger-scale sulphate spraying could alter the ozone layer. Keith argues that the risk is very small because the scale of the experiment is not large enough to alter the climate.

Interestingly David Keith said he opposed the SPICE project mentioned above because, unlike his own experiment, it would not have improved knowledge of the risks or effectiveness of solar geoengineering. He stated in the British Guardian newspaper

"I salute the British government for getting out and trying something ... but I wish they'd had a better process, because those opposed to any such experiments will see it as a victory and try to stop other experiments as well."

How right he was, as you might expect, the anouncement of Keith's proposed experiment was met by the warning that its effects are unpredictable and could have disastrous consequences. Again the now well-rehearsed argument from environmental groups was advanced, including the false claim that there is a "push" to make geoengineering a "plan B" for climate change and that that is a problem because it will undermine efforts to reduce carbon emissions. The argument is that, although Keith's experiment may not harm the climate, the global environmental risks of solar geoengineering have been amply identified through modelling and the study of the impacts of sulphuric dust emitted by volcanoes. Pat Mooney, executive director of the ETC Group (AKA Action Group on Erosion, Technology and Concentration) stated that

"Impacts include the potential for further damage to the ozone layer, and disruption of rainfall, particularly in tropical and subtropical regions – potentially threatening the food supplies of billions of people ... It will do nothing to decrease levels of greenhouse gases in the atmosphere or halt ocean acidification. And solar geoengineering is likely to increase the risk of climate-related international conflict – given that the modelling to date shows it poses greater risks to the global south."^[6].

In conclusion I will make five simple points in response to these discussions:

Yes, the outcomes of the proposed techniques for improving the climate are uncertain. However that is, and always has been the nature of science and engineering. In fact, that is precisely why we need research and large scale trials.
The mathematical models we have are simply not good enough - we need experimental data to support the development of models which can help us assess what full scale deployment of any of these techniques would entail and achieve.
However accurate or otherwise future climate predictions may be (and I suspect hugely innacurate - the time scales are too large and the number of assumptions and unknowns too great for prediction running decades into the future to be anything but wild guesses - as someone with a background in mathematical modelling I take all such predictions with a large pinch of salt), the evidence is that we are facing major changes in the global temperature, probably largely due to CO₂ emissions. Even if we completely stopped emitting CO₂ today, the effect of what is already in the atmosphere will continue for decades to come. Thus reducing emissions simply doesn't cut it - the effects will be too slow and too costly for that to be a realistic proposition. SRM techniques offer a real prospect of doing something effective much more quickly, and in the case of some schemes at least, much more cheaply, than carbon mitigation strategies.
Concern for people of the developing world and of less powerful countries is often cited as a reason for rejecting these technologies. Don't buy into them! Those of us who really are concerned about people in the developing world want them to develop without constraints set by anyone in the developed world. I have lost count of the number of times the fact that the people of Bangladesh will really suffer from a small rise in sea level is brought up. My answer in the past was always the same - if Bangladesh had the level of development of, say, the Netherlands, then they wouldn't have that problem - they would simply build the defences they needed (another engineering solution, but one that is only possible through economic, social and technological advance within that country). While that is still true, I now add that geo-engineering has the potential to empower us to stop the negative effects of climate change, which could mean that the people of a country like Bangladesh will simply not have to deal with that problem.
I think perhaps the most important point is the more general one that someone needs to take up the case for geo-engineering and mount a robust defence of it in principle. The critique of the idea hides behind a technical argument but is actually a much deeper one - it relates to a general distaste for the idea of shaping nature to our own ends. Let us remind ourselves that human beings have been altering the climate ever since the invention of farming (or even the discovery of fire). For most of our history the changes we have caused have been a simple byproduct of our activity and the consequences unintended. So we are engineering the climate, and continuing to do so in an unstructured way makes no sense at all - in fact it is sheer stupidity. The potential for geoengineering research to point the way to consciously directing our efforts to alter climate in whichever direction we think is the right one is one we should not shy away from. It will require confidence, belief in ourselves and belief in our capabilities. It will require a defence of a rational approach to the problems we may face in the coming decades rather than one based on fear and a retreat from belief in the human capacity to change things for the better.

Caspar J M Hewett, September 2012

References

^[1] Geo-Engineering - Giving us time to act?, Institution of Mechanical Engineers report, August 2009
^[2] Geoengineering the climate: Science, governance and uncertainty Royal Society report, September 2009
^[3]Open letter to IPCC on geoengineering
^[4] Advance statement by Joint IPCC Expert Meeting on Geoengineering in Lima, Peru, June 2011
^[5] US geoengineers to spray sun-reflecting chemicals from balloon by Martin Lukacs, The Guardian, July 2012

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