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In order to achieve the Paris Agreement goals of keeping the temperature rise well below 2 °C or even 1.5 °C, all countries would need to make fair and ambitious contributions to reducing emissions. A vast majority of countries have adopted reduction targets by 2030 in their Nationally Determined Contributions (NDCs). There are many alternative ways to analyze the fairness of national mitigation contributions. This article uses a model framework based on six equity principles of effort-sharing, to allocate countries’ reduction targets under global emissions scenarios consistent with meeting the Paris climate goals. It further compares these allocations with the NDCs. The analysis shows that most countries need to adopt more ambitious reduction targets by 2030 to meet 2 °C, and even more for 1.5 °C. In the context of 2 °C, the NDCs of the United States of America and the European Union lack ambition with respect to the approaches that emphasize responsibility; China's NDC projection falls short of satisfying any approach in 2030. In the context of 1.5 °C, only India, by implementing its most ambitious efforts by 2030, could be in line with most equity principles. For most countries, the NDCs would use most of their allowed emissions space for the entire 21 st century by 2030, posing a major challenge to transform to a pathway consistent with their fair contributions in the long-term.

The technological development of preparing bio-oil from low-temperature hydrothermal conversion of agricultural and forestry waste has positive significance for alleviating the shortage of oil energy supply and reducing environmental pollution. This paper selects typical oxides (Al2O3, CeO2, MgO, SiO2, TiO2, and ZnO) as catalysts to set up a low-temperature (220 °C) hydrothermal conversion process of cotton stalk containing pretreatment processes including chopping. For moderate amplification estimation, lab-scale experimental data is used as a benchmark for calculation, and the functional unit for this study is set to be a 1 kg bio-oil product. The results suggest that the cerium dioxide-involved process with the highest bio-oil yield and highest synthetic consumption, and the silica-involved process with the lowest bio-oil yield, caused the highest environmental impact, resulting in greenhouse gas (GHG) emissions of 67.729 kg CO2e/kg and 60.001 kg CO2e/kg, respectively. It indicates that catalysts need to consider the balance between synthetic consumption and catalytic performance. Magnifying lab-scale data to an industrial scale using scale-up frameworks introduces a low model uncertainty, as the practical value had little effect on the overall evaluation results. However, existing equipment data should be used to reduce the uncertainty of the model itself. The environmental sustainability of bio-oil production by low-temperature hydrothermal liquefaction still needs to be improved, especially by catalyst recovery and bio-oil yield improvement.

Abstract This article reviews the current status of research on urban green and blue infrastructure (GBI) in developing countries. We critically analyzed a total of 283 papers addressing urban GBI in selected developing countries in Africa, Asia, Latin America and the Caribbean (LAC), published between 2015 and 2019. The review aimed to a) analyze publication trends and typologies of urban GBI; b) identify innovative problem-solving measures using urban GBI, and c) understand priorities, differences and similarities in the deployment of urban GBI between the regions. The article identifies a growing interest in the urban GBI concept in the Global South, with a focus on local sustainable development. Urban GBI aims to address issues of urban greenery, land use policies, food security and poverty alleviation. There is a large variation in the number of articles across regions, with Asia, and particularly China, as the subject having a much larger number of publications when compared to LAC and Africa. We found that the focus of research topics varied between regions, reflecting regional development needs, so that urban agriculture research predominated in Africa, and green spaces and parks in Asia and LAC. GBI is still not implemented as a low-impact development or innovative strategy, except in China, where researchers have examined several cases of systemic GBI use for addressing urban issues. More recently, studies began exploring the linkages between nature and cities in light of global environmental issues such as biodiversity loss and climate change. We conclude with recommendations to further examine empirical evidence of urban GBI deployment and its outcomes in the Global South, that could contribute toward conceptualizing natural resource management in a multi-scalar, multi-dimensional, and multidisciplinary framework.

Abstract Organic farming is considered as a promising solution for reducing the environmental burden related to agricultural practices. China is one of the top-five countries with the largest organic area in the world and produces a major part of the world's organic rice. Rice cultivation causes a considerable environmental impact and changing from conventional to organic rice cultivation might therefore have a potentially great impact. Meanwhile, it takes time for the organic farming systems to reach a new steady state after conversion to organic. Thus, the environmental profile of the organic products will change over time and it is therefore important to examine whether the difference to conventional will be reduced (and disappear) or be increased over time. The aim of the present study was therefore to assess the environmental impact of organic rice production 5 (OR5), 10 (OR10) and 15 (OR15) years since conversion and compare it to conventional rice (CR) in subtropical China. The life cycle assessment (LCA) method was used to assess environmental impact of rice production systems with regard to nine environmental impact categories: Non-renewable Energy Depletion (NED), Water Depletion (WD), Land Occupation (LO), Global Warming Potential (GWP), Acidification Potential (AP), Eutrophication Potential (EP), Aquatic Toxicity Potential (ATP), Human Toxicity Potential (HTP) and Soil Toxicity Potential (STP). Overall, the results show that the conventional rice production system had the highest comprehensive environmental impact indices (9.65), more than 10 times that of the organic ones. Interestingly, the results showed that the environmental impact indices in the organic rice systems decreased over time from 0.80 (OR5), 0.72 (OR10) to 0.68 (OR15), and thus increased the difference to conventional over the years. The conventional rice had higher impacts from NED, WD, AP, EP, ATP, and HTP, while organic rice had higher LO, GWP and STP indices. The largest environmental index was ATP for conventional and WD for organic rice. Based on this study, organic rice systems have the potential of being recommended as sustainable agricultural practices in comparison with conventional practices. Furthermore, the present study indicated that the difference in the environmental profile of organic versus conventional agricultural products might be underestimated when analyzing organic system that has not yet reached their steady state.

The Urban Intelligence (UI) paradigm conceived by CNR consists of an ecosystem of digital technologies joined within a Digital Twin (DT) of the city aimed at improving the city governance towards goals addressed also by the UN Agenda 2030, such as urban environment, sustainability and resilience, wellbeing and quality of life, local development, and social inclusion. In particular, UI provides a set of candidate policies in complex scenarios, and supports policy makers and stakeholders in designing shared, evidence-based, and integrated solutions. UI is being applied for the first time to two Italian cities, Matera and Catania, paving the way for a deeper scientific framing of the paradigm, as well as for the technological development and testing of the core UI ecosystem in real-life situations. The paper introduces the UI key-concepts and components, illustrates the ongoing experimentations in these pilot cities related to the development of two DTs on parts of the urban areas, and presents some initial results.

An innovative approach was developed by incorporating high-pressure CO2 into the separate hydrolysis-fermentation of aspen leftover branches, aiming to enhance the bioethanol production efficiency. The high-pressure CO2 significantly increased the 72-h enzymatic hydrolysis yield of converting aspen into glucose from 53.8% to 82.9%. The hydrolysis process was performed with low enzyme loading (10 FPU g-1 glucan) with the aim of reducing the cost of fuel bioethanol production. The ethanol yield from fermentation of the hydrolyzed glucose using yeast (Saccharomyces cerevisiae) was 8.7 g L-1, showing increment of 10% compared with the glucose control. Techno-economic analysis indicated that the energy consumption of fuel bioethanol production from aspen branch chips was reduced by 35% and the production cost was cut 44% to 0.615 USD L-1, when 68 atm CO2 was introduced into the process. These results furtherly emphasized the low carbon footprint of this sustainable energy production approach.

The utilization of combined heat and power (CHP) units is a key way to enhance renewable energy accommodation. However, carbon emissions of CHP challenge the pollution and economic optimization of integrated energy system (IES). To tackle this challenge, we propose a novel model and optimal dispatch for CHP with power-to-gas (P2G) and carbon capture system (CCS), which solves the problems of the carbon source required for P2G and the CHP's carbon emissions by the optimal dispatch in IES. The model takes the CHP, P2G, and CCS as a whole system. The operation rule of the model is developed, and its coupling characteristics of electric power, heat power, gas power and carbon are analyzed. Correspondingly, the optimization strategy of IES considers the proposed model and carbon trading mechanism. The optimal dispatch model of IES is established and solved by YALMIP, and GUROBI. Our method is verified by simulation. Compared with other conventional models, the accommodation capacity of renewable energy with the proposed method is enhanced, and the carbon emissions and operating costs of IES are also reduced.

In this research, efforts were put to demonstrate synergistic interactions between bioenergy generation and wastewater treatment. The extent of such synergistic effect was assessed against wastewater effluents released from the beverage industry through the operation of a membrane-less truncated conical (TC) microbial fuel cell (MFC). A graphite-based reactor was operated for five cycles in batch mode using beverage industry wastewater as an organic substrate. Maximum bioelectricity produced on the fifth operating cycle corresponded to a voltage of 338 mV and a power of 1.14 mW at 100 Ω. The MFC recorded a higher substrate degradation rate (0.84 kg of chemical oxygen demand [COD]/m3-day) accompanied by the development of an electroactive biofilm and polarization behavior (e.g., a reduction in internal resistance from 323 Ω to 197 Ω over five operation cycles). Cyclic voltammetry showed a maximum performance of the biofilm during the fifth cycle (through its enrichment) as interpreted by oxidation and reduction currents of 2.48 and -2.21 mA, respectively. The performance of the proposed MFC was superior to other designs reported previously in both effluent treatment and bioenergy generation. A maximum treatment efficiency of 84.4% (in 385 h) was seen at an organic load (COD) of 3500 mg/L with the specific power yield (0.504 W/Kg of substrate (COD) removal) and volumetric power yield (15.03 W/m3). Our experimental studies support that the proposed system could be upscaled to realize the commercial operation.