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Background: The Greenhouse gas Observations of Biospheric and Local Emissions from the Upper sky (GOBLEU) is a new joint project by Japan Aerospace Exploration Agency (JAXA) and ANA HOLDING INC. (ANAHD), which operates ANA flights. GOBLEU aims to visualizes our climate mitigation effort progress in support of subnational climate mitigation by collecting greenhouse gas (GHG) data as well as relevant data for emissions (nitrous dioxide, NO2) and removals (Solar-Induced Fluorescence, SIF) from regular passenger flights. We developed a luggage-sized instrument based on the space remote-sensing techniques that JAXA has developed for Japan's Greenhouse gas Observing SATellite (GOSAT). The instrument can be conveniently installed on a coach-class passenger seat without modifying the seat or the aircraft. Results: The first GOBLEU observation was made on the flight from the Tokyo Haneda Airport to the Fukuoka Airport, with only the NO2 module activated. The collected high-spatial-resolution NO2 data were compared to that from the TROPOspheric Monitoring Instrument (TROPOMI) satellite and surface NO2 data from ground-based air quality monitoring stations. While GOBLEU and TROPOMI data shared the major concentration patterns largely driven by cities and large point sources, regardless of different observation times, we found fine-scale concentration pattern differences, which might be an indication of potential room for GOBLEU to bring in new emission information and thus is worth further examination. We also characterized the levels of NO2 spatial correlation that change over time. The quickly degrading correlation level of GOBLEU and TROPOMI suggests a potentially significant impact of the time difference between CO2 and NO2 as an emission marker and, thus, the significance of co-located observations planned by future space missions. Conclusions: GOBLEU proposes aircraft-based, cost-effective, frequent monitoring of greenhouse emissions by GOBLEU instruments carried on regular passenger aircraft. Theoretically, the GOBLEU instrument can be installed and operated in most commercially used passenger aircraft without modifications. JAXA and ANAHD wish to promote the observation technique by expanding the observation coverage and partnership to other countries by enhancing international cooperation under the Paris Agreement. [ABSTRACT FROM AUTHOR]

The EU faces two economic challenges: managing non-performing exposures (NPEs) and climate change. This paper analyzes the relationship between the NPEs of domestic banking groups and climate risks, including macroeconomic variables such as the GDP growth rate, unemployment rate (UnEmp), and the voice and accountability percentile (VCA) and the interaction variable between the GHG and the Rule of Law Percentile (GhGRLP). The estimation uses ordinary least squares with time-fixed and individual effects. Physical and transition risks significantly affect NPEs, showing that both adverse climate events and the transition to a low-carbon economy worsen the financial situation of European banking institutions. The analysis also revealed that increased levels of VCA lead to a rise in NPEs, while an increase in GhGRLP reduces NPEs. In contrast, financial institutions tend to recognize and report NPEs more accurately in contexts with greater transparency and accountability. In comparison, UnEmp negatively affects NPEs, suggesting that economic support measures during high unemployment can reduce NPEs in the subsequent period. In conclusion, climate risk management represents a crucial challenge for the financial stability of banking institutions. Policymakers and financial institutions must continue to develop and implement climate change mitigation and adaptation strategies to preserve financial system stability amid growing climate uncertainties. [ABSTRACT FROM AUTHOR]

Salt marshes provide many important ecosystem services, key among them being carbon sequestration. However, a large degree of uncertainty remains in salt marsh carbon budgets, particularly during colder months of the year when salt marsh microbial and vegetative activity is assumed to dormant. We also lack data on urban systems. In this study, we used an easily portable carbon dioxide sensor package to directly measure net carbon dioxide (CO2) fluxes throughout the winter in a temperate, urban salt marsh. We sampled across the dormant season both on normal (cold) temperature days and on days that were anomalously warm (defined here as air temperatures 2.8°C above the long-term average). We demonstrated that median (±mad) daytime CO2 fluxes doubled on the warm days, compared to cold days (1.7 ± 2 mmol m-2 h-1, 0.7 ± 1.3 mmol m-2 h-1, respectively). We also show that net CO2 emissions scaled with soil temperature. The high day-to-day variability, however, implies that infrequent or sparse measurements cannot sufficiently capture the temporal dynamics of dormant season salt marsh net CO2 fluxes. The magnitude of the net CO2 source from our sampling during the dormant season leads us to hypothesize that, as mean annual temperatures continue to increase, dormant season CO2 emissions from salt marshes will increasingly offset growing season carbon dioxide uptake. This change compromises the carbon sequestration capacity, and therefore the climate mitigation potential of these ecosystems. Future studies should focus on quantifying the impact of dormant season CO2, and other greenhouse gases on salt marsh carbon budgets. [ABSTRACT FROM AUTHOR]

Climate change mitigation technologies have been a focus in reducing atmospheric carbon levels for the past few years. One such mitigation technology is pyrolysis, where biomass feedstocks are combusted at elevated temperatures for varying durations to produce three main products: biochar, bio-oil, and biogas. While bio-oil and biogas are typically used to produce energy via further combustion, biochar can be used in several different applications. Furthermore, using forest harvest residues as a feedstock for biochar production helps use excess biomass from the forestry industry that was previously assumed unmarketable. In our study, we combined forest carbon analysis modelling with cradle-to-gate life cycle emissions to determine the greenhouse gas emissions of biochar produced from forest harvest residues. We examined three collection scenarios, spanning two harvesting methods in one forest management unit in northern Ontario, Canada. From our analysis, we observed immediate reductions (− 0.85 tCO2eq·tbiochar−1 in year 1) in CO2-equivalent emissions (CO2eq) when producing biochar from forest harvest residues that would have undergone controlled burning, without considering the end use of the biochar. For the forest harvest residues that would remain in-forest to decay over time, producing biochar would increase overall emissions by about 6 tCO2eq·tbiochar−1. Throughout the 100-year timeframe examined–in ascending order of cumulative emissions–scenario ranking was: full tree harvesting with slash pile burn < full tree harvesting with slash pile decay < cut-to-length/tree-length harvesting. Highlights: Cradle-to-gate life cycle analysis for biochar production was evaluated. Forest harvest collection methods influence overall life cycle emissions for biochar. Harvest residues that typically undergo controlled burning are an ideal feedstock. [ABSTRACT FROM AUTHOR]

Research on climate change mitigation has increasingly considered carbon pricing, with these efforts concentrating on reductions in carbon dioxide (CO2) emissions. Our comprehensive cross-country analysis extends this focus by quantitatively evaluating the effects of carbon pricing on four major pollutants: CO2, nitrous oxide (N2O), methane (CH4), and particulate matter (PM). We use regressions and introduce entropy balancing to this research area. Analyzing data from 132 countries from 1992 to 2019, we find that carbon pricing is associated with an average annual reduction in CO2 emissions by 3 percentage points. A one-unit increase in a coverage-weighted carbon price is associated with reductions in N2O emissions by approximately 0.1 percentage points. A shorter panel for 2010–2017 shows a larger impact of 0.3 percentage points for PM. These findings underline the efficacy of carbon pricing not just in curtailing CO2 but in significantly mitigating other harmful pollutants on a global scale. Reductions in pollutants beyond CO2 provide further motivation for policymakers to pursue carbon pricing. [ABSTRACT FROM AUTHOR]

Background: Mangrove ecosystems exhibit significant carbon storage and sequestration. Its capacity to store and sequester significant amounts of carbon makes this ecosystem very important for climate change mitigation. Indonesia, owing to the largest mangrove cover in the world, has approximately 3.14 PgC stored in the mangroves, or about 33% of all carbon stored in coastal ecosystems globally. Unfortunately, our comprehensive understanding of carbon flux is hampered by the incomplete repertoire of field measurement data, especially from mangrove ecosystem-rich regions such as Indonesia and Asia Pacific. This study fills the gap in greenhouse gases (GHGs) flux studies in mangrove ecosystems in Indonesia by quantifying the soil CO2 and CH4 fluxes for different land use types in mangrove ecosystems, i.e., secondary mangrove (SM), restored mangrove (RM), pond embankment (PE) and active aquaculture pond (AP). Environmental parameters such as soil pore salinity, soil pore water pH, soil temperature, air temperature, air humidity and rainfall are also measured. Results: GHG fluxes characteristics varied between land use types and ecological conditions. Secondary mangrove and exposed pond embankment are potential GHG flux sources (68.9 ± 7.0 and 58.5 ± 6.2 MgCO2e ha− 1 yr− 1, respectively). Aquaculture pond exhibits the lowest GHG fluxes among other land use types due to constant inundation that serve as a barrier for the release of GHG fluxes to the atmosphere. We found weak relationships between soil CO2 and CH4 fluxes and environmental parameters. Conclusions: The data and information on GHG fluxes from different land use types in the mangrove ecosystem will be of importance to accurately assess the potential of the mangrove ecosystem to sequester and emit GHGs. This will support the GHG emission reduction target and strategy that had been set up by the Indonesian Government in its Nationally Determined Contributions (NDC) and Indonesia's 2030 Forest and Other Land Use (FOLU) Net Sink. [ABSTRACT FROM AUTHOR]

Widespread adoption of regenerative agriculture practices is an integral part of the US plan to achieve net‐zero greenhouse gas emissions by 2050. National incentives have particularly increased for the adoption of cover crops (CCs), which have presumably large carbon (C) sequestration potential. However, assessments of national CC climate benefits have not fully considered regional variability, changing C sequestration rates over time, and potential N2O trade‐offs. Using the DayCent soil biogeochemical model and current national survey data, we estimate CC climate change mitigation potential to be 39.0 ± 24.1 Mt CO2e year−1, which is 45%–65% lower than previous estimates, with large uncertainty attributed to N2O impacts. Three‐fourths of this climate change mitigation potential is concentrated in the North Central, Southern Great Plains and Lower Mississippi regions. Public investment should be focused in these regions to maximize CC climate benefits, but the national contribution of CC to emissions targets may be lower than previously anticipated. [ABSTRACT FROM AUTHOR]

An accurate quantification of global methane sources and sinks is imperative for assessing realistic pathways to mitigate climate change. A key challenge of quantifying the Global Methane Budget (Saunois et al., 2020, https://doi.org/10.5194/essd‐12‐1561‐2020) is the lack of consistency in uncertainties between sectors. Here we provide a new perspective on bottom‐up (BU) and top‐down (TD) methane uncertainties by using an expert opinion analysis based on a questionnaire conducted in 2021. Expectedly, experts rank highest uncertainty and lowest confidence levels in the Global Methane Budget related to natural sources in BU budgets. Here, we further reveal specific uncertainty types and introduce a ranking system for uncertainties in each sector. We find that natural source uncertainty is related particularly to driver data uncertainty in freshwater, vegetation, and coastal/ocean sources, as well as parameter uncertainty in wetland models. Reducing uncertainties, most notably in aquatic and wetland sources will help balance future BU and TD global methane budgets. We suggest a new methane source partitioning over gradients of human disturbance and demonstrate that 76.3% (75.8%–79.4%) or 561 (443–700) Tg CH4 yr−1 of global emissions can be attributed to moderately impacted, man‐made, artificial, or fully anthropogenic sources and 23.7% (20.6%–24.2%) or 174 (115–223) Tg CH4 yr−1 to natural and low impacted methane sources. Finally, we identify current research gaps and provide a plan of action to reduce current uncertainties in the Global Methane Budget. Plain Language Summary: To effectively address climate change, it's crucial to gain a better understanding of the difficulties involved in estimating global methane sources and sinks. One of the key challenges in this process are the varying levels of uncertainty associated with different sectors responsible for methane emissions and methane uptake. In this study, we conducted a survey to gather expert opinions regarding the uncertainty of methane data. The experts highlighted that the Global Methane Budget has the highest uncertainty and lowest confidence levels when it comes to natural sources in the bottom‐up budgets. This uncertainty primarily stems from uncertain data related to natural sources like freshwater, vegetation, and coastal/ocean areas, as well as the parameters used in wetland models. We show that 76.3% of all global methane emissions are related to human‐impact or fully man‐made. Additionally, we identify existing gaps in research and lay out a plan of action to reduce the current uncertainties associated with the Global Methane Budget. This effort will contribute to a more accurate understanding of methane's role in climate change mitigation. Key Points: Highest uncertainty and lowest confidence levels were identified in bottom‐up natural emissions in the Global Methane BudgetHigh driver data uncertainties are associated with freshwater, vegetation, and coastal/ocean methane sourcesNew methane source partitioning reveals 76% of global emissions are related to moderate to high levels of anthropogenic impacts [ABSTRACT FROM AUTHOR]

Building energy consumption is an essential source of greenhouse gas (GHG) and air pollution. Green roofs can directly absorb ambient CO2 and remove air pollutants through their vegetation layers, but a limited number of studies have examined their effects on GHG and air pollutant reduction associated with building energy savings, especially in the context of climate change. This research examined the performance of green roofs on CO2 and air pollutant reduction, including SO2, PM2.5, and NOx, through building energy demand savings in Shanghai, China. Climate change mitigation effects were assessed based on the energy consumption of five types of buildings before and after the installation of green roofs under 2020 and 2050 climate conditions, respectively. EnergyPlus software 9.5.0 was applied to simulate hourly energy consumption for different building prototypes with and without green roofs. Green roofs on all building types exhibited positive energy savings on annual, monthly, and diurnal scales, and they can save more energy for most of the building types under the projected 2050 climate condition. Moreover, most of the building energy saved by green roofs came from the Heating, Ventilation, and Cooling (HVAC) systems. In addition, this study discovered that the energy-saving benefits of green roofs vary based on the type of building they were installed on. Green roofs were found to have the largest energy saving on the shopping mall, especially on extremely hot summer days. Finally, a Geographic Information System (GIS)-based approach was developed with the ability to quantify the amount of GHG and air pollutant reduction associated with building energy savings for existing buildings in the Huangpu District of Shanghai. This approach was also utilized to present the spatial distribution of buildings with different levels of suitability to install green roofs by considering their location attributes and air pollutant reduction potential together, which is the major innovation of this research. The purpose of this study is to provide valuable guidance to policy makers regarding the performance of green roofs in building energy-saving and air quality improvement in the urban environment when facing the challenge of climate change, which is essential for urban sustainability. [ABSTRACT FROM AUTHOR]

Greenhouse gas (GHG) emissions from the incineration of municipal solid waste (MSW) have become a concern in the solid waste community from the perspective of climate change mitigation and response. In this study, we aimed to estimate the GHG emissions from the incineration of MSW in Seoul, with a population of about 10 million, by using the IPCC (Intergovernmental Panel on Climate Change) 2006 guideline and scenario analysis for 2030 and 2040. In 2021, Seoul generated 2899 kt of MSW/yr. Approximately 40% (1163 kt/yr) of Seoul's MSW was disposable (or non-recyclable) waste. Out of the disposable waste, about 741 kt/yr of combustible waste was treated by incineration, resulting in 545 kt CO2 eq emissions, which was about 7.5 times higher than the 74 kt CO2 eq in 2000. The dominant contributor to the GHG emissions was plastic waste, accounting for the largest fraction of 92% (501 kt CO2 eq/yr in 2021). Scenario analysis showed that if the current situation (BAU scenario) is considered, with the assumption of no reduction in MSW generation, the capacity of Seoul's four incineration facilities will be exceeded in 2029. All other scenarios (S1, S2, and S3) showed reduced amounts of MSW incineration and GHG emissions compared to the BAU scenario. Especially, S3 (waste reduction and increased recycling rate) revealed a 53% reduction when compared to the BAU scenario. Based on the results of our scenario analysis, it is expected that in 2040, the GHG emissions from incineration will be in a range of from about 389 kt CO2 eq to 832 kt CO2 eq, depending on the waste minimization policy and recycling efforts in the future. Strengthened regulations on and efforts towards plastic waste reduction and the recycling of MSW will be crucial with the perspectives of GHG emissions by incineration and resource recovery. [ABSTRACT FROM AUTHOR]

Afforestation and reforestation (AR) on marginal land are nature-based solutions to climate change. There is a gap in understanding the climate mitigation potential of protection and commercial AR with different combinations of forest plantation management and wood utilization pathways. Here, we fill the gap using a dynamic, multiscale life cycle assessment to estimate one-century greenhouse gas (GHG) mitigation delivered by (both traditional and innovative) commercial and protection AR with different planting density and thinning regimes on marginal land in the southeastern United States. We found that innovative commercial AR generally mitigates more GHGs across 100 y (3.73 to 4.15 Giga tonnes of CO2 equivalent (Gt CO2e)) through cross-laminated timber (CLT) and biochar than protection AR (3.35 to 3.69 Gt CO2e) and commercial AR with traditional lumber production (3.17 to 3.51 Gt CO2e), especially in moderately cooler and dryer regions in this study with higher forest carbon yield, soil clay content, and CLT substitution. In a shorter timeframe (=50 y), protection AR is likely to deliver higher GHG mitigation. On average, for the same wood product, low-density plantations without thinning and high-density plantations with thinning mitigate more life cycle GHGs and result in higher carbon stock than that of low-density with thinning plantations. Commercial AR increases the carbon stock of standing plantations, wood products, and biochar, but the increases have uneven spatial distributions. Georgia (0.38 Gt C), Alabama (0.28 Gt C), and North Carolina (0.13 Gt C) have the largest carbon stock increases that can be prioritized for innovative commercial AR projects on marginal land. [ABSTRACT FROM AUTHOR]

Coastal habitats can play an important role in climate change mitigation. As Louisiana implements its climate action plan and the restoration and risk‐reduction projects outlined in its 2017 Louisiana Coastal Master Plan, it is critical to consider potential greenhouse gas (GHG) fluxes in coastal habitats. This study estimated the potential climate mitigation role of existing, converted, and restored coastal habitats for years 2005, 2020, 2025, 2030, and 2050, which align with the Governor of Louisiana's GHG reduction targets. An analytical framework was developed that considered (1) available scientific data on net ecosystem carbon balance fluxes per habitat and (2) habitat areas projected from modeling efforts used for the 2017 Louisiana Coastal Master Plan to estimate the net GHG flux of coastal area. The coastal area was estimated as net GHG sinks of −38.4 ± 10.6 and −43.2 ± 12.0 Tg CO2 equivalents (CO2e) in 2005 and 2020, respectively. The coastal area was projected to remain a net GHG sink in 2025 and 2030, both with and without the implementation of Coastal Master Plan projects (means ranged from −25.3 to −34.2 Tg CO2e). By 2050, with model‐projected wetland loss and conversion of coastal habitats to open water due to coastal erosion and relative sea level rise, Louisiana's coastal area was projected to become a net source of GHG emissions both with and without the Coastal Master Plan projects. However, in the year 2050, the Louisiana Coastal Master Plan project implementation was projected to avoid the release of +8.8 ± 1.3 Tg CO2e compared with an alternative with no action. Reduction in current and future stressors to coastal habitats, including impacts from sea level rise, as well as the implementation of restoration projects could help to ensure coastal areas remain a natural climate solution. [ABSTRACT FROM AUTHOR]

A comprehensive methane (CH4) budget, including spatial and temporal patterns of sources and sinks, is pivotal for effective climatic mitigation and prediction. This study used a bottom‐up approach to evaluate the CH4 budget of Asia during 1970–2021. Natural sources and sinks were evaluated using a process‐based biogeochemical model and with ground and satellite observations. Anthropogenic sources were evaluated using emission inventories produced by socioeconomic studies. During the 1970s and 2010s, anthropogenic emissions accounted for 78% and 84% of the emitted total CH4 budget of 140.2 and 207.6 Tg CH4 yr−1, respectively. Anthropogenic sources were responsible for a 49% increase in total emissions. During 2001–2021, Central, East, South, Southeast, and West Asia accounted for 3.3%, 35.1%, 25.6%, 23.1%, and 13.0%, respectively, of Asian emissions. Sectoral compositions and temporal variations differed among subregions. Emissions from paddy field soils in Asia were smaller in 2021 (33.6 Tg CH4 yr−1) than in 1970 (39.2 Tg CH4 yr−1) because of changes in agricultural production. Among natural sources, wetlands accounted for 63% of total emissions in East Asia, but geological emissions predominated in Central and West Asia. Interannual variability of the net CH4 budget was mainly due to wetland and biomass burning emissions, whereas decadal variability was due to anthropogenic sectors. δ13C‐CH4 and isoflux analysis of sector‐specific fluxes and isotopic ratios indicated the effects of the regional budget on atmospheric trends. Bottom‐up evaluations of regional budgets can provide information critical to the Global Stocktake of the Paris Agreement, the Global Methane Pledge, and other related actions. Key Points: We used a bottom‐up approach to estimate methane emissions from Asia and their spatial distribution during 1970–2021Asia was estimated to be a net source of methane of 207.6 Tg CH4 yr−1 in the 2010s, 84% of which came from anthropogenic sourcesThe estimated net emissions and their δ13C signature suggested that Asia made a large contribution to atmospheric methane trends [ABSTRACT FROM AUTHOR]

Background: Understanding and patterning the possible causal variables of global warming is attributed to the development of effective prevention and mitigation strategies for climate change. Therefore, we aimed to pattern and visualize the possible causal variables of global warming and measure the causality between them. Methods: We patterned and visualized the time series (103 years, from 1918 to 2020) of global surface temperature (GTemp) data with the gross domestic product (GDP) per capita, human population (Pop), and carbon dioxide (CO2) emissions of South Korea using a self-organizing map (SOM) and examined the causable local feature of global warming using the Granger causality (GC) test. The time-series data were trained and mapped in 4 × 4 SOM grids, and causality networks between variables were examined using multivariate Granger test statistics. Results: SOM patterned 103 years of data, and a dominant cluster contained continuous time-series data from 2007 to 2020. Similarly, the CO2 emissions of South Korea were obtained as a predictable unidirectional causal variable for GTemp from GC analysis. Based on data from the past 34 years, significant causality (p-value = 0.01) was observed with the integrated effect of Pop, GDP, and CO2 on GTemp. Conclusion: This study patterned the time-series data using SOM and examined the causal relationship between variables using the GC test. The study framework could be used as a reference by future scholars, ecologists, and the United Nations Sustainable Development Goals. [ABSTRACT FROM AUTHOR]

The race is on to achieve an important level of efficiency in the attainment of a circular economy in agriculture especially with the aim of sustainable nitrogen management. This cycle in the agricultural sector cuts across livestock farming, agriculture-induced waste generation, recycling and utilization, energy generation, crop production, ecosystem protection and environmental management through the mitigation of climate changes. In this work, we assess the process and functionalities of livestock waste generated from the piggery farm and their combinations with other by-products such as biochar and ash in comparison with mineral fertilization as sources of nitrogen applied in agricultural soil. The experiment was performed in a controlled environment with wheat (Triticum aestivum L.) grown in a neutral and an acidic soil. Pig manure was used as the primary feedstock, fed and processed to biogas and nutrient-rich digestate by the anaerobic digestion process. The results revealed that the co-amendments of pig manure digestate with biochar and ash had complimentary positive effect on measured indices such as mobile potassium, phosphorus, biomass yield and nitrogen use efficiency. The mineral nitrogen fertilizer significantly induced carbon dioxide emissions from day 35 when compared to emissions from the organic amendments. In contrast, the organic amendments influenced nitrous oxide emissions from the onset till day 30 before flattening out. The individual combination of pig manure digestate with biochar and ash had a negative influence on enzymatic activity (dehydrogenase). Soil microbial biomass carbon was induced across all treatments in both soil types. Pig manure digestate + ash and pig manure digestate had 32.1 and 48.8% soil microbial biomass increase in neutral soil and acidic soil, respectively. Overall, the processing and application of single-use amendment or in combination with biochar and ash holds huge potential in the optimization of nitrogen and carbon efficiency towards sustainable soil management via improving soil quality, carbon sequestration and climate change. [ABSTRACT FROM AUTHOR]

The aquatic landscapes of the Sacramento-San Joaquin Delta (hereafter, the Delta) and Suisun Bay represent both a significant past and future soil carbon stock. Historical alterations of hydrologic flows have led to depletion of soil carbon stocks via emissions of carbon dioxide (CO2), and loss of elevation as a result of subsidence. Optimizing ecosystem hydrology in the Delta and Suisun Bay could both reduce and reverse subsidence while also providing significant opportunities for climate mitigation and adaptation. Emissions of greenhouse gases (GHGs)--notably CO2, methane (CH4), and nitrous oxide (N2O)--contribute to global warming at different rates and intensities, requiring GHG accounting and modeling to assess the relative benefits of management options. Decades of data collection, model building, and map development suggest that past and current management actions have both caused--and can mitigate--losses of soil carbon. We review here the magnitude of potential GHG offsets, management options that may be achievable, and trade-offs of carbon storage under different land management. Using a land-use/land-cover framework to assess these management options, we describe the potential of three interventions (impoundment to reverse subsidence, agricultural management, and tidal reintroduction and/or maintained connectivity), both in acreage and radiative balance to clarify their relative influence on the region's GHG balance today and in relation to its millennial history. From floodplains to farming to floating aquatic vegetation, we find specific scalable strategies to manage hydrology that can alter regional GHG balance. Preservation of soil carbon stocks and restoration of net atmospheric CO2 fluxes into soils are the primary route to net negative emissions in the Delta and Suisun Bay, with CH4 emission management occurring in a supporting role. Over a 40-year horizon of climate-mitigation markets, the resilience of different aquatic habitats introduces the most uncertainty, from expected and unexpected hydrologic changes associated with land, ocean, and operational water flows. [ABSTRACT FROM AUTHOR]

To effectively mitigate climate change, policymakers worldwide established various GHG tracking and trading systems. In the light of ambitious climate goals, stricter regulations, and increasing demand for climate action, various groups such as researchers and governmental institutions suggested additional approaches. This paper addresses the complexity that arises from the breadth of suggested approaches and implemented systems for GHG tracking and trading. By doing so, it synthesizes relevant dimensions in a way that is understandable to enterprises and policymakers, enabling them to design meaningful systems incorporating the reduction of GHG emissions and advance cleaner production. Therefore, this paper presents a first-of-its-kind taxonomy of GHG tracking and trading approaches through a systematic literature review. It illustrates ten main design and implementation dimensions with 30 corresponding characteristics. To accelerate decarbonization, this paper sets impulses for future GHG tracking in the electricity sector based on semi-structured expert interviews. Consecutively, it provides policy directions for CO 2 -adaptive decision-making for enterprises, formulated as a Call for Action with seven prospective questions. These include, for example, questions concerning technical aspects like data management, legal issues like the sufficiency of existing data security and privacy regulations, as well as economic topics like the calculation of an appropriate local and temporal granularity. • Presenting a first-of-its-kind taxonomy of GHG tracking and trading approaches through a systematic literature review. • Creating targeted knowledge for enterprises and policymakers for designing meaningful systems to reduce GHG emissions. • Setting impulses for future GHG tracking in the electricity sector based on semi-structured expert interviews. • Providing policy directions for CO 2 -adaptive decision-making for enterprises, formulated as a Call for Action. [ABSTRACT FROM AUTHOR]

Forests mitigate climate change by absorbing CO2. However, N2O emissions in forests, which has 298 times larger global warming potential than CO2, can diminish the climate mitigation role of forests. Thus, it is crucial to project not only CO2 absorption but also N2O emissions in forests to provide a scientific basis for the 1.5 °C Paris Agreement goal. This study used a biogeochemical model, called FBD-CAN, to project CO2 absorption and N2O emissions of South Korean forests from 2021 to 2080 under three climate scenarios, including the current climate, Representative Concentration Pathway (RCP) 4.5, and RCP 8.5. From 2021 to 2080, CO2 absorption decreased from 5.0 to 1.4 Mg CO2 ha—1 year—1 under the current climate with the aging of forests, while N2O emissions increased from 0.25 to 0.33 Mg CO2 eq. ha—1 year—1. Climate change accelerated the decreasing trend in CO2 absorption and the increasing trend in N2O emissions. The subalpine region had a faster decreasing trend in CO2 absorption than the central and southern regions due to its older stand age. These findings provide scientific references for future greenhouse gas reduction plans and broaden our knowledge of the impacts of climate change on the climate mitigation role of forests. [ABSTRACT FROM AUTHOR]

Double-cropping rice systems lead to intensive greenhouse gas emissions. No-tillage in late-rice season may be a viable practice to mitigate greenhouse gas emissions without compromising rice yield. A field experiment was conducted with two treatments: tillage for both early-and late-rice (T-T) and tillage for early-rice whereas no-tillage for late-rice (T-NT). The mitigation effect of no-tillage on CH4 was mainly observed in the early vegetative stage. The difference of N2O fluxes between the treatments was mainly observed after fertilization. For the T-T and the T-NT in late-rice season, respectively, seasonal CH4 emissions were 575.1 and 502.9 kg ha−1, seasonal N2O emissions were 0.074 and 0.218 kg ha−1, and rice yields were 5687 and 5169 kg ha−1. CH4 emission was responsible for more than 99% of the global warming potential (GWP). As a result, the T-NT decreased area-scaled GWP by 12.3%, but only decreased yield-scaled GWP by 3.0% due to yield decline by 9.1%. These results reveal that the T-NT is an effective practice in mitigating area-scaled GWP, the risk of yield loss, however, will undermine farmers' willingness to adopt the practice. [ABSTRACT FROM AUTHOR]

Atmospheric methane (CH4) concentrations have shown a puzzling resumption in growth since 2007 following a period of stabilization from 2000 to 2006. Multiple hypotheses have been proposed to explain the temporal variations in CH4 growth, and attribute the rise of atmospheric CH4 either to increases in emissions from fossil fuel activities, agriculture and natural wetlands, or to a decrease in the atmospheric chemical sink. Here, we use a comprehensive ensemble of CH4 source estimates and isotopic δ13C-CH4 source signature data to show that the resumption of CH4 growth is most likely due to increased anthropogenic emissions. Our emission scenarios that have the fewest biases with respect to isotopic composition suggest that the agriculture, landfill and waste sectors were responsible for 53 ± 13% of the renewed growth over the period 2007–2017 compared to 2000–2006; industrial fossil fuel sources explained an additional 34 ± 24%, and wetland sources contributed the least at 13 ± 9%. The hypothesis that a large increase in emissions from natural wetlands drove the decrease in atmospheric δ13C-CH4 values cannot be reconciled with current process-based wetland CH4 models. This finding suggests the need for increased wetland measurements to better understand the contemporary and future role of wetlands in the rise of atmospheric methane and climate feedback. Our findings highlight the predominant role of anthropogenic activities in driving the growth of atmospheric CH4 concentrations. [ABSTRACT FROM AUTHOR]

Can nuclear energy be much help when it comes to fighting climate change? Or have nuclear energy advocates greatly overstated their case? The likelihood that nuclear power will play a significant role in mitigating climate change is very low, absent a game-changing innovation that allows cheaper, safer nuclear power plants to come on-line much more quickly. [ABSTRACT FROM PUBLISHER]

Land use change specially affects greenhouse gas (GHG) emissions, and it can act as a sink/source of GHGs. Alterations in edaphic properties and microbial attributes induced by land use change can individually/interactively contribute to GHG emissions, but how they predictably affect soil CO2, CH4, and N2O emissions remain unclear. Here, we investigated the direct and indirect controls of edaphic properties (i.e., dissolved organic carbon [DOC], soil organic C, total nitrogen, C:N ratio, NH4+‐N, NO3‐‐N, soil temperature [ST], soil moisture [SM], pH, and bulk density [BD]) and microbial attributes (i.e., total phospholipid fatty acids [PLFAs], 18:1ω7c, nitrifying genes [ammonia‐oxidizing archaea, ammonia‐oxidizing bacteria], and denitrifying genes [nirS, nirK, and nosZ]) over the annual soil CO2, CH4, and N2O emissions from the woodland, shrubland, and abandoned land in subtropical China. Soil CO2 and N2O emissions were higher in the afforested lands (woodland and shrubland) than in the abandoned land, but the annual cumulative CH4 uptake did not significantly differ among all land use types. The CO2 emission was positively associated with microbial activities (e.g., total PLFAs), while the CH4 uptake was tightly correlated with soil environments (i.e., ST and SM) and chemical properties (i.e., DOC, C:N ratio, and NH4+‐N concentration), but not significantly related to the methanotrophic bacteria (i.e., 18:1ω7c). Whereas, soil N2O emission was positively associated with nitrifying genes, but negatively correlated with denitrifying genes especially nosZ. Overall, our results suggested that soil CO2 and N2O emissions were directly dependent on microbial attributes, and soil CH4 uptake was more directly related to edaphic properties rather than microbial attributes. Thus, different patterns of soil CO2, CH4, and N2O emissions and associated controls following land use change provided novel insights into predicting the effects of afforestation on climate change mitigation outcomes. [ABSTRACT FROM AUTHOR]

Growing attention has been paid to greenhouse gases (GHG) viz. carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O), due to their contribution to global warming. Biochar is used widely in agricultural soils to improve some soil properties, enhance soil nutrients, and mitigate GHG emissions. However, the previous studies on acidic soils reported contradictory results of CO2, CH4, or N2O emissions due to various factors that vary based on the properties of soil and biochar. The data on the impact of biochar application on GHG emissions in alkaline soils are limited, and because of the alkaline nature of biochar, it is expected to behave similarly as on acidic soil. However, contradictory results are noticed also in the alkaline soils, especially in CO2 and CH4. Therefore, this review gives insight into the contradictory results of CO2, CH4, or N2O emissions as affected by biochar with a special focus on alkaline soils and the potential factors included in this process. Article Highlights: This review is aimed at summarizing the effect of applying biochar on GHG emissions. The data on the impact of biochar application on GHG emissions in alkaline soils are scarce, and because of the alkaline nature of biochar, it is expected not a different behavior compared to acidic soil. This review is designed to give insight into the recent scientific research of the contradictory results of applying biochar to GHG emissions with particular insight into alkaline soils. [ABSTRACT FROM AUTHOR]

The current study makes use of life cycle assessment to evaluate the potential greenhouse gas (GHG) savings in coal electricity generation by 5% co-firing with sorghum pellets. The research models the utilization of 100 thousand hectares of under-utilized marginal land in Flores (Indonesia) for biomass sorghum cultivation. Based on equivalent energy content, 1.12 tons of pellets can substitute one ton of coal. The calculated fossil energy ratio of the pellets was 5.8, indicating that the production of pellets for fuel is energetically feasible. Based on a biomass yield of 48 ton/ha·yr, 4.8 million tons of pellets can be produced annually. In comparison with a coal system, the combustion of only pellets to generate 8,300 GWh of electricity can reduce global warming impacts by 7.9 million tons of CO2-eq, which is equivalent to an 85% reduction in GHG emissions. However, these results changed when reduced biomass yield of 24 ton/ha·yr, biomass loss, field emissions, and incomplete combustion were considered in the model. A sensitivity analysis of the above factors showed that the potential GHG savings could decrease from the initially projected 85% to as low as 70%. Overall, the production of sorghum pellets in Flores and their utilization for electricity generation can significantly reduce the reliance on fossil fuels and contribute to climate change mitigation. Some limitations to these conclusions were also discussed herein. The results of this scenario study can assist the Indonesian government in exploring the potential utilization of marginal land for bioenergy development, both in Indonesia and beyond.

Greenhouse gas (GHG) research has traditionally required data collection and analysis using advanced and often expensive instruments, complex and proprietary software, and skilled technicians. Partly as a result, relatively little GHG research has been conducted in resource-constrained developing countries and a critical data gap exists in these regions. At the same time, these are the same countries and regions in which climate-change impacts will likely be strongest, and in which major science uncertainties are centered, given the importance of dryland and tropical systems to the global carbon cycle and climate. Increasingly, scientific communities have adopted appropriate technology and approach (AT&A) for GHG research, including low-cost and low-technology instruments, open source software and data, and participatory and networking-based research approaches. Adopting AT&A can mean acquiring data with fewer technical constraints and lower economic burden, and is thus a strategy for enhancing GHG research in developing countries. However, AT&A can be characterized by higher uncertainties; these can often be mitigated by carefully designing experimental set-up, providing clear protocols for data collection, and monitoring and validating the quality of obtained data. For implementing this approach in GHG research of developing countries, first, it is necessary to recognize the scientific and moral importance of AT&A. At the same time, new AT&A techniques should be identified and further developed. Finally, these processes should be promoted through training local staff and encouraged for wide use and further innovation in developing countries. [ABSTRACT FROM AUTHOR]

Southeast Asia (SEA) is a key producer and exporter of rice, accounting for around 28% of rice produced globally. To effectively mitigate greenhouse gas (GHG) emissions in SEA rice systems, field methane (CH 4) and nitrous oxide (N 2 O) emissions have been intensively studied. However, an integrated assessment of system-level GHG emissions which includes other carbon (C) balance components, such as soil organic carbon (SOC) or energy use, that can positively or negatively influence the net capacity for climate change mitigation is lacking. We conducted a systematic review of published research in SEA rice systems to synthesize findings across four main components of net system emissions: (1) field GHG emissions, (2) energy inputs, (3) residue utilization beyond the field, and (4) SOC change. The objectives were to highlight effective mitigation opportunities and explore cross-component effects to identify tradeoffs and key knowledge gaps. Field GHG emissions were the largest contributor to net system emissions in agreement with existing scientific consensus, with results showing that practices such as floodwater drainage and residue removal are sound options for CH 4 mitigation. On the other hand, increasing SOC potentially provides a large GHG mitigation opportunity, with long-term continuous rice cropping and practices such as residue incorporation and biochar application promoting SOC increase. A reduction in energy inputs was mainly achieved by optimizing agrochemical use, especially N fertilizers. For residue utilization beyond the field, GHG emission mitigation mainly came from preventing open field burning through residue removal. Removed residue can subsequently be used for producing energy that offsets GHG emissions associated with conventional fuel sources (e.g. fossil fuel-based electricity generation) or substituting material used in other production systems. Integrating all four components of net system emissions into one analysis underscores the following two main takeaways. First, the components of field GHG emissions and SOC change are the biggest opportunities for reducing net system emissions and need to be considered for effective climate change mitigation. Second, the reduction of C inputs through residue removal and increased soil aeration through multiple drainage will lower CH 4 emissions but may also potentially decrease SOC stocks over time. Hence, we argue that future research needs to consider cross-component effects to optimize net system emissions, specifically the "stacking" of best management practices for mitigation related to field GHG emissions or SOC change in long-term experiments. • Net system emissions include field CH 4 /N 2 O emissions, energy inputs, residue utilization, and SOC change. • Integrated review highlights cross-component effects of management including tradeoffs. • Field GHG emissions and SOC change are the largest opportunities for mitigation. • Reduced C inputs and drainage decrease CH 4 emissions, but may negatively affect SOC. • "Stacking" of best management practices is a key knowledge gap that warrants research. [ABSTRACT FROM AUTHOR]

Green manure is a widely applied to increase grain yield, while it also attributes to greenhouse gas (GHG) emissions in agriculture ecosystems. Combining green manure with inorganic fertilizer inputs is a common practice that can influence soil GHG emissions and grain yield, however, its impacts on grain yield and global warming potential (GWP) under different initial soil conditions before rotating experiments and agronomic management in paddy fields remain unclear. We synthesized 508 data pairs to evaluate the responses of CO 2 emissions, CH 4 emissions, N 2 O emissions, and grain yield to combined inputs of green manure plus inorganic fertilizer compared with only inorganic fertilizer application. Our findings indicate that both inorganic fertilizer plus extra green manure (GM-E) and green manure substitutes for inorganic fertilizer (GM-S) could increase CO 2 emissions (22.5 %−76.8 %), CH 4 emissions (100 %−103 %), N 2 O emissions (29.8 %−50.9 %), and yield (2.21 %−19.6 %). Except for GM-E, which showed a non-significant increase in grain yield. The initial soil properties before rotating experiments, the types and timing of green manure application were key drivers of GHG emissions and yield, and extra green manure applied in areas with low initial soil pH and high C:N can increase GWP and yield. Overall, the mixed green manure application had greater impact than leguminous or non-leguminous green manure applied alone. The responses of GHG emissions and yield to GM-S were modulated by mean annual precipitation and initial soil properties before rotating experiments, and green manure substitutes for inorganic fertilizer in areas with high initial soil pH and low C:N can increase GWP and yield. Meanwhile, excessive precipitation caused a reduction in yield and a significant increase in GWP intensity. Our results showed that extra green manure applications of less than 68.1 kg N ha−1 would not significantly increase GWP. Therefore, an effective green manure strategy can achieve a win-win situation for the dual challenge of agricultural production and climate change mitigation. • Green manure inputs significantly increased GHG emissions from paddy fields. • Green manure combined inorganic fertilizer may not increase the yield significantly. • Mixed green manure had greater impact than single-type green manure application. • Green manure substitutes for inorganic fertilizer may not increase the GWPI. • Extra green manure (<68.1 kg N ha-1) is recommended to achieve a win-win situation. [ABSTRACT FROM AUTHOR]

Biochar produced in cookstoves has the potential to contribute to negative carbon emissions through sequestration of biomass carbon while also providing other benefits for sustainable development, including provision of clean renewable energy and increased yields in tropical agriculture. The aim of the reported research was to estimate effects on food production, household energy access and life cycle climate impact from introduction of biochar-producing cookstoves on smallholder farms in Kenya. Participatory research on biochar production and use was undertaken with 150 Kenyan smallholder farming households. Gasifier cookstove functionality, fuel efficiency and emissions were measured, as well as biochar effects on agricultural yields after application to soil. Cookstoves provided benefits through reduced smoke, fuel wood savings and char production, but challenges were found related to labour for fuel preparation, lighting and refilling. On-farm trials with varying rates of biochar inputs, in combination with and without mineral fertilizers, have led to a sustained increase of maize yields following one-time application. The climate impact in a life cycle perspective was considerably lower for the system with cookstove production of biochar and use of biochar in agriculture than for current cooking practices. Climate benefits from biochar production and use are thus possible on smallholder farms in sub-Saharan Africa, through reduced use of biomass in cooking, reduced emissions of products of incomplete combustion and sequestration of stable biochar carbon in soils. Biochar-producing cookstoves can be implemented as a climate change mitigation method in rural sub-Saharan Africa. Successful implementation will require changes in cooking systems including fuel supply, as well as farming systems, which, in turn, requires an understanding of local socio-cultural conditions, including power relations and gender aspects. [ABSTRACT FROM AUTHOR]

Purpose: Consumption- and production-based accounting approaches for national greenhouse gas (GHG) emissions provide different insights to support climate policymaking. However, no study has yet comprehensively assessed the consumption-based GHG emissions of the entire New Zealand's economy. This research, for the first time, quantified New Zealand's GHG emissions using both consumption- and production-based accounting approaches and considered the policy implications for adopting a consumption-based approach over a production-based approach. Methods: A global multi-regional input-output (MRIO) analysis was undertaken to calculate the consumption- and production-based GHG emissions of New Zealand for the year 2012. The MRIO analysis was based on the Eora database, which accounts for 14,839 industry sectors from 189 countries. Given the sectoral classification of each country is quite different and in order to ease interpretation of the results, the industry sectors of each country were classified and aggregated into 16 key sectors, and GHG emissions were calculated for those key sectors. Results and discussion: The MRIO analysis showed that New Zealand's consumption- and production-based GHG emissions in 2012 were 61,850 and 81,667 ktCO2eq, respectively, indicating that the country was a net exporter of GHG emissions in 2012. The dominant contributors to the consumption-based GHG emissions were the other services and construction key sectors (each representing 16% of consumption-based emissions), followed by food and beverages (14%), transport and equipment (12%) and financial and trade services (11%), whereas the dominant contributor to the production-based GHG emissions was the agriculture key sector (representing 52% of production-based GHG emissions). The results of the study provided two key insights to support climate mitigation activities and policymaking. First, the consumption- and production-based accounting approaches results have different rankings for the most dominant sectors contributing to New Zealand's GHG emissions. Second, only the consumption-based accounting approach enables the quantification of the embodied emissions in New Zealand's trade activities, and it indicated that a large proportion of GHG emissions are embodied in New Zealand's trade activities. These insights, therefore, have important implications for future policies that could positively influence the consumption patterns of New Zealand citizens and the production structure and efficiency of New Zealand's trade partners. Conclusions: This research quantified New Zealand's GHG emissions using both consumption- and production-based accounting approaches. Given the two accounting approaches provided different insights, both approaches should be used in a complementary way when developing climate policies. However, implementation of a consumption-based accounting approach to support development and implementation of climate policies and instruments requires further consideration. [ABSTRACT FROM AUTHOR]

Importance Ophthalmology faces imperatives to improve sustainability, but there is uncertainty about how to respond. Background: We sought New Zealand ophthalmologists' opinions on climate change, sustainability and the role of ophthalmologists in responding to these issues, as well as information on the extent that ophthalmology practices are acting on sustainability. Design Anonymous online survey of New Zealand fellows and trainees (178) of the Royal Australian and New Zealand College of Ophthalmologists (RANZCO) was conducted. Participants: Forty‐seven respondents (response rate 26%) were included in the study. Methods: Respondents were asked their level of agreement with statements on climate, health and sustainability and invited to comment. Current sustainability activities were collected from clinical leaders and directors of hospital departments and private practices. Main Outcome Measure: Distribution of agreement scores was the main outcome measure. Results: Agreement with mainstream positions on climate change was as expected. A minority of up to 19% expressed the opinion that climate change was not due to human activity, and did not require mitigation. Younger ophthalmologists tended to have greater agreement with the need for broad‐based political action on climate mitigation than those aged over 50 years. Most practices had room to improve on reducing waste, travel and carbon footprints. Conclusions and Relevance: The majority of New Zealand ophthalmologists are concerned about anthropogenic climate change. Currently, sustainability is not a performance indicator for New Zealand district health boards, so there is limited incentive to drive improvements. These data form a reference point to compare future opinions and ophthalmology carbon footprinting. [ABSTRACT FROM AUTHOR]

It is obvious that Iran agricultural industry, unlike Brazil and USA, cannot afford to provide conventional biomass, i.e. sugary or starchy biomass for bioethanol production, mainly due to climatic and geographic conditions. With some exception of date (fruit), first-generation ethanol production triggers food vs. fuel debates in Iran and put nation to hunger. Agricultural products including apple, barley, carrot, corn, grape, orange, potato, rice, sugar beet, sugarcane, and wheat are consumed domestically, exported, or even lost because of poor harvesting and processing conditions such as transportation or packaging. These products may alone generate 21.56 million ton per annum green wastes upon processing in the food industry. Every year about 5.4 billion liters of bioethanol can be produced by establishing second-generation ethanol plants next to the food processing sectors. Seventy-seven-percent of this amount of bioethanol can easily support 5% ethanol (E5) policy to phase out the consumption of 4.2 billion liters methyl tert-butyl ether (MTBE) for raising the octane number of gasoline in the country. If more comprehensive policy is adopted, larger quantities of lignocellulosic feedstocks can be gathered from agro as well as forestry practices. Second-generation bioethanol technology can help Iran to tackle air pollution in its big cities and to address the adverse effects of MTBE on its populations and ecosystem. The other advantages are improvement of fuel security, mitigation of climate change, and development of economy. The motivation can be created through passing a framework policy to cut fossil fuel subsidies, to mandate bioethanol blends in gasoline, and to impose carbon taxes. Development of coherent socially and environmentally relevant strategies and facilitation of investment in bioethanol industry are also necessary. • Agro-food industry generates more than 21.56 million ton wastes each year in Iran. • 5.4 billion liters of ethanol can be obtained annually by conversion of Iranian wastes. • Iranian law-makers must mandate the use of ethanol or its derivatives in gasoline. • 4.2 billion liters of MTBE can be replaced annually by bioethanol in Iran. • Higher ethanol ratios in gasoline can efficiently reduce air pollution in big cities. [ABSTRACT FROM AUTHOR]

A displacement factor (DF) may be used to describe the efficiency of using wood-based products or fuels instead of fossil-based ones to reduce net greenhouse gas (GHG) emissions. However, the DFs of individual products and their production volumes could not be used alone to evaluate the climate impacts of forest utilization. For this reason, in this study we have developed a methodology to assess a required displacement factor (RDF) for all wood products and bioenergy manufactured and harvested in a certain country in order to achieve zero CO 2 equivalent emissions from increased forest utilization over time in comparison with a selected baseline harvesting scenario. Input data for calculations were produced with the simulation model, Monsu, capable of predicting the carbon stocks of forests and wood-based products. We tested the calculations in Finnish conditions in a 100-year time horizon and estimated the current average DF of manufactured wood-based products and fuels in Finland for the interpretation of RDF results. The results showed that if domestic wood harvesting will be increased by 17–33% compared to the basic scenario, the RDF will be 2.0 to 2.4 tC tC−1 for increased wood use in 2017–2116. However, the estimated average DF of manufactured wood-based products and fuels currently in Finland was less than 1.1 tC tC−1. The results indicate strongly that the increased harvesting intensity from the current situation would represent a challenge for the Finnish forest-based bioeconomy from the viewpoint of climate change mitigation. For this reason, there is an immediate need to improve reliability and applicability of the RDF approach by repeating corresponding calculations in different circumstances and by improving estimations of DF s on country levels. • Displacement factor (DF) describes the substitution climate impact of wood use. • We estimated required displacement factor (RDF) to achieve zero emissions. • RDF should be 2.0–2.4 tC tC−1 for increased wood use in 2017–2116 in Finland. • RDF appears greater than the estimated current average DF. • This is a threat for forest-based bioeconomy from the climate change viewpoint. [ABSTRACT FROM AUTHOR]

Rice is the main staple food for more than half of the world's population, but rice cultivation is a significant source of atmospheric methane (CH 4). Alternate wetting and drying (AWD) reduces CH 4 emission from paddy field, but the effect on rice yield remains unclear. Organic soil amendment increases grain yield but simultaneously increases CH 4 emission. Therefore, the combination of AWD and organic amendment may compensate for each other's shortcomings. The objective of this study was to assess whether AWD and organic amendment can increase rice yield while mitigating CH 4 emission. The experiments were conducted in a farmer's paddy field in Thua Thien Hue province, Vietnam, during five consecutive rice growing seasons in 2019–2021. Two water management practices, continuous flooding (CF) and AWD, with (+O) or without (−O) the application of a commercially available organic fertilizer were examined under normal cultivation conditions. Compared with CF, AWD significantly reduced CH 4 emission by 34 %, increased nitrous oxide (N 2 O) by 46 %, and increased grain yield by 4.4 %. The +O treatment significantly increased the yield by 3.7 % relative to −O. Relative to CF−O by season, AWD+O significantly increased the yield. The integrated global warming potential of CH 4 and N 2 O emissions was decreased by 33 % and irrigation water use was reduced by 33 % in AWD plots relative to that in CF plots. These results indicate that AWD by itself has the potential to increase rice yield as well as reduce CH 4 emission, and the combination of AWD with organic amendment would ensure yield increase. • AWD increased rice yield, reduced CH 4 emission, but increased N 2 O emission. • Organic fertilizer increased rice yield but did not affect CH 4 and N 2 O emissions. • Combined positive effect of AWD and organic fertilizer on rice yield was additive. • Number of drained days in AWD well explained CH 4 emission reduction. [ABSTRACT FROM AUTHOR]

There is a growing focus on the role of renewable energy (RE) policies such as feed-in tariffs (FITs), renewable portfolio standards (RPSs), subsidies, incentives, and research and development in the global energy policy mix and in promoting environmental sustainability. Although most developed countries have well-formulated RE policies, in developing countries, such policies face many barriers. This study analyzes the policies, drivers, and barriers to RE deployment for fostering environmental sustainability in the Gulf Cooperation Council (GCC) countries. In the GCC region, the need for economic diversification to reduce dependency on single resource, diminishing hydrocarbon reserve, loss of oil export revenue, climate change mitigation pledges, and abundant solar energy resource are the key drivers for diversifying energy sources to include RE. However, the apparent lack of consolidated policy framework for wide-scale RE utilization calls for a well-articulated policy to advance RE development in each member state. Although FIT and RPS approaches could be effective for initial deployment of small-scale RE projects, a competitive tendering and auctioning mechanisms are more suitable for large-scale projects. Whereas, developing effective energy codes could successfully promote RE deployment, the increased share of RE in energy supply would have synergistic impacts on the region. The GHG emissions avoidance expected to be achieved by the GCC countries will vary between 5 and 247 million tons of CO2 equivalent by 2030. The fulfillment of inspirational RE targets for 2030 would contribute in fulfilling climate change mitigation pledges, environmental sustainability, economic growth, and generating new jobs. [ABSTRACT FROM AUTHOR]

Abstract Emissions of greenhouse gases (GHG) from paddy rice are significant, so reducing these emissions has significant potential for climate change mitigation. We investigated alternate wetting and drying (AWD) as part of an integrated management approach to enhance mitigation, together with combinations of mineral nitrogen (N), reduced tillage, a suitable combination of plant residues and well decomposed manure. To quantify GHG emissions, and the potential for mitigation without yield decline, a process-based model, DayCent was used to simulate methane (CH 4) and nitrous oxide (N 2 O) emissions from paddy rice (Oryza sativa L.) in Bangladesh. The four test sites selected were amended with mineral N fertilizer or an organic amendment (rice straw). A good agreement (p < 0.05) was observed between model simulated and measured daily CH 4 flux at most of these test sites with no significant bias. The seasonal CH 4 emission from a site receiving mineral N fertilizer at a rate of 110 kg N ha−1 was predicted by the model to be 210 and 150 kg ha−1 for the water management scenarios of continuous flood (CF) and AWD, respectively. These values compare well with estimates of CH 4 emissions using Intergovernmental Panel on Climate Change tier 1 methods for the different water regimes. Our model results suggest emission factors for N 2 O of 0.4% and 0.6% of applied fertilizer under CF and AWD water regimes, respectively. Based on modelling studies, AWD was found to be an important strategy not only with respect to reducing GHG emissions, but also in terms of cost effectiveness. We also found that integrated management is a promising option for farmers and policy makers interested in either yield increase, GHG mitigation or both. Yield scaled emissions intensity under AWD was found to be about 24% lower than under CF, followed by integrated management. Highlights • Greenhouse gas (GHG) emissions from rice were simulated with the DayCent model. • DayCent simulates methane and nitrous oxide emissions well in paddy rice. • Alternate wet and drying is the most effective mitigation option to mitigate GHGs. • Integrated management is promising for increasing yield and for GHG mitigation. [ABSTRACT FROM AUTHOR]

Abstract Despite the overwhelming consensus within the scientific community concerning the causes and effects of climate change, decision-making processes often do not point out in the same direction. In order to effectively and satisfactorily tackle climate change, a legally and politically binding long-term policy architecture is needed. In practice, however, central governments and international policymakers have been unable to provide a successful policy architecture. Yet, city-level initiatives within the Smart City framework are a promising way to tackle climate change. An example of such a Smart City framework is the London Environment Strategy (LES). In this paper, we propose a zero mean reverting model for greenhouse gas emissions to quantitatively analyze its consistency with the 2050 Zero Carbon objectives. We consider different policy scenarios proposed in the LES and the forward-looking policy uncertainty embedded in different economic sectors, primarily domestic, industrial and commercial and transport. We find that, on average, only transport improves the historical greenhouse gas emissions trend, and most of this reduction comes from Smart Mobility and/or Smart Regulation programs focusing on the environment. Highlights • Most actions oriented to mitigate the effects of climate change are being taken at the city level. • The current GHG emission trend in London is not in line with the 2050 zero level objective. • Stress test analysis considering a zero mean reverting process and different policy scenarios • Considering the simulation average trend only Transport sector improves the historical trend. • Industrial and Commercial sector reports the highest level of uncertainty. [ABSTRACT FROM AUTHOR]

Highlights • Restored, managed wetlands sequestered carbon by inhibiting ecosystem respiration. • Agricultural land uses on degraded peat soils lost soil carbon to the atmosphere. • Large CH 4 emissions result in restored wetlands being short-term greenhouse gas sources. • Restoration often resulted in greenhouse gas switchover times of more than a century. Abstract Restoring degraded peat soils presents an attractive, but largely untested, climate change mitigation approach. Drained peat soils used for agriculture can be large greenhouse gas sources. By restoring subsided peat soils to managed, impounded wetlands, significant agricultural emissions are avoided, and soil carbon can be sequestered and protected. Here, we synthesize 36 site-years of continuous carbon dioxide and methane flux data from a mesonetwork of eddy covariance towers in the Sacramento-San Joaquin Delta in California, USA to compute carbon and greenhouse gas budgets for drained agricultural land uses and compare these to restored deltaic wetlands. We found that restored wetlands effectively sequestered carbon and halted soil carbon loss associated with drained agricultural land uses. Depending on the age and disturbance regime of the restored wetland, many land use conversions from agriculture to restored wetland resulted in emission reductions over a 100-year timescale. With a simple model of radiative forcing and atmospheric lifetimes, we showed that restored wetlands do not begin to accrue greenhouse gas benefits until nearly a half century, and become net sinks from the atmosphere after a century. Due to substantial interannual variability and uncertainty about the multi-decadal successional trajectory of managed, restored wetlands, ongoing ecosystem flux measurements are critical for understanding the long-term impacts of wetland restoration for climate change mitigation. [ABSTRACT FROM AUTHOR]

Highlights • The present study explored community-action-oriented projects on litter management. • The study adopted a mixed method of data collection. • Data were collected through: questionnaire and a life-cycle-based model. • Respondents' knowledge scores before and after the intervention were significantly different. • All (100%) the participants were willing to participate in waste recycling business. • 4Rs strategy had potential in saving greenhouse gas emissions in the community. Abstract Throughout the world, waste sector has been implicated in significant contribution to anthropogenic greenhouse gas (GHG) emissions. Involving communities in recycling their solid waste would ensure climate change effect mitigation and resilience. This study was carried out to improve waste management practices through a community-led intervention at Kube-Atenda community in Ibadan, Nigeria. The study adopted a quasi-experimental design, comprising mixed method of data collection such as semi- structured questionnaire and a life-cycle-based model for calculating greenhouse gas generation potentials of various waste management practices in the area. A systematic random sampling was used to select sixty (60) households for a survey on knowledge, attitude and practices of waste management through Recovery, Reduction, Reuse and Recycling (4Rs) before and after the training intervention. Data collected were summarised using descriptive statistics, chi-square test, t -test and ANOVA at p = 0.05. The mean age of the respondent was 49.7 ± 16.7 and 68.3% were females. Respondents' knowledge scores before and after the intervention were significantly different: 7.07 ± 1.48 and 11.6 ± 1.6 while attitude scores were: 8.2 ± 2.3 and 13.5 ± 0.8. There were significant differences in the major waste disposal practices in the community before and after the intervention. All (100%) the participants were willing to participate in waste recycling business and the model predicted that adoption of 4Rs strategy had a great potential in saving greenhouse gas emissions in the community. The behaviour of the community people has changed towards waste management that promote climate change mitigation and adaptation through waste reduction, reuse, and resource recovery. [ABSTRACT FROM AUTHOR]

In 2021, Zimbabwe updated its Greenhouse Gas (GHG) reduction target from a 33% reduction in per capita energy sector GHG emissions to a 40% reduction from all sectors, compared to 2030 baseline emission scenarios. This work aims to demonstrate how the actions identified in Zimbabwe's Nationally Determined Contribution (NDC) can achieve this updated target, and what development benefits could occur in Zimbabwe through the implementation of these actions. The magnitude of GHG emissions in Zimbabwe are modelled historically and to 2030 to quantify GHG emission reduction potentials, and contributions to selected sustainable development goal targets, from implementation of 28 mitigation measures. The estimated ∼37 million tonnes CO 2 -equivalent emissions emitted by Zimbabwe in 2017 are projected to increase by 109% to ∼77 million tonnes without implementation of any mitigation measures. The mitigation measures included in the updated NDC could reduce GHG emissions by 40% in 2030 compared to the baseline, while additional measures included in other plans and strategies in Zimbabwe could achieve a further 23% reduction. Implementing Zimbabwe's NDC could also lead to substantial development benefits locally, including to public health, biodiversity, and sustainable energy use. This assessment therefore provides a clear pathway to achieve Zimbabwe's updated climate change mitigation commitment, as the target is linked to the implementation of specific, concrete mitigation actions. It provides a practical example as to how methods to assess climate mitigation and development priorities can be integrated within climate change mitigation target-setting assessments. The more widespread adoption of prospective, quantitative assessment of development benefits from climate change mitigation actions could provide further motivation for more ambitious climate change action. • Zimbabwe committed to 40% reduction in greenhouse gas emissions by 2030 vs baseline. • Implementation of 17 priority mitigation actions could achieve 40% reduction. • Mitigation in forestry sector makes largest contribution, followed by energy sector. • Priority actions have broad development benefits beyond climate change mitigation. • Including quantifiable health, biodiversity, energy security. [ABSTRACT FROM AUTHOR]