International food trade benefits biodiversity and food security in low-income countries

Artificial intelligence can regulate light and climate systems to reduce energy use in plant factories and support sustainable food production

Plant factories with artificial lighting (PFALs) can boost food production per unit area but require resources such as carbon dioxide and energy to maintain optimal plant growth conditions. Here we use computational modelling and artificial intelligence (AI) to examine plant-environment interactions across ten diverse global locations with distinct climates. AI reduces energy use by optimizing lighting and climate regulation systems, with energy use in PFALs ranging from 6.42 kWh kg-1 in cooler climates to 7.26 kWh kg-1 in warmer climates, compared to 9.5-10.5 kWh kg-1 in PFALs using existing, non-AI-based technology. Outdoor temperatures between 0 °C and 25 °C favour ventilation-related energy use reduction, with outdoor humidity showing no clear pattern or effect on energy use. Ventilation-related energy savings negatively impact other resource utilization such as carbon dioxide use. AI can substantially enhance energy savings in PFALs and support sustainable food production.

Did the International Trade in Crops Lead to Global Cropland Saving or Wasting in the Period 2000-2022?

The international food trade is beneficial for enhancing global food security but also raises issues such as global cropland redistribution, land use efficiency, and environmental problems. While current studies have examined the impacts of the international food trade on these issues, its long-term effects on global cropland use efficiency remain unclear, especially when considering different crops and countries. Utilizing the international trade theory and the principle of virtual cropland, this study explores the relationship between international food trade and global cropland use efficiency from 2000 to 2022. The results illustrate that the global crop trade surged by 142%, outpacing the 102% increase in virtual cropland trade, which was attributed to crop yield enhancements. By 2022, the global virtual cropland trade encompassed 10.7% of the total croplands, with China emerging as the foremost importer, particularly due to soybean imports. Notably, the global crop trade led to substantial cropland savings and higher cropland use efficiency, totaling 1244.9 million hectares (Mha) between 2000 and 2020. These gains were largely attributed to the superior yields of major crop-exporting countries. Despite these gains, socio-economically vulnerable countries face significant challenges, potentially compromising their food security amidst the complexities of the global trade dynamics.

Biodiversity loss through cropland displacement for urban expansion in China

As a result of rapid economic development, urban expansion reduced the cropland in China. To secure the food supply, cropland displacement to maintain the quantity and quality of cropland has been implemented. Here, we quantified the biodiversity losses due to cropland displacement resulting from urban expansion from a telecoupling perspective in China from 1980 to 2020. A comprehensive multimodel assessment demonstrated that the indirect biodiversity losses due to cropland displacement resulting from urban expansion were approximately 2 to 3 times higher than its direct biodiversity losses, at a total loss of approximately 0.6 % to 1.0 %, as indicated by three biodiversity indicators. Displaced cropland with a higher biodiversity cost but lower cropland productivity is the main reason for the excessive indirect losses and suggests that socioecological processes may be detrimental to the synergistic benefits of the UN Sustainable Development Goal (SDG) for food security and terrestrial biodiversity. This study also identified source-sink hotspots for indirect biodiversity losses, which can contribute to improving biodiversity conservation, optimizing the spatial distribution of cropland and thus enhancing socioecological system sustainability.

Leveraging the metacoupling framework for sustainability science and global sustainable development

Sustainability science seeks to understand human-nature interactions behind sustainability challenges, but has largely been place-based. Traditional sustainability efforts often solved problems in one place at the cost of other places, compromising global sustainability. The metacoupling framework offers a conceptual foundation and a holistic approach to integrating human-nature interactions within a place, as well as between adjacent places and between distant places worldwide. Its applications show broad utilities for advancing sustainability science with profound implications for global sustainable development. They have revealed effects of metacoupling on the performance, synergies, and trade-offs of United Nations Sustainable Development Goals (SDGs) across borders and across local to global scales; untangled complex interactions; identified new network attributes; unveiled spatio-temporal dynamics and effects of metacoupling; uncovered invisible feedbacks across metacoupled systems; expanded the nexus approach; detected and integrated hidden phenomena and overlooked issues; re-examined theories such as Tobler's First Law of Geography; and unfolded transformations among noncoupling, coupling, decoupling, and recoupling. Results from the applications are also helpful to achieve SDGs across space, amplify benefits of ecosystem restoration across boundaries and across scales, augment transboundary management, broaden spatial planning, boost supply chains, empower small agents in the large world, and shift from place-based to flow-based governance. Key topics for future research include cascading effects of an event in one place on other places both nearby and far away. Operationalizing the framework can benefit from further tracing flows across scales and space, uplifting the rigor of causal attribution, enlarging toolboxes, and elevating financial and human resources. Unleashing the full potential of the framework will generate more important scientific discoveries and more effective solutions for global justice and sustainable development.

Global decadal assessment of life below water and on land

The United Nations (UN) has adopted the 17 Sustainable Development Goals (SDGs), aiming to provide human welfare and conserve the planet, now and into the future. Two of the SDGs directly address biodiversity conservation and sustainable development - SDG 14 (life below water) and SDG 15 (life on land). Although the UN has issued annual reports on SDGs, the reports did not consistently reveal the progress over time, because of inconsistent methods such as estimation based on different indicators across years. Our research examined the dynamics of the same 10 indicators for SDGs 14 and 15 between 2010 and 2020. Results indicate that the overall SDG 14 scores had a small growth between 2010 and 2020, whereas the substantial increase in SDG 15 scores spotlighted the conservation efforts and sustainable use of terrestrial ecosystem services, especially in countries with biodiversity hotspots. Globally, there was more progress in terms of SDG 15 scores during 2015-2020 than during 2010-2015 (before the UN adopted SDGs in 2015). Surprisingly, SDG 14 score had smaller progress during 2015-2020 than during 2010-2015. Special attention should be given to low-income countries lagging in sustainable development performance when implementing the post-2020 global biodiversity framework.

Freshwater species diversity loss embodied in interprovincial hydroelectricity transmission with ecological network analysis

A major strategy for addressing the imbalance in source-network-load distribution is interprovincial electricity transmission; however, this process also causes various environmental effects. Previous studies have mainly examined thermal power transmission, and few insights have been gained into the challenges hydroelectricity transmission poses for biodiversity conservation. Here, we innovatively incorporated the freshwater species diversity footprint into a hydropower environmental impact assessment, calculating the interprovincial transfer of freshwater species diversity embodied in hydroelectricity transmission. We proposed an evaluation model of an interprovincial hydroelectricity transmission network using freshwater species diversity as the ecological element and creatively identified significant nodes and paths of the network. Up to 28% of the transfer of freshwater species diversity was related to the demand for hydroelectricity consumption in Shanghai. 64% of the relationships in the hydroelectricity transmission network were implemented at the expense of ecological losses on one side. Shanghai and Sichuan provinces and some transmission lines related to them were significant nodes and paths for improving the overall status of the network. This research can help policymakers comprehend the challenges to freshwater species presented by interprovincial hydroelectricity transmission and serve as a reference for ecological compensation for hydropower development.

Effects of global shocks on the evolution of an interconnected world

As the world grows more interconnected through the flows of people, goods, and information, many challenges are becoming more difficult to address since human needs are increasingly being met through global supply chains. Global shocks (e.g., war, economic recession, pandemic) can severely disrupt these interconnections and generate cascading consequences across local to global scales. To comprehensively evaluate these consequences, it is crucial to use integrated frameworks that consider multiple interconnections and flows among coupled human and natural systems. Here we use the framework of metacoupling (human-nature interactions within as well as across adjacent and distant systems) to illustrate the effects of major global shocks on the evolution of global interconnectedness between the early 1900s and the 2010s. Based on these results we make a few actionable recommendations to reduce the negative impacts of an ongoing global shock, the COVID-19 pandemic, to promote global sustainability.

Navigating Chinese cities to achieve sustainable development goals by 2030

Achieving the 17 United Nations sustainable development goals (SDGs) in China largely depends on the transition of cities toward sustainable development. However, significant knowledge gaps exist in evaluating the SDG index at the city scale and in understanding how to simulate pathways to achieve the 17 SDGs for Chinese cities by 2030. This study aimed to quantify the SDG index of 285 Chinese cities and developed a forecasting model to simulate the performance of each SDG in each city until 2030 using varied scenarios. The results indicated that although the SDG index in Chinese cities increased by 33.97% during 2005-2016, Chinese cities, which continued their past paths, achieved an average of only five SDGs by 2030. To promote the joint achievement of all SDGs, we designed different paths for all SDGs of each of the 285 cities and simulated their SDG index until 2030. Under the scenarios, 216 Chinese cities (75.79%) could achieve 9-13 more SDGs in 2030 and the overall SDG index can improve from 74.57 in 2030 to 97.49 (target score 100) by adopting more intensive path adjustment. We lastly determined a cost-effective path for each SDG of each city to promote joint achievement of all SDGs by 2030. The proposed simulation model and cost-effective path serve as a foundation for other countries to simulate SDG progress and develop pathways for achieving SDGs in the future.