Stories 1 - MAgPIE stories #1

The transition to more sustainable diets is critical to achieve the Sustainable Development Goals and meet the Paris Agreement commitments. In China, this transition is particularly urgent due to the double burden of malnutrition and environmental degradation. In this study, we explored the potential of alternative diets in China to enhance public health, ensure food affordability and reduce adverse environmental impacts. We assessed these patterns through a multi-objective diet optimization model combined with MAgPIE-China, which captures key socio-economic and biophysical dynamics in China. The proposed healthy, affordable and low-environmental-impact diets substantially improve dietary quality and are projected to reduce food expenditures by 20–28% (US$128–186 capita−1 in power purchasing parities of 2005) by 2050. These diets also bring environmental benefits, including a 3–11% (4–13 Mha) expansion of non-forest natural vegetation area and modest biodiversity gains.

Target 3 of the Kunming-Montreal Global Biodiversity Framework (GBF) aims to conserve 30% of global land, inland waters and seas by the year 2030. An important question is which areas we wish to protect. Here we present a plan to explore three scenarios which distribute the conservation responsibility - geographically and politically - in three different ways. We use an algorithm from Jung et al., Nat Ecol Evol (2021), which minimizes the extinction risk for terrestrial vertebrates and plants. In the first scenario, called “global”, we find the globally most critical 30% of land area. The second scenario, called “national”, distributes the responsibility evenly across each country, while the third scenario, called “biome”, instead chooses to distribute the conservation responsibility evenly across biogeographical realms of nature (tropical forest, grasslands, etc). This work demonstrates MAgPIE’s powerful spatial data pre-processing capabilities and the Land Conservation module.

The Scenario Model Intercomparison Project (ScenarioMIP) for CMIP7 aims to deliver the next generation of emissions, land-use, climate change, and climate impact projections that are consistent across research communities. It proposes a limited set of scenarios spanning a wide and plausible range. Beginning with qualitative descriptions of alternative futures, integrated assessment models derive emission projections and land-use patterns based on a detailed representation of the energy and land system. These serve as input for Earth system models to simulate future climate change. By incorporating both climate-related and direct human forcers, consistent projections of climate impacts can be produced. This integrative role across research communities puts ScenarioMIP in a unique position to address policy-relevant research questions and provide crucial input for the IPCC AR7. We provide an overview of the ScenarioMIP process and present preliminary REMIND-MAgPIE results.

Food systems are essential for the achievement of the United Nations Sustainable Development Goals in China. Here, using an integrated assessment modelling framework that considers country-specific pathways and covers 18 indicators, we find that most social and environmental targets for the Chinese food system under current trends are not aligned with the United Nations Agenda 2030. We further quantify the impacts of multiple measures, revealing potential trade-offs in pursuing strategies aimed at public health, environmental sustainability and livelihood improvement in isolation. Among the individual packages of measures, a shift towards healthy diets exhibits the lowest level of trade-offs, leading to improvements in nutrition, health, environment and livelihoods. In contrast, focusing efforts on climate change mitigation and ecological conservation, or promoting faster socioeconomic development alone, have trade-offs between social and environmental outcomes.