Let us ‘bring back the forest’

Detecting dynamic system regime boundaries with Fisher information: the case of ecosystems Abstract The direct measurement of the resilience (resistance to disturbances) of an ecosystem’s current regime (or “alternative stable state”) remains a key concern for managing human impacts on these ecosystems and their risk of collapse. Approaches which utilize statistics or information theory have demonstrated utility in identifying regime boundaries. Here, we use Fisher information to establish the limits of the resilience of a dynamic regime of a predator–prey system. This is important because previous studies using Fisher information focused on detecting whether a regime change has occurred, whereas here we are interested in determining how much an ecological system can vary its properties without a regime change occurring. We illustrate the theory with simple two species systems. We apply it first to a predator–prey model and then to a 60-year wolf–moose population dataset from Isle Royale National Park in Michigan, USA. We assess the resilience boundaries and the operating range of a system’s parameters without a regime change from entirely new criteria for Fisher information, oriented toward regime stability. The approach allows us to use system measurements to determine the shape and depth of the “cup” as defined by the broader resilience concept. Graphic abstract The direct measurement of the resilience (resistance to disturbances) of an ecosystem’s current regime remains a key concern for managing human impacts on these ecosystems and their risk of collapse. Here, we use Fisher information to establish the limits of stability of a dynamic regime of a predator–prey system. The region of stability is represented by the “floor of the canyon” in the adjacent graphic. While the theory is illustrated with an ecosystem example, it is applicable in its present form to dynamic systems in general.

Impact of prefabrication technology on the cradle-to-site CO 2 emissions of residential buildings Abstract In recent years, the industrialization of construction has been promoted to achieve sustainable development within the construction industry; accordingly, prefabrication technology has been utilized substantially. Due to enormous carbon emission reduction pressure, the carbon-reducing potential of prefabrication has attracted widespread interest. To deepen the current understanding of the carbon emission performance of prefabrication, this study investigates the differences in CO2 emissions between the prefabricated and conventional construction methods and the effect of the prefabrication rate on building carbon emissions. A quantitative model is established based on life-cycle assessment (LCA) to calculate the cradle-to-site CO2 emissions of the two construction methods. The LCA model is then parameterized to simulate the cradle-to-site CO2 emissions at varying prefabrication rates. The simulation is conducted based on three scenarios, i.e., some slabs and staircases are prefabricated, all transverse members are prefabricated, and all components are prefabricated. Two sample buildings in China, where housing industrialization has developed rapidly, are used for a preliminary examination. The results show that the conventional building produces 185.13 kgCO2/m2, whereas the prefabricated building produces 151.84 kgCO2/m2, which is approximately 18% lower than the former value. Additionally, the CO2 emissions do not necessarily decrease with an increase in the prefabrication rate. The building with some prefabricated slabs and staircases produces the least CO2 emissions, and the building with the highest prefabrication rate still produces less CO2 emissions than the conventional building. Moreover, as the prefabrication rate increases, the carbon emissions during the construction cycle present a shift towards manufacturing and transportation. Therefore, adopting prefabrication technology contributes to significant environmental benefits for reducing CO2 emissions; the optimal prefabrication rate can be chosen according to the demand. Carbon reduction in manufacturing and transportation should be a new focus. Graphic abstract

Biochar farming: defining economically perspective applications Abstract Biochar refers to the high-carbon, black fine-grained product of biomass pyrolysis. Independent studies repeatedly confirmed that its incorporation into arable land is a reliable carbon sequestration method that significantly improves soil quality. The latest development leads to a reduction in the production cost (− 10 to 30 USD t−1); however, the use of biochar in commercial agriculture remains scarce. The reason is that biochar can substitute lower-quality charcoals (150–300 USD t−1). Therefore, farmers tend to sell their biowaste for energy purposes, respectively, preferring a quick profit over the forgotten soil-improving practices, which hold long-term benefits. A review of the current state of the art was performed in order to search directions toward the most profitable biochar farming applications. There are indications that a promising direction might be its on-farm production followed by on-farm use and nutrient recycling, or more precisely, special fertilization applications. Graphic abstract

Process-to-Policy (P2Pol): using carbon emission pinch analysis (CEPA) tools for policy-making in the energy sector Abstract Global warming is a major international issue due to rising levels of greenhouse gases such as CO2. Many countries now face the challenge to find cost-effective ways to deploy low-carbon technologies in order to meet commitments to the Paris Agreement. Process systems engineering (PSE) can play an essential role in supporting high-level policy decisions to help mitigate climate change. Within PSE, carbon-constrained planning will become increasingly critical for policy-making on provision of sustainable energy in electricity generation as well as other economic sectors. There are existing carbon-constrained planning tools but these often consider energy issues from limited perspectives at specific scales. In this perspective paper, we argue for a Process-to-Policy framework that centres on carbon-constrained planning which includes various stakeholders at various scales for developing strategies to address global warming. There is an urgent need for research on the development of such tools at multiple scales to effectively allocate countermeasures such as negative emission technologies. We also discuss potential extensions for carbon-constrained planning in conjunction with other established tools. Graphic abstract

An emergy ternary diagram approach to evaluate circular economy implementation of eco-industrial parks Abstract Eco-industrial parks could play a positive role in reducing consumption of natural resources and environmental pollution by circular economic development, improving the ecological environment, and enhancing the capacity for sustainable development of economic development zones. However, assessing the ecological and economic efficiency of eco-industrial parks inevitably encounters difficulties, such as the comparability of analysis objects, the unification of dimensions, and the determination of the scope of calculations. These problems can be solved based on emergy analysis methods, specifically by the collection of information on the natural environment, geography, society, and economy of industrial parks. Furthermore, the analysis of the status quo of eco-economy systems in eco-industrial parks can be conducted by means of emergy analysis. This paper analyzes the circular economic sustainability of Shenyang Economic and Technological Development Zone by the emergy ternary diagram. Eco-industrial parks can be scientifically planned to improve the structure, function, and efficiency of the park’s complex ecosystem. The method of emergy ternary diagram can effectively evaluate the eco-economic efficiency of the industrial agglomeration area. An emergy ternary diagram intuitively reflects the system’s resource allocation. With the aid of the emergy ternary diagram, the analysis on the relationship between the ratio of energy use of system resources and the indicators can not only fully evaluate the sustainability of the existing industrial agglomeration system, but also can predict the future development direction of the system. For the selection of development paths, more explicit direction indications and references are provided, and the application of the emergy theory is more scientific in program optimization, decision-making, and selection. Graphic abstract

Investigations for the optimal combination of zinc oxide nanoparticle-diesel fuel with optimal compression ratio for improving performance and reducing the emission features of variable compression ratio diesel engine Abstract The continual hike in environmental pollution from diesel engines has raised the concern of researchers to identify certain clean fuels. For this purpose, experimental investigations are carried out to inspect the consequences of ZnO nanoparticles addition for performance and emissions features of a 4-stroke, single-cylinder diesel engine. ZnO nanoparticles were mixed with pure diesel in varying proportions ranging from 5 to 25 mg. The better dispersion of ZnO nanoparticles in diesel was attained by means of magnetic stirrer and ultrasonication process. The test fuels were experimented at varying engine loads of 2 kW, 4 kW, 6 kW, 8 kW, 10 kW and 12 kW at 1500 rpm engine speed. It was observed that among different test fuels, an enhancement in brake thermal efficiency was achieved by 15.58% and reduction of 11.11% in brake specific fuel consumption for 20ZnO60DF (20 mg ZNP + 20 mg CTAB surfactant + 600 ml diesel) at 12 kW engine load as compared with neat diesel. The toxic emissions of NOX, HC, CO, CO2 and particulate matter with the inclusion of 20ZnO60DF were significantly decreased by 57.46%, 78.78%, 58.93%, 41.85% and 42.51%, respectively, as correlated with pure diesel fuel at 12 kW condition with 18 compression ratio. The recommended optimal combination of ZnO nanoparticle-diesel with optimal compression ratio for better performance and reduced emissions level was found out to be 20ZnO60DF with compression ratio 18. So, it is concluded that ZnO nanoparticles addition to diesel could be accepted as a clean alternative fuel as it emits lesser emissions and acts as environmental-friendly fuel. Graphic abstract

Oxidative desulfurization of dibenzothiophene via high-shear mixing with phosphotungstic acid: the influence of calcination temperature on kinetics and catalytic activity Abstract The mixing-assisted oxidative desulfurization (MAOD) of model fuel was performed where the effect of calcination temperature on the catalytic activity of phosphotungstic acid (HPW) was evaluated. The MAOD system utilized tetraoctylammonium bromide as phase transfer agent (PTA) and HPW as catalyst. Calcined HPW was characterized by Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy. The influence of operating conditions such as calcination temperature, reaction time and PTA:HPW molar ratio on the catalytic activity of HPW was investigated. HPW calcined at 400 °C attained the highest sulfur removal of 100.0% and rate constant of 0.1485 min−1, which is followed by HPW calcined at 300 °C (0.1328 min−1) and 200 °C (0.1192 min−1). Under all calcination temperature range studied, high coefficient of determination values (R2 ≥ 0.95), low values of root-mean-square error (RMSE ≤ 8.5157) and average relative error (ARE ≤ 6.9361) indicate that the pseudo-first-order equation correlated well with the experimental data. The oxidation rate of dibenzothiophene in a MAOD system can be arranged in the order: HPW calcined at 400 °C > 300 °C > 200 °C. Graphic abstract

Managing plastic waste from agriculture through reverse logistics and dynamic modeling Abstract Agrofood companies in the region of southern Sonora, Mexico, including those in Valle del Yaqui, employ agrochemical products (insecticides, herbicides, fertilizers, adhesives, fungicides) in the production of foods and face the problem of plastic waste management, specifically from the empty containers and packages from the different products used. This paper proposes a reverse logistics model in the tomato supply chain to economically and environmentally assess the collection process and final disposal of the empty agrochemical packages using dynamic hypotheses and scenario assessment. The challenge in the proposal was to create a dynamic model to observe the current behavior with special attention to environmental pollution and its effects on the health of the communities with the greatest exposure. The results show that this proposal is viable following these stages: (1) analysis of the product supply chain; (2) characterization of the production process; (3) preparation of the causal diagram and dynamic hypotheses; (4) construction of the Forrester diagram and equations; (5) simulation and sensitivity analysis; and (6) design of the user interface. The application of the proposed model supports decision making in the organization regarding the use of containers of discarded agrochemicals, with the aim of reducing their environmental impact. Graphical abstract

Environmental and social life cycle assessment to enhance sustainability of sugarcane-based products in Thailand Abstract This paper aims to identify the environmental, socioeconomic, and social hot spots and to find ways to enhance the sustainability of selected food, fuel, and fiber products from sugarcane, i.e., sugarcane, sugar, electricity from bagasse, and molasses-based ethanol. Life cycle assessment (LCA) and social life cycle assessment (S-LCA) were used to examine the environmental, socioeconomic, and social performances of the various sugarcane-based products. All data from the field were collected during the production year 2014/2015. The environmental data were analyzed using the ReCiPe life cycle impact assessment method. Social data were analyzed using performance reference points method, using social indicators from relevant standards/guidelines. Interesting results from the study are that some problems such as cane trash burning and overuse of chemical fertilizers and agrochemicals are the main causes not only of negative environmental performance, but also of negative socioeconomic and social performances. Moreover, recommendations to help increase the sustainability of the Thai sugar industry for each stakeholder group have been provided. These include, for example, using demonstration farms in the same areas, zoning of agricultural crops, implementing large area-based agriculture policy, and making local regulation to prohibit cane trash burning. Graphic abstract