Home Search Collections Journals About Contact us My IOPscience Of Malthus and Methuselah: does longevity treatment aggravate global catastrophic risks? This content has been downloaded from IOPscience. Please scroll down to see the full text. 2014 Phys. Scr. 89 128005 (http://iopscience.iop.org/1402-4896/89/12/128005) View the table of contents for this issue, or go to the journal homepage for more Download details: IP Address: 130.237.29.138 This content was downloaded on 28/11/2014 at 09:49 Please note that terms and conditions apply. | Royal Swedish Academy of Sciences Physica Scripta Phys. Scr. 89 (2014) 128005 (7pp) doi:10.1088/0031-8949/89/12/128005 Invited Comment Of Malthus and Methuselah: does longevity treatment aggravate global catastrophic risks? Karim Jebari Institute for Future Studies, Postal address: Holländargatan 13, 101 30 Stockholm, Sweden E-mail: karim.jebari@iffs.se and jebarikarim@gmail.com Received 12 August 2014, revised 3 November 2014 Accepted for publication 5 November 2014 Published 27 November 2014 Abstract Global catastrophic risk is a term that refers to the risk of the occurrence of an event that kills at least millions of people across several continents. While it has been argued by a number of scholars that one major potential risk comes from technology, the obscure nature of future technologies makes it difficult to utilize traditional probabilistic risk for the meaningful study of these risks. This article describes an alternative approach and applies it to a research program that has attracted a considerable amount of resources recently: namely longevity research. The aim of this research is to delay or reverse the ageing process. This article argues that this research program is much more risky or less beneficial than its proponents argue. In particular, they tend to underestimate the concerns associated with the potentially drastic population growth that longevity treatment could cause. The ethical benefit often ascribed to longevity treatment is that such treatment would add more subjective life-years that are worth living. However, in light of contemporary environmental problems, such an increase of the human population might be reckless. Drastically reducing fertility to reduce risks associated with environmental stress would make the benefits of such technology much less compelling. Keywords: emerging technology, global catastrophic risk, ethics 1. Introduction their sheer number ought to dominate our ethical considerations. These ideas have been discussed more thoroughly by Nick Bostrom [1]. It has been argued by a number of scholars that a major potential risk comes from technology [2]. While natural disasters with the power to exterminate mankind are very unlikely, arriving at a similar assessment of future misuse of technology—either intentional or accidental—is considerably more uncertain. The assumption in this field is that while technology has a great potential to improve the human condition, it can also cause great harm. When studying risks associated with novel or possible technologies, it might seem like a good idea to use probabilistic risk analysis (PRA) tools. However, as Sven-Ove Hansson has argued in a number of publications, these tools are not very helpful in this context [3]. PRA was developed to evaluate well-defined dangers associated with well-known technologies. Yet, as discussed Global catastrophic risk (CGR) is a term that refers to the risk of the occurrence of an event that kills at least millions of people across several continents. Such events could be sudden and violent, such as wars and natural disasters, or slow and silent, such as malaria or HIV/AIDS. A subset of global catastrophic risks threatens the very existence of our species. These are known as existential catastrophes. While these may be unlikely, the opportunity cost of such a catastrophe is vast due to the number of lives that can exist in the absence of such a disaster. Unless we ascribe very little value to the lives of future generations, people who might exist in the future, 1 This paper was presented at a meeting on Emerging Technologies and the Future of Humanity held at the Royal Swedish Academy of Sciences. 0031-8949/14/128005+07$33.00 1 © 2014 The Royal Swedish Academy of Sciences Printed in the UK Phys. Scr. 89 (2014) 128005 K Jebari inherent in new technologies into account. I have argued elsewhere that the heuristics developed by engineers are very useful for understanding and developing strategies to reduce global catastrophic risks [6]. Whereas PRA departs from known ‘worst-case scenarios’, the set of heuristics proposed by Hansson departs from ‘mere possibility arguments’ [7]. This class of arguments makes claims about the risk of a technology based on a mere possibility. For example: ‘nanotechnology could result in selfreplicating nano-robots converting all matter to more nanorobots’. As such, these arguments allow us to consider possibilities that are ‘outside model’, i.e. outside of the realm of our expectations. However, these arguments are sometimes ridiculously speculative, yet when dealing with great uncertainty about existential risks it might be irresponsible not to consider such arguments, as when the physicist Edward Teller raised the speculative possibility that an atomic bomb could ignite the atmosphere [8]. How to strike a balance? A number of considerations and tests have been proposed by Hansson to assess these claims systematically. While being unable to provide the apparent rigor of PRA, this method may prove to be an important additional tool in this crucial yet daunting research program. First, a number of scenarios need to be collected in as systematic and non-partisan way as possible. Some examples of this can be found in the recent book Global Catastrophic Risks [2]. The scenarios should be subdivided into more specific outcomes. Consider the claim ‘geoengineering poses a huge risk to the biosphere’. This claim could be specified into a number of different and more precise claims. Some scenarios can, when specified, be discarded at this point, if subjected to a scientific analysis. For example: whereas the claim ‘electromagnetic radiation poses a grave danger to human health’ is too vague to evaluate, the claim ‘nonionizing radiation from mobile telecommunication causes cancer in humans’ is specific enough to discard. At this point we may apply what Hansson refers to as ‘the symmetry test’. A mere possibility argument can be deflated if the phenomena has some other possible effect that is opposite in value and that has equal or superior moral weight than the postulated effect. For example, it has been claimed that crops that have been genetically modified to produce toxins that kill insects could cause a massive loss of ecosystem diversity. On the other hand, it also possible that these modifications could reduce the use of pesticide, that could have an opposite effect. Thus, the negative effect of this hypothetical modification is countered by an opposite positive effect. By contrast, most reckless acts, such as driving under the influence of alcohol, have small benefits in comparison to the risks that such behavior is associated with. A mere possibility argument could also be countered by an alternate effect. Such an effect occurs if the failure to implement the intervention under consideration could lead to equally appalling consequences. For example, it has been argued that research in biotechnology might result in the intentional or accidental creation of a superbug that could pose an existential threat. However, the failure to pursue this elsewhere at this meeting, we all agree that what we face when evaluating emerging and future technologies is not a ‘risk’ in the technical sense, which differs from the ordinary meaning (Seth 2014). Rather, we are dealing with great uncertainty. In decision theory, a decision is under certainty when the agent knows which outcome each decision entails [4]. This is often the case in philosophical thought experiments, where we are asked to assume for example that pushing a man from a bridge will kill him, while stopping a runaway trolley, thereby saving five (innocent) persons. In this popular thought experiment, we know with absolute certainty that pushing the man will kill him and we also know with the same degree of confidence that not doing so will lead to the death of five persons. A decision is under risk when there is more than one possible outcome of a decision and the objective probability of each outcome is known. This is typically the situation when playing an (unbiased) game of roulette in a casino. By contrast, in a decision under uncertainty, the objective probabilities of the outcomes are not known with sufficient precision, yet other features about the situation are often assumed to be well-defined and known. These may include, for example, potential outcomes, their respective utility and the distribution of this utility across time and space [5]. For example, the decision to raise or fold in a game of poker involves uncertainty about the other player’s hand. While the probability that the other player may have a better hand than yours is unknown, the utility of losing or winning the game is usually well known. This is hardly the case when we evaluate new or possible technologies. Rather, as Hansson and others have argued, in these situations we are dealing with great uncertainty. This refers to a situation where the decision maker not only lacks precise probabilities of the different outcomes; the decision maker must also assume that there are possible outcomes that are not known. Furthermore, the possibility that the probability space is dominated by some of the unknown possible outcomes cannot be excluded. For example, when declaring war, a list of possible outcomes and their respective utilities could be compiled. Yet no reasonable military planner would be too confident about this list being comprehensive, or that the utility assigned to each outcome is certain. The astronomical opportunity costs of an existential catastrophe and the notion that considerations of how to reduce existential risk must account for great uncertainty may open the door to total paralysis. Any new technology could be the last one, and a failure to invent any technology could also be our last. How can we approach the subject of existential risk under great uncertainty in a constructive way? 2. Mere possibility arguments Engineers have managed risk in complex systems for hundreds of years, knowing that new technology often fails in unpredictable ways. Engineering safety is a set of partly overlapping practices and heuristics that take the uncertainties 2 Phys. Scr. 89 (2014) 128005 K Jebari pharmacological intervention is inevitable, according to a review published in Nature last year [13]. The proponents of this technology make a simple claim of its benefits: ageing and morbidity related to ageing kills approximately 100 000 persons daily, or two thirds of all deaths. In rich countries, the proportion killed by ageing is roughly 90% [14]. Surely, these people matter no less than the people who die from HIV/ AIDS or malaria? Any risk, in comparison to ‘the ongoing slaughter’, cannot be taken seriously, de Grey argues [12]. Would de Grey be correct in his claim that if ageing is to be considered as an ongoing moral disaster, we should be prepared to accept major risks when introducing this technology? However, this idea either fails to fully appreciate the contributive value of future generations and the opportunity cost of an existential catastrophe [15]. The mere possibility argument presented here is that longevity treatment could aggravate concerns about the possibility of avoiding catastrophic demographic collapse due to environmental, social and economic constraints. Can the argument in favor of longevity treatment be assessed according to the heuristics proposed above? To explore this challenge, we need to consider the following scenarios with regards to human fertility. To clarify: in a general academic context ‘fertility’ refers to the average number of children that women are expected to have over their lifetime. However, for the purposes of this paper, I will use the term ‘fertility’ to refer to the number of children per woman that are expected to be born each year. We will further assume that longevity treatment would become widely available for a large fraction of mankind in a few decades after its introduction. Now consider two possibilities. research may expose us to some natural microbe that could pose a similar threat. The next step is to evaluate the mere possibility argument according to the following heuristic tools. These should be seen as rules of thumb to give us an idea about how much attention we should pay to mere possibility arguments. 1. Novelty: the more well-known and well tested a technology is, the less room there is to make a mere possibility argument. For example, we should be more concerned about cloning animals than about selective breeding. 2. Spatio-temporal limitation: an intervention that is limited to a particular time and place is less vulnerable to mere possibility arguments. For example, manipulating a local ecosystem by removing a forest is less dangerous than trying to manipulate the whole biosphere through geoengineering. 3. Interference with complex systems: the more complex a system, the greater the risk for an intervention in the system. Complex systems typically have nonlinear responses to stress, such that an intervention may either have negligible or drastic effects. For example, for geoengineering to have an effect, interventions on a massive scale are required. Yet, the uncertainty of how such an intervention may affect other planetary systems is still considerable. Thus, an incremental approach is recommended when dealing with systems such as the climate or the economy. In summary, mere possibility arguments are an alternative tool for considering global catastrophic risks from technological innovation when PRA is not possible. Mere possibility arguments can be systematically evaluated by using a number of tests. I will now turn to a potentially disruptive technology: the control of the many kinds of cellular damage that are commonly referred to as ageing, and apply these heuristics to consider the risks and benefits of the implementation of a cure for senescence. (a) Fertility is drastically reduced to keep actual population growth in line with current projections. Since ageing causes two thirds of all deaths, universal usage of this treatment would require a corresponding reduction in fertility. (b) Fertility follows current projections and, as a result, population grows faster, possibly much faster than anticipated. 3. Longevity treatment In both these scenarios, it has been assumed that longevity treatment would proliferate quickly. If such treatment became possible, it is hard to imagine that it would not be in high demand. Consider the almost universal demand for ‘rejuvenating’ cosmetic products. It seems plausible to assume that the willingness to pay for treatment that could actually delay (or reverse) ageing would be considerable. If longevity treatment consisted of some expensive surgical procedure, then costs would probably restrict its adoption to the wealthy2. However, if such treatment consisted of a drug, then research costs would be shared by a huge number of buyers, thereby driving down prices and increasing availability. While longevity treatment may sound fantastic, it seems plausible that substantial progress in this field could materialize over the next decades. Medical interventions that arrest or reverse ageing are likely to come in small steps, where each innovation increases lifespan a few years at a time. A study from 2011 suggests the possibility of slowing down the ageing process by activating an enzyme that protects the chromosomes in cells [9]. A recent outlook in the journal Nature surveyed the frontier in understanding the biochemical mechanisms involved in this process [10]. Google announced recently that they were setting up a research company, Calico, with the explicit goal of producing a medicine or treatment for ageing [11]. In the UK, Aubrey de Grey and his research foundation for engineered negligible senescence (SENS) recently received generous donations from a number of internet entrepreneurs [12]. Many experts believe that a 2 However, it is worth pointing out that according to current projections GDP per capita in corrected for purchasing power (PPP) in developed and emerging economies are going to converge. For example, China’s GDP per capita as a proportion of the US is expected to increase from 18% in 2011 to 44% in 2050 [16]. 3 Phys. Scr. 89 (2014) 128005 K Jebari These scenarios could also be conceived as a continuum, where (a) and (b) represent the outliers in the question of fertility. While scenario (a) could be characterized as (relatively) low risk/low value outcome, scenario (b) represents high risk/high value. considered to be self-evident, the positive right to life, i.e. the right to have one’s life extended, is more complicated. In the healthcare system, choices are made all the time on who to prioritize, and some people’s lives are not extended for a variety of reasons, not all related to the right of life of others. To be sure, some philosophers argue that we have a responsibility to maximize utility, and this often means trying to save as many lives as possible [20]. While such an outlook is admirable, most of us believe that we have no obligation to donate all our money to life-saving charities, and that we are allowed to take our own welfare into consideration when making choices that could have saved other people’s lives. When considering the risks and benefits of life extension, we may consider the right of existing people to extend their lives, but this right needs to be balanced by other considerations, such as whether or not introducing such technology would constitute an existential risk. Thus, in hypothetical scenario (a) no additional value is added, unless we discriminate against non-existing people. This means that if scenario (a) took place, longevity treatment could not appeal to the symmetry test, since the value created by this intervention would at best be negligible. In addition, scenario (a) may result in a number of longterm risks, as the characteristics of widely available longevity treatment correspond to a ‘high risk’ intervention according to the heuristic model presented above. Longevity treatment would be very difficult to contain in space and time. It could be argued that longevity treatment is hardly new, since life expectancy has been increasing for more than a century and society has been able to adapt to this change to a reasonable degree. Yet, this claim conflates the increases in life expectancy (the average number of years that an infant can expect to live) and life span (the average number of years that an adult can expect to live). While modern medicine and public health has dramatically increased the former, the latter has hardly increased as much. A male adult member of the English aristocracy in 1500 could expect to live to age 71 [21]. Thus, the expected radical extension of life span that longevity treatment is likely to bring about is something completely new. Longevity treatment would also interfere with highly complex social relations across many domains of life. We can, at this point, only speculate about the social effects of this change. Yet, it is worth pointing out that death, and the awareness of our limited time, is a major aspect in many individual decisions of great importance, such as when to procreate, where and when to invest, and when to take risks or abstain from doing so. By adding a large and uncertain number of life-years to each existing person’s expected life span, the utility function of a large number of individuals would change in ways that could have profound and unpredictable consequences across many domains. What would happen with the generation of new ideas and new projects? It is a sad fact about us that we rarely change our minds [22]. The greatly reduced pace of generational change in scenario (a) is likely to adversely affect innovation and scientific progress. For example, it has been observed that in the history of science, new insights and scientific models 3.1. Low fertility Start with scenario (a). In this scenario, we merely replace future people with existing people. As Gustaf Arrhenius has argued, this scenario is no better than allowing existing people to die and replacing them with new people [17]. This claim is supported by what in contemporary moral philosophy is known as neutrality, a widely accepted condition in population ethics. According to this condition, if two outcomes A and B have the same amount of welfare and equality, then A and B are equally good, other things being equal. This condition applies equally to actual populations and populations that are merely possible. We may have reason to believe that additional life-years add increasing marginal utility, i.e. that a number of subjective life-years are better if concentrated in fewer people rather than more. In other words, we may believe that the life of a person that has lived for 60 years is more than twice as good as the life of one person that has lived for 30 years. However, while it is plausible that additional life-years add increasing marginal utility for people with very short lives, this may not be true for very long lives. We can only speculate about the merits and flaws of very long lives, but it is quite reasonable to assume that the net benefits of extreme longevity are quite limited. Our brains, even when rejuvenated, may not be able to fully enjoy a multicentenarian life. These considerations make it quite plausible that two hundred years lived by two different people is at least as good as the same number of years lived by one person. An outcome where existing people displace future people would not necessarily be better all things considered, even if it would be better for the existing people. It is worth noting that the abovementioned condition, neutrality, is consistent with a large number of theories about value, including most forms of consequentialism [18]. In particular, neutrality is a condition that is accepted by most scholars that are concerned about existential risks. The assumption that the lives of nonexisting but possible future people may have some contributive value is crucial to the claim that existential catastrophes are much worse than catastrophes that are ‘almostexistential’. This means that we are assuming that the lives of people in the future have a positive value, i.e. they make an outcome better3, and that we should be concerned about the existence and welfare of these people. Daniela Cutas argues that the right to life also implies that that we have a duty to prevent death and that longevity treatment should, if available, be seen as a universal right [19]. Yet while we may sympathize with the idea of a positive ‘right to life’, this cannot be an unconditional right. While the negative right to life, i.e. the right to not be killed, is by many 3 Assuming that these people have lives worth living. 4 Phys. Scr. 89 (2014) 128005 K Jebari this outcome open to a negative mere possibility argument. I should add here that an objection from distributive justice against longevity treatment can be made and is indeed plausible. Yet, the argument here shall focus only on the argument from global risks. For a discussion on equity related objections, see [26]. While the concerns associated with scenario (a) are still prevalent in scenario (b), an additional, risk is associated with scenario (b). We can refer to this as the ‘Malthusian risk’. It will be argued that this additional risk is of such a magnitude that it makes longevity treatment vulnerable to a negative mere possibility argument. Thomas Robert Malthus predicted in An Essay on the Principle of Population that once population growth outpaced agricultural production, mankind would be forced to return to subsistence level conditions. Modern Malthusians have on a number of occasions predicted that such a Malthusian catastrophe was imminent, yet these predictions have consistently failed [27]. However, this should not inflate our confidence that such concerns are inherently implausible. Although large-scale population declines have not occurred in the modern era, a number of demographical collapses have occurred historically. One such example is the crisis of the Late Middle Ages, where famine, plague and war dramatically reduced the population of Western Europe [28]. While a similar demographic collapse is unlikely to pose an existential risk by itself, it makes some such risks more likely. For example, our advanced civilization has the means to survive a number of large natural disasters that could pose an existential risk for agricultural or hunter-gatherer civilizations. It is hypothesized that our ancestors barely survived one such major disaster in our prehistory [29]. Rebuilding civilization after a large-scale collapse could be hampered by the relative scarcity of easily extractable fossil fuels. A large global catastrophe that would permanently reduce life quality and number of lives to preindustrial levels has opportunity costs that are comparable to those of a ‘real’ existential catastrophe. Modern Malthusians have recently argued that the current situation in terms of climate change, ocean acidification, nitrogen cycle and species extinction is dire [30]. If global GDP continues to grow at 3% a year, as is expected, the stress on the planetary boundaries may already be too great to avoid a disaster. Adding a large number of lives to this predicament is likely to aggravate the problem severely. Note also that the extra lives anticipated in scenario (b) would be concentrated among the richest people, the group that also contributes most to environmental stress. This makes longevity treatment different from other lifesaving innovations that are often compared to it, such as malaria vaccines. People who could be saved by malaria vaccines are among the poorest in the world and consume negligible amounts of planetary resources. Moreover, efforts to control malaria also seem to reduce fertility [31]. To sum up, scenario (b) would create the risks described in scenario (a) and also seriously aggravate prevailing Malthusian risks. have often triumphed because their opponents eventually die [23]. Young people are typically more inclined to take risks [24], which suggests that a society without ageing and with very little intergenerational mobility might be much more stagnant than ours. Such a society may be particularly vulnerable to new and unexpected threats that require a lot of people to change their way of life. For example, older people seem to be more skeptical about the existence of anthropogenic climate change and less inclined to favor political reforms to address this problem [25]. In summary, scenario (a) is not obviously morally superior to the status quo, and is associated with drastic changes that are spatiotemporally unrestricted. Moreover, longevity treatment introduces a novel and potentially highly disruptive change in demography, social structure and complex social dynamics across many domains. These changes are problematic from a risk perspective in that they may make us more vulnerable to risks that require flexibility, adaptation and innovation. 3.2. Moderate fertility Scenario (b) represents an outcome where fertility follows current projections. According to these projections, the number of children born per woman is likely to contract substantially, approaching the replacement level at 2.4 children per woman during 2025–20304. On these projections, the global population is expected to reach nine billion by 2040 and ten billion by 2100. The fall in children per woman across the world that is already accounted for makes scenario (b), or an outcome closer to (b) on a continuum, more likely. It would take a lot of political effort to limit population growth further. Furthermore, if longevity treatment is costly in the first years after its introduction, the expected population increase will be most notable in rich countries and among the elite in poor countries. This is due to the fact that age-related mortality accounts for a much larger fraction of deaths in these groups, up to 90%. Since these people contribute relatively little to total world fertility, the reductions in fertility would have to come from those groups who are likely to be the last ones to benefit from longevity treatment. This makes it more difficult to make longevity treatment conditional on strict measures to control fertility. Such measures are likely to be required to bring about the reductions in fertility that could significantly offset the large number of age-related deaths that would no longer occur. Yet, scenario (b) adds many subjective life-years in comparison to the status quo, or scenario (a). These life-years add value to the world on the view espoused here. This is because billions of subjective life-years that would otherwise not have existed would exist in scenario (b). Therefore, only if we have reason to believe that scenario (b) brings about unacceptable risks for a global or existential catastrophe is 4 The global replacement level is somewhat higher than the replacement level in OECD-countries (2.1) due to higher rates of infant and child mortality in poor countries. 5 Phys. Scr. 89 (2014) 128005 K Jebari 4. Additional concerns Thus, the geopolitical instability that such collapse could produce is much more dangerous than in previous collapses. Thomas Malthus was famously mistaken in his predictions of recurring population collapses, as was the most notable modern Malthusian, Paul Ehrlich. Agricultural technology averted the mass starvation that they predicted. However, there are some reasons to believe that the challenges posed by contemporary concerns are different. The risks in scenario (b) require that three challenges need to be addressed. First, it is a considerable technological challenge to provide food, water and electricity for a growing population. This includes technology to increase agricultural yields, store and generate large quantities of electricity, and so on. Proponents of longevity research are typically very optimistic on this issue. For example, Ray Kurzweil (director of engineering at Google) predicts that this will not be a problem [32]. Let us grant, for the sake of the discussion, this premise. The second challenge, to overcome social resistance to technology, is just as daunting. Futurists like Kurzweil seem to overlook the political and social challenges of implementing technology. For example, we already seem to have technology to decarbonize electricity production. Why is this technology not already in use? Huge amounts of fresh food are discarded in the EU and the US, even though a perfectly safe and effective technology has been available for decades that could drastically increase shelf-life: food irradiation. Genetically modified crops are still highly regulated in the EU, even though most mere possibility arguments concerning this technology have been answered adequately. Religious resistance against vaccines, condoms and other contraceptives shows that technology is only a necessary, and not a sufficient condition to address our Malthusian concerns. These suggestions illustrate the point that technologically plausible interventions are not necessarily socially plausible. It should be added that these technologies are not even implemented when they could avert large-scale disasters, as is the case with Golden Rice, a vitamin-fortified crop that, had it been adopted a decade ago, would have prevented the deaths of thousands of children [33]. The third challenge concerns the lack of political institutions with the legitimacy and ability to mobilize resources to deal with prevailing global problems. As Persson and Savulescu argue in their recent book, Western democracies seem ill-equipped to handle the problems of environmental stress [34]. It is true that democracies have shown a remarkable ability to act forcefully in the face of a sudden crisis. Yet this ability has not yet been demonstrated in dealing with the current environmental problems. How to build political institutions that are apt to deal with global problems remains an unsolved problem. Even if there were technology available to avoid a Malthusian scenario, the social and political challenges could prove insurmountable even in the absence of longevity treatment. In scenario (b) these challenges would be much worse. Such demographic collapse has never occurred on a global scale in a world with weapons of mass destruction. 5. Conclusions When dealing with potentially disruptive technological innovation, we cannot afford to wait and collect data to make a rigorous risk analysis. The risks involved require that we engage in enquiries in the possibilities even when such investigation requires some level of speculation. However, such speculation can be constrained by the heuristics proposed by Hansson. I have shown how this approach can be applied to the study of global catastrophic risks. 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