This is a linkpost for International risk of food insecurity and mass mortality in a runaway global warming scenario by C.E. Richards, H.L. Gauch, and J.M. Allwood, published on June 2023. The abstract, factors over and underestimating starvation, and my quick overall take are below.

Abstract

Climate and agriculture have played an interconnected role in the rise and fall of historical civilizations. Our modern food system, based on open-environment production and globalised supply chains, is vulnerable to a litany of abiotic and biotic stressors exacerbated by anthropogenic climate change. Despite this evidence, greenhouse gas emissions continue to rise. Current trajectories suggest global warming of ∼2.0–4.9 °C by 2100, however, a worst-case emissions scenario with rapid combustion of all available fossil fuels could cause a rise of ∼12 °C. Even if emissions decline, unprecedented atmospheric CO₂-e concentrations risk triggering tipping points in climate system feedbacks that may see global warming exceed 8 °C. Yet, such speculative ‘runaway global warming’ has received minimal attention compared to mainstream low- to mid-range scenarios. This study builds on The Limits to Growth to provide new insights into the international risk of mass mortality due to food insecurity based on a higher-resolution illustration of World3’s ‘runaway global warming’ scenario (∼8–12 °C+). Our simulation indicates rapid decline in food production and unequal distribution of ∼6 billion deaths due to starvation by 2100 [or is it 5 billion^[1]?]. We highlight the importance of including high-resolution simulations of high-range global warming in climate change impact modelling to make well-informed decisions about climate change mitigation, resilience and adaptation.

Factors overestimating starvation

Holding land use constant^[2]:

We sourced grid cell data on land use classifications for the base year (2020)—noting that we hold land use constant in preparing this dataset as crop land growth is accounted for separately—from Chen et al. (2020).

Not including all sources of food:

This approach—as adopted by other studies (e.g., Hasegawa et al. (2021)) for computational simplicity, and where crops constitute ∼90 % of human food energy intake (Su et al., 2017)—accounts for conventional crop-based agriculture but does not include aquaculture, animal-based agriculture (though

...

Climate risk skepticism

Related entries

Further reading