8.1. Climate change and the ambivalence of technology

For decades, climate change has been a major topic in scientific, philosophical, public and political debates. The United Nations Framework Convention on Climate Change and the regular international climate change conferences, most recently that held in Paris in 2015, are their most visible expression at a global level. The diagnoses of the causes, the attributions of responsibility, suggested solutions and problems of implementation have become a regular component of social conflict at the national, regional and local level. From today’s point of view, it is possible to distinguish three phases of the climate debate [GAR 10a]:

• – in a first phase of shock at the extent of the human influence on global environmental conditions and the climate starting in the 1970s, it became clear for many that a solution could only be found in decreasing the influence exerted by humans on the environment, i.e. their ecological footprint. In the climate issue, this corresponds to the strategy of reducing the discharge of greenhouse gases into the atmosphere as rapidly as possible and to stop it entirely in the long run. This strategy is termed mitigation;
• – starting in the 1990s, it became increasingly clear that the impact of mitigation was too slow to be able to prevent climate change to a great extent. The greenhouse gases that have already been emitted into the atmosphere and the further emissions that can be anticipated in the coming years and decades would lead to a considerable change in the climate, even if mitigation were to be successful in the long term. Consequently and despite all the efforts at avoidance, society must prepare for the coming change in climate and adapt such as by making preparations for increasingly extreme meteorological events or by taking precautions against a rising sea level. For this reason, one speaks of adaption;
• – for several years [CRU 06], the duality of mitigation and adaptation has been in the process of being extended to form a triad. Climate engineering is an approach to counter climate change by using technical measures in order to keep the Earth cool (for its history, see [KEI 00]). This approach has already attracted great political interest [COR 10, ROY 09, CAV 14] and is the object of intensive scientific as well as ethical discussion [BET 12b]. This announces a new phase of the climate debate.

Climate engineering has thus attracted a great deal of attention in light of expected major global problems that are generally thought to be caused by climate change. Again and again, it is stated that “tipping points” may exist in the climate system with potentially catastrophic consequences. The conclusion has been drawn that humankind should prepare itself and develop strategies to counteract climate change by active interventions into the climate system aiming at cooling effects. Many scientists, however, dismiss climate engineering because of unpredictable, dangerous and irreversible side effects and also argue against research commitment and funding that is too high [ROB 08]. Politics is interested in the suggested concepts because they could be adapted to fit national and international strategies of environmental and climate policies. Prerequisites to take up climate engineering as an acceptable tool would be safety, economic viability and public acceptance.

“However, we are facing an unfortunate reality. The global climate is already changing and the onset of climate change impacts may outpace the world’s political, technical, and economic capacities to prevent and adapt to them. Therefore, policymakers should begin consideration of climate engineering research now to better understand which technologies or methods, if any, represent viable stopgap strategies for managing our changing climate and which pose unacceptable risks” [GOR 10].

The nature of this argument, given its references to highly uncertain knowledge about consequences in both directions – for and against climate engineering – and the high relevance attributed at the same time to decisions on climate policy make orientation, on the one hand, urgently necessary but, on the other hand, also difficult if not impossible to achieve in a consequentialist manner. Climate engineering is consequently a suitable case study for this book’s propositions (see Chapter 1).

Lurking behind the three-stage history of the climate debate are different expectations placed on technology. In general, the relationship between technology and sustainability is ambivalent. Technology is one of the factors causing sustainability problems such as climate change, yet great hopes are also placed in technology as a solution to those problems. Technology is equally a cause of the problems as it is a solution to them [GRU 12d]. The views of technology as a solution have differed in the three stages of the debate:

• – the approach represented by mitigation is molded by the idea of employing more efficient technology to reduce greenhouse emissions. This is supposed to fight climate change at its roots by using better technology to go after the causes of the change;
• – the program of adaptation relies on technology to reduce the consequences of climate change, while the question of the cause does not play a role here;
• – climate engineering adds a new approach to this spectrum; using technical means to attack climate change itself, not merely its consequences, by going after its symptoms but not its roots. One could speak of an “end of pipe” approach.

This chapter briefly presents, first, in contrast to the possible limitations of the previous approaches (section 8.2), the technical options offered by climate engineering (section 8.3). Then the opportunities and risks posed by climate engineering measures are considered in the conventional consequentialist mode (section 8.4), whose limits can be quickly recognized. This is the motivation for the question regarding the shift or extension of the object of responsibility (Chapter 3) in the RRI debate over climate engineering. In fact, we see that the debate about climate engineering itself – and not just concrete technological measures – has consequences that are or could be relevant even in the present. It is therefore important for them to also be made a topic in the RRI debate (section 8.5). This opens the hermeneutic dimension of climate engineering, which in conclusion provides the reason to subject the imperative of responsibility [JON 84] to a reinterpretation in situations of this type.

8.2. Limitations of the previous approaches to finding a solution

Since the industrial revolution, mankind has interfered in the climate system to an increasing degree, especially through the discharge of carbon dioxide from the use of fossil fuels, but also through the emissions of methane in agriculture and other greenhouse gases. Since the emissions of greenhouse gases that are caused by man are the primary cause of global warming [IPC 14], the therapy appears to be obvious: to reduce the emissions of greenhouse gases, for example, by using more efficient technology, by replacing fossil energy carriers with renewable energy and by living a more sustainable lifestyle. Admittedly, our previous success has been modest, at best. Worldwide, the emission of greenhouse gases continues to increase (by 5.8% in 2012). This trend will continue for a long time even if mitigating measures should have an impact on a larger scale. Significant reasons for this are the continued strong global growth in population, economic growth in large portions of the world that leads to a higher consumption of energy and to more emissions, insufficient efforts at mitigation in many industrialized countries and the partially rapid economic development in the emerging economies of countries such as China, India and Brazil as well as in many developing countries¹.

In the meantime, the fact that adaptation strategies are necessary has been accepted as a matter of course. The point is to live with climate change, i.e. to make preparations for an increase in sea level and for an increase in the number and dramatic nature of extreme meteorological events. Today, it almost appears noteworthy that a good 10 years ago it was not politically correct in Germany to even talk in public about adapting to climate change. It was feared that this could undermine a systematic implementation of mitigation strategies [STE 08].

Yet, there are limits to adaptation strategies should climate change exceed certain thresholds. In view of the sluggish political steps in the last few decades², the inertia of the switch to non-fossil sources of energy at the global level, economic growth in the emerging economies that gives little consideration to ecological interests and the continued growth in the Earth’s population with an increasing hunger for energy, concerns are increasing that dramatic consequences of climate change are becoming more probable. The climate could tip, as some fear. Developments that are dangerous and hard to predict could take place, such as:

• – the accelerated warming caused by a further melting of the arctic ice pack in the summer and the Earth’s thus reduced albedo;
• – a strong and rapid increase in the sea level resulting from a melting of the Greenland or West Antarctic ice sheets;
• – the accelerated increase in the concentration of greenhouse gases resulting from the degassing of methane hydrates on the sea floor or a rapid thawing of the permafrost regions.

Such developments that could occur if the climate exceeded tipping points (assumed but not proven) could make adaptation increasingly difficult if not impossible. Positive, i.e. self-reinforcing, feedback effects could lead to a world in many parts of which the climate conditions would no longer be comfortable for humans, to put it cautiously.

The debate over climate engineering [BUN 09, ELL 10, GAR 10b] cannot be understood without being aware of the growing skepticism that the strategies of mitigation and adaptation may not suffice to keep the climate in a range that is hospitable to life and humans. Even though this is just a matter of concern and not reliable prognoses or even just plausible scenarios, it is comprehensible and perhaps even morally imperative for us to undertake precautionary considerations to search for further possibilities for dealing with the consequences of climate change.

8.3. Climate engineering as a technical option

Climate engineering was introduced into the debate as a possible measure of last resort to intentionally influence the climate system for the purpose of cooling the Earth. It is supposed to be developed as a last chance (ultima ratio) should all other efforts to contain climate change fail [CRU 06]. This is precautionary argumentation. Measures for climate engineering are to be studied and developed in order to be prepared for emergencies in climate change. Accordingly, climate engineering is only to be employed in such emergencies. Otherwise, the efforts to mitigate and adapt should be continued and intensified. Climate engineering is supposed to be, one could say metaphorically, something like a fire extinguisher that is hanging on the wall for an emergency and whose availability of course does not make fire prevention measures obsolete.

Climate engineering differs from mitigation and adaptation in its fundamentally different perspective on the climate system. It is seen with the eyes of an engineer as an entire system which could be managed by engineering intervention. While climate change has so far been an unintended consequence of industrialization and economic growth, the objective is now to identify intentional interventions to counteract climate change. Features are being sought that can be adjusted, just like a set screw, in order to be used technically to achieve an impact on the climate in order to cool the Earth. There are two conceptually differing approaches:

1. 1) The reflection of solar energy back into space could be increased so that only a smaller portion of it would be absorbed by the Earth’s atmosphere. Technically, this could be achieved, for example, by the targeted insertion of small particles (aerosols) into the upper layers of the atmosphere that reflect sunlight back into space. Among other measures that are possible is the widespread painting of streets and roofs white. This type of measure is referred to as solar radiation management (SRM) [LEI 10];
2. 2) Efforts could also be made to remove large amounts of carbon dioxide or other greenhouse gases from the atmosphere and to store them in, e.g., the oceans or to press them into subterranean caverns such as those from natural gas deposits. The deep carbon export experiment of the ship Polarstern in 2009, which for this purpose was supposed to stimulate algae growth in a targeted manner and attracted substantial media attention, was conducted in this context but produced rather sobering results. However, gentler measures, such as large-scale forestation, also belong to the spectrum of such carbon dioxide removal strategies (CDRs) [RÖS 10].

These options differ greatly in many regards. What they have in common is the high degree of unawareness and uncertainty about their use and possible consequences. CDR measures would have to be employed on a large scale and would nonetheless work very slowly. By the time we could know whether and how well they were working, it might be too late if there were an emergency in the development of the climate. Most thought has therefore been focused on modifying the composition of the atmosphere in a targeted manner so that a cooling effect would occur as rapidly as possible. The topic that is most commonly mentioned is the sulfur option, which was already noted by Crutzen [CRU 06]. A role model is nature itself in view of the observation that there was a measureable reduction in global temperatures for several years as a consequence of powerful volcano eruptions, which are linked to the discharge of sulfate aerosols into the upper atmosphere [LEI 10, p. 28ff.].

First model calculations show that the insertion of approximately a million tons of sulfate aerosols into the upper layers of the atmosphere could achieve a significant cooling effect. This would occur practically immediately, making this option appear destined for use in a climate emergency. Gravity, however, would gradually pull the aerosols down to the ground so that they would have to be reinserted after a certain period, which is calculated to be several years. The extent of the desired cooling could be regulated by adjusting the concentration of the aerosols. This would then even make it possible to fine tune the global mean temperature.

The aerosols could be spread by a fleet of airplanes. Initial very rough calculations of the costs run to several billion dollars a year, which would be downright little compared to the estimated costs of adaptation to climate change. An implementation of this option would be significantly more difficult because of unresolved legal issues. It is uncertain at which political level a decision could be made about a technology with such an undoubtedly global impact and how diverging interests should be handled [WIE 10].

8.4. Chances and risks of climate engineering

Viewed superficially, the sulfate option seems to be – in terms of technology and economics – an astonishingly simple solution to climate change. If greenhouse gases caused by humans lead to the warming, the sulfates could in the same way be an appropriate antidote that uses a cooling effect to compensate for the warming. To use the metaphor of the fire extinguisher: if a fire starts despite all the preventive measures, then you need a rapidly working fire extinguisher. In case the avoidance strategies are not sufficient to keep the climate in a range that is compatible with human life, or in case unforeseen systemic effects occur that could trigger a substantial acceleration of climate change, a rapidly working measure from climate engineering could possibly prevent or help to mitigate catastrophic developments, at least for a limited period. It would therefore be good, according to this argumentation, to have climate engineering technology at our disposal in order to be able to employ them in an emergency.

In addition to this central argument for the development (not the use) of climate engineering technology [CRU 06], other arguments have also been given [BET 12a, BET 13, OTT 10, SCH 96]. Climate engineering will increase the number of options for dealing with climate change, providing more options for the coming generations. The “lesser evil argument” operates under the assumption that climate engineering itself is the lesser evil than unchecked climate change, even if it were to have unintended consequences of its own. Climate engineering, especially the aerosol option, would ultimately constitute a response that is economically much more efficient and easier to implement than painstaking and economically expensive strategies of mitigation and adaptation, a reorganization of the economic system or even a change in lifestyles. Adopting this last option would, however, depart from the line that Crutzen [CRU 06] takes that climate engineering may only play the role of an emergency technology. In contrast, intended technological interventions in the climate system are considered a genuine substitute for mitigation and adaptation in this argumentation [BET 13]. This concludes the small set of narratives concerning the potential of climate engineering.

The fundamental motivation for reflecting on climate engineering is fed by concern about the possible failure or inadequacy of mitigation and adaptation (see section 8.2) and is ethically legitimate on the basis of precautionary arguments. Yet even if the ultima ratio arguments are taken seriously, the risks have to be analyzed carefully and integrated into an overall assessment. The ultima ratio argument does not create blanket legitimation for climate engineering but solely legitimation for it to be taken into account. Considering the possible negative effects and balancing them with the benefits are necessary prerequisites.

The fundamental ambivalence of technology has been generally acknowledged for several decades. In particular, the manifestation of unintended and often problematic side effects in the environmental sphere was one of the factors motivating the establishment of technology assessment [GRU 09a]. Similarly, climate change can also be interpreted as an unintended consequence of the techno-economic progress of the last 200 years. Carbon dioxide, the most important greenhouse gas, is inevitably generated during the utilization of fossil energy carriers whose use is central to the global economy. While the point of mitigation is to reduce the unintended consequences and thus go to the root of the problem, climate engineering addresses the symptoms of climate change at the end of the causal chain. Historically, a belated repair of damages that have already appeared is not unusual. New types of technology are often employed to cope with the unintended consequences of older forms of technology. History shows that as a rule, these new forms then also have unintended consequences [GRU 09a]. One of the driving forces of technological progress is for new technology to cope with the unintended consequences of earlier technology.

Thus, with climate engineering, there are also questions as to the unintended consequences and risks, as to their specific characteristics and as to their possible extent. Even if we often cannot make a final judgment on this due to our inadequate knowledge, it is possible to distinguish the following areas of risk (for example the aerosol option) [BET 13, OTT 10, GRU 11d, ROB 08]:

• – Risks from preparatory experiments: experiments are necessary to overcome deficits in our knowledge. At least some of these experiments would have to be conducted in the real atmosphere and arranged on a sufficiently large scale to be able to learn reliably from it. Even these experiments could have unwanted and potentially large-scale consequences;
• – Risks during operation: some of the suggested climate engineering measures, such as the insertion of aerosols, will deliberately modify the composition of the atmosphere. The resulting small modifications, for example, in the spectral distribution of the light reaching the Earth’s surface could trigger unexpected biological effects. Or the gradual sinking of the aerosols to the ground could cause ecological problems in the medium or long term. Sulfates, for example, lead to an acidification of the ground and water. Unanticipated effects on the climate also cannot be excluded since we do not fully understand the climate system. In view of the long period over which a climate engineering measure might have to be maintained, such long-term scenarios must be examined carefully;
• – Risks in maintenance over a long period: if the climate engineering measures would have to be maintained for centuries or millennia, stable political and economic conditions would be necessary. This is by no means the rule over long periods, however, as a look at history shows;
• – Risks from aborting operation: if the operation of a global climate engineering system would have to be discontinued for a longer period or be completely terminated, such as for inadequate resources or a war or because of obvious negative consequences for the environment, the cooling effect would abate quite quickly and over a few years there would be a rapid increase in the global mean temperature. Large portions of humanity would then be confronted by substantial, even presumably catastrophic challenges. The time needed to prepare comprehensive measures to adapt to the situation would presumably not be available;
• – Risks in the political process: climate engineering requires global governance because it is a global technology with global consequences. Since there are winners and losers, such as in the political handling of climate change, there can be political conflicts such as when individual economically stronger countries rush ahead or when decision making is blocked because of different interests [WIE 10].

These stories of risk do not represent secure or even reliable knowledge, but are speculative. They can be regarded as expression of the ethical obligation that we must consider the distant effects of our actions [JON 84]. However, the results of these efforts cannot be qualified epistemologically. It is unclear how plausible, to be expected, or probable the chances and risks are. The attribution of quantitative probabilities of occurrence and the amount of damage is clearly not possible due to the deficits in our knowledge. Balancing the chances and risks fails because of our insufficient knowledge of the consequences. The consequentialist view does not provide orientation for action but leads to perplexity (Chapter 3) or ideology.

Perplexity can be carried to extremes. On the one hand is the ultima ratio argument. Let us assume that the previous and future measures for mitigation and adaptation cannot keep the climate within tolerable limits. The opposite of this assumption can at any rate not be proven. Accordingly, it would be a moral obligation to study climate engineering and to make it applicable. Forgoing climate engineering would endanger the continued existence of a humane form of life on the Earth and would thus violate Hans Jonas’s categorical imperative [JON 84].

The above-named risks can, however, also lead to the opposite conclusion. Let us assume that climate engineering measures were developed. The development would result in a reduction in the efforts to achieve adaptation and mitigation. Climate change would hardly be slowed down, and it could in fact lead to dramatic developments. Climate engineering would then be employed as a form of emergency technology. Yet if after some time there were dramatic side effects for ecosystems, then the only alternative would be to abandon it, risking the increase in temperatures that might follow, or to accept the risk of serious and further escalating ecological consequences. In both cases, the entirety of human life on the planet Earth would be endangered, which must be avoided according to Jonas. It would thus be a consequence of the categorical imperative to not develop climate engineering [JON 84].

The result of this is a typical aporia. To act in accordance with the imperative of the ethics of responsibility demands at one and the same time the development of climate engineering as well as the refusal to pursue this development. Taken to an extreme, this represents the collapse of consequentialist argumentation (Chapter 3).

Currently, it is impossible to resolve this aporia. We lack the empirical and the modeling knowledge about the possible technical options, their conditions of use and their consequences. Viewed in this light, additional research in engineering, natural, social and legal sciences appears to be a legitimate task, if not one that is prescribed, to enable us first of all to assess the technical options. As long as this is not possible in view of the speculative nature of the statements about chances and risks, our only alternative is to ask about other forms of orientation.

8.5. The hermeneutics of climate engineering

One possibility for searching for orientation consists of asking whether climate engineering has a meaning that goes beyond technology and its immediate application. Uncovering such meaning could support the RRI debates without having to argue in a consequentialist manner (section 8.5.1). Furthermore, in accordance with the idea of extending the subject area of responsibility (Chapter 2), we can ask about responsibility for current communication (section 8.5.2).

8.6. Epilogue: hermeneutic extension of the imperative of responsibility?

At this point, I will only briefly mention a topic whose inclusion here would go beyond the scope of this book. It has often been noted that the imperative of responsibility [JON 84] rides on precisely the same aporia that was identified above for climate engineering. In the texts “The Heuristics of Fear” and “Prevalence of the Bad over the Good Prognosis”, Jonas [JON 84] considers the pure conceivability of action A having catastrophic consequences as being sufficient to raise a demand for a cessation of action A. This, however, regularly results in aporias of the same type. The low threshold represented by pure conceivability can as a rule lead to thoughts about consequences according to which both the execution of action A and its rejection might result in catastrophic consequences. Action A is therefore supposed to be carried out as well as rejected. This consideration obviously does not lead us any further.

The reason for this is that the pure conceivability of the consequences of future actions does not constitute a suitable basis for drawing conclusions. Purely conceivable considerations of consequences are arbitrary and do not suffice as a basis for deriving orientation (see also Chapter 3). The question is whether this argumentative weakness in the imperative of responsibility could be overcome through the inclusion of a hermeneutic perspective.

At the very least, the present book shows in several examples that something can be learned from technology debates, techno-visionary futures and controversies over definitions and characterizations of new fields of technology even in the absence of knowledge about their consequences. The proposal that the subject area of reflection on responsibility should be extended (Chapter 2; on climate engineering section 8.5) could contribute to overcoming the restriction of the imperative of responsibility to the distant impact of new forms of technology and to asking about the responsibility for the course of today’s debates and decision-making processes. This would constitute contributions to self-enlightenment and orientation in present-day debates, not more and not less. It is still expected that this will lead in the medium term to a responsible implementation and use of future forms of technology.