Three futures for Argentina: modelling the Nexus approach to harmonize decarbonation with biodiversity, ecosystem services and human health

Argentina is a relevant producer and exporter of food for near 400 million people. It is nowhere near as relevant as a GHG emitter, it emits 400 MTCO2eq per year (0.77% of the global total); near 41% (166 MtCO2eq) are emitted by food systems and land-use change. Paradoxically, this enormous amount of food does not correlate with a healthy diet for children and adolescents who will be the adults of 2050, and its production causes deforestation, pollution, loss of biodiversity and ecosystem services, water stress and an unbalanced redistribution of GDP. We have created the One Health Hub to model a trajectory inspired by the IPBES’ Nexus approach, which is much more comprehensive than the "carbon-centrism" of the dominant paradigm. Using a multi-model package, we have developed three future trajectories for Argentina: the current trend trajectory (CT), the National Commitments trajectory (NC), and the trajectory we propose in this work (GAPA1800). To this end, the team's doctors and nutritionists developed a healthy diet prescription for children and adolescents, (the so-called GAPA1800), modified from EAT-LANCET 2025 and the Dietary Guidelines for Argentina (GAPA), including a reduction in daily caloric food intake to 1800 kcal/day/person and intermittent afternoon and night fasting. We have assumed that these foods come from healthy production (agroecological, hydroponics, organic agriculture) and also from the stock from the discarding of food in the field for marketing reasons, approximately 30% of the harvested volume. In terms of biodiversity, we have carried out ecological niche models of 349 species of vertebrates threatened with extinction in Argentina, delimiting the Area of Habitat (AOH) using Maxent. We then calculate the number of hectares that are gained and lost in the AOH of each species in each trajectory to 2050. The trajectory GAPA1800, apart from being healthy, is the most beneficial for climate and biodiversity, contributes to improving SDG indicators 1, 2, 3, 10, 12, 13, and 15; between 60 and 100 Mt CO2eq/year are reduced; near 100 million hectares are gained in the AOH in comparison to the CT scenario and 40 million hectares are gained in comparison to the NC scenario.