Recovery and characterisation of carbon fibres from waste CFRP using supercritical n-butanol

ABSTRACT

The high-performance carbon fibres can be recycled from waste carbon fibre/epoxy resin composites by supercritical n-butanol. Recycling experiment designed by response surface method was used to investigate quantitative relation between degradation rate of epoxy resin and process parameters. Thus, the optimum process parameters could be obtained, and effects of process parameters and layers on degradation rate and mechanical performance of the recycled carbon fibres were analysed. The tensile strength of the recycled carbon fibre under the optimum process parameters was 94.53% of that of the original carbon fibre, tensile modulus was 93.57% of that of the original carbon fibre and interfacial shear strength was 90% of that of the original carbon fibre.     

基于最优拍卖数量和资金再分配模型的碳市场有偿分配机制研究

拍卖作为一种有偿分配机制已经确立为我国碳市场配额分配的基本方式之一,而拍卖机制的灵活运用以及与市场运行之间的关系也成为实践中亟待解决的难题。传统的排放权拍卖理论以政府收入最大化作为目标函数,并没有将企业预算和交易策略纳入到分析框架中,同时对于拍卖收入资金的再分配方法缺乏可行的指导。本文将企业的成本约束(或预算)作为一个因素引入,提出了最优拍卖数量模型以及基于双重红利思想的资金再分配模型。分析表明最优拍卖数量由企业的边际减排成本和二级市场弹性系数决定,二级市场弹性系数则取决于排放的不确定性水平;边际减排成本越高的企业,其承受的拍卖成本随着拍卖价格增长越快,这可能导致减排空间小的企业承担的拍卖成本增长过高,从而产生不公平问题,因此本文提出了一种基于多轮竞价的资金分配策略,根据企业参加拍卖的投标情况间接评估企业的边际减排成本水平,并制定相应的补贴标准。最后以广东碳市场为例,从市场结构、履约成本、市场价格三个方面深入讨论了拍卖对碳市场的影响以及最优参数的选择策略。广东的经验为拍卖机制的引入提供了良好的建议:在二级市场流动性不足,价格发现能力较弱的情况下,引入拍卖机制可以快速建立一级市场的价格发现机制;由于历史法的不可靠,拍卖会将履约成本分配不合理的问题进一步放大,加剧市场的不公平问题,甚至出现劣币驱逐良币的现象,但拍卖收入资金的循环利用可以在一定程度上纠正这一问题;短期内拍卖底价是政府建立市场预期的辅助工具,是在二级市场供求关系尚未建立时的一种过渡手段,但从长期来看随着二级市场的成熟,底价政策应该逐渐放松或退出,建立起一级市场价格与二级市场价格联动的定价机制。     

碳交易背景下中国石化行业2020年碳减排目标情景分析

石化行业作为中国八大典型高碳排放产业之一,也是碳市场参与的重要行业.在国家2020年碳排放强度目标的约束下,客观评价其行业减碳的压力,对于政府部门科学制定各个行业碳排放配额的分配方案具有重要支撑作用.同时,亦对于通过低碳转型升级实现行业的可持续发展和支撑国家的工业减排目标具有理论和现实意义.本文针对石化行业9个子部门,结合我国经济发展的总体背景和趋势以及石化行业的相关数据,以2010年为基准情景,在2020年国家碳排放强度分别下降45％和50％的减排约束目标下,构建了一个动态CGE模型——PCCGE,借助GAMS软件模拟分析,预测了到2020年国家和石化行业经济总量、能源消费结构和碳排放量及碳强度等的变化趋势.研究结果表明,相比基准情景,在45％、50％的碳强度减排目标下,国家和石化行业的经济增长、能源消费结构和碳排放强度等指标分别受到一定程度影响,其中,50％的减排目标对国家整体经济增速影响更为明显;对煤炭、石油这两种高碳能源的需求产生了较显著的约束效应;相比国家45％-50％的低碳发展目标,石化行业减碳承受压力达到60.63％至64.78％,面临着艰巨的减排任务与挑战.最后,文章结合低碳市场化背景提出了如下建议:科学预测典型离碳行业的减碳潜力,谨慎应对石化等行业企业参与碳市场交易过程中碳配额指标的制定与分配;充分利用技术创新和能源结构调整等战略,提高可再生能源的使用规模,促进能源消耗结构的优化和调整;构建石化行业节能低碳技术产学研协同创新体系,解决共性节能技术瓶颈;实施石化行业企业低碳发展战略,建设完善碳排放管理体系是行业节能减碳的重要手段.     

A carbon footprint analysis in the textile supply chain

This research work focuses on the application of life-cycle assessment methodology to determine the carbon footprint of different players involved in a supply chain of the textile sector. A case study of a product by a textile leader company was carried out. This study demonstrates that, in the textile chain, the main contribution to the greenhouse effect is provided by the electrical and thermal energy used and by the transportation (since different production phases are delocalised in a wide range that goes from South Africa, Italy, Romania and all around the world, from the distribution centre to the stores). The Monte Carlo analysis has been used in order to obtain, for each calculated impact, not only the average value but also the distribution curve of the results characterised by uncertainty parameters. Moreover, a sensitivity analysis was carried out to evaluate the impact of management choices such as:

??a change in the transportation modality, from aeroplane to boat;

??a combination of road and rail transportation; and

??a selection among suppliers that allows the firm to cut environmental impacts.     

中国工业碳排放达峰的情景预测与减排潜力评估

实现2030年碳排放达峰不仅是中国为应对全球气候变化向国际社会做出的郑重承诺,也是中国未来经济结构转型与可持续发展的必然选择。基于中国实现2030年碳排放达到峰值的宏观目标为背景,本文以中国碳排放的主要行业工业为研究对象,首先运用拓展的STIRPAT模型对工业及其9个细分行业的碳排放达峰进行了情景预测,然后基于公平和效率的双重视角对工业细分行业的减排潜力进行评估。研究表明:(1)仅有低碳情景和抑制排放情景2可以实现中国碳排放2030年达峰,低碳情景是实现中国工业碳排放达峰的最佳发展模式,达峰时间最早(2030年),峰值最低(140.43亿t)。激进排放情景则是最差的发展模式,达峰时间最晚(2036年),峰值也最高(150.09亿t)。(2)工业内部各细分行业碳排放的最优达峰情景差别较大。建材和纺织制造业能够实现提前达峰,可以在这类行业率先实施达峰管理措施,使其带动其他行业陆续达峰。(3)最具减排潜力的行业是石油制造业,其次是电力行业,这些减排潜力较大的行业应该成为国家节能减排的重点对象。(4)基于工业各细分行业在减排公平性和效率性上的差异将工业9个细分行业分为四类。其中,石油、钢铁制造业和电力行业属于"高效高公平行业";化工、建材制造业属于"低效高公平行业";采掘业属于"高效不公平行业";纺织、轻工和机电制造业属于"低效不公平行业"。中国应针对不同类型的行业制定出相应的减排战略,将减排重点放在各行业最具潜力的方面。最后,文章对实现中国工业碳排放达峰管理提出了几点政策建议。     

CGE model-based analysis of the neutralized hybrid carbon policy and its decomposed effects on economic growth,carbon reduction,and energy utilization costs

The hybrid policy is a flexible policy tool that combines features of carbon trading and carbon taxation.Its economic and environmental effects under China's background are still not studied in detail.Given the exogenous carbon reduction targets,carbon prices,and carbon tax-rates,by computable general equilibrium modeling methods and factor decomposition methods,this article investigates direct and cascaded effects of the hybrid policy on economic growth,energy utilization,and carbon emission on the national level and the sector level,with China's national input-output data-set.Stepwisely,policy scenarios with irrational estimated results are selectively excluded based on comprehensive evaluation among economic,carbon reduction and other policy targets.As a result,against national economic conditions in 2007,the hybrid policy,with a carbon reduction target of -10%,a carbon tax-rate of around $10,and a ceiling carbon price of $40,is highly recommended,because of its significant lower economic loss,lower energy utilization cost,and practical robustness against fluctuation of energy market and carbon market.Furthermore,by decomposition analysis,carbon reduction-related costs are decomposed into a direct part that includes carbon allowance price and carbon tax,and an indirect part as the energy price incremental induced by direct carbon costs.Gross carbon reduction may be decomposed into three parts such as energy intensity,economic scale,and technical progress.And,carbon taxation is the main policy tool that stimulates to improve the energy efficiency.     

中国出口隐含碳排放影响因素研究——基于反事实法的分析

中间消耗的"消耗规模与部门构成"是影响中国出口碳排放的重要因素。基于世界投入产出数据库(WIOD)1995—2015年数据,在部门归类与形式变换基础上,本文选取"单位产出碳排放量"、"完全消耗系数"与"出口值"为中国出口隐含碳排放的影响因子,构建"因子变动—反事实构造—效果评价"分析框架,借助规模指数与结构指数对影响因子的变化动态进行描述,并通过反事实构造对"因子变动"的影响效果进行评价。研究发现:"单位产出碳排放量"规模指数单调递减,Spearman偏度系数为右偏态,说明相比于意愿产出而言,非意愿产出"碳排放量"具有内在的规模不经济;"中间消耗"规模指数与碳偏向性指数在截面上始终处于高位水平,时序上出现了显著的递增趋势,说明中国单位出口值的中间消耗量偏大,消耗投入在结构上偏向于高碳部门,与"技术前沿国"美国存在显著"技术差距";"出口值"规模指数呈现"平缓扩张——快速攀升——V型震荡"的阶段性特征,结构指数经历了以基期2002年为顶点、"先下降、后上升、再平稳"的变化轨迹,说明"出口值"作为最具弹性的影响因子,受"亚洲金融危机"、"加入世界贸易组织"与"美国次债危机"等外部冲击的影响明显,对出口碳排放的推动作用存在伸缩性与阶段性差异。从"因子变动"影响效果来看,中国产出、中间消耗与出口的部门构成具有内生关联,均显著偏向于高碳部门,对出口隐含碳排放增长产生了叠加性的"正向"扩张效应。基于此,本文认为,总量控制与结构优化的视角需从产品环节向中间消耗环节扩展,现阶段应深化要素市场改革,加速要素禀赋升级,借力要素价格机制与差别化产业规制政策,从上游环节抑制出口碳排放的输入来源。     

An analysis of the environmental pressure exerted by the eucalyptus-based kraft pulp industry in Thailand

The study reported here focuses on the environmental pressure exerted by large-scale eucalyptus-based kraft pulp industry in Thailand. The objective of this study was to identify the most important sources of greenhouse gases, acidifying and eutrophying compounds and tropospheric ozone precursors, human toxicity compounds and solid waste associated with the kraft pulp industry. To this end, we performed an environmental systems analysis of the kraft pulp industry system in which we distinguished between two subsystems: the eucalyptus forestry subsystem and the kraft pulp production subsystem. The results indicate that the environmental pressure is caused by the kraft pulp production subsystem rather than by the eucalyptus forestry one. The chemical recovery unit was found to be the most important source of carbon dioxide (CO₂) and sulfur dioxide (SO₂) and responsible for more than one-half of the emissions of greenhouse gases and acidifying compounds from eucalyptus-based kraft pulp production in Thailand. Biomass combustion in the energy gene ration unit is an important source of nitrogen oxide (NO _x ) and carbon monoxide (CO) which in turn are responsible for over 50% of the emissions of tropospheric ozone precursors. About 73% of the eutrophication is caused by biological aerobic wastewater treatment emitting phosphorus (P). With respect to the eucalyptus forestry, only fertilizer use in eucalyptus plantations is a relevant source of pollution through the emission of nitrous oxide (N₂O) and phosphate (PO ₄ ³⁻ ).     

Some methodological and conceptual uncertainties in estimating the income component of the forest carbon cycle

Consideration is given to uncertainties related to methods for assessing the above and belowground phytomass and primary production of forest stands in test plots, as well as for extrapolating the results to forested areas.     

中国碳排放权交易促进低碳技术创新机制的研究

碳排放权交易已成为我国实施以市场为基础的重要环境规制之一,但此交易市场建设能否诱发我国低碳技术创新的有关研究仍然不足。以我国七个碳排放权交易试点为研究对象,采用合成控制法进行准自然实验,选取2004—2016年全国282个城市的面板数据,评估碳排放权交易试点政策对低碳技术创新的诱发效果,并使用排列检验法进行有效性检验;进而,定量分析碳排放权交易试点正式运行后对低碳技术创新的影响因素,探索七个试点效果差异的成因。研究发现:①碳排放权交易试点政策整体上诱发了试点地区的低碳技术创新活动。②各试点的政策效果存在一定差异,除重庆外的六个试点对政策响应较为迅速,其中北京、上海的诱发效果最显著,天津、广东、深圳和湖北次之,而重庆试点未能对政策作出充分的响应。③碳排放权交易对低碳技术创新作用中的政策"信号-预期"机制在我国首次得到验证,该机制在除重庆外的试点地区都得到了较好的构建。④碳排放权交易市场建设与区域产业结构升级产生了良好的协同作用,促进低碳技术创新,但其未能与外商直接投资形成相同作用;除重庆外,碳排放权交易这一市场型环境规制与控制型环境规制也呈现出协同作用。据此,应积极推进全国性碳排放权交易市场建设,以发挥其对低碳技术创新的诱发作用;但在统一市场建设过程中应重视地区差异,分步骤稳步推进;还应注重加强政府政策信号管理,引导企业开展低碳技术创新活动。     

中国旅游业碳生产率区域差异及其格局演变:1995—2014

利用"自下而上"法核算1995—2014年中国大陆30个省(市、区)旅游业碳生产率,采用标准差、变异系数等指标衡量旅游业碳生产率区域差异,并通过空间自相关分析探讨中国旅游业碳生产率区域差异格局演变特征。结果表明:1995—2014年中国旅游业碳生产率总体呈增长趋势,但增长幅度不大,其年均增长率为2.07%,旅游业碳生产率具体数值由1995年的1.120 1万元/t增长至2014年的1.653 0万元/t;旅游业碳生产率区域差异明显,但区域绝对差异和区域相对差异均逐步缩小;旅游业碳生产率空间分布不均,总体呈东高西低的空间格局;旅游业碳生产率的空间分布存在显著正空间自相关性,以及局部的不连续性;旅游业高碳生产率集聚区域主要分布在华北地区,以北京、天津、河北为主要代表;旅游业低碳生产率集聚区域主要分布在西北地区,以新疆、青海和陕西为主要代表;中国旅游业碳生产率整体水平较低,多数省区位于旅游业低碳生产率行列,研究期内旅游业低碳生产率的区域重心逐渐由西部向中部转移。基于上述结论,本文提出针对性建议:政府应制定低碳旅游相关的系列标准规范、行动方案以及保障性政策等,同时应加大对先进低碳技术和低碳设备的引进与推广;各省区应秉持低碳发展理念并将其融入目的地开发与管理之中;旅游企业应积极利用新能源、新材料和新技术,研发低碳旅游系列产品与服务;加大宣传生态环保理念,引导旅游者树立低碳旅游意识,优先选择低碳旅游景区和低碳出行方式,自觉抵制高碳排旅游活动。     

中国资本回报率:考虑碳减排成本的新核算

对资本回报率进行绿色核算既符合当前绿色发展的新理念,同时也是判断我国经济增长可持续性的重要依据。使用超越对数生产函数估算1960—2014年碳排放的影子价格;利用Hall-Jorgenson租金公式测算剔除碳减排成本的中国资本回报率的动态演变趋势。对中国资本回报率重新估算克服了因忽略碳减排成本而导致的高估,估算结果更加科学可靠。研究结果:(1)中国碳排放的影子价格由1960年的56.34元/t上升到2011年的1651.69/t,根据影子价格计算的碳减排成本占GDP总量的份额年均为31%。(2)不考虑碳减排成本和税收因素的基础资本回报率变动趋势可以划分为三个阶段。1952-1983年为第一阶段,资本回报率在波动中由高位逐步回落。1984—2010年是第二个阶段,基础资本回报率保持平稳。2011年以来是第三个阶段,这一阶段中国的资本回报率呈台阶式下降趋势,特别是2012—2014年,税后的资本回报率已经难以抵补企业投资的机会成本。(3)考虑碳减排成本将导致资本回报率平均下降约12%。其中1960—1975年资本回报率呈下降趋势。1976—2008年资本回报率基本保持稳定,资本回报率平均值为15.2%。2009年以后,资本回报率则表现出逐年下降的趋势,2014年的估算值甚至降为-1%。本文仅考虑了碳减排成本,如果再考虑诸如二氧化硫等废气排放、废水与固废排放的成本后,绿色资本回报率的估算值将更低。建议:在当前的经济形势下,应实施激励企业技术创新以及减税(尤其是生产税)政策遏制资本回报率下降的趋势。另外,需要采取分阶段递增的环境规制政策,逐步实现企业环境外部成本的内部化。     

Long-term dynamics of terrestrial carbon stocks in Austria: a comprehensive assessment of the time period from 1830 to 2000

This article presents a comprehensive data set on Austria’s terrestrial carbon stocks from the beginnings of industrialization in the year 1830 to the present. It is based on extensive historical and recent land use and forestry data derived from primary sources (cadastral surveys) for the early nineteenth century, official statistics available for later parts of the nineteenth century as well as the twentieth century, and forest inventory data covering the second half of the twentieth century. Total carbon stocks—i.e. aboveground and belowground standing crop and soil organic carbon—are calculated for the entire period and compared to those of potential vegetation. Results suggest that carbon stocks were roughly constant from 1830 to 1880 and have grown considerably from 1880 to 2000, implying that Austria’s vegetation has acted as a carbon sink since the late nineteenth century. Carbon stocks increased by 20% from approximately 1.0 GtC in 1830 and 1880 to approximately 1.2 GtC in the year 2000, a value still much lower than the amount of carbon terrestrial ecosystems are expected to contain in the absence of land use: According to calculations presented in this article, potential vegetation would contain some 2.0 GtC or 162% of the present terrestrial carbon stock, suggesting that the recent carbon sink results from a recovery of biota from intensive use in the past. These findings are in line with the forest transition hypothesis which claims that forest areas are growing in industrialized countries. Growth in forest area and rising carbon stocks per unit area of forests both contribute to the carbon sink. We discuss the hypothesis that the carbon sink is mainly caused by the shift from area-dependent energy sources (biomass) in agrarian societies to the largely area-independent energy system of industrial societies based above all on fossil fuels.     

FDI对中国物流业碳排放影响的实证研究

近年来,全球气候变暖现象严重,为了实现人类的可持续发展,各国普遍重视发展低碳经济。中国是世界上碳排放量最多的国家,作为负责任的大国,我国发展低碳经济势在必行。物流是经济中不可缺少的一环,低碳物流直接影响到我国低碳经济的发展,因而,对于物流业碳排放问题的研究显得十分必要与紧迫。在经济全球化的背景下,我国大力推行外资政策,积极引进FDI,FDI在推动我国经济发展的同时,也对我国的生态环境产生了影响。正是在这一背景下,本文尝试探讨FDI对我国物流业碳排放的影响;因为产业之间具有关联性,这里的FDI既包括物流业的FDI,也包括其他与物流业相关性较强行业的FDI。本文首先采用投入产出分析方法具体分析了物流业与其他产业的关联程度,得出制造业、商业和金融业是物流业的强相关行业的结论;进而通过构建分行业FDI对我国物流业碳排放影响的时间序列回归模型进行实证分析,结果表明,FDI总体上显著减少了我国物流业的CO2排放量和排放强度,其中物流业、制造业的FDI在减少我国物流业碳排放方面是显著的,而商业与金融业FDI对我国物流业二氧化碳排放强度影响均不显著;上述结果说明FDI对我国物流业碳排放的技术效应明显,"污染天堂假说"在我国物流业并不成立。此外,行业规模、能源消费强度、贸易开放程度、城镇化率以及环境治理投资等因素都会对物流业的碳排放产生影响。最后,在总结全文的基础上得出合理引进FDI,调整能源消费结构,发展节能减排技术的政策建议。     

Soil organic carbon dynamics of croplands in European Russia: estimates from the “model of humus balance”

The Model of Humus Balance was used to estimate the influence of climate effects and changing agricultural practices on carbon (C) levels in soddy–podzolic soils in the Russian Federation for the years 2000–2050. The model was linked with a spatial database containing soil, climate and farming management layers for identification of spatial change of C sequestration potential. Analysis of relationships between C, soil texture and climate indicated that compared with a business-as-usual scenario, adaptation measures could increase the number of polygons storing soil organic carbon (SOC) by 2010–2020. The rate of possible C loss is sensitive to the different climate scenarios, with a maximum potential for SOC accumulation expected in 2030–2040, thereafter decreasing to 2050. The effect is most pronounced for the arid part of the study area under the emission scenario with the highest rate of increase in atmospheric CO₂ concentration, supporting findings from the dynamic SOC model, RothC. C sequestration during the study period was permanent for clay and clay loam soils with a C content of more than 2%, suggesting that C sequestration should be focused on highly fertile, fine-textured soils. We also show that spatial heterogeneity of soil texture can be a source of uncertainty for estimates of SOC dynamics at the regional scale. Figures in color are available at     

基于LCA的废旧资源循环利用节能减排效果评估模式与方法研究——以吉林省某钢铁企业为例

促进废旧资源循环利用是加快推进我国生态文明建设,完成节能减排目标的必然选择。本文基于生命周期评价模式,从微观企业层面入手,构建产品全生命周期基准流程,引入能量输入与环境输出参数,建立废旧资源循环利用节能减排效果量化核算模型,评估再生产品的节能减排经济成效,并以吉林省某钢铁企业为例,评估"废钢-电炉"短流程和"铁矿石-高炉-转炉"长流程的能源、环境、成本差异,辨识影响废钢再循环节能减排效果的主要因素和重要环节。结果显示,再生钢铁全生命周期与原生钢铁全生命周期相比,节能588.48kgce/t,节能率为84%;主要污染物中SO2减排率最高,达92%;CO2总减排1 180.92 kg/t,减排率为67%;总成本却高出198元/t。其中,炼铁工序的节能量和减碳量最大,烧结工序SO2、NOx和烟(粉)尘减排量最大,焦化工序COD和氨氮减排量最大,回收、加工处理、炼钢环节节能量和减碳量以及SO2、NOx和烟(粉)尘减排量均为负。成本方面,再生钢铁生产成本高于原生钢铁308元/t,虽然再生钢铁由于污染减排可节省56元/t的排污费并获取54元/t的碳交易收益,但都不足以扭转电炉炼钢费用较高的现状。因此,国家应在电炉炼钢方面给予钢企及相关企业适当的财税扶持政策,在电价方面给予钢企一定的优惠或补贴,并完善废钢回收加工体系等,以促进废钢循环利用。基于LCA的废旧资源循环利用节能减排效果评估可以实现对产品生命周期全过程的资源、环境、成本的优化管理。     

中国西北寒旱区农牧民生活碳排放评估

围绕碳排放权开展的气候谈判愈来愈关注贫困人口与弱势群体的生存权与发展权,一方面由于受制于其薄弱的社会经济水平,贫困人口与弱势群体在气候变化实践中表现出更高的脆弱性,另一方面则因气候变化减缓与适应行动而造成的贫困人口生活成本的增加以及生活水平的下降。然而,对这些地区和人口的排放权判断主要基于国家层面和地区层面宏观数据的分析,其结果掩盖了国家和地区内部不同社会经济水平下的人口排放差异,不能准确揭示贫困人口和脆弱群体的低碳排放事实。本文基于国际碳排放评估对人口生活排放的需求,结合IPCC参考方法,利用投入产出分析模型构建了人口生活碳排放评价指标体系,并用于对甘肃、青海和宁夏干旱-高寒地区农牧民生活碳排放的样本调查和分析。评估表明,中国西北干旱—高寒区人口生活碳排放仅为1.85tCO2/人,其中用于满足基本生活需要的碳排放量达到87.25%。研究发现,生活在更冷(海拔更高)区域内的人口生活排放量更高;随着家庭收入的增长,人口生活排放量也随之上升;家庭成员数量越多,家庭的人均碳排放量就会越低。     

Changes in mineral soil organic carbon stocks in the croplands of European Russia and the Ukraine, 1990–2070; comparison of three models and implications for climate mitigation

Three soil carbon models (RothC, CANDY and the Model of Humus Balance) were used to estimate the impacts of climate change on agricultural mineral soil carbon stocks in European Russia and the Ukraine using detailed spatial data on land-use, future land-use, cropping patterns, agricultural management, climate and soil type. Scenarios of climate were derived from the Hadley Centre climate Version 3 (HadCM3) model; future yields were determined using the Soil–Climate–Yield model, and land use was determined from regional agricultural and economic data and a model of agricultural economics. The models suggest that optimal management, which entails the replacement of row crops with other crops, and the use of extra years of grass in the rotation could reduce Soil organic carbon (SOC) loss in the croplands of European Russia and the Ukraine by 30–44% compared to the business-as-usual management. The environmentally sustainable management scenario (SUS), though applied for a limited area within the total region, suggests that much of this optimisation could be realised without damaging profitability for farmers.