1 Introduction
A number of catastrophic events could cause a roughly 10 % global agricultural shortfall, including a medium-sized asteroid/comet impact (Napier
2008), a large but not super volcanic eruption, full-scale nuclear war if the impacts are less than anticipated (Turco et al.
1990), regional nuclear war (for example, India-Pakistan (Özdoğan et al.
2013)), abrupt regional climate change (Valdes
2011), complete global loss of bees as pollinators (Aizen et al.
2009), a super crop pest or pathogen, and coincident extreme weather, resulting in multiple breadbasket failures (Bailey et al.
2015). Other events would not directly affect food production, but still could have similar impacts on human nutrition. Some of these include a conventional world war or pandemic that disrupts global food trade, and the resultant famine caused in food-importing countries (Keller
1992; Waldman
2001; Goodhand
2003). Other issues that do not affect food production directly include overreaction to oil prices, phosphorus prices, nitrogen prices, desertification, salinization, erosion, depletion of aquifers, and slow climate change (Ehrlich and Ehrlich
2013). These all could occur with concomitant price speculation, pricing the global poor out of food.
Generally, the technical solution for feeding everyone in these scenarios would be to (1) increase cultivated area; (2) reduce the amount of preharvest losses (for example, from pests and weeds) (Oerke
2006); (3) reduce yield underachievement (for example, because of insufficient fertilizers and not optimal plant varieties) (Foley et al.
2011); (4) reduce food wasted in the process of distribution (Godfray et al.
2010) and at the household level; and (5) reduce the use of edible food for the production of biofuels and feed for livestock and pets (Denkenberger and Pearce
2015). Another solution to these problems is storing more food, but this would be expensive and cannot be done rapidly without exacerbating hunger among the world’s destitute people (Baum et al.
2015). Thus, conventional approaches to a 10 % global agricultural shortfall would not be adequate to stop an escalation in current hunger-related disease and death (UNICEF
2006).
Recently, 10 alternative food solutions that do not involve conventional agriculture have been proposed for global catastrophes (Denkenberger and Pearce
2014). Here the solutions that would likely be the most relevant in the event of a 10 % agricultural shortfall are discussed (Table
1). One solution for an alternate is substituting for human edible animal feed using the commercially demonstrated technology that converts stranded (remote from markets) natural gas to animal feed using bacteria (Unibio
2014). Many other solutions involve converting agriculture and logging residues to food/feed. For cellulose digesters, such as cattle, sheep, and goats, as well as horses kept as pets, the practice of feeding excrement from other animals could be expanded. With this high-nitrogen food source, lower-nitrogen sources could be used in addition, such as agricultural residues that are not green and tree leaves that have been depleted of their nutrients and shed. For noncellulose digesting animals such as pigs, turkeys, and chickens, as well as cats and dogs kept as pets, discarded food waste can be used more extensively; this is a new solution that was not very relevant for the 100 % agricultural shortfall studied previously (Denkenberger and Pearce
2014). Although much of the current food waste is appropriate for human consumption, even food that is regarded as spoiled by human standards could be acceptable for animals (Henneberg
1998).
Table 1
Human food sources and the alternate feedstock inputs for these foods
Cattle, sheep, goats, horses | Natural gas digesting bacteria, excrement, leaf litter, agricultural residues, wood residue from growing mushrooms |
Pigs, turkeys, chickens, cats, and dogs | Food discarded by humans, natural gas digesting bacteria |
Leaf tea | Green leaves and agricultural residues |
Mushrooms | Woody residues |
Sugar produced by enzymes | Leaf litter, agricultural residues |
Fish | Algae grown because of ocean fertilization |
The difficulty of providing solutions is reduced for such a relatively small percentage of agricultural shortfall. Ideally, solutions would require minimum lifestyle changes for everyone. A way of doing this is finding alternate feed sources for livestock and pets. Grains make up about half of global calorie production (Meadows et al.
2004) and livestock consume 35 % of the world’s grain (Earth Policy Institute
2011). Therefore, if grains were completely replaced with alternate feed sources in animal diets, this could make up for an 18 % global agricultural shortfall and would be more than sufficient for a 10 % global agricultural shortfall. This solution, however, does not even account for the possibility of substituting non-grain edible food used as animal feed (though animal only-feed such as grass could be impacted by the catastrophe).
Another range of options enables direct human food production from tree-related biomass, such as extracting sustenance from leaves (for example, pine needle tea) (Kim and Chung
2000), and mushrooms growing on woody residues. The waste from this process can be fed to cellulose digesting animals (Spinosa
2008). Another alternative direct mechanism for providing human food from conventionally non-food sources is utilizing current cellulosic biofuel techniques. For example, enzymes could be used on agricultural residues to create human edible sugars (Langan et al.
2011). With the reclamation of nutrients from excrement and food waste and the possible injection of new nutrients into the food system from leaf litter, for example, the need for artificial fertilizer would fall. This would enable macronutrient (for example, nitrogen) fertilization of part of the ocean, which could allow significant ramping of fish harvesting (Denkenberger and Pearce
2015). Many of these alternate food sources may be valuable even outside a catastrophe for reducing the world’s current undersupply of food (FAO
2015) to the poorest people (Gwatkin
1980).
A 10 % global agricultural shortfall would roughly triple the price of grain (Bailey et al.
2015), which would be expected to aggressively exacerbate global food insecurity. Many of these alternate food solutions, if ramped up quickly to cover a 100 % agricultural shortfall individually, could be much more expensive than the new high grain price. However, in a 10 % agricultural shortfall, each food source would only have to provide a relatively small amount of food. Therefore, less extreme measures would have to be taken, lowering the cost. These costs, however, have not been quantified. Neither has the cost of each of the alternative foods been quantified as a function of preparation and planning, research and development, and training.
In order to overcome this knowledge gap and provide planners with better cost estimates on various alternative food interventions, an analysis was performed here with a numerical model to estimate the cost-effectiveness of (1) planning at the international level; (2) investing in research including experiments to prove the concepts; (3) the development of the technologies to demonstrate scalability; and (4) the training of professionals and citizens. For each of the four interventions, five cost-effectiveness measures were calculated: cost per life saved, benefit to cost ratio, net present value, payback time, and internal rate of return. The results are discussed and conclusions are drawn about the cost-effectiveness of food security preparations for global catastrophes.
3 Results and Discussion
The credible intervals are increased as multiple variables are combined. This means that the reliability of the final result is the same as the reliability of the input intervals. Table
3 shows the 95 % credible interval for the five cost-effectiveness measures for each of the four interventions. The 2.5 percentile row has all the lower values in the distribution, and the 97.5 percentile row has the higher values. Sometimes low values indicate high cost-effectiveness, and sometimes they indicate low cost-effectiveness, so there is not a consistent scenario across the row. For the plan, research, and development, even the upper bound of USD 400 per life saved is significantly lower than the minimum that is paid to save a life in global poverty. Many of these alternative food interventions are able to provide greater food security to the world’s most destitute now. The value of these lives saved (which could amount to over 17,000 lives/day) was not factored into the calculations here, making all of these calculations exceptionally conservative. With the very high benefit to cost ratio, only investing millions of dollars yields billions or even trillions of dollars of benefits. The strikingly short time to pay back the investment once the project is completed demonstrates the urgency of completing these projects. In reality, to maximize benefit, it would make sense to spend more money to accelerate the project, including having interim deliverables.
Table 3
95 % credible interval for the five cost-effectiveness measures for each of the four interventions
Plan | 2.5 percentile | 0.3 | 30 | 0.2 | 0.00,002 | 400 |
97.5 percentile | 300 | 500,000 | 2000 | 0.3 | 5000,000 |
Research | 2.5 percentile | 0.3 | 20 | 0.8 | 0.00,006 | 100 |
97.5 percentile | 400 | 400,000 | 10,000 | 0.7 | 2000,000 |
Development | 2.5 percentile | 0.2 | 20 | 0.8 | 0.00,003 | 100 |
97.5 percentile | 400 | 700,000 | 20,000 | 0.7 | 3000,000 |
Training | 2.5 percentile | 200 | 0.02 | −60 | 0.02 | 0.2 |
97.5 percentile | 700,000 | 500 | 10,000 | 600 | 5000 |
Full-scale training is significantly less cost-effective because it is so much more expensive than the other options. Still, the median cost per life saved is USD 6000, which is similar to the best global poverty interventions such as mosquito bed nets for malaria prevention (GiveWell
2015a). Therefore, it is likely beneficial to implement at least some training activities. The opportunity cost of not implementing these interventions was estimated. The probability of feeding everyone given no interventions was subtracted from the probability of success given all four interventions, truncated at an improvement of 4 % (the sum of the individual minimum improvements). The result was that every day delay of the implementation of these interventions costs 10 to 40,000 expected lives. Overall, the four interventions taken together would save between 1 million and 300 million lives.
For the costs per life saved, the mortality of the catastrophe without alternate foods was the most important input variable by a significant margin. However, the other cost-effectiveness metrics depended on the statistical value of life, while the costs per life saved do not. For these other cost-effectiveness metrics, the most important variable was the statistical value of life. For this sensitivity analysis, the mortality of the catastrophe without alternate foods is made into an independently sampled probabilistic parameter, with values of 20 million, 200 million, and 2 billion. Similarly, the values used for the statistical value of life are USD 1000, USD 30,000, and USD 1 million. Besides the statistical value of life not affecting the cost per life saved, these variations affect all 20 cost-effective measures in the same way. The NPV value of the plan is chosen to illustrate the effect in Table
4. When the mortality is being varied, the statistical value of life retains its regular distribution. Similarly, when the statistical value of life is being varied, the mortality retains its regular distribution. The variation in NPV due to these sensitivity studies is smaller than the variation in cost per life saved due to the independent variation of all the input variables. Therefore, the distributions shown in Table
3 can be thought of as a form of sensitivity analysis.
Table 4
Plan cost per life saved sensitivity with respect to mortality and VSL
20 million | 20 | $1000 | 2 |
200 million | 200 | $30,000 | 70 |
2 billion | 2000 | $1 million | 2000 |
The planning and research can be done in parallel. The development should be done after the research in order to focus on the feed organisms that are most promising. The expected mean cost-effectiveness of training is still good, and this could be done in parallel with development. Seen as a program, the first year could be a few tens of millions of dollars to plan and research. Then successive years could be billions of dollars per year, mostly for training, but a little for development.
These solutions would reduce the possibility of civilization collapse. If civilization collapsed, it is not guaranteed that it would recover, so it could affect many future generations (Beckstead
2013). These considerations further demonstrate how conservative the analysis is. These solutions could also protect biodiversity (Baum et al.
2016). If there were mass starvation, not only would few humans care about protecting other species from the impacts of the catastrophe, but humans would actively eat some species to extinction. Clearing land to expand conventional agriculture would negatively affect biodiversity. Therefore, alternate foods, by reducing the chance of mass starvation, would have important environmental benefits.
There are also catastrophes that could cause order of magnitude 100 % agricultural shortfall for years, such as a large asteroid/comet impact (Napier
2008), a super volcanic eruption (Rampino
2008), and nuclear winter. These are generally lower probability events. Globally there is less than 1 year of food storage (Do et al.
2010), so alternate food would be required to feed everyone. The economics of interventions in this case have been analyzed for the United States, but future work is needed to analyze the economics of interventions for this case globally. Since many of the interventions for the order of magnitude 10 % agricultural shortfalls would ameliorate the order of magnitude 100 % agricultural shortfalls, this further underscores the conservatism of the cost-effectiveness of these interventions. Additional work is also needed to quantify the value of developing alternative food approaches now to help reduce mortality from hunger and hunger-related diseases in the present.
The limitations of this study were primarily the lack of data that resulted in sometimes large ranges in the variables. Future work is needed to better focus the analysis and to reduce the uncertainties. For example, experiments on a few of the alternative foods could provide more robust values of study duration, which would provide a tighter range on the costs of research.