Research on environmental behaviour is often overlooked in literature on regime destabilization in energy transitions.This study addresses that gap by focusing on socio-political and demographic factors shaping suppor...Research on environmental behaviour is often overlooked in literature on regime destabilization in energy transitions.This study addresses that gap by focusing on socio-political and demographic factors shaping support for carbon regime destabilization policies in one of the most carbon-intensive regions of Europe.Carbon-intensive industries,especially coal mining and coal-based power generation,are often concentrated in a few carbon-intensive regions.Therefore,decarbonization actions will affect those regions particularly strongly.Correspondingly,carbon-intensive regions often exert significant political influence on the two climate mitigation policies at the national level.Focusing on Poland,we investigate socio-political and demographic factors that correlate with the approval or rejection of the two climate mitigation policies:increasing taxes on fossil fuels such as oil,gas,and coal and using public money to subsidize renewable energy such as wind and solar power in Poland and its carbon-intensive Silesia region.Using logistic regression with individual-level data derived from the 2016 European Social Survey(ESS)and the 2014 Chapel Hill Expert Survey(CHES),we find partypolitical ideology to be an important predictor at the national level but much less so at the regional level.Specifically,voting for right-wing party is not a divisive factor for individual support of the two climate mitigation policies either nationally or regionally.More interestingly,populism is a strong factor in support of increasing taxes on fossil fuel in the carbon-intensive Silesia region but is less important concerning in support of using public money to subsidize renewable energy in Poland overall.These results show the heterogeneity of right-wing party and populism within the support for the two climate mitigation policies.Socio-demographic factors,especially age,gender,education level,employment status,and employment sector,have even more complex and heterogeneous components in support of the two climate mitigation policies at the national and regional levels.Identifying the complex socio-political and demographic factors of climate mitigation policies across different national versus carbon-intensive regional contexts is an essential step for generating in situ decarbonization strategies.展开更多
This review focuses on major contemporary empirical studies that examine both the physical and regulatory sides of climate risk. These studies explore how climate risk affects firms’ operating performance and leverag...This review focuses on major contemporary empirical studies that examine both the physical and regulatory sides of climate risk. These studies explore how climate risk affects firms’ operating performance and leverage, stock and bond valuation, cost of capital, and managerial behavior. We also discuss how the effect of climate risk on real estate markets depends on individuals’ beliefs about climate change. Furthermore, we summarize papers on climate risk activism and how firms can employ financial devices and technology to mitigate their climate risk. Finally, we make some recommendations for further research areas.展开更多
Individual countries are requested to submit nationally determined contributions(NDCs)to alleviate global warming in the Paris Agreement.However,the global climate effects and regional contributions are not explicitly...Individual countries are requested to submit nationally determined contributions(NDCs)to alleviate global warming in the Paris Agreement.However,the global climate effects and regional contributions are not explicitly considered in the countries’decision-making process.In this study,we evaluate the global temperature slowdown of the NDC scenario(ΔT=0.6°C)and attribute the global temperature slowdown to certain regions of the world with a compact earth system model.Considering reductions in CO_(2),CH_(4),N_(2)O,BC,and SO_(2),the R5OECD(the Organization for Economic Co-operation and Development in 1990)and R5ASIA(Asian countries)are the top two contributors to global warming mitigation,accounting for 39.3%and 36.8%,respectively.R5LAM(Latin America and the Caribbean)and R5MAF(the Middle East and Africa)followed behind,with contributions of 11.5%and 8.9%,respectively.The remaining 3.5%is attributed to R5REF(the Reforming Economies).Carbon Dioxide emission reduction is the decisive factor of regional contributions,but not the only one.Other greenhouse gases are also important,especially for R5MAF.The contribution of short-lived aerosols is small but significant,notably SO_(2)reduction in R5ASIA.We argue that additional species beyond CO_(2)need to be considered,including short-lived pollutants,when planning a route to mitigate climate change.It needs to be emphasized that there is still a gap to achieve the Paris Agreement 2-degree target with current NDC efforts,let alone the ambitious 1.5-degree target.All countries need to pursue stricter reduction policies for a more sustainable world.展开更多
Climate change is a global challenge that threatens global ecological security and sustainable development.Find-ing ways to mitigate their impacts is paramount through engineering carbon storage,low-carbon energy tran...Climate change is a global challenge that threatens global ecological security and sustainable development.Find-ing ways to mitigate their impacts is paramount through engineering carbon storage,low-carbon energy tran-sition,or natural climate solutions(NCS).NCS involve a set of measures(e.g.,afforestation,land restoration,biochar reuse or sustainable land use practices).Implementing NCS increases carbon sequestration and mitigates climate change at the lowest costs and greenest ways.In addition,NCS practices can improve multiple ecosystem services(ES)such as air quality,flood and erosion regulation,pest control,water purification,wild food biomass,recreation or landscape aesthetics.However,unsustainable implementation of NCS,such as over-afforestation of dense mono-forest,can lead to tradeoffs with water supply,wildfire risk,and decreased grasslands and crop-lands.Therefore,to optimise the NCS implementation,reducing the tradeoffs associated and transforming the“expand ecosystem area”to“improve ecosystem management efficiency”is vital.Although NCS can contribute significantly to mitigating climate change,systematic climate actions must be accompanied by a transformation in the global society and investment in new technologies.This will be key to addressing global challenges such as the achievement of Sustainable Development Goals(SDGs),such as SDG 13(Climate Action),SDG 15(Life on Land),SDG 2(Zero Hunger),SDG 3(Good Health and Wellbeing),SDG 6(Clean Water and Sanitation),and SDG 14(Life Bellow Water).展开更多
An improved understanding of biodiversity-productivity relationships(BPRs)along environmental gradients is crucial for effective ecosystem management and biodiversity conservation.The stress-gradient hypothesis sugges...An improved understanding of biodiversity-productivity relationships(BPRs)along environmental gradients is crucial for effective ecosystem management and biodiversity conservation.The stress-gradient hypothesis suggests that BPRs are stronger in stressful environments compared to more favorable conditions.However,there is limited knowledge regarding the variation of BPRs along elevational gradients and their generality across different landscapes.To study how BPRs change with elevation,we harnessed inventory data on 6,431 trees from152 plots surveyed twice in eight to ten year intervals in mountain forests of temperate Europe and subtropical Asia.We quantified the relationship between aboveground productivity and different biodiversity measures,including taxonomic,functional,and phylogenetic diversity.To elucidate the processes underlying BPRs,we studied the variation of different functional traits along elevation across landscapes.We found no general pattern of BPRs across landscapes and elevations.Relationships were neutral for all biodiversity measures in temperate forests,and negative for taxonomic and functional diversity in subtropical forests.BPRs were largely congruent between taxonomic,functional and phylogenetic diversity.We found only weak support for the stress-gradient hypothesis,with BPRs turning from negative to positive(effect not significant)close to the tree line in subtropical forests.In temperate forests,however,elevation patterns were strongly modulated by species identity effects as influenced by specific traits.The effect of traits such as community-weighted mean of maximum plant height and wood density on productivity was congruent across landscapes.Our study highlights the context-dependence of BPRs across elevation gradients and landscapes.Species traits are key modulating factors of BPRs and should be considered more explicitly in studies of the functional role of biodiversity.Furthermore,our findings highlight that potential trade-offs between conserving biodiversity and fostering ecosystem productivity exist,which require more attention in policy and management.展开更多
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 sequ...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.展开更多
We chose a definition of heatwaves (HWs) that has ~4-year recurrence frequency at world hot spots. We first examined the 1940-2022 HWs climatology and trends in lifespan, severity, spatial extent, and recurrence frequ...We chose a definition of heatwaves (HWs) that has ~4-year recurrence frequency at world hot spots. We first examined the 1940-2022 HWs climatology and trends in lifespan, severity, spatial extent, and recurrence frequency. HWs are becoming more frequent and more severe for extratropical mid- and low-latitudes. To euphemize HWs, we here propose a novel clean energy-tapping concept that utilizes the available nano-technology, micro-meteorology knowledge of temperature distribution within/without buildings, and radiative properties of earth atmosphere. The key points for a practical electricity generation scheme from HWs are defogging, insulation, and minimizing the absorption of infrared downward radiation at the cold legs of the thermoelectric generators. One sample realization is presented which, through relay with existing photovoltaic devices, provides all-day electricity supply sufficient for providing air conditioning requirement for a residence (~2000-watt throughput). The provision of power to air conditioning systems, usually imposes a significant stress on traditional city power grids during heatwaves.展开更多
Guyana’s capacity to address the impacts of climate change on its coastal environment requires the ability to mon-itor,quantify and understand coastal change over short-,medium-and long-term.Understanding the drivers...Guyana’s capacity to address the impacts of climate change on its coastal environment requires the ability to mon-itor,quantify and understand coastal change over short-,medium-and long-term.Understanding the drivers of change in coastal and marine environment can be achieved through the accurate measurement and critical anal-yses of morphologies,flows,processes and responses.This manuscript presents a strategy developed to create a central resource,database and web-based platform to integrate data and information on the drivers and the changes within Guyana coastal and marine environment.The strategy involves four complimentary work pack-ages including data collection,development of a platform for data integration,application of the data for coastal change analyses and consultation with stakeholders.The last aims to assess the role of the integrated data sys-tems to support strategic governance and sustainable decision-making.It is hoped that the output of this strategy would support the country’s climate-focused agencies,organisations,decision-makers,and researchers in their tasks and endeavours.展开更多
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 compa...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.展开更多
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 compl...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.展开更多
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 o...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.展开更多
The aim of this study was to assess Acacia senegal trees’ characteristics as well as evaluate the carbon stock under a variety of ages in the El Demokeya forest in Sudan, where the Gum Arabic belt is located. 12 samp...The aim of this study was to assess Acacia senegal trees’ characteristics as well as evaluate the carbon stock under a variety of ages in the El Demokeya forest in Sudan, where the Gum Arabic belt is located. 12 sample plots, in 2021 were randomly distributed to represent the entire area of the forest prior to the required measurements. The sample was designed as squire plots with one hectare. In each sample plot, all trees were counted, their height (m), and Diameters Breast Height (DBH in cm), respectively. The results showed the highest number of trees per ha at age 20 years old and the lowest number at age 47 years, while the highest values of DBH and volume were found at age 47 years old. As a result, the maximum and minimum values of the aboveground biomass were found in the age 47 years old and 16 years, accounting for 19.87 tons and 1.9 tons respectively. Thus, the amount of carbon stock was 11.92 tons/ha in the 35-years-old and 1.19 tons/ha in the 21-year stands. Furthermore, the average carbon stock in all plots was estimated as 18.70 tons/ha and hence the total carbon stock in the El Demokeya forest is equal to 620.11 tons. Conclusively, the characteristics of trees, amount of aboveground biomass and carbon stock in the El Demokeya forest varied among the uneven-aged plantation groups. The study recommends and encourages the protection of A. senegal in order to increase the carbon sink as well as protect the environment in the era of climatic changes.展开更多
Land surface temperature (LST), which is heavily influenced by urban surface structures, is a significant parameter in urban environmental analysis. This study examined the effect impervious surfaces (IS) spatial ...Land surface temperature (LST), which is heavily influenced by urban surface structures, is a significant parameter in urban environmental analysis. This study examined the effect impervious surfaces (IS) spatial patterns have on LST in Beijing, China. A classification and regression tree model (CART) was adopted to estimate IS as a continuous variable using Landsat images from two seasons combined with QuickBird. LST was retrieved from the Landsat Thematic Mapper (TM) image to examine the relationships between IS and LST. The results revealed that CART was capable of consistently predicting LST with acceptable accuracy (correlation coefficient of 0.94 and the average error of 8.59%). Spatial patterns of IS exhibited changing gradients across the various urban-rural transects, with LST values showing a concentric shape that increased as you moved from the outskirts towards the downtown areas. Transect analysis also indicated that the changes in both IS and LST patterns were similar at various resolution levels, which suggests a distinct linear relationship between them. Results of correlation analysis further showed that IS tended to be positively correlated with LST, and that the correlation coefficients increased from 0.807 to 0.925 with increases in IS pixel size. The findings identified in this study provide a theoretical basis for improving urban planning efforts to lessen urban temperatures and thus dampen urban heat island effects.展开更多
Forests provide diverse co-benefits, including livelihoods enhancement, poverty alleviation, and biodiversity conservation and ecosystem services such as climate mitigation. Consequently, Ghana has embraced several gl...Forests provide diverse co-benefits, including livelihoods enhancement, poverty alleviation, and biodiversity conservation and ecosystem services such as climate mitigation. Consequently, Ghana has embraced several global, regional, national, and local forest policy interventions to safeguard its forest resources’ sustainable management. However, the forest policy interventions have not adequately addressed the co-benefits issues of forest resources leading to several forest illegalities that drive forest resources degradation and loss. These forest policies and interventions on the ground primarily favour carbon stocks enhancement and sequestration activities for carbon mitigation purposes compared to the benefits, access and rights that forest-dependent people and communities are supposed to derive from forest resources. These perceived injustices in the access and distribution of forest resources have culminated into all forms of forest illegalities driving Ghana’s forest resources into massive degradation and loss. Currently, Ghana is experiencing a 2% rate of annual deforestation and forest degradation, which translates into approximately 135<span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">,</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">00</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">0</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> ha/year of forest cover loss due to anthropogenic causes. Our review is based on relevant and critical forest documents, and scientific peer-reviewed papers on Ghana’s forest policy interventions and dynamics recently published. The information gathered enabled us to highlight the perceived injustices in the forest policy interventions and their effects on forest resources. Unjust forest resources sharing and distribution are critical drivers of forest resources degradation and loss. We thus offer lessons for remedying the unfair distribution and injustices to promote equitable forest resources rights and benefit access to local forest-dependent people. It is expected that this review will offer and assist forest policy, intervention spatial and other planners and designers to find a possible way forward to avoid nature degradation, including biodiversity loss, to resolve perceived injustices in the forestry sector, to use adequate all ecosystem services provided by forests as well as to promote local livelihood and sustainability.</span></span></span>展开更多
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 environmen...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.展开更多
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 pr...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.展开更多
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 ...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.展开更多
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 establis...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.展开更多
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 cli...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展开更多
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 ...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.展开更多
基金funding from the European Union’s Horizon 2020 Research and Innovation Programme under grant agreement No:884539“Carbon Intensive Regions in Transition-Unravelling the Challenges of Structural Change(CINTRAN)”。
文摘Research on environmental behaviour is often overlooked in literature on regime destabilization in energy transitions.This study addresses that gap by focusing on socio-political and demographic factors shaping support for carbon regime destabilization policies in one of the most carbon-intensive regions of Europe.Carbon-intensive industries,especially coal mining and coal-based power generation,are often concentrated in a few carbon-intensive regions.Therefore,decarbonization actions will affect those regions particularly strongly.Correspondingly,carbon-intensive regions often exert significant political influence on the two climate mitigation policies at the national level.Focusing on Poland,we investigate socio-political and demographic factors that correlate with the approval or rejection of the two climate mitigation policies:increasing taxes on fossil fuels such as oil,gas,and coal and using public money to subsidize renewable energy such as wind and solar power in Poland and its carbon-intensive Silesia region.Using logistic regression with individual-level data derived from the 2016 European Social Survey(ESS)and the 2014 Chapel Hill Expert Survey(CHES),we find partypolitical ideology to be an important predictor at the national level but much less so at the regional level.Specifically,voting for right-wing party is not a divisive factor for individual support of the two climate mitigation policies either nationally or regionally.More interestingly,populism is a strong factor in support of increasing taxes on fossil fuel in the carbon-intensive Silesia region but is less important concerning in support of using public money to subsidize renewable energy in Poland overall.These results show the heterogeneity of right-wing party and populism within the support for the two climate mitigation policies.Socio-demographic factors,especially age,gender,education level,employment status,and employment sector,have even more complex and heterogeneous components in support of the two climate mitigation policies at the national and regional levels.Identifying the complex socio-political and demographic factors of climate mitigation policies across different national versus carbon-intensive regional contexts is an essential step for generating in situ decarbonization strategies.
文摘This review focuses on major contemporary empirical studies that examine both the physical and regulatory sides of climate risk. These studies explore how climate risk affects firms’ operating performance and leverage, stock and bond valuation, cost of capital, and managerial behavior. We also discuss how the effect of climate risk on real estate markets depends on individuals’ beliefs about climate change. Furthermore, we summarize papers on climate risk activism and how firms can employ financial devices and technology to mitigate their climate risk. Finally, we make some recommendations for further research areas.
基金funded by the undergraduate student research training program of the Ministry of Education, the National Natural Science Foundation of China (Grants Nos. 41771495, 41830641, and 41988101)the Second Tibetan Plateau Scientific Expedition and Research Program Grant 2019QZKK0208+1 种基金funded by the European Research Council Synergy project “Imbalance-P ” (Grant No. ERC-2013-Sy G-610028)the European Union’s Horizon 2020 research and innovation project “CONSTRAIN” (Grant No. 820829)
文摘Individual countries are requested to submit nationally determined contributions(NDCs)to alleviate global warming in the Paris Agreement.However,the global climate effects and regional contributions are not explicitly considered in the countries’decision-making process.In this study,we evaluate the global temperature slowdown of the NDC scenario(ΔT=0.6°C)and attribute the global temperature slowdown to certain regions of the world with a compact earth system model.Considering reductions in CO_(2),CH_(4),N_(2)O,BC,and SO_(2),the R5OECD(the Organization for Economic Co-operation and Development in 1990)and R5ASIA(Asian countries)are the top two contributors to global warming mitigation,accounting for 39.3%and 36.8%,respectively.R5LAM(Latin America and the Caribbean)and R5MAF(the Middle East and Africa)followed behind,with contributions of 11.5%and 8.9%,respectively.The remaining 3.5%is attributed to R5REF(the Reforming Economies).Carbon Dioxide emission reduction is the decisive factor of regional contributions,but not the only one.Other greenhouse gases are also important,especially for R5MAF.The contribution of short-lived aerosols is small but significant,notably SO_(2)reduction in R5ASIA.We argue that additional species beyond CO_(2)need to be considered,including short-lived pollutants,when planning a route to mitigate climate change.It needs to be emphasized that there is still a gap to achieve the Paris Agreement 2-degree target with current NDC efforts,let alone the ambitious 1.5-degree target.All countries need to pursue stricter reduction policies for a more sustainable world.
基金C.Y.and W.Z.were supported by National Natural Science Founda-tion of China(Grant No.42271292)State Key Laboratory of Earth Sur-face Processes and Resource Ecology(Grant No.2022-ZD-08)+1 种基金the Fundamental Research Funds for the Central Universities of ChinaP.P.was supported by the project MApping and Forecasting Ecosystem Ser-vices in URban areas(MAFESUR),financed by the Lithuanian Research Council.Nr.P-MIP-23-426.
文摘Climate change is a global challenge that threatens global ecological security and sustainable development.Find-ing ways to mitigate their impacts is paramount through engineering carbon storage,low-carbon energy tran-sition,or natural climate solutions(NCS).NCS involve a set of measures(e.g.,afforestation,land restoration,biochar reuse or sustainable land use practices).Implementing NCS increases carbon sequestration and mitigates climate change at the lowest costs and greenest ways.In addition,NCS practices can improve multiple ecosystem services(ES)such as air quality,flood and erosion regulation,pest control,water purification,wild food biomass,recreation or landscape aesthetics.However,unsustainable implementation of NCS,such as over-afforestation of dense mono-forest,can lead to tradeoffs with water supply,wildfire risk,and decreased grasslands and crop-lands.Therefore,to optimise the NCS implementation,reducing the tradeoffs associated and transforming the“expand ecosystem area”to“improve ecosystem management efficiency”is vital.Although NCS can contribute significantly to mitigating climate change,systematic climate actions must be accompanied by a transformation in the global society and investment in new technologies.This will be key to addressing global challenges such as the achievement of Sustainable Development Goals(SDGs),such as SDG 13(Climate Action),SDG 15(Life on Land),SDG 2(Zero Hunger),SDG 3(Good Health and Wellbeing),SDG 6(Clean Water and Sanitation),and SDG 14(Life Bellow Water).
基金supported by the Sino-German Postdoc Scholarship Program of the China Scholarship Council(CSC)the German Academic Exchange Service(DAAD)+4 种基金supported in part by the National Natural Science Foundation of China(Nos.32071541,41971071)the Ministry of Science and Technology of China(Nos.2021FY100200,2021FY100702,2023YFF0805802)the Youth Innovation Promotion Association,CAS(No.2021392)the International Partnership Program,CAS(No.151853KYSB20190027)the“Climate Change Research Initiative of the Bavarian National Parks”funded by the Bavarian State Ministry of the Environment and Consumer Protection.
文摘An improved understanding of biodiversity-productivity relationships(BPRs)along environmental gradients is crucial for effective ecosystem management and biodiversity conservation.The stress-gradient hypothesis suggests that BPRs are stronger in stressful environments compared to more favorable conditions.However,there is limited knowledge regarding the variation of BPRs along elevational gradients and their generality across different landscapes.To study how BPRs change with elevation,we harnessed inventory data on 6,431 trees from152 plots surveyed twice in eight to ten year intervals in mountain forests of temperate Europe and subtropical Asia.We quantified the relationship between aboveground productivity and different biodiversity measures,including taxonomic,functional,and phylogenetic diversity.To elucidate the processes underlying BPRs,we studied the variation of different functional traits along elevation across landscapes.We found no general pattern of BPRs across landscapes and elevations.Relationships were neutral for all biodiversity measures in temperate forests,and negative for taxonomic and functional diversity in subtropical forests.BPRs were largely congruent between taxonomic,functional and phylogenetic diversity.We found only weak support for the stress-gradient hypothesis,with BPRs turning from negative to positive(effect not significant)close to the tree line in subtropical forests.In temperate forests,however,elevation patterns were strongly modulated by species identity effects as influenced by specific traits.The effect of traits such as community-weighted mean of maximum plant height and wood density on productivity was congruent across landscapes.Our study highlights the context-dependence of BPRs across elevation gradients and landscapes.Species traits are key modulating factors of BPRs and should be considered more explicitly in studies of the functional role of biodiversity.Furthermore,our findings highlight that potential trade-offs between conserving biodiversity and fostering ecosystem productivity exist,which require more attention in policy and management.
基金supported by the “Project funded by the European Union-Next Generation EU”
文摘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.
文摘We chose a definition of heatwaves (HWs) that has ~4-year recurrence frequency at world hot spots. We first examined the 1940-2022 HWs climatology and trends in lifespan, severity, spatial extent, and recurrence frequency. HWs are becoming more frequent and more severe for extratropical mid- and low-latitudes. To euphemize HWs, we here propose a novel clean energy-tapping concept that utilizes the available nano-technology, micro-meteorology knowledge of temperature distribution within/without buildings, and radiative properties of earth atmosphere. The key points for a practical electricity generation scheme from HWs are defogging, insulation, and minimizing the absorption of infrared downward radiation at the cold legs of the thermoelectric generators. One sample realization is presented which, through relay with existing photovoltaic devices, provides all-day electricity supply sufficient for providing air conditioning requirement for a residence (~2000-watt throughput). The provision of power to air conditioning systems, usually imposes a significant stress on traditional city power grids during heatwaves.
基金We appreciate United Nations Development Programme-Indonesia and Archipelagic&Island States(AIS)Forum for the 2021 Archipelagic&Island States Innovation Challenges Award given for this idea on Joint Research Programme in Climate Change Mitigation and Adaptation.
文摘Guyana’s capacity to address the impacts of climate change on its coastal environment requires the ability to mon-itor,quantify and understand coastal change over short-,medium-and long-term.Understanding the drivers of change in coastal and marine environment can be achieved through the accurate measurement and critical anal-yses of morphologies,flows,processes and responses.This manuscript presents a strategy developed to create a central resource,database and web-based platform to integrate data and information on the drivers and the changes within Guyana coastal and marine environment.The strategy involves four complimentary work pack-ages including data collection,development of a platform for data integration,application of the data for coastal change analyses and consultation with stakeholders.The last aims to assess the role of the integrated data sys-tems to support strategic governance and sustainable decision-making.It is hoped that the output of this strategy would support the country’s climate-focused agencies,organisations,decision-makers,and researchers in their tasks and endeavours.
基金the project"Determination of carbon pools in old-growth forests located within the Sila National Park—CARBOSIL"funded by the Ministry of the Environment,Land and Sea Protection—Department for Nature Protection under the Directive on Biodiversity。
文摘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.
基金supported by the National Natural Science Foundation of China(71874133)the Youth Innovation Team of Shaanxi Universities,and the Annual Basic Scientific Research Project of Xidian University(2019).
文摘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.
基金Fujian Provincial Department of Science and Technology(Grant Number:2021I0014)Fujian Provincial Department of Housing and Construction(Grant Number:2022-K-67+5 种基金Fujian Provincial Department of Education(Grant Number:JAT201518)Additionally,Authors are grateful to Quanzhou Tongjiang Scholar Special Fund for financial support throughGrant Number:(600005-Z17X0234)Quanzhou Science and Technology Bureau for financial support through Grant Number:(2018Z010)Huaqiao University through Grant Number:(17BS201)the Fujian Provincial Department of Science and Technology for financial support through Grant(2018J05121)Authors are also grateful for financial support from the Fujian Provincial Department of Science and Technology through Grants Numbers:2021I0014 and 2018J05121.
文摘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.
文摘The aim of this study was to assess Acacia senegal trees’ characteristics as well as evaluate the carbon stock under a variety of ages in the El Demokeya forest in Sudan, where the Gum Arabic belt is located. 12 sample plots, in 2021 were randomly distributed to represent the entire area of the forest prior to the required measurements. The sample was designed as squire plots with one hectare. In each sample plot, all trees were counted, their height (m), and Diameters Breast Height (DBH in cm), respectively. The results showed the highest number of trees per ha at age 20 years old and the lowest number at age 47 years, while the highest values of DBH and volume were found at age 47 years old. As a result, the maximum and minimum values of the aboveground biomass were found in the age 47 years old and 16 years, accounting for 19.87 tons and 1.9 tons respectively. Thus, the amount of carbon stock was 11.92 tons/ha in the 35-years-old and 1.19 tons/ha in the 21-year stands. Furthermore, the average carbon stock in all plots was estimated as 18.70 tons/ha and hence the total carbon stock in the El Demokeya forest is equal to 620.11 tons. Conclusively, the characteristics of trees, amount of aboveground biomass and carbon stock in the El Demokeya forest varied among the uneven-aged plantation groups. The study recommends and encourages the protection of A. senegal in order to increase the carbon sink as well as protect the environment in the era of climatic changes.
基金Project supported by the Pilot Project of Knowledge Innovadon Program of Chinese Academy of Sciences (No. KZCX32SW2424).
文摘Land surface temperature (LST), which is heavily influenced by urban surface structures, is a significant parameter in urban environmental analysis. This study examined the effect impervious surfaces (IS) spatial patterns have on LST in Beijing, China. A classification and regression tree model (CART) was adopted to estimate IS as a continuous variable using Landsat images from two seasons combined with QuickBird. LST was retrieved from the Landsat Thematic Mapper (TM) image to examine the relationships between IS and LST. The results revealed that CART was capable of consistently predicting LST with acceptable accuracy (correlation coefficient of 0.94 and the average error of 8.59%). Spatial patterns of IS exhibited changing gradients across the various urban-rural transects, with LST values showing a concentric shape that increased as you moved from the outskirts towards the downtown areas. Transect analysis also indicated that the changes in both IS and LST patterns were similar at various resolution levels, which suggests a distinct linear relationship between them. Results of correlation analysis further showed that IS tended to be positively correlated with LST, and that the correlation coefficients increased from 0.807 to 0.925 with increases in IS pixel size. The findings identified in this study provide a theoretical basis for improving urban planning efforts to lessen urban temperatures and thus dampen urban heat island effects.
文摘Forests provide diverse co-benefits, including livelihoods enhancement, poverty alleviation, and biodiversity conservation and ecosystem services such as climate mitigation. Consequently, Ghana has embraced several global, regional, national, and local forest policy interventions to safeguard its forest resources’ sustainable management. However, the forest policy interventions have not adequately addressed the co-benefits issues of forest resources leading to several forest illegalities that drive forest resources degradation and loss. These forest policies and interventions on the ground primarily favour carbon stocks enhancement and sequestration activities for carbon mitigation purposes compared to the benefits, access and rights that forest-dependent people and communities are supposed to derive from forest resources. These perceived injustices in the access and distribution of forest resources have culminated into all forms of forest illegalities driving Ghana’s forest resources into massive degradation and loss. Currently, Ghana is experiencing a 2% rate of annual deforestation and forest degradation, which translates into approximately 135<span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">,</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">00</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">0</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> ha/year of forest cover loss due to anthropogenic causes. Our review is based on relevant and critical forest documents, and scientific peer-reviewed papers on Ghana’s forest policy interventions and dynamics recently published. The information gathered enabled us to highlight the perceived injustices in the forest policy interventions and their effects on forest resources. Unjust forest resources sharing and distribution are critical drivers of forest resources degradation and loss. We thus offer lessons for remedying the unfair distribution and injustices to promote equitable forest resources rights and benefit access to local forest-dependent people. It is expected that this review will offer and assist forest policy, intervention spatial and other planners and designers to find a possible way forward to avoid nature degradation, including biodiversity loss, to resolve perceived injustices in the forestry sector, to use adequate all ecosystem services provided by forests as well as to promote local livelihood and sustainability.</span></span></span>
基金supported by the National Natural Science Foundation of China (71690243 and 51861135102)the Ministry of Science and Technology of the People’s Republic of China (2018YFC1509006)the World Bank Group (7202065)
文摘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.
基金the National Key Research and Development Program of China(2018YFE0204100).
文摘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.
基金Tarbiat Modares University for financial, laboratory and scientific support
文摘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.
基金supported by a TWAS-ENEA Research Training Fellowship Programme in Italy。
文摘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.
基金supported by the National Natural Science Foundation of China (Grant No.71390525)
文摘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
基金This study was funded by The Rufford Foundation(Rufford small grant#206761,to N.M.-S.)the Instituto de Ecologia,A.C.(project INECOL,20030-10281,to J.L.)the Consejo Nacional de Ciencia y Tecnologia(CONACYT,Scholarship#263474,to N.M.-S.).
文摘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.