2.2.6.2 Food security

Food systems are highly vulnerable to tipping point impacts as they are affected by multiple environmental dimensions, with particular sensitivity to precipitation and temperature (Figure 2.2.8). Agricultural systems are strongly sensitive to changes in the functioning of a wide range of supporting systems in soil, water, pollination and natural pest suppression. Rapid environmental changes threaten to disrupt such functions in ways that are likely to impair agricultural production (Benton et al., 2017). The global food system is also a potential amplifier of tipping point impacts as it sits within a complex set of interacting biophysical and social systems. For example, ocean current tipping elements such as AMOC and the North Atlantic Subpolar Gyre could have immediate impacts on food production. Moreover, harvest failures occurring simultaneously in more than one major crop-producing region would pose a major threat to global food security (Kornhuber et al., 2023). Significant reductions in global production are likely to produce wide-ranging social, economic and political disturbance (Gaupp, 2020). Consequently, the activation of climate tipping elements could drive significant structural changes in agriculture, with profound consequences for global food security (Benton, 2020).

An AMOC collapse could have significant impacts on food production through various pathways. Impacts on crop productivity could be negative in many regions but positive in others, with overall global net primary productivity simulated to reduce by 5 per cent (Vellinga and Wood, 2002). Crop productivity in Europe would decrease due to colder and drier conditions (Jackson et al., 2015). Rainfall reductions in Britain due to AMOC collapse are simulated to be too large for irrigation to be economically feasible as a mitigation measure (Ritchie et al., 2020). 

Tipping elements in the cryosphere have the potential to produce regional to global impacts on food systems. (Defrance et al., 2017) suggested that the loss of significant ice mass from the Greenland Ice Sheet could lead to droughts and significant disruption to agriculture in the Sahel region by reducing West African monsoon rainfall. Kwiatkowski et al., (2019) projected how Greenland Ice Sheet loss could reduce primary productivity in the North Atlantic. 

An AMOC collapse could also have large impacts on the marine ecosystem and consequently marine food systems by causing a large reduction of plankton in the Atlantic (Schmittner, 2005), potentially affecting the development of fish. Economic impacts on key Barents Sea fisheries and economies are one possible outcome from a reduction in the strength of the AMOC (Link and Tol, 2009).