Comparing trends of crop and pasture in future land-use scenarios for climate change mitigation

Revegetation of former agricultural land is a key option for climate change mitigation and nature conservation.Expansion and abandonment of agricultural land is typically influenced by trends in diets and agricultural inten-sification,which are two key parameters in the Shared Socioeconomic Pathways(SSPs).Datasets mapping future land dynamics under different SSPs and climate change mitigation targets stem from different scenario assump-tions,land data and modelling frameworks.This study aims to determine the role that these three factors play in the estimates of the evolution of cropland and pastureland in future SSPs under different climate scenarios from four main datasets largely used in the climate and land surface studies.The datasets largely agree with the rep-resentation of cropland at present-day conditions,but the identification of pastureland is ambiguous and shows large discrepancies due to the lack of a unique land-use category.Differences occur with future projections,even for the same SSP and climate target.Accounting for CO_(2)sequestration from revegetation of abandoned agri-cultural land and CO_(2)emissions from forest clearance due to agricultural expansion shows a net reduction in vegetation carbon stock for most SSPs considered,except SSP1.However,different datasets give differences in estimates,even when representative of the same scenario.With SSP1,the cumulative increase in carbon stock until 2050 is 3.3 GtC for one dataset,and more than double for another.Our study calls for a common classifica-tion system with improved detection of pastureland to harmonize projections and reduce variability of outcomes in environmental studies.

Can the bullet train speed up climate change mitigation in China?

Infrastructure systems play a fundamental role in reducing greenhouse gas(GHG)emissions to avert global climate change(Kennedy et al.,2014).Transportations are recognized as one of the key factors for facilitating climate change mitigation(Shaw et al.,2014).Approximately 19%of global energy consumption and 23%of energy-related carbon dioxide(CO2)emissions come from the transportation sector(IEA,2012).The demands are still increasing at an annual average rate of 1.4%(EIA,2016).Scholars

Effects of scenario-based carbon pricing policies on China's dual climate change mitigation goals: Does policy design matter?

Although the carbon pricing policy is a critical driving factor that will help China achieve economic growth,energy transition,and dual climate change mitigation goals,the kind of carbon pricing policy that will complement the country's current development situation remains controversial.We apply the World Induced Technical Change Hybrid(WITCH)model to explore the heterogeneity and synergy of different carbon pricing policies,and the results indicate that it will be challenging to achieve carbon neutrality before 2060.The study find that the combined policy-a mix of carbon tax and carbon market policies--has the optimal emission reduction effect but comes with the highest economic cost,proving to be unsuitable in the long run.The carbon tax policy is an important transitional means to assist in emission reduction,which can serve as an important supplement to carbon market policy and be phased out after the market mechanism matures.

Climate Changes in Brazil： the Expected Financial Benefits by Implementing Smart Grids as a Mitigation and Adaptation Strategy

This research aims to estimate the long-term financial benefits of using smart grids to mitigate and adapt the power sector to climate change. In order to do that, twelve scenarios were analyzed applying an energy accounting model （LEAP （Long-range Energy Alternatives Planning System）） that was developed using Brazilian historical data from 1970 to 2015. To conduct the analysis, the Sathaye and Ravindranath＇s three steps methodology was used. The main final results include a long-term cost-benefit analysis that is developed for each considered scenario. The initial phase includes the analysis of the projections for the power sector up to 2030. The following phase consists on the estimation of costs for operation, maintenance, losses and new electrical projects investments. And finally, all scenarios＇ results were compared and the benefits of implementing smart grids in the sector were estimated. The attained results show that smart grid implementation would contribute to reduce electricity tariffs, the generation costs as well as the costs associated with theft and fraud.

Land-use change and carbon stocks: A case study, Noor County, Iran

Land-use changes and land cover strongly influence carbon stock and distribution within ecosystems. Changing the land-use from natural forest to other land-uses has been more rapid in the past few decades than at any time in Iran＇s history. In this study, we investigated the effects of changing the land-use from natural forest to other land-uses on carbon stocks in northern Iran. We selected five sites for this study： （I） a natural forest, （II） an agricultural field and （III） plantations of three different species （Alnus subcordata .L, Acer velutinum .Boiss and Cu- pressus sempervirens）. We examined the effects of land-use changes on： （I） soil carbon stock （0-50 cm depth）, （II） biomass and carbon content of grassy vegetation and litter and （III） above- and below-ground biomass C in trees. Soil C stock was higher under A. velutinum and C. sempervirens whereas it was lower under A. subcordata and agricultural sites. Biomass and C content of grassy vegetation were significantly higher at A. veluti- num and C. sempervirens plantations. However, litter biomass and C content were significantly higher at the natural forest site. Natural forest had the highest amount of C content in above- and below-ground bio- mass. Total ecosystem C stocks declined following land-use changes.

A review of methane leakage from abandoned oil and gas wells:A case study in Lubbock,Texas,within the Permian Basin

In the pursuit of global net zero carbon emissions and climate change mitigation,ongoing research into sustainable energy sources and emission control is paramount.This review examines methane leakage from abandoned oil and gas(AOG)wells,focusing particularly on Lubbock,a geographic area situated within the larger region known as the Permian Basin in West Texas,United States.The objective is to assess the extent and environmental implications of methane leakage from these wells.The analysis integrates pertinent literature,governmental and industry data,and prior Lubbock reports.Factors affecting methane leakage,including well integrity,geological characteristics,and human activities,are explored.Our research estimates 1781 drilled wells in Lubbock,forming a foundation for targeted assessments and monitoring due to historical drilling trends.The hierarchy of well statuses in Lubbock highlights the prevalence of“active oil wells,”trailed by“plugged and abandoned oil wells”and“inactive oil wells.”Methane leakage potential aligns with these well types,underscoring the importance of strategic monitoring and mitigation.The analysis notes a zenith in“drilled and completed”wells during 1980-1990.While our study's case analysis and literature review reiterate the critical significance of assessing and mitigating methane emissions from AOG wells,it's important to clarify that the research does not directly provide methane leakage data.Instead,it contextualizes the issue's magnitude and emphasizes the well type and status analysis's role in targeted mitigation efforts.In summary,our research deepens our understanding of methane leakage,aiding informed decision-making and policy formulation for environmental preservation.By clarifying well type implications and historical drilling patterns,we aim to contribute to effective strategies in mitigating methane emissions from AOG wells.

Carbon sequestration in a bamboo plantation:a case study in a Mediterranean area

In the Mediterranean region,despite bamboo being an alien species that can seriously alter plant and ani-mal biocoenosis,the area occupied by bamboo plantations continues to increase,especially for the purpose to seques-ter carbon(C).However,the C dynamics in the soil-plant system when bamboo is grown outside its native area are poorly understood.Here we investigated the C mitigation potential of the fast-growing Moso bamboo(Phyllostachys edulis)introduced in Italy for climate-change mitigation.We analyzed aboveground(AGB)and belowground(as root/shoot ratio)biomass,litter and soil organic C(SOC)at O-15-and 15-30-cm depths in a 4-year-old bamboo plantation in comparison with the former annual cropland on which the bamboo was established.To have an idea of the maximum C stored at an ecosystem level,a natural forest adjacent the two sites was also considered.In the plantation,C accumulation as AGB was stimulated,with 14.8±3.1 Mg C ha^(-1) stored in 3 years;because thinning was done to remove culms from the first year,the mean sequestration rate was 4.9 Mg C ha^(-1) a^(-1).The sequestration rates were high but comparable to other fast-growing tree species in Italy(e.g.,Pinus nigra).SOC was significantly higher in the bamboo plantation than in the cropland only at the 0-15 cm depth,but SOC stock did not differ.Possibly 4 years were not enough time for a clear increase in SOC,or the high nutrient uptake by bamboos might have depleted the soil nutrients,thus inhibiting the soil organic matter formation by bacteria.In comparison,the natural forest had significantly higher C levels in all the pools.For C dynamics at an ecosystem level,the bamboo plantation on the former annual cropland led to substantial C removal from the atmosphere(about 12 Mg C ha^(-1) a^(-1)).However,despite the promising C sequestration rates by bamboo,its introduction should be carefully considered due to potential ecological problems caused by this species in overexploited environments such as the Mediterranean area.

Drivers of the development of global climate-change-mitigation technology:a patent-based decomposition analysis

The development of the climate-change-mitigation technology has received widespread attention from both academic and policy studies.Nevertheless,very few studies have explained how and why economies contribute differently to global development.This paper decomposed the development of the global climate-change-mitigation technology,proxied by patent-based indicators,from 1996 to 2015 into several predefined factors.The results show that the worldwide surge of climate-change-mitigation-technology patents from 1996 to 2011 is driven by increased concentration on green invention,improved research intensity,and enlarged economic scale,while the falling of patent counts from 2011 to 2015 is predominantly due to less concentration on green invention.Among different climate-change-mitigation technologies,the type-specific development is attributed to different dominant factors,and the resulting priority change can reflect the shift of both global research and development(R&D)resource and market demand.Regarding regional contributions,the resulting economy-specific contributions to each driving factor can be used to design the policies to promote the development of the global climate-change-mitigation technology.

Climate Change and the Sendai Framework for Disaster Risk Reduction

This article reviews climate change within the Sendai Framework for Disaster Risk Reduction 2015–2030(SFDRR), analyzing how climate change is mentioned in the framework’s text and the potential implications for dealing with climate change within the context of disaster risk reduction. Three main categories are examined. First,climate change affecting disaster risk and disasters,demonstrating too much emphasis on the single hazard driver and diminisher of climate change. Second, crosssectoral approaches, for which the SFDRR treads carefully,thereby unfortunately entrenching artificial differences and divisions, although appropriately offering plenty of support to other sectors from disaster risk reduction. Third,implementation, for which climate change plays a suitable role without being overbearing, but for which other hazard influencers should have been treated similarly. Overall, the mentions of climate change within the SFDRR put too much emphasis on the hazard part of disaster risk. Instead,within the context of the three global sustainable development processes that seek agreements in 2015, climate change could have been used to further support an allvulnerabilities and all-resiliences approach. That could be achieved by placing climate change adaptation as one subset within disaster risk reduction and climate change mitigation as one subset within sustainable development.

China’s Energy Transition Pathway in a Carbon Neutral Vision

China’s energy system requires a thorough transformation to achieve carbon neutrality.Here,leveraging the highly acclaimed the Integrated MARKAL-EFOM System model of China(China TIMES)that takes energy,the environment,and the economy into consideration,four carbon-neutral scenarios are proposed and compared for different emission peak times and carbon emissions in 2050.The results show that China’s carbon emissions will peak at 10.3–10.4 Gt between 2025 and 2030.In 2050,renewables will account for 60%of total energy consumption(calorific value calculation)and 90%of total electricity generation,and the electrification rate will be close to 60%.The energy transition will bring sustained air quality improvement,with an 85%reduction in local air pollutants in 2050 compared with 2020 levels,and an early emission peak will yield more near-term benefits.Early peak attainment requires the extensive deployment of renewables over the next decade and an accelerated phasing out of coal after 2025.However,it will bring benefits such as obtaining better air quality sooner,reducing cumulative CO_(2) emissions,and buying more time for other sectors to transition.The pressure for more ambitious emission reductions in 2050 can be transmitted to the near future,affecting renewable energy development,energy service demand,and welfare losses.

Toward Carbon-Neutral Water Systems:Insights from Global Cities

Many cities have pledged to achieve carbon neutrality.The urban water industry can also contribute its share to a carbon-neutral future.Using a multi-city time-series analysis approach,this study aims to assess the progress and lessons learned from the greenhouse gas(GHG)emissions management of urban water systems in four global cities:Amsterdam,Melbourne,New York City,and Tokyo.These cities are advanced in setting GHG emissions reduction targets and reporting GHG emissions in their water industries.All four cities have reduced the GHG emissions in their water industries,compared with those from more than a decade ago(i.e.,the latest three-year moving averages are 13%–32%lower),although the emissions have“rebounded”multiple times over the years.The emissions reductions were mainly due to various engineering opportunities such as solar and mini-hydro power generation,biogas valorization,sludge digestion and incineration optimization,and aeration system optimization.These cities have recognized the many challenges in reaching carbon-neutrality goals,which include fluctuating water demand and rainfall,more carbon-intensive flood-prevention and water-supply strategies,meeting new air and water quality standards,and revising GHG emissions accounting methods.This study has also shown that it is difficult for the water industry to achieve carbon neutrality on its own.A collaborative approach with other sectors is needed when aiming toward the city’s carbon-neutrality goal.Such an approach involves expanding the usual system boundary of the water industry to externally tap into both engineering and non-engineering opportunities.

Qinghai-tibetan plateau peatland sustainable utilization under anthropogenic disturbances and climate change

Often referred to as the“Third Pole,”China’s Qinghai-Tibetan Plateau developed large amounts of peatland owing to its unique alpine environment.As a renewable resource,peat helps to regulate the climate as well as performing other important functions.However,in recent years,intensifying climate change and anthropogenic disturbances have resulted in peatland degradation and consequently made sustainable development of peatland more difficult.This review summarizes peatland ecological and economic functions,including carbon sequestration,biodiversity conservation,energy supplies,and ecotourism.It identifies climate change and anthropogenic disturbances as the two key factors attributing to peatland degradation and ecosystem carbon loss.Current problems in environmental degradation and future challenges in peatland management under the effects of global warming are also discussed and highlighted.

Carbon concentrations and carbon storage capacity of three old-growth forests in the Sila National Park,Southern Italy

Old-growth forests play a key-role in reducing atmospheric carbon dioxide(CO_(2)) concentrations by storing large CO_(2)amounts in biomass and soil over time.This quantifies the carbon pool into different forest compartments in three Mediterranean old-growth forests of Southern Italy populated by Pinus laricio,Fagus sylvatica and Abies alba.Ecosystem carbon pools have been assessed per compartment,i.e.,living trees,dead wood,litterfall(foliar and woody),roots and 0-20 cm topsoil,combining the whole old-growth forest mass,(i.e.,using tree allometric relationships,deadwood factor conversions,root-to-shoot ratios,litterfall and soil samplings) by the respective organic carbon concentrations.The results show the considerable capacity of these forest ecosystems in storing CO_(2)in biomass and soil,with carbon pool values ranging from 532.2to 596.5 Mg C ha-1.Living trees and 0-20 cm topsoil had larger carbon pool,contributing 53.0 and 22.1%,respectively.In most cases,organic carbon concentration was higher(more than 60%) than the average carbon conversion rate of 50%,especially in living trees,deadwood,and woody litterfall.This study contributes further scientific evidence of the capacity of old-growth forests in storing CO_(2)in their different compartments,with special evidence on tree biomass,litterfall and mineral soil,thereby highlighting the key role of old-growth forests within the challenge of climate change mitigation.

Geoengineering: Basic science and ongoing research efforts in China

Geoengineering （also called climate engineering）, which refers to large-scale intervention in the Earth＇s climate system to counteract greenhouse gas-induced warming, has been one of the most rapidly growing areas of climate research as a potential option for tackling global warming. Here, we provide an overview of the scientific background and research progress of proposed geoengineering schemes. Geo- engineering can be broadly divided into two categories： solar geoengineering （also called solar radiation management, or SRM）, which aims to reflect more sunlight to space, and carbon dioxide removal （CDR）, which aims to reduce the CO2 content in the atmosphere. First, we review different proposed geoengineering methods involved in the solar radiation management and carbon dioxide removal schemes. Then, we discuss the fundamental science underlying the climate response to the carbon dioxide removal and solar radiation management schemes. We focus on two basic issues： 1） climate response to the reduction in solar irradiance and 2） climate response to the reduction in atmospheric COe. Next, we introduce an ongoing geoengineering research project in China that is supported by National Key Basic Research Program. This research project, being the first coordinated geoengineering research program in China, will systematically investigate the physical mechanisms, climate impacts, and risk and governance of a few targeted geoengineering schemes. It is expected that this research program will help us gain a deep understanding of the physical science underlying geoengineering schemes and the impacts of geoengineering on global climate, in particular, on the Asia monsoon region.

Carbon stocks in a highly fragmented landscape with seasonally dry tropical forest in the Neotropics

Background:Global modeling of carbon storage and sequestration often mischaracterizes unique ecosystems such as the seasonally dry tropical forest of the central region of the Gulf of Mexico,because species diversity is usually underestimated,as is their carbon content.In this study,aboveground and soil carbon stocks were estimated to determine the climate mitigation potential of this highly degraded landscape(<25%of forest cover).Results:Tree species in the study area had carbon content values that were 30%–40%higher than the standard value proposed by the IPCC(i.e.,50%).Tropical oak forest in the region,despite its restricted distribution and low species richness,accounted for the highest mean carbon stocks per unit area.The main factors driving spatial variability in carbon stocks were:maximum precipitation,soil organic matter,clay and silt content.No strong relationship was found between aboveground carbon stocks and soil organic carbon in the study area.Quanti-fication of carbon stocks is an important consideration in the assessment of the conservation value of remnants of native vegetation in human-modified landscapes.Conclusions:This study demonstrates the importance of the highly fragmented tropical dry regions of the Neo-tropics in maintaining landscape functionality and providing key ecosystem services such as carbon sequestration.Our results also highlight how crucial field-based studies are for strengthening the accuracy of global models.Furthermore,this approach reveals the real contribution of ecosystems that are not commonly taken into account in the mitigation of climate change effects.

Organic matter quality of forest floor as a driver of C and P dynamics in acacia and eucalypt plantations established on a Ferralic Arenosols, Congo

Background: Land-use change and forest management may alter soil organic matter(SOM) and nutrient dynamics,due in part to alterations in litter input and quality. Acacia was introduced in eucalypt plantations established in the Congolese coastal plains to improve soil fertility and tree growth. Eucalypt trees were expected to benefit from N2 fixed by acacia. However, some indicators suggest a perturbation in SOM and P dynamics might affect the sustainability of the system in the medium and long term. In tropical environments, most of the nutrient processes are determined by the high rates of organic matter(OM) mineralization. Therefore, SOM stability might play a crucial role in regulating soil-plant processes. In spite of this, the relationship between SOM quality, C and other nutrient dynamics are not well understood. In the present study, OM quality and P forms in forest floor and soil were investigated to get more insight on the C and P dynamics useful to sustainable management of forest plantations.Methods: Thermal analysis(differential scanning calorimetry(DSC) and thermogravimetry(TGA)) and nuclear magnetic resonance(solid state13 C CPMASS and NMR and31 P-NMR) spectroscopy have been applied to partially decomposed forest floor and soils of pure acacia and eucalypt, and mixed-species acacia-eucalypt stands.Results: Thermal analysis and13 C NMR analysis revealed a more advanced stage of humification in forest floor of acacia-eucalypt stands, suggesting a greater microbial activity in its litter. SOM were related to the OM recalcitrance of the forest floor, indicating this higher microbial activity of the forest floor in this stand might be favouring the incorporation of C into the mineral soil.Conclusions: In relation with the fast mineralization in this environment, highly soluble orthophosphate was the dominant P form in both forest floor and soils. However, the mixed-species forest stands immobilized greater P in organic forms, preventing the P losses by leaching and contributing to sustain the P demand in the medium term.This shows that interactions between plants, microorganisms and soil can sustain the demand of this ecosystem.For this, the forest floor plays a key role in tightening the P cycle, minimizing the P losses.

Estimation of carbon storage of forest biomass for voluntary carbon markets:preliminary results

Estimating the carbon storage of forests is essential to support climate change mitigation and promote the transition into a low-carbon emission economy.To achieve this goal,voluntary carbon markets(VCMs)are essential.VCMs are promoted by a spontaneous demand,not imposed by binding targets,as the regulated ones.In Italy,only in Veneto and Piedmont Regions(Northern Italy),VCMs through forestry activities were carried out.Valle Camonica District(Northern Italy,Lombardy Region)is ready for a local VCM,but carbon storage of its forests was never estimated.The aim of this work was to estimate the total carbon storage(TCS;t C ha^−1)of forest biomass of Valle Camonica District,at the stand level,taking into account:(1)aboveground biomass,(2)belowground biomass,(3)deadwood,and(4)litter.We developed a user-friendly model,based on site-specifi c primary(measured)data,and we applied it to a dataset of 2019 stands extracted from 45 Forest Management Plans.Preliminary results showed that,in 2016,the TCS achieved 76.02 t C ha^−1.The aboveground biomass was the most relevant carbon pool(48.86 t C ha^−1;64.27%of TCS).From 2017 to 2029,through multifunctional forest management,the TCS could increase of 2.48 t C ha^−1(+3.26%).In the same period,assuming to convert coppices stands to high forests,an additional TCS of 0.78 t C ha^−1(equal to 2.85 t CO 2 ha^−1)in the aboveground biomass could be achieved without increasing forest areas.The additional carbon could be certifi ed and exchanged on a VCM,contributing to climate change mitigation at a local level.

Effects of green bonds on bioenergy development under climate change: A case study in Taiwan province, China

Bioenergy development improves energy security and mitigates climate change.Because the stable supply of agricultural resources provides a solid basis for efficient bioenergy production,the climate-induced impacts such as changes in lempeniture and precipitation that potentially alter the farming decisions and cropping patterns should be taken into account.This study designs two-stage stochastic programming with recourse model to investigate the net bioenergy production and emission reduction,as well as the bioenergy producers'strategies under various market operations and climate scenarios.The results show that the net production of biopower and biofuel are relatively stable because the supply of bioenergy feedstocks could remain at a constant level,but the farming decisions,cropping pattern,and resource utilization are likely to be altered by climate-induced impacts.The results also indicate that for efficient bioenergy production,approximately 41.5 billion TWD(9.65 billion CNY)and 33.6 billion TWD(7.81 billion CNY)of bond principal should be invested in crop-based and residual-based technology,respectively.In the face of strict environmental regulations and emission management,biopower technology becomes more competitive,and under such a circumstance,more than 98.3%of the low-cost bond should be invested in biopower development to achieve development efficiency.

Modelling and Optimization of Clean and Affordable Electricity Solution for Small-Scale Savings and Credit Cooperatives(SACCOs)

Renewable energy exploitation is among the development strategies set by the government of Rwanda on the roadmap to 2023/2024 universal electricity access and theUnitedNations plans by 2030.Numerous previous studies oncleanenergy technologies inRwandahavemostly focusedonhouseholds’usagebut there are currentlynostudies describing the feasibility of clean energy technologies for financial institutions.The skepticism on renewable energy in Africa was previously reported by some personnel.Having realized that most SACCOs(Savings and Credit Co-Operatives)in Rwanda use diesel technology for backup/emergency electricity supply,taking consideration of abundant solar resources in Rwanda,having seen the viability and feasibility studies from other countries of renewable energy for different institutions(financial included);thiswork uses theHOMEREnergy Software and the electricity load profile of a typical SACCO in Rwanda to analyse the affordability and viability of on-site renewable energy generation for SACCO in Rwanda.The results reveal that a solar PV systemwith storage can be the optimal solution(with levelized cost of electricity(LCOE)of 0.713$/kWh which is cheaper than 0.73$/kWh for diesel technology)for SACCOs located in both off-grid areas and grid-connected areas(with 0.041$/kWh LCOE which is lower than the current electricity tariff in Rwanda).The findings in this work can serve as basic tools/materials for policy drafters in Rwanda on how financial institutions can contribute to climate change mitigation through self-renewable energy exploitation.

Sweet Sorghum Genotypes Testing in the High Latitude Rainfed Steppes of the Northern Kazakhstan （for Feed and Biofuel）

Twenty-eight sweet sorghum （Sorghum bicolor （L.） Moench） genotypes of the different ecological and geographic origins： Kazakhstan, Russia, India, Uzbekistan, and China were tested in the high latitude rainfed conditions of northern Kazakhstan. The genotypes demonstrated high biomass production （up to 100 t＇ha1 and more）. The genotypes ripening to full reproductive seeds were selected for seed production and introduction in the northern Kazakhstan. Lactic acid bacteria Lactobacillus plantarum S-1, Streptococcus thermophilus F-1 and Lactococcus lactis F-4 essentially enhance the fermentation process, suppressing undesirable microbiological processes, reducing the loss of nutrient compounds, accelerating in 2 times maturation ensilage process and providing higher quality of the feed product.