CO2 Mitigation Research Articles

Microalgae cultivation: from CO2 fixation to single-cell protein production

Bio-sequestration of CO2 using microalgae to recycle CO2 into valuable products such as single-cell proteins (SCP) is one of the most promising fields nowadays. Microalgae are able to use CO2 as their carbon source and subsequently build carbohydrates, proteins, nucleic acids, and lipids. Nevertheless, all microalgae strains do not have the same CO2 tolerance and culture conditions. Moreover, pure CO2 is less soluble in water, which leads to a low carbon capture and fixation rate. Thus, to optimise SCP production in relation to CO2 mitigation, studies of the enhancement of solubilization of CO2 in water as well as the determination of the optimum process parameter for CO2 fixation and SCP production need to be done. Consequently, this study aims to review the cultivation conditions for single-cell protein production.

Assessing different glazing types for energy savings and CO2 reduction in a tropical climate: A comparative study

Energy efficiency in buildings and the mitigation of CO2 are key factors in the advancement of contemporary architecture, which includes aesthetic elements such as skylights, façades, and windows. Therefore, in this work the impact of different glazing types on energy savings and CO2 reduction was presented. A comparative analysis was conducted taking into account the climate-oriented approach in a specific climate context, Aw Köppen Climate Classification. Based on numerical results of the conjugate heat transfer in a two-dimensional geometry in a transient state, first, the glazing thermal performance under extreme weather conditions was evaluated, subsequently, an annual thermal evaluation was conducted. Triple glazing was highlighted as an effective option as it reduced heat loss by 56.5 % on the coldest day and reduced heat gain by 31.0 % on the warmest day in Mérida, Yucatán. Triple glazing also showed efficiency in reducing the total heat flux per unit area by 32.7 % under extreme temperature and solar radiation conditions, coldest day – south orientation and warmest day – west orientation. While glazing orientation showed a significant role in overheating, triple glazing decreased electricity consumption and CO2 emissions by 29 % per year, making it a leading choice for sustainable architecture.

Urban Pollutant Dispersion on a Turbulent Fluid Model

In 2019, more than 90% of the world’s population was living in places where pollutantconcentrations exceeded the air-quality guidelines. Anthropogenic activity has been the main cause of climate change in the last 20 years, especially in urban centres where industrial activities and motorized traffic mainly occur. This article presents a study of air pollutant dispersion by computational fluid dynamics modelling using OpenFOAM for urban street canyon simulations. The aim of this study was to investigate the influence of vegetation on natural ventilation, dispersion and CO2 mitigation. The behavior of pollutants was modeled by the Reynolds-averaged Navier–Stokes equations (RANS) and the k−ε fluid turbulence model. The results indicate that aerodynamic effects are more important at lower pollutant wind velocities, as they reduce turbulent dispersion and allow a higher reduction in the concentration of air pollutants. In addition, the direction of the wind, relative to the main axis of the street, had a significant impact on the results found. In general, in the presence of trees, perpendicular winds can lead to higher concentration of pollutants, while parallel winds allow improve air quality, considerably reducing those pollutant concentrations.

Sulfur-Doped porous carbon Adsorbent: A promising solution for effective and selective CO2 capture

The effective and selective capture of CO2 through the rational design of microstructures and the synthesis of carbon materials with enriched surface functionality is of utmost importance in mitigating CO2 emissions. In this study, we successfully prepared a novel type of S-doped porous carbon material with a high surface area and a significant volume of micropores in a straightforward manner. This was achieved by pyrolyzing carbonized coconut shells (CS) with potassium thiosulfate K2S2O3 (PT) as an activating and sulfur supply agent. By adjusting the pyrolysis temperature within the range of 650–750 °C, we obtained carbon materials with varying surface areas (887–1924 m2/g), pore volumes (0.35–0.95 cm3 g−1), and a homogeneous distribution of sulfur content (up to 12.26 wt%) within the carbon framework. The optimal S-doped porous carbon demonstrated the adsorption capacities of 3.59 mmol g−1 at 25 °C and 5.31 mmol g−1 at 0 °C under 1 bar. Additionally, the prepared sorbent exhibited favorable CO2/N2 selectivity, high isosteric heat, and stable cycling performance. These excellent CO2 capture properties can be attributed to the materials' high microporosity and well-dispersed sulfur functionality in the carbon framework. Collectively, these findings highlight the potential of these novel carbon materials with heteroatom doping as efficient adsorbents for the selective capture of CO2, presenting a viable solution in the quest for effective CO2 mitigation.

Five-dimensional assessment of China's centralized and distributed photovoltaic potential: From solar irradiation to CO2 mitigation

Owing to China's escalating demand for renewable energy and carbon emissions reduction, and given its prominent position as one of the fastest-growing nations in photovoltaic (PV) development, a comprehensive assessment of the potential of both centralized and distributed photovoltaic systems in China is crucial. However, current research on PV potential assessment presents several challenges. Therefore, this study presents a five-dimensional assessment model, encompassing geographical, technical, economic, CO2 mitigation, and realizable potential, to systematically map China's centralized photovoltaic (CPV) and distributed photovoltaic (DPV) potential. The findings underscore the vast PV potential across the country, with areas of 3.11 million km2 and 252.72 thousand km2 deemed suitable for CPV and DPV development, respectively. This corresponds to a technical potential of 416,383.27 and 28,261.53 TWh/yr for CPV and DPV, respectively. Furthermore, this study explored the economic potential of CPV and DPV, revealing that the generation costs of both CPV and DPV in China are in proximity to the feed-in tariffs. With technological advancements and economies of scale, a broader PV potential is projected to be economically feasible by 2030. Full implementation of the current economic potential can yield an annual CO2 mitigation of 54.20 and 8.39 gigatonnes (Gt) using CPV and DPV, respectively. Notably, China's PV potential exhibits distinct regional heterogeneity, with CPV potential concentrated primarily in the western region and DPV potential distributed predominantly across the eastern provinces. This study identified the most resource-intensive areas in the western region of Inner Mongolia for CPV and in the coastal regions of Guangdong and Shandong provinces for DPV. Considering policy imperatives and the development status, China's PV sector holds tremendous potential to significantly contribute to carbon reduction targets. Based on the findings, policy recommendations are proposed, emphasizing the imperative of jointly developing CPV and DPV systems, as well as implementing phased and planned growth strategies for PV growth.

Energy, economic, and environmental analysis of converging air-based photovoltaic-thermal (air/PV-T) systems: A yearly benchmarking

Two converging channel configurations of photovoltaic-thermal (PV-T) systems, i.e., inlet and outlet at different sides (Case 1) and the inlet at the middle and outlets at the sides (Case 2), are investigated numerically. The results reveal that Case 1 features a nearly uniform and lower temperature distribution (up to 7 °C) for practical air flows, and the appropriate convergence ratio is 2:1 (inlet to outlet channel height) for which the PV surface temperature is lower by 8 °C than that of a similar conventional collector. Meanwhile, energy analyses based on the so called ‘rate of extra energy gain per PV surface area, E˙Ac (W/m2)’ show that the air mass-flow rate has an optimal limit of ∼0.1 kg/m2. s for a typical conventional power plant conversion factor (PPCf) of 0.3–0.4. At this limit, up to 500 W extra power per unit area of PV module can be gained by changing a PV to its proposed counterpart PV-T system reducing the levelized cost of energy (LCOE) by an order of magnitude for the PV-T (0.02–0.054 $/kWh) compared to a standalone PV (0.037–0.146 $/kWh). Such PV-Ts show 10% and 150% net CO2 mitigation in comparison to the conventional PV-Ts and the corresponding standalone PVs.

Climate-smart fisheries: CO2 emissions reduction and food security are complementary

In the global north, climate-smart fisheries (CSF) policies prioritise steps to combat CO2 emissions from SSF, in a response to the fact that globally, CO2 emissions from small-scale fisheries (SSFs) increased by over 5.8 times between 1950 and 2016. However, in the global south, CSF policies on SSF prioritise food and income security over CO2 emission reduction. In this paper, we examine this apparently contrasting interpretation of CSF as a conceptual framework to interpret the case study of Sierra Leone, one of Africa’s poorest countries where we found that small-scale coastal fishers are preoccupied with mitigating the impact of climate change on their food and income security rather than with lowering their CO2 emissions. The self-image of SSF in Sierra Leone is that of being victims of climate change rather than perpetrators of it, and they justify this stance by claiming their livelihoods are being threatened by climate change. However, it could be argued that the best way to keep Sierra Leonean SSF CO2 emissions low is to prioritise their food and income security: in other words, that food security and CO2 reductions are complementary not contradictory. This, at any rate, is the argument of the current paper. The fieldwork for this study entailed co-created research in Sierra Leone and it involved 103 stakeholders who met face-to-face and online between January and March 2022 and through village meetings. The results of this fieldwork showed that food and income security and not CO2 emissions are the priorities in the stakeholders’ interpretation of CSF. However, if food and income security are not prioritised, communities are likely to adopt maladaptive strategies which undermine marine protected areas (MPAs) and exacerbate overfishing, thereby increasing CO2 emissions. Moreover, investment in aquaculture as a supplementary or alternative livelihood can directly increase food security and incomes and at the same time indirectly serve as a CO2 mitigation measure. In addition, weather information communication is an important CSF measure which both protects fishers from the impact of climate change and reduces their CO2 emissions. Accordingly, we argue that the contrast between reducing CO2 emissions and protecting food security from climate change may be more apparent than real in Sierra Leone coastal fisheries, since both policies may work in tandem together. This study therefore contributes a new interpretation of CSF in the global south: instead of seeing it as posing a conflict between CO2 emissions reductions and food security, we have shown the two objectives can be complementary. The wider implication of this paper is that CSF strategies for SSFs do not have to be polarised between the global north’s focus on the reduction of CO2 emissions from fishing vessels and the global south’s focus on the mitigation of the impact of global warming on SSFs. There are circumstances when the two objectives may be in harmony.

Comparative techno-economic and life cycle analyses of synthetic “drop-in” fuel production from UK wet biomass

Renewable synthetic hydrocarbon “drop-in” fuels can help mitigate greenhouse gas emissions from transport, particularly in hard-to-abate sectors like freight and aviation. However, no study has extensively addressed the concerns over biomass availability, cost viability, and CO2 reduction feasibility that are associated with diverse production configurations and feedstocks. Here, we report detailed techno-economics and life cycle greenhouse gas emission assessments of drop-in fuel productions via hydrothermal liquefaction to assess their economic viabilities, CO2 mitigation potentials, and prospects for scale-up specifically within the UK context. Our approach integrates key production factors which include regional availability of main feedstocks (digestates, food waste, biodegradable municipal waste, and sewage sludge), plant configurations (centralised vs decentralised) and hydrogen sources (grey, blue, green). We demonstrated the economic trade-off between economy-of-scale and feedstock transport distances in the centralised/decentralised configurations, and also the economic and emissions trade-offs associated with the use of different hydrogen sources. We find that co-processing of different waste feedstocks is an important strategy to minimise fuel selling price by enabling better economy of scale and feedstock transport, resulting in a fuel selling price of £14.76 – 20.30 per GJ. The corresponding greenhouse gas emissions from the co-processing case vary from 11.4 to 24.9 kgCO2eqperGJ for 2021, based on the consequential life cycle assessment approach. Furthermore, we estimated that the utilisation of key UK wet feedstocks could only provide 4.5 % of current fuel consumptions and reduce emissions by 4.5–5.4 Mt CO2eq/year, which translates to 3.4–4.0 % reduction in the UK’s 2021 transport emissions.

Technological changes and carbon neutrality targets in European countries: A sustainability approach with Fourier approximations

The diffusion of net-zero technologies is highly recommended as European Union (EU) countries aim for carbon neutrality by 2050. Germany, France, and the Netherlands are EU countries that invest heavily in environmental patents, and the relationship between patent development and carbon reduction in these countries provides important clues for carbon neutrality goals. Therefore, this study examines the effects of technological change (environmental patents), human capital, and income on carbon (CO2) emissions for three EU member countries over the period 1974–2019 under the Environmental Kuznets Curve (EKC) hypothesis. For this purpose, the study applies the Fourier-ADL approach and various time series estimators. The results of the study show that the EKC hypothesis is valid for EU countries and that human capital contributes to carbon reduction. Moreover, environmental patents contribute to CO2 mitigation in Germany, but environmental patents do not have a significant effect on emission reduction in France and the Netherlands. These results suggest that France and the Netherlands should invest more in environmental patents and, like Germany, benefit from the CO2 reduction effects of environmental patents.

Techno-economic analysis on CO2 mitigation by integrated carbon capture and methanation

Carbon capture and utilization (CCU) by methanation combines CO2 capture and Power-to-Gas (PtG) routes, and could simultaneously realize excess clean energy storage and industrial flue gas carbon mitigation. However, a problem of large energy consumption is associated with the long-chain CCU-methanation process. In contrast, integrated carbon capture and utilization (ICCU) could largely reduce energy consumption by integrating CO2 capture and methanation in just one reaction device. Although progressive work has been done on the development of ICCU-methanation, it still lacks of quantitative evaluation on the energy consumption and production cost. Herein, techno-economic analysis is conducted on calcium looping-based ICCU-methanation and the reference CCU-methanation. Results show that ICCU-methanation only requires 1/3 coal consumed by CCU-methanation to complete carbon capture of a 1000 MWe coal-fired power plant. When waste heat recovery is considered, the plant equipped with ICCU releases 83.6 kg CO2 per 1 MWe h−1 of electricity comparing to 148.93 kg of CCU. Meanwhile, CH4 cost by ICCU scheme is 837.1 € t−1, much lower than the 962.86 € t−1 of CCU. After taking the recovery of waste heat and carbon tax into account, the cost of CH4 produced by ICCU becomes to be 443.26 € t−1, approaching the market price of natural gas (429 € t−1), showing a promising application perspective.

Quantifying voyage optimisation with wind propulsion for short-term CO2 mitigation in shipping

The global shipping sector requires deep and rapid carbon reductions within a decade to align with Paris Agreement goals. Wind propulsion offers a retrofit option where sails provide renewable power to reduce emissions from a ship's engine. Combining wind propulsion with voyage optimisation shows synergistic potential, but the underlying technical mechanisms at play are poorly understood. Here, we model wind propulsion on globally distributed routes to show how voyage optimisation amplifies carbon saving to over 30% on ideal routes as ships exploit a critical dependency on wind speed and angle. Reduced shipping speeds further increase savings, and all technologies combine to reduce carbon by up to 60%, demonstrating the potential for substantial CO2 cuts from existing technologies. The findings challenge the sector to urgently broaden its narrow focus on alternative fuels by providing a steer on how to cut shipping's committed emissions and bring shipping closer to Paris Agreement goals.

Decarbonization of Agriculture: The Greenhouse Gas Impacts and Economics of Existing and Emerging Climate-Smart Practices.

The worldwide emphasis on reducing greenhouse gas (GHG) emissions has increased focus on the potential to mitigate emissions through climate-smart agricultural practices, including regenerative, digital, and controlled environment farming systems. The effectiveness of these solutions largely depends on their ability to address environmental concerns, generate economic returns, and meet supply chain needs. In this Review, we summarize the state of knowledge on the GHG impacts and profitability of these three existing and emerging farming systems. Although we find potential for CO2 mitigation in all three approaches (depending on site-specific and climatic factors), we point to the greater level of research covering the efficacy of regenerative and digital agriculture in tackling non-CO2 emissions (i.e., N2O and CH4), which account for the majority of agriculture's GHG footprint. Despite this greater research coverage, we still find significant methodological and data limitations in accounting for the major GHG fluxes of these practices, especially the lifetime CH4 footprint of more nascent climate-smart regenerative agriculture practices. Across the approaches explored, uncertainties remain about the overall efficacy and persistence of mitigation-particularly with respect to the offsetting of soil carbon sequestration gains by N2O emissions and the lifecycle emissions of controlled environment agriculture systems compared to traditional systems. We find that the economic feasibility of these practices is also system-specific, although regenerative agriculture is generally the most accessible climate-smart approach. Robust incentives (including carbon credit considerations), investments, and policy changes would make these practices more financially accessible to farmers.

Environmental impact and thermodynamic comparative optimization of CO2-based multi-energy systems powered with geothermal energy

The continuous increase in global population and energy demands has enhanced the use of fossil fuels. The evident climate change effect in recent years has brought about the necessity to reduce fossil fuels. Hence, there exists an aggregate problem of meeting energy demands and reducing carbon emissions. Renewable energy sources have been proffered as the probable solution; however, multi-energy systems are effective options/alternatives to solving this problem. In recent literature, geothermal energy has been proposed as a renewable energy source that can continuously meet energy demands. However, there exists a significant gap in literature about the most viable temperature range for geothermal energy applications in multi-energy systems. In this study, two innovative CO2-based systems namely, high-temperature geothermal multi-energy system (HTGMES) and low-temperature geothermal multi-energy system (LTGMES) are designed, modelled, analyzed, and compared using a thermodynamic approach. While the HTGMES is modelled to predominantly use CO2 as a working fluid, a novel modified absorption system is integrated with the LTGMES. The two systems are modelled to produce electricity, cooling/refrigeration effect, space heating, hydrogen, and hot water. The energy, exergy environmental, exergy destruction, and exergoeconomic methodology is used to evaluate the performance of the innovative GMESs. Also, multi-objective optimization of the HTGMES and the LTGMES is carried out in a bid to minimize the total product unit cost and maximize overall exergy efficiency. The environmental impact analysis of the proposed system is presented considering CO2 mitigation. The results from analyses showed that the overall energetic and exergetic efficiencies in steady state are 44. 22 % and 33.5 % for the HTGMES and 45.40% and 32.9 % for the LTGMES. The optimized LCOE, LCOC, and LCOH based on the total unit cost are 0.0573 $/kWh, 0.1833 $/kWh, and 11.59 $/kg for the HTGMES; 0.0323 $/kWh, 0.0032 $/kWh, and 11.9$/kg for the LTGMES. Furthermore, the optimized exergetic performance showed that the LTGMES can achieve as high as 64.54 % and 40.96 % energy and exergy efficiency.

Comparative experimental investigations on a low-cost solar cooker with energy storage materials for sustainable development

Solar energy has been the focus of attention in recent decades due to its abundance, inexhaustibility, and cost-effectiveness. To promote solar cooking, a cooking pot integrated with energy storage is developed and studied. It features a concentric cylindrical arrangement, with the inner cylinder used for cooking and the outer cylinder used for energy storage. Solar energy was concentrated using a parabolic dish, with water serving as the load. The thermal performance during non-sunshine hours was analyzed using energy storage media.Initially, four cases were considered. In case 1, no energy storage medium was used, while in cases 2, 3 and 4, pebbles, stearic acid and erythritol were used as the storage medium, respectively. Water was heated to nearly 100 °C, and the results were analyzed for heat retention and temperature variations. The cooking pot using erythritol recorded a maximum instantaneous energy efficiency of 52 % and exergy efficiency of 37 %. In all four cases, the water was maintained at higher temperatures than the surroundings until the next morning, a maximum temperature difference of around 27–28 °C between the load and surroundings was reported during case 3. For high temperature cooking, sunflower oil was used as heating load with erythritol in case 5. A temperature difference of 8–9 °C higher than the case 3 was observed in case 5. Heat loss coefficient for case 4 was lowest i.e., 2.75 W/m2K. The payback period for the cooking unit was around 10 months considering the cost of energy saved and CO2 mitigation.

Thermo-enviro-economic analysis of conventional steam distillation system for peppermint oil extraction

Present study explored thermo-enviro-economic analysis of commercial scale conventional steam distillation system for peppermint oil extraction. Effect of peppermint batch sizes on energy measures, net CO2 mitigation and net carbon credit earned are also investigated. Life cycle energy production factor (EPFs) and life cycle conversion efficiency (LCCE) are estimated to be 29.2, 33.1 and 38.9, and 12.6 %, 14.8 % and 17.9 % for 1500, 1700 and 1900 kg batch sizes, respectively, for 18 years of life span. Maximum energy and fuel consumption were 4,966 MJ and 193 kg for 1500 kg, respectively. Plant is anticipated to produce 24 kiloliters of peppermint oil per year with an estimated annual selling price of US$153,960 and profit after tax (PAT) of US$15,592 at a tax rate of 18 %. Return on investment (ROI), internal rate of return (IRR) and payback period (PBP) were 73.9 %, 85.7 % and 1.26 years, respectively. Distillation system has a total embodied energy of 166,237 kWh. Lifetime CO2 mitigation and net carbon credit earned are estimated to be 426.6, 438.5 and 568.8 tonnes and ₹1,95,239 (US$2,383.9), ₹2,63,049 (US$3,211.9) and ₹3,61,518 (US$4,414.3) for 1500, 1700, and 1900 kg batch size, respectively, if traded at the rate of 14.85 $/tonne. Profitability analysis pilot plant is highly rewarding and must be captivating for investors.

Climber ecology and CO2 mitigation potential in an urban landscape

Climber ecology and CO2 mitigation potential in an urban landscape

Modeling fuel moisture dynamics under climate change in Spain’s forests

BackgroundCurrent assessments of the effects of climate change on future wildfire risk are based on either empirical approaches or fire weather indices. No study has yet used process-based models over national scales to understand how and where will increases in climate aridity affect the likelihood of fire activity through changes in the moisture content of live (LFMC) and of dead (DFMC) fuels. Here, we used process-based models to forecast changes in LFMC and DFMC under the 21st century climatic conditions projected from moderate and high greenhouse gas emission scenarios (RCP4.5 and RCP8.5). Predictions were performed across broad productivity gradients in peninsular Spain to understand how productivity mediates the effects of climate change on fuel moisture dynamics.ResultsLFMC and DFMC were predicted to decline under the climatic conditions projected for the coming decades. Increases in the annual frequency of days with fuel moisture content below wildfire occurrence thresholds were predicted to extend fire season lengths by 20 days under RCP4.5 and by 50 days under RCP8.5. The effects of climate change on LFMC and DFMC varied linearly and negatively with productivity (stronger fuel moisture decreases in least productive environments). Although we observed a significant mitigation effect from rising CO2 (via increases in water-use efficiency), it was not enough to offset LFMC declining trends induced by increased temperature and aridity.ConclusionsWe predicted that the warmer and more arid climatic conditions projected for the 21st century will lead to generalized declines in fuel moisture, lengthening fire seasons, and increasing wildfire danger. The use of process-based models to forecast LFMC dynamics allowed the consideration of plant species capabilities to buffer climate change impacts. Significant increases in the fire season length predicted in the most productive environments, currently with large fire return intervals, would pose an increase of fire danger in major Spanish carbon sinks. Finally, the CO2 mitigation effect would not be enough to offset climate change-driven declines in seasonal LFMC levels.

SEWGS integration in a direct reduction steelmaking process for CO2 mitigation

The iron and steel industry represents one of the most carbon intensive sectors accounting for roughly 25% of CO2 emissions generated by the industrial sectors and for 7% of total energy sector emissions. The aim of this work is to assess the techno-economic analysis of the integration of the SEWGS technology in the DRI-EAF process to reduce the carbon footprint of this steelmaking route. The study has been carried out using plant data taken from literature and investigating possibilities of GHG mitigation by introducing carbon-capture technologies such as MEA and MDEA scrubbing or the SEWGS technology. The latter solution shows environmental and economic advantages compared to the cases based on amine scrubbing. A reduction of CO2 emissions close to 90%, with respect to the BF-BOF route, can be achieved with the implementation of the SEWGS when a renewable electricity scenario is considered. Economic KPIs such as the Levelised Cost of Hot Rolled Coil and the Cost of CO2 avoided have been computed for all the plants. In addition, a sensitivity analysis on natural gas and electricity prices has been carried out. The integration of the SEWGS technology represents a promising solution for the reduction of the carbon footprint of the DRI-EAF process and, potentially, it could be commercially viable in the near future considering that the DRI and EAF processes are already globally commercialised.

Iron and Steel Industry Emissions: A Global Analysis of Trends and Drivers.

The iron and steel industry (ISI) is important for socio-economic progress but emits greenhouse gases and air pollutants detrimental to climate and human health. Understanding its historical emission trends and drivers is crucial for future warming and pollution interventions. Here, we offer an exhaustive analysis of global ISI emissions over the past 60 years, forecasting up to 2050. We evaluate emissions of carbon dioxide and conventional and unconventional air pollutants, including heavy metals and polychlorinated dibenzodioxins and dibenzofurans. Based on this newly established inventory, we dissect the determinants of past emission trends and future trajectories. Results show varied trends for different pollutants. Specifically, PM2.5 emissions decreased consistently during the period 1970 to 2000, attributed to adoption of advanced production technologies. Conversely, NOx and SO2 began declining recently due to stringent controls in major contributors such as China, a trend expected to persist. Currently, end-of-pipe abatement technologies are key to PM2.5 reduction, whereas process modifications are central to CO2 mitigation. Projections suggest that by 2050, developing nations (excluding China) will contribute 52-54% of global ISI PM2.5 emissions, a rise from 29% in 2019. Long-term emission curtailment will necessitate the innovation and widespread adoption of new production and abatement technologies in emerging economies worldwide.

Mitigation of CO2 Emissions in Agro-Ecosystems by Composting of Tree Leaf Litter with Effective Microorganisms and Green Sunnhemp Plants

ABSTRACT Managing leaf litter by using different composting methods may be an alternative approach to solid waste management in rural areas. The purposes of the study were to prepare compost from an admixture of tree leaf litter using effective microorganisms (EM) and green sunnhemp plants and assess the patterns and cumulative amounts of carbon dioxide (CO2-C) emission and CO2 mitigation potential. The N content of leaf litter from both compost methods was significantly higher. The EM-treated compost had better concentrations of microbial biomass carbon (MBC), potassium, calcium, and magnesium. The low germination and vigor index were observed in compost treated with green sunnhemp plants. The CO2 emission patterns were similar in both leaf litter compost treatments. The composting techniques used in this study can save roughly 310 kg CO2eq in greenhouse gas (GHG) emissions. Composting leaf litter with EM and green sunnhemp plants could be a useful technique for lowering agriculture’s GHG emissions, besides helping to mitigate climate change, reducing the solid waste from rural areas, and minimizing the use of mineral fertilizer in agriculture.