Food–energy–water nexus optimization brings substantial reduction of urban resource consumption and greenhouse gas emissions

Urban sustainability is a key to achieving the UN sustainable development goals (SDGs). Secure and efficient provision of food, energy, and water (FEW) resources is a critical strategy for urban sustainability. While there has been extensive discussion on the positive effects of the FEW nexus on resource efficiency and climate impacts, measuring the extent to which such synergy can benefit urban sustainability remains challenging. Here, we have developed a systematic and integrated optimization framework to explore the potential of the FEW nexus in reducing urban resource demand and greenhouse gas (GHG) emissions. Demonstrated using the Metropolis Beijing, we have identified that the optimized FEW nexus can reduce resource consumption and GHG emissions by 21.0 and 29.1%, respectively. These reductions come with increased costs compared to the siloed FEW management, but it still achieved a 16.8% reduction in economic cost compared to the business-as-usual scenario. These findings underscore the significant potential of FEW nexus management in enhancing urban resource efficiency and addressing climate impacts, while also identifying strategies to address trade-offs and increase synergies

Energy constrains to increasing complexity in the biosphere

Thirty years ago, the systems ecologist Howard T. Odum introduced the concept of transformity, which is a thermodynamic measure of quality within the trial and error evolutionary dynamics of ecosystems, namely an indicator of rank in the hierarchical system structure of the biosphere. Based on a global database of individual processes and whole economies, this paper extends, refines, and updates Odum’s idea, demonstrating the strength of the postulated relation. In particular, an inverse linear logarithmic relationship is shown to hold between resource quantity (exergy) and quality (emergy), which is the result of an overall energetic efficiency characteristic of energy transformation processes of the biosphere. This relation extends from natural renewable energy sources to human information (including global internet data flows) and know-how embedded in national economies, thus identifying a consistent theory of hierarchical organization of the biosphere grounded in energetics and ultimately setting constraints to illusions of unlimited growth

Solutions for recycling emerging wind turbine blade waste in China are not yet effective

Wind power supply chains are evolving as markets expand to reach climate goals. With the largest installed wind power capacity globally, China must deal with increasing composite turbine waste and anticipate its associated costs. Here we predict the quantity and composition of wind turbine blade waste based on historic deployment. A high-resolution database containing 14 turbine capacities (150–5500 kilowatts) was compiled based on 104 turbine models. The environmental and financial costs of waste treatment options were evaluated using a bottom-up approach. Based on current installations and future projections, 7.7 to 23.1 million tonnes of blade waste will be generated in China by 2050. Technologies exist to recycle glass fibre from blade waste, but these solutions vary in level of maturity and are not always commercially available, cost-competitive, or environmentally sustainable. Our findings can inform decision-makers in governments and industry on the pathways to carbon neutrality

Urban food-energy-water nexus: a case study in Beijing

Food, energy and water (FEW) are indispensable, irreplaceable and safeguarding resources with tangled interlinkages among each other, often framed in terms of ‘nexus’. Cities have become the bustling hubs of resource consumption and production, facing the most intense stress. Globally, food security, fresh water shortage and fossil energy exhaustion have become the greatest challenge for the sustainable development of cities in the future. Systematic analysis and simulation of dynamic evolution of urban FEW demand and supply and its nexus would add significant and practical value for macro-management such as ensuring the security of urban resource. Taking Beijing as the case study, we established a dynamic model for the FEW demand and supply from the perspective of cross-ectoral and cross-regional nexus with the Stella modelling platform, then it was run for simulating the dynamic changes and nexus characteristics of FEW during the interval between 2016 and 2035.The results showed that:①The gap between local production and demand of these three resources in Beijing will continue to increase. In 2035, Beijing will need 2.16 million tons of grain, 0.83 million tons of meat, 4.6 billion m3 of water and 91.65 million tons of standard coal of energy while the resources produced and supplied by locality independently will be 0.21 million tons, 0.23 million tons, 3.3 billion cubic meters and 16.5 million tons of standard coal respectively. Beijing has to draw on cross-boundary production to meet FEW-use with the increasing gap between local supply and demand. ②There is a developing trend of the absolute quantity of interaction among FEW. Structurally, the ‘outsourcing’ feature is obvious and the indigenous nexus links of three resources are shifting to back-end supply chain such as transportation and treatment. ③The change of nexus indexes are mainly affected by the mutual and strong dependence between food and water. Food and energy depend more and more on each other; in contrast, the inter-relationship between water and energy is more stable. In addition, inter-regional FEW nexus is strengthened. ④To improve systematic management of urban resources, we need to capture multi-tradeoffs of the FEW system comprehensively and establish a multi-regional and multi-factor integrated and collaborative resource management mechanism

Clusterin Reduces Cold Ischemia-Reperfusion Injury in Heart Transplantation Through Regulation of NF-kB Signaling and Bax/Bcl-xL Expression

Background/Aims: Ischemia-reperfusion (I/R) injury is an unavoidable event occurring during heart transplantation and is a key factor in graft failure and the long-term survival rate of recipients. Therefore, there is an urgent need for the development of new therapies to prevent I/R injury. Clusterin is a hetero-dimeric glycoprotein with an antiapoptotic function. In this study, we investigated whether clusterin was cardioprotective in heart transplantation against I/R injury using an in vivo rat model and an in vitro cell culture system, and examined the underlying mechanisms of I/R injury. Methods: Heart grafts from wild-type C57BL/6 mice were preserved in UW solution (control) or UW solution containing recombinant human apolipoprotein-J (hr clusterin) for 24 h. The preserved hearts were implanted into recipient mice of the same strain as the donors for 72 h, and the heart grafts were then taken for histopathological and gene expression analyses. An in vitro ischemia reperfusion model using H9C2 cells or H9C2/clusterin cDNA cells was constructed. The expression of clusterin, p65, Bax, Bcl-xL, IL-1β, and TNF-α protein and mRNA in heart tissue and H9C2 cells was detected by western blot, reverse transcription-polymerase chain reaction (RT-PCR), and quantitative RT-PCR assays; IL-1β and TNF-α protein was detected by enzyme-linked immunosorbent assays; NF-kB activity was detected by an electrophoretic mobility shift assay; cell apoptosis was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling and flow cytometric analyses. Results: Cold I/R caused severe morphologic myocardial injury to heart grafts from wild-type C57BL/6 mice, whereas grafts from hr clusterin preservation showed less damage, as demonstrated by decreased cell apoptosis/death, decreased neutrophil infiltration, and the preservation of the normal structure of the heart. Clusterin reduced the expression of p65, pre-inflammatory IL-1β, and TNF-α, and the pro-apoptotic gene Bax, while it enhanced the expression of the anti-apoptotic gene Bcl-xL in vitro and in vivo. Clusterin inhibited cell apoptosis/death and reduced pre-inflammatory. Conclusion: Clusterin is a promising target for preventing cold I/R injury in heart transplantation. This study also shows that the resultant protective effects of clusterin are mediated by NF-κB signaling and Bax/Bcl-xL expression

Unveiling spatiotemporal dynamics and factors influencing the provision of urban wetland ecosystem services using high-resolution images

Although extensive studies have investigated changes in regional ecosystem services (ESs) under rapid urbanization, few analyses have used high-resolution image data to investigate urban wetlands. Taking the Xixi wetland region as a case area, this study aimed to investigate the temporal and spatial variation and influencing factors of typical ESs during 1984–2018 using high-resolution images. The results showed that the Xixi wetland region underwent substantial changes of land use as well as in different ESs. While carbon storage presented an increasing trend from 223.25 t/ha to 368.11 t/ha from 1984 to 2018, the changes of other services illustrated an overall degradation in this important urban wetland. Evident trade-off and synergy effects were observed between water yield and carbon storage and between biodiversity protection and recreation and cultural services. Redundancy analysis revealed the detrimental impacts of impervious cover on the provision of ESs in this urban wetland area. The results obtained in this study highlight the great challenges that urban wetland parks face in balancing wetland conservation and sustainable use

Small hydropower development in Tibet: Insights from a survey in Nagqu Prefecture

Due to its large hydraulic power potential, Tibet has been proposed as the main hydropower development base in China after 2020. This is likely to result in the construction of large and medium sized hydropower projects in this region. To date, small hydropower (SHP) has played an essential role in rural electrification in Tibet. Here we present a review of the status of SHP plants in Tibet and explore its potential based on a field survey conducted in the summer of 2014 in Nagqu Prefecture. The survey revealed that SHP in Nagqu has made it possible for approximately 80,000 local residents (16.3% of the total population) to have access to electricity. Our study shows that SHP suffers from problems such as low utilization of the installed power capacity, high scrap ratio and has severe impacts on the local ecosystem. Moreover, the role of SHP in Tibet's rural electrification is gradually changing with the arrival of the main power grid, which has also impacted existing SHP plants. In order to improve SHP overall sustainability, optimization of existing plants and construction of new plants with highers tandards are deemed necessary. This has to be done with due consideration to the fragile ecosystem in Tibet. Therefore, any expansion in the development of SHP in Tibet should have an appropriate strategy for sustainability and ecosystems conservation and protection