To explore how city-level international partnerships can succeed, this study focuses on the sister-city relationship between Wuhan (China) and Manchester (UK), which has demonstrated strong outcomes in sustainability collaboration. Through a detailed analysis of this case, the study identifies three key factors for enduring international collaboration – sustained mutual benefit, broad partnership areas, and deep grassroots engagement – and reveals how they adapt and consolidate over time. These results suggest that international partnerships need to be designed not only to ensure mutual benefit but also to promote inclusiveness and multi-level participation.

The importance of global collaborations in achieving sustainable development is widely recognised. However, establishing and maintaining international partnerships remains a significant challenge. To understand how effective international partnerships can be developed to address sustainability challenges, this study conducts a case study of the Manchester–Wuhan sister-city relationship, a highly successful and representative example of international cooperation on sustainable development. Drawing on insights from 27 semi-structured interviews with stakeholders involved in organising and participating in the initiative, the study shows that the longevity of international partnerships is determined by three core factors: the preservation of mutual benefit, the breadth of cooperation, and profound grassroots involvement. These factors generate both economic and emotional capital, which incentivises governmental and non-governmental actors to deepen their engagement in sustainable urbanisation. This engagement also serves as a buffer against bilateral tensions between the UK and China. These results offer implications for how local initiatives can serve as effective mechanisms for fostering international cooperation in advancing sustainable development.

Building international partnerships for global sustainability requires mutual benefit, inclusiveness, and engagement at multiple levels.

The need for critical minerals for various technologies for commercial and defense use has led to a range of national policy interventions. However, many of these new laws to encourage mining, or protect local industries have not considered as scientific data on mineral reserves or the economic viability of setting specific targets. The EU’s Critical Raw Materials Act is a pivotal case in point that illustrates this challenge. We present a review of the range of laws and policies that have been set forth worldwide.

Growing international conflict between countries that have large mineral production and processing capacity and those which are in demand of critical raw materials for new technologies has led to a proliferation of policies that promote resource nationalism or ‘friend-shoring’. We analyzed over 400 critical raw material policies to date that have been documented by the International Energy Agency's policy tracking tool and present the findings of the six most active jurisdictions. The EU's Critical Raw Materials Act which came into force in May 2024 stands out as the most significant legislative step taken thus far but needs better interface with environmental and social data on impacts and benefits. By analyzing the challenges faced by lithium mining projects across a range of technologies and geographic locations in Europe, we suggest the use of data generated from life cycle analyses, economic geological calculations, and ecosystem service valuation in improving the implementation of such policies and also mitigate social conflicts.

There are now more than 400 critical raw material policies worldwide, but they need to be predicated in economic and geological data to be effective.

In transdisciplinary sustainability, scientists take responsibility for the long-term impact they have on practitioners in the research field and beyond. However, the duration of a career and amounts of funding are finite. One way out is to perform a responsible exit from the field. This study extracts lessons to realizing researchers’ responsible exit from their field through detailed description of the experiences of two researchers and a practitioner in collaboration in transdisciplinary research, weaving together the perspectives of all parties. The following lessons were extracted: (1) Imagining the extent of mutual understanding, (2) Production of knowledge entrusted to practitioners, and (3) Researchers’ acceptance of being unneeded. This study does not claim that these approaches are universally effective. We suggest that the reader transfer this case study and its approaches to his or her own case to seek better relationships. The validity of this qualitative study's suggestions should be tested by readers.

In the discipline of transdisciplinary sustainability, researchers must responsibly manage their impact on their partner practitioners. Balancing this with limited career durations and limited research funds is challenging. One potential solution involves responsibly exiting from the research field. This study investigates the experience of two researchers and a practitioner in collaborative transdisciplinary research. The lessons include acknowledging researchers’ amateurism, anticipating the challenges in achieving mutual understanding, and embracing researchers’ acceptance of feeling unneeded. The universality of these principles should be investigated in the future research. This research encourages readers to apply these principles to their own cases to develop better relationship between researchers and practitioners that leave no seeds of misfortune.

In transdisciplinary sustainability, scientists take responsibility for the long-term impact they have on practitioners in the research field and broader communities. However, the duration of a career as a scientist and amounts of funding are finite. One way out is to responsibly exit from the field. This study extracts lessons to realizing researchers’ responsible exit from their field by providing a detailed account of the collaborative experiences of two researchers and a practitioner engaged in transdisciplinary research, weaving together the perspectives of all parties. The following lessons were extracted: acknowledging researchers’ amateurism, anticipating the challenges in achieving mutual understanding, and embracing researchers’ acceptance of feeling unneeded. This study does not claim that these principles are universally effective. We suggest that the reader transfer this case study and its approaches to his or her own case to seek better relationships.

In transdisciplinary sustainability, researchers must responsibly manage their impact on their research partner practitioners. Balancing this with limited career durations and funds is challenging. Researchers’ responsible exit from the research field is a possible solution. This research derives insight from researchers’ and a practitioner's experiences in collaborative transdisciplinary research. Lessons include acknowledging researchers’ amateurism, anticipating the challenges in achieving mutual understanding, and embracing researchers’ acceptance of feeling unneeded. However, these approaches might not be universal. Readers are encouraged to apply these lessons to their own case for better relationship building.

As cities like Beijing expand rapidly, green and blue spaces (GBS)—essential for ecosystem services (ESs) such as clean air, flood control, and recreation—are increasingly threatened. This 20-year study examines how urban expansion and policy interventions have shaped Beijing’s GBS. While green initiatives have increased natural areas, unchecked urban sprawl has fragmented these spaces, reducing their environmental benefits. Satellite data and urban planning analyses underscore a key lesson: maintaining well-connected natural zones is critical for urban resilience. These findings are broadly applicable for rapidly growing cities globally, urging urban planners to integrate ecological conservation with development, and to safeguard healthy environments and vibrant communities.

This study quantifies the spatiotemporal dynamics of urban GBS in Beijing, evaluating their essential role in delivering ESs and strengthening urban resilience. Although China has achieved substantial progress in urban greening, the ecological impacts of rapid urbanization on GBS configuration and connectivity have not been comprehensively quantified. Using an integrated analytical framework combining principal component analysis and multiple linear regression, we reveal how urban development strategies have shaped GBS dynamics over two decades. A spatially explicit analysis, utilizing geographically weighted regression, further elucidates the heterogeneous relationships among the normalized difference vegetation index, human footprint index, and ESs delivery capacity. Notably, socioeconomic incentives and green infrastructure governance—especially objective indicators such as forest, garden, and greenspace area—have effectively driven GBS expansion. However, urban expansion has led to pronounced fragmentation of peri-urban GBS, suggesting potential degradation of their ecosystem service support functions. These findings emphasize the need for adaptive GBS management strategies that balance ecological conservation with sustainable urban growth in rapidly developing cities.

Urban growth fragments green and blue spaces, reducing vital ecosystem services. Balancing conservation with development is essential for sustainable cities.