Nuclear Winter

This study determines the nuclear pragmatic limit where the direct physical negative consequences of nuclear weapons use are counter to national interests, by assuming all unknowns are conservatively optimistic. The only effect considered is nuclear winter (" nuclear autumn " in the low weapons limits) and the resultant effects on the aggressor nation. First, the ability of low nuclear weapon limits is probed for maintaining deterrence in the worst-case scenario of attacking the most-populous nation. Second, the ability of aggressor nations to feed themselves is assessed without trade and industry resultant from a nuclear attack causing " nuclear autumn " (10% global agricultural shortfall). Third, the best-case wealthy aggressor nation with abundant arable land is analyzed for starvation and economic impacts given 7000, 1000, and 100 nuclear weapons scenarios. The results found that 100 nuclear warheads is adequate for nuclear deterrence in the worst case scenario, while using more than 100 nuclear weapons by any aggressor nation (including the best positioned strategically to handle the unintended consequences) even with optimistic assumptions (including no retaliation) would cause unacceptable damage to their own society. Thus, 100 nuclear warheads is the pragmatic limit and use of government funds to maintain more than 100 nuclear weapons does not appear to be rational.

Abrupt sunlight reduction scenarios (ASRS) following catastrophic events, such as a nuclear war, a large volcanic eruption or an asteroid strike, could prompt global agricultural collapse. There are low-cost foods that could be made available in an ASRS: resilient foods. Nutritionally adequate combinations of these resilient foods are investigated for different stages of a scenario with an effective response, based on existing technology. While macro-and micronutrient requirements were overall met, some-potentially chronic-deficiencies were identified (e.g., vitamins D, E and K). Resilient sources of micronutrients for mitigating these and other potential deficiencies are presented. The results of this analysis suggest that no life-threatening micronutrient deficiencies or excesses would necessarily be present given preparation to deploy resilient foods and an effective response. Careful preparedness and planning-such as stock management and resilient food production ramp-up-is indispensable for an effective response that not only allows for fulfilling people's energy requirements, but also prevents severe malnutrition.

The literature suggests there is ~0.3 percent chance per year of full-scale nuclear war. This event would have ~20 percent probability of causing U.S. mass starvation due to collapse of conventional agriculture from smoke blocking the sun. Alternate foods exploit fossil fuels (e.g. methane digesting bacteria) and stored biomass (e.g. mushrooms growing on dead trees) and are technically capable of saving all Americans from starving. However, current awareness is low and the technologies need to be better developed. This Monte Carlo study investigates the economics of three interventions including planning, research and development. Even the upper bound of $20,000 per life saved is far lower than the millions of dollars typically paid to save an American life. Therefore, it should be a high priority to implement these interventions as they would improve American resilience and reduce the possibility of civilization collapse.

Many global catastrophic risks threaten major disruption to global food supplies, including nuclear wars, volcanic eruptions, asteroid and comet impacts, and plant disease outbreaks. This paper discusses options for increasing the resilience of food supplies to these risks. In contrast with local catastrophes, global food supply catastrophes cannot be addressed via food aid from external locations. Three options for food supply resilience are identified: food stockpiles, agriculture, and foods produced from alternative (non-sunlight) energy sources including biomass and fossil fuels. Each of these three options has certain advantages and disadvantages. Stockpiles are versatile but expensive. Agriculture is efficient but less viable in certain catastrophe scenarios. Alternative foods are inexpensive pre-catastrophe but need to be scaled up post-catastrophe and may face issues of social acceptability. The optimal portfolio of food options will typically include some of each, and will additionally vary by location as regions vary in population and access to food input resources. Furthermore, if the catastrophe shuts down transportation, then resilience requires local self-sufficiency in food. Food supply resilience requires not just the food itself, but also the accompanying systems of food production and distribution. Overall, increasing food supply resilience can play an important role in global catastrophic risk reduction. However, it is unwise to attempt maximizing food supply resilience, because doing so comes at the expense of other important objectives, including catastrophe prevention. Taking all these issues into account, the paper proposes a research agenda for analysis of specific food supply resilience decisions.

Purpose

During a global catastrophe such as a nuclear winter, in which sunlight and temperatures are reduced across every latitude, to maintain global agricultural output it is necessary to grow some crops under structures. This study designs a method for scaling up crop production in low-tech greenhouses to contribute to global food sustainability during global catastrophic conditions. Constructing low-tech greenhouses would obviate growing crops using more expensive and energy intensive artificial light.

Methods

A nuclear winter climate model is used to determine conditions for which greenhouses would need to compensate. The greenhouse structures are designed to utilize global markets of timber, polymer film, construction aggregates, and steel nails.

Results

The limiting market that determines the growth rate of the greenhouses is the rate at which polymer film and sheet are currently extruded. Conditions under low-tech greenhouses in the tropics would feasibly accommodate the production of nearly all crops. Some supplemental lighting would be required for long day crops.

Conclusions

The analysis shows that the added cost of low-tech greenhouses is about two orders of magnitude lower than the added cost of artificial light growth. The retail cost of food from these low-tech greenhouses will be ~2.30 USD/kg dry food higher than current costs; for instance, a 160% retail cost increase for rice. According to the proposed scaling method, the greenhouses will provide 36% of food requirements for everyone by the end of the first year, and feed everyone after 30 months.