Food Security after Nuclear Winter: A Preliminary Agricultural Sector Analysis for Aotearoa New Zealand

Abstract

We aimed to estimate the dietary energy content of food exports in the business-as-usual situation for Aotearoa New Zealand (NZ) and then its contribution to food security after a potential nuclear war-induced “nuclear winter”. From published sources we estimated dietary energy available from the major domains of food exports, with adjustments for wastage. We specifically considered a severe case nuclear winter model by Xia et al (2021) ie, 150 Tg of soot ejected into the stratosphere. We found that the current NZ population has an estimated dietary energy intake of 44.4 billion kJ per day (8686 kJ per person per day). Current major food exports are equivalent to 3.9 times this amount ie, 34,100 kJ (8150 kcal) per person per day. Exported dairy products were estimated to be able to provide 338% of all the current dietary energy, followed by exports of: meat (34%); fruit (8.6%), alcohol (4.8%), marine products (4.6%), and vegetables (2.7%). After a severe case nuclear winter scenario that reduced food production by 58%, there would still be 1.7 times current daily intakes available from diverted exported foods (or 14,321 kJ [3423 kcal] per person per day). In conclusion, this country appears to have excess food production capacity even after a severe case nuclear winter scenario that more than halved food production. Nevertheless, NZ Government planners could build the resilience of the country’s food systems and plan to ensure that food can be fairly distributed with the likely accompanying post-war collapse of the global trading economy.

Impact of the Tambora volcanic eruption of 1815 on islands and relevance to future sunlight-blocking catastrophes

“…But other considerations for island refuge location are the findings of simulation studies of the global climate impacts of nuclear war (see “ Introduction ” section), and the risk of islands being directly attacked in a nuclear war (e.g., those in military alliances with nuclear weapon states such as Australia, Iceland and Japan). Other relevant features of island refuges include excess food production capacity 8 , 53 , capacity to survive extreme pandemics 18 , and to have the socio-economic and technological characteristics to be a “node of persisting complexity” 17 .…”

Island refuges for surviving nuclear winter and other abrupt sun-reducing catastrophes

“…The 1980s models indicated that pasture growth might reduce by 34-66% in spring months according to location, or by 19-36% for the year (Green, 1989). However, this would not reduce New Zealand's food production below 2,200 kcal/capita/day, given baseline DEP of 9,570 kcal/capita/day (Schramski et al, 2019), including currently exported food totalling at least 8,150 kcal/capita/day (accounting for wastage) (Wilson et al, 2022). Diverted export dairy alone (eg, milk powder, cheese and butter) could provide 142% of dietary energy requirements in a 150 Tg scenario (Wilson et al, 2022).…”

“…This modelling covered most countries in the world, modelled crops and marine sh, and modelled six nuclear winter scenarios ranging from 5 Tg to 150 Tg. We identi ed all the island nations in Xia et al's analysis, and then obtained independent assessments of baseline dietary energy production (DEP) from two sources (1) peer-reviewed analysis of global food production, namely 2013 DEP (Schramski et al, 2019), and (2) our own bottom-up calculation of DEP for New Zealand exports using the Statistics New Zealand Harmonised System for export data (Wilson, Prickett, & Boyd, 2022). We then applied the modelled calorie reduction (%) results obtained by Xia et al for the major crops and marine sh averaged over the rst ve years for 5, 27 and 150 Tg nuclear war scenarios, to these independent estimates of DEP.…”

Island refuges for surviving nuclear winter and other abrupt sun-reducing catastrophes

“…The 1980s models indicated that pasture growth might reduce by 34-66% in spring months according to location, or by 19-36% for the year (Green, 1989). However, this would not reduce New Zealand's food production below 2,200 kcal/capita/day, given baseline DEP of 9,570 kcal/capita/day (Schramski et al, 2019), including currently exported food totalling at least 8,150 kcal/capita/day (accounting for wastage) (Wilson et al, 2022). Diverted export dairy alone (eg, milk powder, cheese and butter) could provide 132% of dietary energy requirements in a 150 Tg scenario (Wilson et al, 2022).…”

“…This modelling covered most countries in the world, modelled crops and marine sh, and modelled six nuclear winter scenarios ranging from 5 Tg to 150 Tg. We identi ed all the island nations in Xia et al's analysis, and then obtained independent assessments of baseline dietary energy production (DEP) from two sources (1) peer-reviewed analysis of global food production, namely 2013 DEP (Schramski et al, 2019), and (2) our own bottom-up calculation of DEP for New Zealand exports using the Statistics New Zealand Harmonised System for export data, in which we converted export tonnage into food energy availability, accounting for published estimates of wastage (Wilson, Prickett, & Boyd, 2022). We then applied the modelled calorie reduction (%) results obtained by Xia et al for the major crops and marine sh averaged over the rst ve years for 5, 27 and 150 Tg nuclear war scenarios, to these independent estimates of DEP.…”