Current Research in Environmental Sustainability最新文献

Biochar amendment to soils is regarded as the potential practice to mitigate climate change while also increasing yields. However, geographical differences in the effects of biochar on cereal production and greenhouse gas emissions are not well understood at the global scale. Random forest, a classic machine learning algorithm, was employed to reveal the drivers of geographical differences in the effects of biochar on cereals yield and greenhouse gas emissions. The potential for yield increases and greenhouse gas emission reduction was predicted in this study. The results indicate that nitrogen fertilizer rate is the most important factor determining the impact of biochar on cereal yield, while biochar application rate strongly affected greenhouse gas emissions. Globally, the maximum increase in cereal crop yields under biochar application was 14.1%. To achieve the largest increment globally, recommended values of biochar application, mineral nitrogen application rate and pyrolysis temperature were predicted to be around 36.3 t ha⁻¹, 193.7 kg N ha⁻¹ and 420 °C, respectively. The maximum reductions of methane and nitrous oxide emissions from paddy fields around the world were 21.6% and 31.0%, and from maize and wheat fields 35.7% and 36.1%, respectively. Although biochar can potentially improve yields while reducing greenhouse gas emissions worldwide under proper management, the performance of biochar showed great heterogeneity.

Constructed wetlands have been used worldwide as an alternative for wastewater treatment. The purpose of this study was to evaluate two constructed wetlands for wastewater treatment using two different species of macrophyte in order to reduce pollution levels in the Curiquingue Creek belonging to the Baños parish in Cuenca, Ecuador. A pilot plant was constructed using Equisetum spp and Zantedeschia aethiopica with a constant flow of $0.32m^3{d}^{-1}$. Each unit was filled with sand and gravel as the porosity medium with a hydraulic retention time of 5 days. To analyze the efficiency of the wetlands, physical and chemical parameters were analyzed in the laboratory. The results obtained in the laboratory showed that the two species of macrophyte showed good efficiency in the removal of organic matter (100% COD-100% BOD₅). On the other hand, Equisetum spp showed better efficiency in the removal of NO₃⁻ (80.28%) and PO₄³⁻ (98.57%) meanwhile, Zantedeschia aethiopica showed better efficiency in the removal of TSS (85.71%). Constructed wetlands are an effective and sustainable option for wastewater treatment.

The rapid worldwide increase in resource extraction is evident in Madagascar—a global biodiversity hotspot. This study examines the localized effects of operational and planned large-scale extractive investments on social-ecological systems in Madagascar and links them to the Sustainable Development Goals. The focus is on sites owned or explored by foreign investors, specifically Ambatovy Moramanga, Ambatovy Tamatave, QIT Madagascar Minerals/Rio Tinto, Ranobe, and Tantalum Rare Earth Malagasy. Employing a counterfactual approach, we gathered survey responses from 459 small-scale farming, agro-pastoral, and artisanal-fisheries-based households. The survey provided information on general household characteristics, land use, land management, livelihoods, well-being, and any perceived changes to these variables, as well as any perceived mining impacts related to the changes. Overall, respondents reported predominantly negative effects on land (and sea) use, livelihoods, well-being, and security. Mining pollution, primarily from operational sites, had reduced access to water and fisheries resources, and natural forest areas had diminished. Reduced productivity due to pollution of soils, water, and air had a negative impact on various land uses and affected people's health, particularly in the surroundings of QIT Madagascar Minerals/Rio Tinto. Although some projects, such as Ambatovy, had eventually improved healthcare and infrastructure, most negative mining impacts had occurred during both the exploratory and the operational phases of the projects. Overall, this study offers a comprehensive view of how large-scale extractive investments affect land (and sea) use and human well-being. In addition, we highlight policy implications that must be considered if large-scale extractive investments are to support progress on the 2030 Agenda.

The relationship between ecosystem services (ES) and urbanization is crucial for sustainable development. Rapid urbanization threatens the natural capital of Dhaka city, affecting the delivery of ES through changes in land use and land cover. We used vertical growth (VG), nighttime light data (NTL), and population density (PD) as standard urbanization indicators alongside technomass, a three-dimensional indicator, to evaluate the degree of urbanization as a continuous spatial process. We modeled the spatiotemporal relationships between urbanization degrees and ES using the ecosystem service value (ESV) dataset applied in Dhaka, with regional modified value coefficients. Results from the geographically weighted regression (GWR) model showed that technomass emerged as a more appropriate indicator to analyze urbanization for ESV analysis (r > 0.61), followed by NTL (r > 0.56), and PD (r > 0.54) across all zones from 2000 to 2021. We observed a 68.34% decrease in net ESV, equivalent to $245.88 million (in 2021 USD), from 2000 to 2021. This decline was driven by the conversion of water bodies (−70.93%), agricultural land (−60.08%), forest and vegetation (−70.18%) into urban built-up areas and other uses. In contrast, net technomass increased by 243.11% due to the city's vertical growth. The digital building height (DBH) model revealed that the built-up area had expanded by 94.94% over the study period, with an average annual growth rate of 4.52%. Significant correlations (p < 0.05) were observed between ES and urbanization. The rural-urban fringe area exhibited the most significant increase in urbanization (r > 0.90), along with a 440.47% growth in technomass. Our results provide insights into the impact of urbanization on ES, particularly at the regional scale, and have highlighted the importance of integrating VG and technomass for urbanization analysis. These findings could be useful for environmental management, policymaking, spatial planning, and coordinating future ES protection and urban development.

As green bonds continue their dynamic growth trajectory to finance the transition to a more sustainable future, a gap in the literature remains on how companies have overcome internal barriers to successful green bond issuance. This case-based study analyzes how five Nordic energy companies have successfully surmounted internal barriers to issuing green bonds by leveraging their sustainable business models. The findings show a number of antecedental features of sustainable business models prior to green bond issuance including: a focus on environmental betterment as part of the mission and strategy; investments into assets that provide an environmental benefit and a divestiture of those that do not; the active pursuit to reduce CO₂ emissions through R&D; and, strong governance mechanisms. Throughout the process of issuing green bonds, companies introduce changes to their sustainable business models, most notably, green finance frameworks and additional governance practices. As a result of the green bond issuance, reinforcing choices and consequences emerge to create virtuous cycles. In turn, the virtuous cycles support environmental objectives and foster more economic and environmental value for the company, investors, and society. Our study offers a process-based theoretical outline of how sustainable financing can make a business model more sustainable by removing internal barriers and strengthening company strategy, asset choices, and governance.

Sustainability implementation efforts, relevant to all Sustainable Development Goals (SDG), can succeed or fail based on how the program activities effectively align with local community norms. Conflict arises when implementers incorrectly assume the ways in which local communities and other stakeholders share their world views. A novel approach was applied to identify conflicts between stakeholder norms through the example of wildlife conservation. This case is based on 62 systematically collected interviews involving law enforcement staff (wildlife police officers [WPOs]) and local community members in four of Zambia's Game Management Areas. Cultural consensus analysis (CCA) was used to extract and compare cultural models across groups. Discordant cultural norms were identified for resource protection, which reflected frailty of collaborative strategies. Concordant norms were relevant to shared understandings of the disproportionate burdens to GMA-based communities from conservation and some potential benefits of collaboration. This case shows exemplar application of CCA to capture and compare stakeholder norms associated with livelihoods and conservation, allowing better program design that reduces conflict and builds on shared values to better support SDGs, especially SDG15 (Life on Land).

Sikkim is a Himalayan state in the northeastern part of India. Its capital Gangtok, is one of the most scenic places is visited by several tourists for a close view of nature. Springs are one of the major sources of water supply for the city, especially for the city's outskirts, and are used for irrigation for the villages around the city. With the rapid population growth, expanding urbanisation, and effects of rapidly changing climatic conditions, Sikkim is struggling to fill the increasing water demand-supply gap jeopardizing the long term security of water resources for its residents. While challenging terrain significantly affects water access, the pre-existing notion that water availability is simply a physical shortage has been debated. This fails to consider issues of water equity, where unequal distribution and social dynamics can limit access for certain groups. This paper employs an intersectional ecofeminism approach to deconstruct the pre-existing notion of how water availability is considered a physical shortage rather than being able to envision other factors that hinder the involvement of women in conserving or managing water resources. Furthermore, the paper also establishes links between such local management practices and responsible tourism growth in the region.