Implication of soil C sequestration on sustainable agriculture and environment

Soil organic matter (SOM) is the largest C stock of the continental biosphere with 1550Pg. The size of C reservoir in the soil and environmental concerns on climate change have recently attracted the attention of scientist and politicians on C sequestration as an effective strategy to tackle greenhouse gas (GHG) emissions. It has been estimated that the potential for C storage in world cropland is relevant (about 0.6-1.2PgCy(-1)). However, there are several constraints of C sequestration that raise concern about its effectiveness as a strategy to offset climate change. C sequestration is finite in quantity and time, reversible, and can be further decreased by socio-economic restrictions. Given these limitations, C sequestration can play only a minor role in the reduction of emissions (2-5% of total GHG emission under the highest emission scenarios). Yet, C sequestration is still attractive for two main reasons: it is likely to be particularly effective in reducing atmospheric CO2 levels in the first 20-30yr of its implementation and presents ancillary benefits for environment and sustainability that make it a real win-win strategy. These beneficial implications are discussed in this paper with emphasis on the need of C sequestration not only to offset climatic changes, but also for the equilibria of the environment and for the sustainability of agriculture and of entire human society.     

Resilience: A New Consideration for Environmental Remediation in an Era of Climate Change

There has been a growing movement within the environmental industry to develop more sustainable approaches in environmental remediation. These have generally included carbon footprint analysis, life cycle assessment, and best management practices to reduce the overall net environmental, social, and economic impacts of investigation and remediation activities. One of the foundational reasons net environmental impacts are currently evaluated is to identify and, subsequently, reduce contributions to climate change, primarily greenhouse gas emissions. While this trend toward sustainability and reduction in impact to the global environment is both important and admirable, the approach to remediation design and long‐term planning now needs to evolve further to better incorporate climate resilience into sustainable remediation design and implementation: designing remediation solutions that account for the projected impacts of climate change, as well as have the capacity to adapt to changing conditions. As a global population, we are now beyond the point of being able to prevent climate change and instead need to plan for adapting to it. In remediation, the effects of climate change create both risks and opportunities which should be considered during remedial design and long‐term planning. Responsible parties may see the push for—and management of—these considerations through their internal corporate risk management. The authors of this paper propose a simple framework for climate adaptation and resilience evaluations and plan development for remediation projects. ©2015 Wiley Periodicals, Inc.     

Co-benefit as an approach to align climate change concerns with national development objectives: solid waste management

Impinging local environmental problems on the one hand and constantly persuasive climate change concerns on the other put developing Asian cities in a dilemma as to which direction they should channel their efforts. While local matters are their immediate mandate, increasing awareness of climate change vulnerabilities adds weight to global problems. In this context, the concepts of co-benefits and ancillary benefits play an important role in aligning climate change concerns into sector-specific developmental goals. This article presents the conceptual aspects of co-benefits and the integration of climate concerns into sustainable development goals. The possible synergies between these two different but very important strategic pathways are examined along with possible ways to align them. The bottlenecks that can occur during such integration are also highlighted.     

Carbon sequestration in European soils through straw incorporation: limitations and alternatives

We compared alternate uses of cereal straw (4.25t dry matter ha(-1) containing 1.7t carbon (C)) for their effectiveness in relation to climate change mitigation. The scenarios were (1) incorporation into soil to increase soil organic carbon (SOC) content ("carbon sequestration") and (2) combustion to generate electricity. The Rothamsted Carbon Model was used to estimate SOC accumulation in a silty clay loam soil under the climatic conditions of north-west Europe. Using straw for electricity generation saved seven times more CO2 than from SOC accumulation. This comparison assumed that electricity from straw combustion displaced that generated from coal and used the mean annual accumulation of SOC over 100yr. SOC increased most rapidly in the early years, but then more slowly as a new equilibrium value was approached. We suggest that increased SOC from straw incorporation does not represent genuine climate change mitigation through carbon sequestration. In Europe, most straw not already incorporated in the field where it is grown is subsequently returned elsewhere, e.g., after use for animal bedding and production of manure. Only additional retention of C in soil compared to the alternative use represents sequestration. Maintenance of SOC for soil functioning is a more appropriate rationale for returning straw to soil than climate change mitigation. This analysis shows that considerably greater climate change mitigation is achieved through saved CO2 emissions by burning straw for electricity generation, replacing some use of fossil fuel.     

Current and future solid waste management system in Northern Viet Nam with focus on Ha Noi: climate change effects and landfill management

The contribution investigates the solid waste management system in Ha Noi under consideration of the interrelation between climate change effects and landfill management by means of a cause-and-effect-analysis as well as water balances using the HELP 3.95 model and gas emission data, followed by a Strength, Weakness, Opportunities, Threats (SWOT) analysis. Even landfills are sources of methane (CH₄) emissions they are also impacted by climate change. The main effects on landfill sites are the change of climatic conditions, namely the regional water balance, extreme precipitation and storm events. The results of the water balance model results show that a geomembrane surface sealing can reduce the leachate formation significantly, a fact that is also valid for the climate change scenario with higher precipitation. The risk of flooding and erosion at the landfill sites increases, which will require a customized water management. In parallel landfill gas offers the opportunity for recovery of Greenhouse Gases (GHG) and the generation of renewable energy. Some further management options are wind turbines, photovoltaic systems or biomass for biogas conversion, which was grown on closed landfill sites. The inclusion of climate friendly management options of closed landfills in a “Good Landfill Aftercare Practice” is recommended.     

Wood Residues as Raw Material for Biorefinery Systems: LCA Case Study on Bioethanol and Electricity Production

Fossil energy and chemical sources are depleting. There is a critical need to change the current industry and human civilization to a sustainable manner, assuring that our way of life actual continues on the path of improvement after the depletion of fossil energy sources. The utilization of agricultural residues as raw materials in a biorefinery is a promising alternative to fossil resources for production of energy carriers and chemicals, thus mitigating climate change and enhancing energy security. Biorefinery is a concept of converting lignocellulosic biomass or grains (such as corn) to chemicals, materials and energy on which human civilization runs, replacing the need for petroleum, coal, natural gas, and other nonrenewable energy and chemical sources. Lignocellulosic biomass is renewable, that is plant synthesizes chemicals (by drawing energy from the sun and carbon dioxide) and water from the environment, while releasing oxygen. Combustion of biomass releases energy, carbon dioxide and water. Therefore, biorefinery plays a key role in satisfying human needs for energy and chemicals by using the biomass production and consumption cycle. This paper focuses on a biorefinery concept and in particular on the bioethanol production from wood residues. In order to evaluate the environmental reliability of the system under study, the biorefinery plant (producing bioethanol and electricity from wood residues) was compared, by using the LCA methodology, to both conventional refinery system (producing light fuel oil and electricity from petroleum) and biorefinery plant based on corn feedstock producing the same goods. Interesting considerations about LUC emissions effect on biorefinery sustainability are also reported. The obtained results show that by assigning reasonable values to the three damage categories used in the eco-indicator 99 methodology the biorefinery system is preferable, from an environmental point of view, to the conventional refinery system analysed. This finding confirms the high potentials of this innovative plant technology.     

Climatic and Environmental Changes in the Source Areas of Dust Storms in Xinjiang, China, during the Last 50 Years

The desert environmental changes in the source areas of dust storms occurring in Xinjiang are discussed based on the climate changes and the impacts of human activities in Xinjiang during the past 50 years. The results show that the climate in Xinjiang is changing from a warm-dry type to a warm-wet one. The warm-wet climate has been obvious since the mid-1970's, and especially the sensitivity of the regional climate change in this arid area is obviously revealed by many factors, such as the characteristics of the local climate change in south Xinjiang and north Xinjiang, the difference of climate change in the alpine zones and the basins, and the change of areas of the waters bodies. Furthermore, these factors also reveal the difference in the regional climate change between Xinjiang and central and eastern areas of China. The occurrence and development of dust storms are directly affected by the precipitation, air humidity, status of underlying surface, etc. in the arid areas. The frequency and intensity of dust storms are closely related to the natural conditions, changes of climate and desert environment, as well as the dynamic conditions (i.e., weather systems) in the source areas of dust storms. Therefore, global warming is one of the main causes resulting in the degradation of the ecological environment and the frequent occurrence of natural disasters, especially the disasters of sand drift and dust storms in the arid areas since the late-1980's, which reveals that the inland arid areas are sensitive regions to climate changes.     

Modelling Change in Ground Vegetation Response to Acid and Nitrogen Pollution, Climate Change and Forest Management at in Sweden 1500–2100 a.d.

The ForSAFE model, designed for modelling biogeochemical cycles (water, acidity, base cation, nitrogen and carbon) in terrestrial ecosystems, was modified with a vegetation response module (VEG), incorporating the effects of: nitrogen pollution, acidification, soil moisture, temperature, wind chill exposure, light and shading by trees, grazing by animals, competition between plants, above ground for light and below ground for water and nutrients. The model calculates the response of number ground vegetation plant groups. The integrated model was tested and validated at integrated level II forest monitoring sites across Sweden, four have been shown here, and used to assess the effect of acidification and nitrogen pollution in relation to factors such as climate change, forest management and changing grazing pressure. The response functions have been derived from single-factor experiments and integrated through the model structure for use on whole systems. The tests with the model suggest that the ground vegetation composition is reasonably well predicted, that much research remains before the model is fully tested and operational, and that the model may serve as a tool for assessing impacts of climate change, acid rain and forest management on plant biodiversity in forested areas.     

Climate Change Implications on Flood Response of a Mountainous Watershed

The modification of the flood response due to future climate change is presented for the Illecillewaet watershed of British Columbia, Canada. The Canadian Centre for Climate Modeling Analysis General Circulation Model (CGCMa1) was used for the assessment of changes of precipitation and temperature due to climate change. The runoff was simulated using the UBC watershed model and considering, also, changes on the spatial distribution of precipitation with elevation, cloud cover, glaciers, vegetation distribution, vegetation biomass production, and plant physiology. The results show that the future climate would be wetter and warmer than the present climate affecting the type, the magnitude and the temporal distribution of floods as well as the frequency of flood peaks. The above changes in the flood response of the study watershed could be explained by the change of the form of precipitation from snowfall to rainfall, the consequent decrease of the snowpack, and the initiation of the snowmelt earlier in the season, under the altered climate.     

Recent developments in Korea’s Framework Act on Resource Circulation: toward a resource-circulating society

Korea is moving toward a sustainable resource-circulating society to fight climate change and resource scarcity. To achieve this goal, the Framework Act on Resource Circulation (FRC) was enacted on May 29, 2016 and came into effect on January 1, 2018. This act not only acknowledges the importance of resource efficiency and the transition to a resource-circulating society, but also plays a significant role in the progress of important and relevant market and industry developments. This study primarily focuses on an analysis of the FRC. It aims to evaluate key concepts such as a resource-circulating society, circular resources, important provisions including major principles and allocation of responsibilities, and measures to be taken to promote resource circulation. In addition, it explores whether the FRC is sufficiently comprehensive and ambitious to contribute to the transition to a more resource-circulating society.     

Framework for integrating sustainability into remediation projects

The US Sustainable Remediation Forum (SURF) created this Framework to enable sustainability parameters to be integrated and balanced throughout the remediation project life cycle, while ensuring long‐term protection of human health and the environment and achieving public and regulatory acceptance. Parameters are considerations, impacts, or stressors of environmental, social, and economic importance. Because remediation project phases are not stand‐alone entities but interconnected components of the wider remediation system, the Framework provides a systematic, process‐based approach in which sustainability is integrated holistically and iteratively within the wider remediation system. By focusing stakeholders on the preferred end use or future use of a site at the beginning of a remediation project, the Framework helps stakeholders form a disciplined planning strategy. Specifically, the Framework is designed to help remediation practitioners (1) perform a tiered sustainability evaluation, (2) update the conceptual site model based on the results of the sustainability evaluation, (3) identify and implement sustainability impact measures, and (4) balance sustainability and other considerations during the remediation decision‐making process. The result is a process that encourages communication among different stakeholders and allows remediation practitioners to achieve regulatory goals and maximize the integration of sustainability parameters during the remediation process. © 2011 Wiley Periodicals, Inc.     

Possibilities and limitations of life cycle assessment (LCA) in the development of waste utilization systems – Applied examples for a region in Northern Germany

Against the background of increasing concerns about climate change, the reduction of greenhouse gas emissions has become an integral part of processes in both the waste management and the energy industries. This is reflected in the development of new waste treatment concepts, in which domestic and commercial waste is treated with the aim of utilizing its energy content, while at the same time recycling as much of its material content as possible. Life cycle assessment (LCA) represents a method of assessing the environmental relevance of a waste management system, the basis of which is a material flow analysis of the system in question. GHG emissions from different options for thermal treatment and energy recovery from waste as applied to a region in Northern Germany have been analyzed by the LCA approach and an indicative LCA, which only considers those emissions resulting from operating stages of the system. Operating stages have the main share of emissions compared to pre-processing stages. Results show that through specific separation of waste material flows and highly efficient energy recovery, thermal treatment and energy generation from waste can be optimized resulting in reduction of emissions of greenhouse gases. There are also other areas of waste utilization, currently given little attention, such as the solar drying of sewage sludge, which can considerably contribute to the reduction of greenhouse gas emissions.     

The potential role of compost in reducing greenhouse gases.

The contribution of the agricultural sector to emissions of climate change gases is becoming better understood. At the same time, the potential role of the sector as a means through which to tackle climate change, widely neglected in the past, is becoming more widely acknowledged. The absorption potential of agricultural soils could contribute significantly to constraining growth in greenhouse gas emissions, while also contributing to improvements in soil quality in some areas. In addition to the measures listed above, other benefits of compost application may have some relevance. Some of these measures include replacement of chemical fertilizers (implying avoidance of greenhouse gases related to their production) reduced use of pesticides (avoiding emissions associated with their production), improved tilth and workability (less consumption of fuels). Typically, life-cycle analyses (LCAs) exhibit limitations related to assessing the effects of 'time-limited' carbon sequestration in soils. This has tended to obscure the potentially important effect of composting, in which biogenic carbon is held in soils for a period of time before the carbon is released. The paper seeks to understand these effects and offers comments on the contribution of biological treatments to tackling climate change issues. Key issues include the replacement of fertilizers, reduction of N2O emissions, and peat replacement.     

Near‐Surface Disposal Performance Assessment: Modeling Monthly Precipitation and Temperature in Various Climate Environments

A more stable and extensive analysis of climate is necessary to simulate long‐term impacts associated with climate change. The exponential dispersion model (EDM) family of distributions, a popular choice when characterizing precipitation levels and temperature in different climate environments, is being considered for its applicability to near‐surface disposal performance assessments. In this study, the EDM family is examined to determine if there is a preferred distributional form within the family for these parameters using data from two sites whose climate environments are quite different. One site is in a semiarid environment and the other is in a humid environment. In addition, the merits of selecting a different distributional form to represent each calendar month of precipitation and temperature data are explored. Results show that the gamma distribution was most often determined to be the best fit to recorded precipitation data. When considering temperature, however, the Weibull distribution proved to be a better fit. These results suggest that greater precision may be possible when temperature and precipitation serve as inputs to modeling activities, if these parameters are allowed to be represented by different distributions and derived by calendar month. Ultimately, the approach provides a more far‐reaching examination of historical records and provides an increase in confidence, when used in the evaluation of long‐term climate impacts associated with near‐surface disposal facilities. © 2013 Wiley Periodicals, Inc.     

Financial sustainability in municipal solid waste management – Costs and revenues in Bahir Dar,Ethiopia

Providing good solid waste management (SWM) services while also ensuring financial sustainability of the system continues to be a major challenge in cities of developing countries. Bahir Dar in northwestern Ethiopia outsourced municipal waste services to a private waste company in 2008. While this institutional change has led to substantial improvement in the cleanliness of the city, its financial sustainability remains unclear. Is the private company able to generate sufficient revenues from their activities to offset the costs and generate some profit?This paper presents a cost-revenue analysis, based on data from July 2009 to June 2011. The analysis reveals that overall costs in Bahir Dar’s SWM system increased significantly during this period, mainly due to rising costs related to waste transportation. On the other hand, there is only one major revenue stream in place: the waste collection fee from households, commercial enterprises and institutions. As the efficiency of fee collection from households is only around 50%, the total amount of revenues are not sufficient to cover the running costs. This results in a substantial yearly deficit. The results of the research therefore show that a more detailed cost structure and cost-revenue analysis of this waste management service is important with appropriate measures, either by the privates sector itself or with the support of the local authorities, in order to enhance cost efficiency and balance the cost-revenues towards cost recovery. Delays in mitigating the evident financial deficit could else endanger the public-private partnership (PPP) and lead to failure of this setup in the medium to long term, thus also endangering the now existing improved and currently reliable service.We present four options on how financial sustainability of the SWM system in Bahir Dar might be enhanced: (i) improved fee collection efficiency by linking the fees of solid waste collection to water supply; (ii) increasing the value chain by sales of organic waste recycling products; (iii) diversifying revenue streams and financing mechanisms (polluter-pays-, cross-subsidy- and business-principles); and (iv) cost reduction and improved cost-effectiveness.We argue that in a PPP setup such as in Bahir Dar, a strong alliance between the municipality and private enterprise is important so that appropriate solutions for improved financial sustainability of a SWM system can be sought and implemented.     

European Union waste management strategy and the importance of biogenic waste

In the European Union (EU), waste management is almost totally regulated by EU directives, which supply a framework for national regulations. The main target in view of sustainability is the prevention of direct disposal of reactive waste in landfills. The tools to comply with these principles are recycling and material recovery as well as waste incineration with energy recovery for final inertization. The adaptation of the principles laid down in EU directives is an ongoing process. A number of countries have already enacted respective national regulations and their realization shows that recycling and incineration are not in competition but are both essential parts of integrated waste management systems. In the EU, the amount of residual waste available for energy recovery can supply approximately 1% of the primary energy demand. About 50% of the energy inventory of municipal solid waste (MSW) in most EU countries is of biogenic origin, and MSW is to the same extent to be looked upon as regenerative fuel. Hence part of the CO₂ released from waste incineration is climate neutral. In the EU, this share could produce savings of the order of 1% of annual CO₂ emissions if energy from MSW replaced that derived from fossil fuel.     

Climate-influenced hydrobiogeochemistry and groundwater remedy design: A review

The process of designing a remedy for contaminated groundwater historically has not commonly included climate-future, hydrologic, and biogeochemical aquifer characteristics. From experience, the remedy design process also has not consistently nor directly integrated or projected future hydrologic and biogeochemical effects of the human-induced or developed environment—aka the anthropogenic influence—on potential remedy performance. The apparent practice of (1) not regularly assessing anthro-influenced hydrological (termed here as anthrohydrology) or biogeochemical characteristics (collectively hydrobiogeochemistry) of a site and (2) rarely accounting for future climatic shifts as design factors in remedy design may be due, in part, to the general practice-level view that groundwater remediation systems (whether in situ or ex situ) have seldom been anticipated to last more than a few years (or one or two decades at the most). Second, methods to reliably and quantitatively estimate site-specific, climate-future shifts in groundwater conditions using global and/or regional climate models and the resultant impacts on contaminant plume characteristics have not been readily available. The authors here suggest that while the concept of remedy design resilience and durability, within an envelope of climate change and anthropogenic influence, has been discussed in some technical circles as a component of “sustainable remediation,” we have found that direct application of these technical concepts in quantifiable terms remains rare. By incorporating the potential influence of future hydrobiogeochemical scenarios into remedy design, however, the design process could account for reasonable climate-induced influence on the groundwater system for a given site. These scenarios could then be applied within the remedy selection process to assess performance durability under potentially changing hydrologic, biological, and chemical conditions.     

Sustainable Remediation Considerations for Treatment of 1,4‐Dioxane in Groundwater

1,4‐Dioxane remediation is challenging due to its physiochemical properties and low target treatment levels. As such, applications of traditional remediation technologies have proven ineffective. There are a number of promising remediation technologies that could potentially be scaled for successful application to groundwater restoration. Sustainable remediation is an important consideration in the evaluation of remediation technologies. It is critically important to consider sustainability when new technologies are being applied or new contaminants are being treated with traditional technologies. There are a number of social, economic, and environmental drivers that should be considered when implementing 1,4‐dioxane treatment technologies. This includes evaluating sustainability externalities by considering the cradle‐to‐grave impacts of the chemicals, energy, processes, transportation, and materials used in groundwater treatment. It is not possible to rate technologies as more or less sustainable because each application is context specific. However, by including sustainability thinking into technology evaluations and implementation plans, decisions makers can be more informed and the results of remediation are likely to be more effective and beneficial. There are a number sustainable remediation frameworks, guidance documents, footprint assessment tools, life cycle assessment tools, and best management practices that can be utilized for these purposes. This paper includes an overview describing the importance of sustainability in technology selection, identifies sustainability impacts related to technologies that can be used to treat 1,4‐dioxane, provides an approximating approach to assess sustainability impacts, and summarizes potential sustainability impacts related to promising treatment technologies. ©2016 Wiley Periodicals, Inc.     

Debunking myths about sustainable remediation

Sustainable remediation concepts have evolved during the decade 2007–2017. From the establishment of the first Sustainable Remediation forum (SURF) in 2007, to publication of ASTM and ISO standards by 2017. Guidance has been developed around the world to reflect local regulatory systems, and much has been learned in applying sustainability assessment to contaminated site management projects. In the best examples, significant improvements in project sustainability have been delivered, including concurrent reduction of the environmental footprint of the remediation program, improved social performance, and cost savings and/or value creation. The initial advocates for the concept of sustainable remediation were quickly supported by early adopters who saw its potential to improve the remediation industry's performance, but they also had to overcome some inertia and scepticism from other parties. During the debates and discussions that occurred at numerous international conferences and SURF workshops around the world, various opinions were formed and positions stated. Some proved to be correct, others not so. With the recent publication of ISO Standard 18504 and the benefit of a decade's‐worth of hindsight on sustainable remediation programs implementation and project delivery, this paper summarizes a number of myths and misunderstandings that have been stated regarding sustainable remediation and seeks to debunk them. Sustainable remediation assessment shows us how to manage unacceptable risks to human health and the environment in the best, that is to say the most sustainable, way. It provides the contaminated land management industry a framework to incorporate sustainable development principles into remediation projects and deliver significant value for affected parties and society more broadly. In dispelling some myths about sustainable remediation set out in this paper, it is hoped that consistent application of ISO18504/SuRF‐UK (or equivalently robust guidance) will facilitate even wider use of sustainable remediation around the world.     

VinylPlus, the new European PVC industry’s voluntary programme toward sustainability

Over the past 10?years, the Vinyl 2010 programme has been highly effective in assisting the European PVC industry tackling various stakeholder concerns related to PVC sustainability. The Vinyl 2010 partners decided in 2009 to launch a follow-up programme, VinylPlus. Vinyl 2010’s success was to a large extent due to the close cooperation of the entire PVC value chain, and to clear targets and deadlines allowing transparent progress monitoring. These key features have been retained. Climate change and availability of non-renewable resources are now widely recognised as major challenges. Health and safety concerns about chemical substances are increasingly prevalent. In this context, a fundamental assessment of the sustainability features of PVC as material and as industry was carried out. An in-depth reflection involving scores of business managers and industry experts, stakeholders and NGOs took place. It produced collective insights and a credible pathway for progress over the next 10?years. Both the reflection process and its results are described, with particular emphasis on recycling. The issue of “legacy additives”, a potential major hurdle of recycling, is given particular attention.