Revisiting the application and methodological extensions of the planetary boundaries for sustainability assessment

Multi-objective ecological restoration priority in China: Cost-benefit optimization in different ecological performance regimes based on planetary boundaries

In the context of the "United Nations Decade on Ecosystem Restoration", optimizing spatiotemporal arrangements for ecological restoration is an important approach to enhancing overall socioecological benefits for sustainable development. However, against the background of ecological degradation caused by the human use of most natural resources at levels that have approached or exceeded the safe and sustainable boundaries of ecosystems, it is key to explain how to optimize ecological restoration by classified management and optimal total benefits. In response to these issues, we combined spatial heterogeneity and temporal dynamics at the national scale in China to construct five ecological performance regimes defined by indicators that use planetary boundaries and ecological pressures which served as the basis for prioritizing ecological restoration areas and implementing zoning control. By integrating habitat conservation, biodiversity, water supply, and restoration cost constraints, seven ecological restoration scenarios were simulated to optimize the spatial layout of ecological restoration projects (ERPs). The results indicated that the provinces with unsustainable freshwater use, climate change, and land use accounted for more than 25%, 66.7%, and 25%, respectively, of the total area. Only 30% of the provinces experienced a decrease in environmental pressure. Based on the ecological performance regimes, ERP sites spanning the past 20 years were identified, and more than 50% of the priority areas were clustered in regime areas with increased ecological stress. As the restoration area targets doubled (40%) from the baseline (20%), a multi-objective scenario presents a trade-off between expanded ERPs in areas with highly beneficial effects and minimal restoration costs. In conclusion, a reasonable classification and management regime is the basis for targeted restoration. Coordinating multiple objectives and costs in ecological restoration is the key to maximizing socio-ecological benefits. Our study offered new perspectives on systematic and sustainable planning for ecological restoration.

Resource efficiency analysis through planetary boundary-based life cycle assessment: a case study of sugarcane in Pakistan

Purpose

Extensive agriculture activities for crop production have led to increasing environmental impacts that threaten to exceed environmentally safe limits. The purpose of this study is to analyze resource efficiency of the agri-food industry, considering the case of sugarcane production in Pakistan.

Methods

A holistic approach has been applied by determining the relevant impact categories and Sustainable Development Goals (SDGs), and linking them with Planetary Boundary-based Life Cycle Assessment (PB-LCA). Both the spatially generic and spatially resolved approaches were considered with application of different sharing principles.

Results and discussion

Application of different sharing principles showed high variations in the assigned share of the safe operating space values. When taking a spatially generic approach, most of the impacts (except marine eutrophication and water consumption) were within the safe operating space for equal per capita, economic, caloric, and grandfathering sharing principles. However, all the impacts exceeded their limits considering the agri-land sharing and land use impact surpassed its budget considering the grandfathering sharing. In the spatially resolved approach, most of the impact values surpassed the available budgets. Furthermore, the failure to attain the pertinent SDG targets from a PB-LCA perspective is indicated by the exceeding of safe operating space for relevant impact categories.

Conclusions

Overall, the production of sugarcane was found to be unsustainable, requiring urgent action to promote resource improvement and contain the impacts within safe limits. The developed framework enabled the evaluation of the SDGs using PB-LCA at the product level. The target-driven impact reduction values would help in achieving the targets and prioritizing the efforts by making informed decisions for reducing impacts within safe limits.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11367-023-02185-7.

Assessing coupling interactions in a safe and just operating space for regional sustainability

Human activities affect the Earth System with an unprecedented magnitude, causing undesirable irreversible degradation. The United Nation's Sustainable Development Goals (SDGs) provide an integrated global action plan for sustainable development. However, it remains a great challenge to develop actionable strategies to achieve regional sustainability within social-environmental constraints. Here we proposed a framework, integrating safe and just operating space (SJOS) with SDGs, to assess regional sustainability and interactions between environmental performance and human well-being across scales. Despite China has not fully achieved sustainable development from 2000 to 2018, most provinces have shown significant improvements. Our analyses further delineated four development patterns (i.e., coupled and developed, coupled and underdeveloped, uncoupled and underdeveloped, and coupled and underdeveloped), and developed targeted strategies and pathways for each pattern to transition towards sustainability. Our operationalizable framework is broadly applicable to other regions or nations to actualize sustainable development.

Metrics for a nature-positive world: A multiscale approach for absolute environmental sustainability assessment

Absolute environmental sustainability (AES) metrics include nature's carrying capacity as a reference to provide insight into the extent to which human activities exceed ecosystem limits, and to encourage actions toward restoration and protection of nature. Existing methods for determining AES metrics rely on the frameworks of Planetary boundaries (PB) and Ecosystem Services. This work provides new insight into the relationship between these methods and demonstrates that AES metrics based on the framework of techno-ecological synergy (TES) are better suited to encouraging nature-positive decisions. PB-based AES metrics downscale planetary boundaries or upscale local ecosystem services, but they partition available services among all users across the planet and make limited use of biophysical information. In contrast, TES-based metrics follow a multiscale approach that accounts for local ecosystem services estimated by biophysical data and models, and combine them with downscaled services from multiple coarser scales. These metrics can provide credit to stakeholders for local ecosystem services, thus encouraging ecosystem protection and restoration. Generally, the PB framework focuses on processes of global importance which currently include nine planetary boundaries that are critical for global stability. The TES framework considers ecosystem services from local to global scales and can be used for determining absolute environmental sustainability precisely at any spatial scale. Theoretical analysis shows that TES-based metrics are more general and can be specialized to PB-based metrics under certain conditions. Through case studies at multiple spatial scales and for various ecosystem services, we show that TES-based metrics are more robust, less subjective, and better suited for encouraging transformation to a nature-positive world.

Analyzing the Consequences of Sharing Principles on Different Economies: A Case Study of Short Rotation Coppice Poplar Wood Panel Production Value Chain

Quantifying the environmental impacts of value chains on the earth’s ecological limits is crucial to designing science-based strategies for environmental sustainability. Combining the Planetary Boundaries (PB) and Life Cycle Assessment (LCA) framework can be used to estimate if a value chain can be considered as Absolute Environmentally Sustainable (AES) in relation to the PB. One of the crucial steps in implementing the PB-LCA framework is using sharing principals to downscale the global PB to smaller scales (e.g., country) and calculate an assigned Safe Operating Space (aSOS). This study assesses the potential AES of a wood panel value chain in Austria and Slovakia to understand the consequences of applying diverse sharing principles on different economies. Two economic and one emission-based sharing principles were compared. The results show that depending on the sharing principle implemented, different conclusions on the AES and potential strategies at a value chain and national level are achieved. Economic-based sharing principles are biased to the value chain’s economical contribution. As for the emission-based approach, greater aSOS is given to systems with a higher contribution of emissions. A potential downside of either approach is that it can lead to misleading environmental strategies, such as hindering the development of less wealthy value chains and giving less incentive to improve environmental efficiency. These outcomes highlight the importance of further research into resolving the issues about just assignment of SOS. Moreover, our study contributes to the effort of making the PB-LCA framework relevant for strategic decision-making at a value chain level.

Bridging planetary boundaries and spatial heterogeneity in a hybrid approach: A focus on Chinese provinces and industries

Communicating the finiteness of the Earth system at sub-global scales is necessary to guide human activities within a safe operating space. Despite the numerous efforts committed to downscaling planetary boundaries (PBs) at multiple scales, neither top-down nor bottom-up approaches adequately account for the spatial heterogeneity and integrity of local and global natural systems. To overcome these shortcomings, we developed a hybrid approach that combines bottom-up aggregation and top-down adjustment for downscaling five crucial PBs (i.e., climate change, nitrogen and phosphorus cycles, freshwater use, and land use change) to Chinese provinces and industries. In addition to the widely applied equity principle, we further incorporated the eco-efficiency principle into the downscaling of PBs under the proposition that safeguarding finite PBs should be reconciled with the pursuit of maximizing human welfare. Environmental sustainability at multiple scales was subsequently assessed with the complementary use of environmental footprints and downscaled PBs. The results demonstrate that 1) China suffers from severe unsustainability because of the transgression of PBs for phosphorus and nitrogen cycles, carbon emissions, and cropland use; 2) provinces in West and North China perform worse than other provinces in terms of the eco-efficiency in manufacturing industries, including Electronic equipment, Textiles, and Wood processing and furnishing, rendering these industries that are more unsustainable; and 3) industries with varying eco-efficiencies account differently for the provincial PBs. Construction dominates the provincial shares of carbon PBs, whereas Agriculture and Food processing and tobacco contribute most to the other four PBs. Our findings suggest that improving eco-efficiency in most manufacturing industries is the key to saving resources, reducing emissions, and safeguarding local boundaries.