Annual Greenhouse Gas Emissions Research Articles

Conversion of tropical forests to water buffalo pastures in lower Amazonia: Carbon losses and social carbon costs

AbstractTropical peat swamp forests provide many important ecosystem services, especially their function as global carbon sinks. These carbon‐rich wetlands are widespread in South America, yet few studies have examined carbon stocks or losses due to land use change. In the lower Amazon, they are being converted to pastures largely utilized by domestic water buffalo (Bubalus bubalis). We quantified carbon stocks in intact peat forests and recently converted pastures (<10 years) at the Lago Piratuba Biosphere Reserve (LPBR) in the lower Amazon of Brazil. The soils of intact forests were typified by shallow organic (peat) horizons at the soil surface. The mean total ecosystem carbon stock (TECS) in intact forests was 354 ± 28 Mg C ha−1. In contrast, the TECS of disturbed sites was significantly lower (p = 0.02) with a mean of 248 ± 17 Mg C ha−1. We estimated greenhouse gas (GHG) emissions from water buffalo (due to enteric fermentation and manure deposition) to be 7.5 Mg CO2e ha−1 year−1. Considering GHG emissions from this land use, the social carbon costs (SCCs) arising from the degradation of coastal Amazon peatlands are as high as US$2742 ha−1 year−1. The SCC of meat produced from this land use is as high as US$100/kg of meat produced, which far exceeds the economic returns from livestock. Based on the estimated numbers of water buffalo for the southern portion of the LPBR and the time since initial disturbance, the annual GHG emissions from this land use are estimated to be 602,846 Mg CO2e year−1 with an SCC as high as US$111,526,524 million year−1. This land use also eliminates opportunity values and services of carbon storage and biodiversity that would be possible from a regenerating biosphere reserve.

Pathways to reduce global plastic waste mismanagement and greenhouse gas emissions by 2050.

Plastic production and plastic pollution negatively affect our environment, environmental justice, and climate change. Using detailed global and regional plastics datasets coupled with socio-economic data, we employ machine learning to predict that, without intervention, annual mismanaged plastic waste will nearly double to 121 Mt (100 - 139 Mt 95% CI) by 2050. Annual greenhouse gas emissions from the plastic system are projected to grow by 37% to 3.35 Gt CO2 equivalent (3.09 - 3.54 CO2e) over the same period. The United Nations plastic pollution treaty presents a unique opportunity to reshape these outcomes. We simulate eight candidate treaty policies and find that just four could together reduce mismanaged plastic waste by 91% (86% - 98%) and gross plastic-related greenhouse gas emissions by one third.

Assessment of the polygeneration approach in wastewater treatment plants for enhanced energy efficiency and green hydrogen/ammonia production

Wastewater treatment plants (WWTPs) offer opportunities to optimize resource utilization and enhance energy efficiency. This study provides a comprehensive analysis of using the polygeneration approach in WWTPs to reduce grid energy dependence, optimize energy distribution, and utilize surplus energy for hydrogen (H2) and ammonia (NH3) production. Several models were employed, including photovoltaic (PV) cells, parabolic trough collectors (PTCs), steam methane reforming, and polymer electrolyte membranes, to assess the feasibility of this approach. Three scenarios were evaluated and compared: Scenario 1 (Baseline) represents the current situation, Scenario 2 maximizes the Net Present Value (NPV), and Scenario 3 minimizes NH3 production costs. Real data from As-Samra WWTP in Jordan was used to accurately assess the feasibility of each scenario. The results show that Scenario 2 offers the highest profitability and efficiency, with a NPV of 87.48 million USD and an annual NH3 production of 15,417 tons, reducing both grid dependency and biogas fuel consumption. Both Scenarios 2 and 3 demonstrate the ability to meet thermal demands efficiently while generating significant revenue from NH3 production. Scenario 3, in particular, achieves competitive H2 and NH3 production costs. Environmentally, Scenario 2 significantly reduces annual greenhouse gas emissions by 12.66 kilotons of CO2eq, with near-zero carbon intensity for thermal energy due to solar reliance. In conclusion, the polygeneration approach offers a promising pathway for WWTPs to achieve greater sustainability, economic gains, and reduced environmental impact, providing valuable insights for decision-makers.

Applying trade mechanisms to quantify dynamic GHG emissions of electricity consumption in an open economy - The case of Switzerland

Quantifying greenhouse gas (GHG) emissions from electricity consumption presents a significant challenge due to the variable nature of the generation mix throughout the year and the complex dynamics of cross-border electricity trade. In this paper, we introduce an innovative methodology designed to accurately capture the hourly GHG emissions linked to electricity imports, and thus electricity consumption. Contrary to conventional approaches, our methodology identifies the relevant generation technologies in exporting countries which are activated for export. This selection is based on (i) the classification of the technologies according to their dispatch cost (merit order), and (ii) considers trade mechanisms from economic theory.We apply this methodology to Switzerland, a country characterized by a low-carbon electricity generation mix, which however heavily relies on imports from neighbouring countries, particularly during the winter months. Over the period from 2017 to 2021, we find that 88 % of Switzerland's domestic electricity demand is met by its own generation—primarily hydro and nuclear—while the remaining 12 % is imported, mainly from fossil-fuel-based sources. Consequently, the average annual GHG emission factor for electricity consumption in Switzerland is 98 g-CO2eq/kWh, with 29 % attributed to domestic generation and 71 % to imports. This figure is 40 % higher than the 70 g-CO2eq/kWh estimated using a conventional approach, which typically underestimates the specific impacts of electricity imports.The disparity between these approaches becomes even more pronounced when considering the seasonal and hourly variations in the electricity mix and the resulting emission factors. These insights are particularly crucial in the context of emerging electricity demands, such as heat pumps and electric vehicles, where accurate GHG accounting can significantly influence policy and investment decisions.

The Environmental Impacts of Future Global Sales of Hydrogen Fuel Cell Vehicles

During the last decade, developing more sustainable transportation modes has become a primary objective for car manufacturers and governments around the world to mitigate environmental issues, such as climate change, the continuous increase in greenhouse gas (GHG) emissions, and energy depletion. The use of hydrogen fuel cell technology as a source of energy in electric vehicles is considered an emerging and promising technology that could contribute significantly to addressing these environmental issues. In this study, the effects of Hydrogen Fuel Cell Battery Electric Vehicles (HFCBEVs) on global GHG emissions compared to other technologies, such as BEVs, were determined based on different relevant factors, such as predicted sales for 2050 (the result of the developed prediction model), estimated daily traveling distance, estimated future average global electricity emission factors, future average Battery Electric Vehicle (BEV) emission factors, future global hydrogen production emission factors, and future average HFCBEV emission factors. As a result, the annual GHG emissions produced by passenger cars that are expected to be sold in 2050 were determined by considering BEV sales in the first scenario and HFCBEV replacement in the second scenario. The results indicate that the environmental benefits of HFCBEVs are expected to increase over time compared to those of BEVs, due to the eco-friendly methods that are expected to be used in hydrogen production in the future. For instance, in 2021, HFCBEVs could produce more GHG emissions than BEVs by 54.9% per km of travel, whereas in 2050, BEVs could produce more GHG emissions than HFCBEVs by 225% per km of travel.

Canadian Association of Radiologists Statement on Planetary Health Education in Radiology.

The health of Canadians is already impacted by climate change due to wildfire smoke, heat domes, floods, droughts, and the changing distribution of vector borne disease. The healthcare sector contributes to climate change, accounting for approximately 4.6% of annual greenhouse gas emissions in Canada. Healthcare teams have a responsibility and opportunity to reduce harm by limiting emissions and waste, and engaging the public in understanding the planetary health links between clean air and water, a stable climate, a healthy planet and human health. Transformation of Canadian healthcare to a low carbon, climate resilient system will be enhanced by physician engagement and leadership. Cornerstones to physician participation include knowledge of the anthropogenic etiology of the climate crisis, the human health impacts, and the contribution providing healthcare makes to the climate crisis. Integration of climate change knowledge into the Canadian Radiology educational curricula is essential to position radiologists to lead transformative change in mitigation and adaptation of the healthcare system to the climate crisis. This statement is intended to provide guidelines to optimize education and research for current and future Canadian radiologists, and builds on existing planetary healthcare education publications and the Canadian Association of Radiologists Statement on Environmental Sustainability in Medical Imaging.

PSV-10 Vaccination of beef cattle to reduce enteric methane emissions

Abstract Livestock methane (CH4) emissions total over 3 billion tonnes per year of carbon dioxide equivalents (CO2e) and are responsible for approximately 6% of total annual greenhouse gas emissions. The contribution of livestock CH4 emissions are only to be exacerbated as the global demand for meat and dairy products increases. Greater than 75% of livestock CH4 emissions are generated in dispersed production environments (e.g., cow-calf and stocker segments), which are not addressable by methane mitigation strategies requiring constant inputs. Thus, strategies that fit into standard agronomic practices, in particular dispersed production environments, are urgently needed to address the increasing carbon footprint associated with livestock production. Methane-reducing vaccines are a promising solution for addressing this need, due to their longevity of action, low cost, and ease of integration into standard agronomic practices, which could lower the barrier for adoption. Thus, this study aimed to assess the effects of a prototype vaccine on total and antigen-specific immune response, CH4 yield, and average daily gain (ADG) in cattle. Angus crossbred steers [n = 20; initial body weight (BW) = 537 ± 15 kg) fed on a high-forage diet were randomly assigned to either placebo- or vaccine-treated groups blocked by BW, breed, and feed intake. Steers were subcutaneously inoculated (2 mL dose) in the anterior region of the neck. Blood and saliva samples were collected, and total sera and salivary immunoglobulin (Ig) G and IgA were quantified using ELISA (Bethyl laboratories, Montgomery, TX). Antigen-specific sera IgG was measured using ELISA. Daily CH4 emissions and dry matter intake (DMI) were measured using GreenFeed systems (C-Lock Inc. Rapid City, SD) and GrowSafe feed bunks (Vytelle, Lenexa, KS), respectively. Body weights were recorded bi-weekly. Total sera IgA and IgG did not differ between the placebo-treated and vaccinated steers (P = 0.584 and P = 0.425, respectively), nor did total salivary IgA and IgG (P = 0.577 and P = 0.548, respectively). However, antigen-specific sera IgG did significantly increase following booster vaccination in the vaccinated steers, as compared with placebo-treated steers (d 0 vs. d 28; P < 0.001). CH4 yield was significantly reduced in vaccinated steers following booster vaccination despite significantly increasing in placebo-treated steers over the same period (P = 0.002). This reduction in CH4 yield was not associated with a reduction in DMI nor ADG (P = 0.181 and P = 0.314, respectively), suggesting that vaccination did not negatively affect treated animals. These findings underscore the potential of vaccine-based solutions to mitigate the environmental impact of livestock CH4 emissions, especially from dispersed production environments where current options for mitigation strategies are limited.

Identifying a sustainable rice-based cropping system via on-farm evaluation of grain yield, carbon sequestration capacity and carbon footprints in Central China

ContextRice-based cropping system is a major anthropogenic source of direct greenhouse gases (GHG) emissions, agricultural inputs also produces numerous indirect GHG emissions and environmental problems. Identification of rice cropping systems with lower GHG emissions and higher grain yields is of great significance to ensure food security while minimizing agricultural carbon footprint (CF). ObjectiveThis study aimed to identify the optimal rice-based cropping system with lower greenhouse effects and comparable annual yield in central China. MethodsUsed life cycle assessment, a two-year field experiment was performed to evaluate the direct and indirect GHG emissions, CF, and carbon sequestration capacity in the six rice-based cropping systems widely used in central China, which consisted of fallow-early rice-late rice, rapeseed-early rice-late rice, fallow-ratoon rice, rapeseed-ratoon rice (RRaR), fallow-middle rice, and rapeseed-middle rice. ResultsThe results showed that compared with the three systems with fallow season, the three systems with rapeseed had lower annual CH4 emissions. The two systems with ratoon rice had lower annual indirect and direct GHG emissions than the two systems with double rice. The three systems with rapeseed had higher annual biomass, grain yields, and fixed carbon in biomass and significantly lower CF than the three systems with fallow season, and RRaR had the highest value of fixed carbon in biomass. The systems with ratoon rice had lower average CF than those systems with double rice. CH4 emissions from paddy fields were the primary source of total annual GHG and the main component of CF. Compared with the three systems with fallow season, the three systems with rapeseed had significantly higher annual carbon sequestration capacity based on net ecosystem production (NEP). Ratoon rice systems had higher average NEP than double- and middle-rice systems. RRaR had the lowest CF per unit yield and highest NEP among all the six systems. ConclusionsThe results indicated that appropriate rice-based cropping systems may alleviate the greenhouse effect via reducing GHG emissions and enhancing paddy NEP, RRaR could achieve relatively higher annual grain yield and carbon sequestration capacity as well as lower CF. SignificanceThis study highlight conversion of double rice and middle rice systems to RRaR may help improve grain yield and mitigate greenhouse effect. The findings may provide a theoretical basis for selection of sustainable development of rice based cropping systems in central China.

4E evaluation and optimization of a hybrid CCHP system integrated PEM fuel cell and adsorption chiller

In order to promote the sustainable development of green energy, this study developed a hybrid combined cooling, heating and power system primarily consisting of proton exchange membrane fuel cells and an adsorption chiller. The system is designed to provide both power generation and heating, while also offering cooling capabilities. Initially, the models of the proton exchange membrane fuel cell stack and adsorption chiller were rigorously validated against experimental data, showcasing remarkable consistency with discrepancies below 3.5 %. Subsequently, the investigation delved into the influence of operational parameters for the proton exchange membrane fuel cell stack and adsorption chiller on various performance. These metrics encompassed energy efficiency, exergy efficiency, annual costs, and annual greenhouse gas reduction. Finally, the NSGA-II optimization algorithm was employed to perform multi-objective optimization on the system. The outcomes demonstrated that, in comparison to the initial configuration, the optimized system achieved a 22.51 % reduction in annual greenhouse gas emissions, while simultaneously enhancing energy efficiency by 14.72 %, exergy efficiency by 0.34 %, cooling power by 3.14 %, and heating power by 42.63 %. Moreover, the annual cost experienced a substantial decrease of 69.86 %.

The potential climate benefits of seaweed farming in temperate waters

Seaweed farming is widely promoted as an approach to mitigating climate change despite limited data on carbon removal pathways and uncertainty around benefits and risks at operational scales. We explored the feasibility of climate change mitigation from seaweed farming by constructing five scenarios spanning a range of industry development in coastal British Columbia, Canada, a temperate region identified as highly suitable for seaweed farming. Depending on growth rates and the fate of farmed seaweed, our scenarios sequestered or avoided between 0.20 and 8.2 Tg CO2e year−1, equivalent to 0.3% and 13% of annual greenhouse gas emissions in BC, respectively. Realisation of climate benefits required seaweed-based products to replace existing, more emissions-intensive products, as marine sequestration was relatively inefficient. Such products were also key to reducing the monetary cost of climate benefits, with product values exceeding production costs in only one of the scenarios we examined. However, model estimates have large uncertainties dominated by seaweed production and emissions avoided, making these key priorities for future research. Our results show that seaweed farming could make an economically feasible contribute to Canada’s climate goals if markets for value-added seaweed based products are developed. Moreover, our model demonstrates the possibility for farmers, regulators, and researchers to accurately quantify the climate benefits of seaweed farming in their regional contexts.

Assessment of land-based negative emissions options in Thailand

To keep the average global temperature below 1.5 °C as specified under the Paris Agreement, implementing negative emissions technologies (NETs) is imperative. This study aims to put a spotlight on negative emissions as a possible climate change mitigation option by establishing an assessment of land-based NETs in Thailand. The assessment is based on GIS analysis to identify possible lands for implementing NETs and existing factors to estimate the carbon removal potential of each technology. Different implementation scenarios are analyzed to explore the maximum implementation potential. The results show that 3% − 32% of Thailand’s areas would be available for NETs implementation depending on the land constraints of each option. Moreover, the literatures point out that Thailand is suitable for some NET options, which could increase the potential of NETs implementation. In terms of carbon removal potential, the combination of selected options could help Thailand compensate approximately 29% to 100% of the annual greenhouse gas emissions and achieve the target of Thailand’s Nationally Determined Contribution (NDC).

Monitoring CH4 Fluxes in Sewage Sludge Treatment Centres: Challenging Emission Underreporting

In this manuscript, CH4 emissions from sludge treatment centres are quantified using an unmanned aerial vehicle (UAV) framework, with particular focus on anaerobic digesters and digestate storage tanks. The outcomes are compared to those obtained using the carbon accounting workbook (CAW), which is the most commonly used industry tool by UK and Irish water companies to estimate the annual greenhouse gas emissions from their process operations. Path integrated concentrations are monitored with the use of an open-path tuneable diode laser absorption spectroscopy sensor embedded on a UAV. Measurements are interpolated using geostatistics (Kriging) and coupled with the mass balance approach to estimate emissions. The findings show that the CAW seems to underestimate emissions from digestate storage tanks by up to an order of magnitude. The results also show that CH4 emissions are linked with the residence time in the tank and temperature of the digestate. This study highlights the limitations of assumptions made using current reporting methods based on the carbon accounting workbook. This study proves that the UAV framework, together with the mass balance approach, provides high spatial resolution data; it captures the dynamic nature of emissions compared to the CAW and can be a cost-effective solution to estimate CH4 fluxes compared to other sensor-based systems.

Three years of CO2, CH4 and N2O fluxes from different sheepfolds in a semiarid steppe region, China

To better assess greenhouse gas (GHG) emissions from livestock folds in semi-arid steppe zones and reduce uncertainties in regional and national GHG emission inventories, we measured the fluxes of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) from sheepfolds under contrasting management regimes (i.e., summer sheepfolds under continuous and rotational grazing strategies and the winter sheepfold) for 3 consecutive years. Our results showed that these GHG fluxes had high intra-annual and interannual variations, emphasizing the importance of multi-year measurement for achieving temporally representative annual budgets. Sheep presence and temperature appeared to be the key factors driving CH4, CO2 and N2O fluxes from sheepfolds, e.g., higher GHG emissions usually occurred in seasons with sheep presence. However, the sheepfold type exerted a distinct influence on the temperature sensitivity of GHG fluxes, i.e., the Q10 values for GHG fluxes were generally higher in summer sheepfolds than in winter sheepfold. The annual CH4, CO2 and N2O emissions for the 3 sheepfolds were estimated to be 1.5–16.5 kg C ha−1 yr−1 (or 1.9–2.6 g C yr−1sheep−1), 8.6–16.0 t C ha−1 yr−1 (or 5.1–6.6 kg C yr−1sheep−1) and 28.3–41.9 kg N ha−1 yr−1 (or 19.0–26.8 g N yr−1sheep−1), respectively. Averaging across the 3 years, the annual net GHG emissions (CH4 + CO2 + N2O) for all sheepfolds ranged from 47 to 71 t CO2-eq ha−1 yr−1 (or 27–36 kg CO2-eq yr−1 sheep−1), of which CO2 and N2O emissions contributed the most; moreover, the annual net GHG emissions had no significant differences between sheepfold types or grazing strategies. Given that local steppe soils have a lower magnitude of soil respiration (CO2) and N2O emissions and are also net sink for atmospheric CH4, the sheepfold sites in this region are undoubtedly one of the significant hotspots for GHG emissions and could be key areas to focus mitigation action.

The environmental impacts and sustainable pathways of the global diamond industry

Mining diamond poses significant and potentially underestimated risks to the environment worldwide. Here, we propose a Diamond Environmental Impacts Estimation (DEIE) model to forecast the environmental indicators, including greenhouse gas (GHG) emissions, mineral waste, and water usage of the diamond industry from 2030 to 2100 in the top diamond production countries under different Shared Socio-economic Pathways (SSPs). The DEIE projection results indicate that the annual GHG emissions, mineral waste, and water usage of the global diamond industry will reach 9.65 Mt, 422.80 Mt, and 78.68 million m3 under the SSP1-1.9 scenario, and 13.26 Mt, 582.84 Mt, and 107.95 million m3 under the SSP2-2.6 scenario in 2100, respectively. We analyze the environmental impact heterogeneities and the associated driving factors across the major diamond production countries identified by our DEIE framework. In addition, we find that lab-grown diamonds can reduce annual GHG emissions, mineral waste, and water usage by 9.58 Mt, 421.06 Mt, and 66.70 million m3 in 2100. The lab-grown diamond substitution policy can annually save 714 million cubic meters of landfill space, harvest 255 million kilograms of rice, feed 436 million people, and lift 1.19 million households out of hunger. The lab-grown diamond substitution policy could contribute to the diamond industry’s GHG mitigation and sustainability efforts in a cost-saving manner.

Assessing the Impact of Climate Changes, Building Characteristics, and HVAC Control on Energy Requirements under a Mediterranean Climate

Assessing the Impact of Climate Changes, Building Characteristics, and HVAC Control on Energy Requirements under a Mediterranean Climate

Constraining Trifluoromethane (HFC‐23) Emission in Eastern China Based on Two‐Year Online Measurements

AbstractTrifluoromethane (CHF3, HFC‐23) is one of the most potent greenhouse gases (GHGs), and eastern China has been recognized as a major source region, yet highly inconsistent emission estimates warrant more extensive studies. In this study, we conducted 2‐year online measurements of halocarbons during 2021–2023 at an urban site in the Pearl River Delta region. The observed average HFC‐23 mixing ratios of 43.6 ± 7.8 ppt were ∼20% enhanced compared to observations at the Mace Head global baseline station. Unlike other halocarbons with significant local emissions, HFC‐23 mixing ratios showed distinct seasonal variations with peak values in winter and bottom values in summer. Similar seasonal patterns and highly significant correlation were observed between HFC‐23 and perfluorocyclobutane (c‐C4F8, PFC‐318), a co‐product from manufacturing PTFE using chlorodifluoromethane (CHClF2, HCFC‐22) as feedstock. The weighted potential source contribution function analysis also demonstrated eastern China was the major source area for both HFC‐23 and PFC‐318. Tracer‐based estimation revealed HFC‐23 emissions of 6.7 ± 3.1 Gg yr−1 (equivalent to 98 Tg‐CO2 yr−1 or 0.7% China's annual GHG emissions in 2021) in eastern China. Our results highlight the importance of HFC‐23 emission control in eastern China for China's GHG and F‐gases emission reductions, and suggest that greater attention should be given to HFC‐23 emissions from PTFE production, which is emerging as a more substantial source than previously anticipated.

Manure replacing synthetic fertilizer improves crop yield sustainability and reduces carbon footprint under winter wheat–summer maize cropping system

Manure replacing synthetic fertilizer is a viable practice to ensure crop yield and increase soil organic carbon (SOC), but its impact on greenhouse gas (GHG) emissions is inconsistent, thus remains its effect on CF unclear. In this study, a 7-year field experiment was conducted to assess the impact of replacing synthetic fertilizer with manure on crop productivity, SOC sequestration, GHG emissions and crop CF under winter wheat–summer maize cropping system. Five treatments were involved: synthetic nitrogen, phosphorus, and potassium fertilizer (NPK) and 25%, 50%, 75%, and 100% of manure replacing synthetic N (25%M, 50%M, 75%M, and 100%M). Compared with NPK treatment, 25%M and 50%M treatments maintained annual yield (winter wheat plus summer maize) and sustainable yield index (SYI), but 75%M and 100%M treatments significantly decreased annual yield, and 100%M treatment also significantly reduced annual SYI. The SOC content exhibited a significant increasing trend over years in all treatments. After 7 years, SOC storage in manure treatments increased by 3.06–11.82 Mg ha−1 relative to NPK treatment. Manure treatments reduced annual GHG emissions by 14%–60% over NPK treatment. The CF of the cropping system ranged from 0.16 to 0.39 kg CO2 eq kg−1 of grain without considering SOC sequestration, in which the CF of manure treatments lowered by 18%–58% relative to NPK treatment. When SOC sequestration was involved in, the CF varied from −0.39 to 0.37 kg CO2 eq kg−1 of grain, manure treatments significantly reduced the CF by 22%–208% over NPK treatment. It was concluded that replacing 50% of synthetic fertilizer with manure was a sound option for achieving high crop yield and SYI but low CF under the tested cropping system.

Social Equity and Renewable Energy Access in Developing Countries

The need for energy access is still a major challenge in developing countries, where millions do not have access to reliable and affordable power. Notably, this inequality has far-reaching implications, particularly for rural and marginalised communities, and only exacerbates socio-economic disparities while stifling opportunities for sustainable development. Renewable energy is a game-changing solution, providing local, clean, and scalable replacements for conventional fossil fuel systems. The paper focuses on linking renewable energy and social equity by examining the role of off-grid solar systems, mini-grids and decentralized energy technologies to connect energy bridges. What are the barriers for equitable acceptance of energy, and how can we integrate strategies for equity in renewable energy interventions; these constitute the key objectives of our study. The results show that decentralized renewable solutions have led to improved energy access rates by over 80%, lowered the cost of household energy bills by more than 30%, and reduced annual greenhouse gas emissions by 1,000 metric tons in beneficiary regions. And inclusive strategies, like participatory planning and targeted subsidies, improved gender equity as well, with women making up 60% of energy decision-makers in some projects. Despite these assets, ongoing challenges such as high installation costs and policy gaps emphasize the need for enhanced international cooperation and funding. The study recommends that renewable energy transitions be inclusive, sustainable, and transformative, and concludes with robust recommendations to do so: inclusion of alley equity-oriented policies in regulatory frameworks, a strengthened regulatory framework for all future renewable energy projects, and addressing the structural inequalities that exist at the community level through community engagement and participation.

Light-duty passenger vehicle electrification in China from 2021 to 2050 and associated greenhouse gas emissions: A dynamic fleet perspective

The electric vehicle is seen as a promising technology to decarbonize road transportation. However, the long-term and fleet-scale impacts of the electric vehicle promotion in China are still underexplored. To investigate the mitigation potential of light-duty passenger vehicles electrification, a dynamic fleet-based life cycle assessment framework is constructed to calculate the annual greenhouse gas (GHG) emissions in China from 2021 to 2050. It is estimated that the annual fleet GHG emissions will peak at 1.10 ∼ 1.18 Gt between 2028 and 2031, and gradually decrease to 0.53 ∼ 1.04 Gt CO2 eq in 2050. Under the most sustainable pathway (SSP1), the aggressive electrification scenario (SSP1-EV2040) is projected to reduce accumulative life cycle GHG emissions by 5.4Gt CO2 eq (17 % of the accumulative emissions in SSP2-BAU). The regional distribution of GHG emissions and electricity use shows a downward trend from east to west, revealing the necessity of China’s regional-specified strategy..

The limited potential of soil and vegetation in urban greenspace for nature‐based offsetting of institutional carbon emissions

AbstractThe soil and vegetation of urban greenspace can potentially contribute to ambitious climate action plans declared by city institutions and councils. To assess how urban greenspace could make a contribution to institutional carbon management, we measured soil carbon at 42 sampling locations across three land‐covers and vegetation carbon of 490 trees (67 species), over the city campus of Newcastle University. Soil carbon varied with pH and land‐cover classes (lawned with some free‐standing trees, woodland park, sports fields), and tree cover significantly enhanced soil carbon storage. Soil carbon storage from 0 to 30 cm depth averaged 18.85 kg·m−2, more than double the tree carbon storage (average 7.66 kg·m−2) estimated using biomass empirical equations. According to our scenarios, even if all currently available urban greenspace were converted to woodland, this would offset only 1% of current annual greenhouse gas emissions of Newcastle University or, if implemented more widely, of Newcastle city overall. While urban woodland brings benefits beyond carbon storage, the limit to what can be achieved within cities emphasizes the need for urban–rural partnerships. In exchange for helping cities with carbon abatement, their surrounding rural regions could benefit from carbon offsetting payments to improve their infrastructure provision. Overall, a carbon‐friendly and nature‐based land management strategy should be developed with full consideration of collaborative partnerships between urban and surrounding rural areas, particularly placing a high value on soil and tree carbon.