Effects of Reduced Nitrogen Fertilization and Biochar Application on CO_2 and N_2O Emissions from a Summer Maize-Winter Wheat Rotation Field in North China

This experiment was conducted in Xinxiang, Henan from June 2013 to June 2014. Total four treatments were designed including farmers ’ common practice （F, 250 kg/hm^2）, 80% F （LF, 200 kg/hm^2）, 80% F＋biochar （LFC） and no fertilizer （CK） to measure the dynamic emissions of CO2 and N2O from a summer maize-winter wheat field by static chamber-gas chromatography method. The results showed that the soil CO2 emission was 21.8-1 022.7 mg/（m^2·h）, and was mainly influenced by soil temperature and moisture content. During the growth of summer maize, the soil CO2 emission was more significantly affected by soil moisture con-tent; and in winter wheat growing season, it was more significantly affected by soil temperature in the top 5 cm. The LF and LFC treatments significantly reduced the soil cumulative CO2 emission, especial y during the growth of winter wheat. Fertiliza-tion and irrigation were the main factors influencing the soil N2O emission. The soil N2O emission during the fertilization period accounted for 73.9%-74.5% and 40.5%-43.6% of the soil cumulative N2O emission during the summer maize-and winter wheat-growing season, respectively. The peak of emission fluxes was determined by fertilization amount, while the occurrence time of emission peak and emission re-duction effect were influenced by irrigation. The LF treatment reduced the soil cu-mulative N2O emission by 15.7%-16.8% and 18.1%-18.5% during the growth period of summer maize and winter wheat, respectively. Reduced nitrogen fertilization is an effective way for reducing N2O emission in intensive high-yielding farmland. Under a suitable nitrogen level （200 kg/hm^2）, the application of biochar showed no significant effect on the soil N2O emission in a short term. The N2O emission factors of the L and LF treatments were 0.60% and 0.56%, respectively. ln the intensive high-yield-ing farmland of North China, reducing the nitrogen application amount is an appro-priate measure to mitigate greenhouse gas emissions without crop yield loss.

Comparison of the ＂Global Levy Scheme＂ with the ＂Emissions Trading Scheme＂ to Reduce Greenhouse Gas Shipping Emissions

Climate change is widely recognized as the major environmental problem facing the globe today. One of the most urgent environmental problems facing shipping industry is the reduction of GHG （greenhouse gas） emissions from its operations. Given the growing concern of the international community on ＂the deep reduction of global GHG emissions＂, it cannot be expected that the non-regulation of maritime GHG emissions can further continue. This paper investigates the main challenges and threats of the development of two MBMs （market-based measures） for the reduction of GHG emissions from international shipping, i.e., the ＂global levy scheme on maritime GHG emissions＂ and the ＂maritime emission trading scheme＂. A SWOT （strengths weaknesses opportunities threat） analysis is used, in this survey, to evaluate the environmental effectiveness as well as the easiness of implementation of the two policy options. Moreover, we make apparent their strengths and weaknesses concerning abatement of maritime GHG emissions. Given the fact that the discussion regarding the implementation of some MBMs with maritime GHG-emission reduction potential is still carried out with the exception of EEDI （energy efficiency design index） and SEEMP （ship energy efficiency management plan）, this paper＇s results present special significance, as they could be further analyzed and taken into account during the adoption of any future MBM for the reduction of maritime GHG emissions.

Power industry to reduce sulfur dioxide emissions

China has published a stricter emission standard for thermal power plants in order to help reduce the power industry's sulfur dioxide emissions by over six

Development of Direct Reduced Iron in China:Challenges and Pathways

The steel industry is considered an important basic sector of the national economy,and its high energy consumption and carbon emissions make it a major contributor to climate change,especially in China.The majority of crude steel in China is produced via the energy-and carbon-intensive blast furnace–basic oxygen furnace(BF–BOF)route,which greatly relies on coking coal.In recent years,China’s steel sector has made significant progress in energy conservation and emission reduction,driven by decarbonization policies and regulations.However,due to the huge output of crude steel,the steel sector still produces 15%of the total national CO_(2) emissions.The direct reduced iron(DRI)plus scrap–electric arc furnace(EAF)process is currently considered a good alternative to the conventional route as a means of reducing CO_(2) emissions and the steel industry’s reliance on iron ore and coking coal,since the gas-based DRI plus scrap–EAF route is expected to be more promising than the coal-based one.Unfortunately,almost no DRI is produced in China,seriously restricting the development of the EAF route.Here,we highlight the challenges and pathways of the future development of DRI,with a focus on China.In the short term,replacing natural gas with coke oven gas(COG)and byproduct gas from the integrated refining and chemical sector is a more economically feasible and cleaner way to develop a gas-based route in China.As the energy revolution proceeds,using fossil fuels in combination with carbon capture,utilization,and storage(CCUS)and hydrogen will be a good alternative due to the relatively low cost.In the long term,DRI is expected to be produced using 100%hydrogen from renewable energy.Both the development of deep processing technologies and the invention of a novel binder are required to prepare high-quality pellets for direct reduction(DR),and further research on the one-step gas-based process is necessary.

Challenges of Integration the Policies and Measures in the National and Local Strategy of Reducing Emissions from Deforestation and Forest Degradation in Mozambique

Global political forums on climate have identified deforestation and forest degradation actions as the main sources of atmospheric emissions. Therefore, its reduction is basically the main international agenda. The objectives of environmental policy seem to prevail conflicting, between the global, which aims to stabilize emissions with sequestration of forest carbon and local poverty reduction. REDD＋ （Reducing Emissions from Deforestation and Forest Degradation） is considered cheap proposal for mitigation and adaptation to climate changes. Thus, Mozambique is preparing for accessing to forest carbon financing. The study analyzed interaction of policies and measures in the national and local strategy of REDD＋ in Mozambique and resorted three methodological procedures, review of previous study, interviews and seminars, in a non-probabilistic sampling. Conflicting visions among nations hinder consensus on reducing emissions and REDD＋ aims to replace the KP （Kyoto Protocol）. National strategy of REDD＋ should suggest measures and policies to reduce deforestation in key sectors contributing to emissions. Interviewees suggested technological approach （30%）, agrarian reform （26%）, institutional reform （21%） and decentralization （20%）. Therefore, 77.3% supported technological use to increase production and productivity and for the forest sector, 86.4% supported forest concessions. They also highlighted conservation agriculture, SAFs （Agroforestry Systems）, energy accessibility and mining licensing. However, REDD＋ is being projected from the global to the local, but the debate must extrapolate negotiations restricted to government participation, as well as policy options and incentives to generate co-benefits that address local community priorities.

A hefty target of reducing the intensity of carbon dioxide emissions

At the end of January, China formally handed over the report on pollution reduction targets to the United Nations.

Technical Analysis of Energy Saving and Emission Reducing in China's Cement Industry Based on LEAP Model

[Objective] The study aimed at evaluating the ability to save energy and reduce CO2 emission in China＇s cement industry. [Method] Based on long-term energy alternative planning system software （LEAP）, ＂LEAP of China＇s cement industry＂ model was established to simulate energy conservation and emission reduction in China＇s cement industry from 2010 to 2040 in different technologic situations. E ResultJ To save ener- gy and reduce CO2 emissions, new dry process kiln has priority over other technologies or measures, followed by equipment enlargement, mechani- cal shaft kiln, power generation system based on waste heat, as well as high-efficiency and energy-saving grinding technology, and new prepara- tion technology. If all the advanced technologies and measures are adopted, energy consumption and C02 emissions can be reduced by about 40.76% and 42.97% respectively. [ Condusion] LEAP of model is suitable for analyzing energy saving and emission reducing in China＇s cement industry and other industrial fields.

Saving Energy and Reducing Emission When Recycling Acetone dudng the Production of Soy Phospholipid

Acetone,which is volatile,flammable,toxic,expen- sive and causing serious air pollution,is often used as extracting solvent in the production of powdery soy phospholipid.Recycling and reusing acetone is the key of reducing the cost of production. Therefore,saving energy and reducing emission when recycling acetone are the most important technologies during the production of phospholipid.On the basis of the productivity of powdery phospholipid being 2.4 t every day,43.2 t acetone is reused every 8 h and the total volume of acetone gas emitted is 450.75 m3 (about 901.5 kg).According to the current price of acetone,the lost money is about 7212 yuan RMB.

Present situation and development of saving energy and reducing emission technology in iron ore sintering process

The energy consumption of iron ore sintering process is about 10%- 15%of the total of iron and steel industry.Therefore,it is of great significance to take effective measures to reduce the energy consumption in the iron ore sintering process to reduce the costs of sintering product and cut down the emissions of harmful gases,such as CO_2 and SO_2.In this study,the technology development of saving energy and reducing emission in iron ore sintering process was reviewed and discussed;some new directions and measures of saving energy were presented for the sintering process in the future.

Kenya Airways Launches New Project to Reduce Carbon Emissions

Kenya Airways announced its new carbon offset project in May,aiming to have guests directly take part in a carbon emissions reduction plan for environmental protection.Titus Naikuni,Managing Director

稻田甲烷产生与排放的影响因素及减排措施研究进展

稻田甲烷(CH_(4))排放是农业生产中主要碳排放源之一。如何在保证丰产的前提下,有效降低水稻生产中CH_(4)的排放量成为现代农业科研工作者研究的焦点。围绕稻田CH_(4)的产生、排放与减排方式,本文综述了目前稻田CH_(4)产排的相关研究进展,阐述了稻田CH_(4)的产生、氧化过程、排放方式及其主要影响因素。稻田甲烷的产生排放与土壤理化性状(pH值、关键酶活性、含水量、温度、氧化还原程度、质地等)、水稻品种(根系形态活力与分泌物、通气组织、收获指数、株高等)、栽培技术(轮作模式、水肥调控、种植方式)、气候变化(气温、大气CO_(2)浓度、UV-B辐射)等因素密切相关。本文重点从选育高产低排新品种、研发稻田CH_(4)减排新物质、稻-渔低碳循环种养、土壤持续固碳减排、多种栽培调控方式耦合的新技术等方面入手,系统总结了稻田CH_(4)减排的技术措施,提出应根据不同稻区的生产特点,因地制宜,探索建立稻田CH_(4)减排高效综合技术体系。在此基础上,讨论了未来重点研究方向,以期为水稻丰产减排生产提供技术支撑,为顺利实现国家“双碳”目标提供有益参考。

基于LCA的扭王字块物化阶段碳排放核算及减排措施

扭王字块作为量大面广的护堤结构,其碳排放的量化计算对于节能减排具有重要意义。基于LCA理论,将扭王字块物化阶段划分为原材料生产、原材料运输、构件制作、构件转运和现场施工5个阶段,采用碳排放系数法构建扭王字块物化阶段的碳排放测算模型,并以某大型护堤工程为例,演示计量扭王字块物化阶段碳排放的具体流程。结果表明:扭王字块物化阶段的碳排放主要来自原材料生产和运输;通过对比砂石材料不同运距和运输方式的碳排放量,得出就近取材和长距离采用铁路或水路运输可有效降低碳排放;对比公路运输不同燃料车辆的碳排放,汽油车和LNG车的碳排放低于柴油车。

北京公交集团绿色低碳转型经验及未来发展路径研究

在全球气候变暖的背景下,绿色低碳转型已成为公共交通行业实现可持续发展的核心战略。本文深入探讨了北京公交集团在绿色低碳转型过程中的实践经验,分析了其在推动新能源公交车应用、优化能源结构、提升运营效率等方面的具体做法和取得的成效。同时,指出了在转型过程中存在的技术挑战、基础设施配套不足、实现碳中和难等问题。基于此,提出了未来北京公交集团绿色低碳转型的主要路径,包括进一步调整车辆能源结构、提升车辆使用效率、利用数据手段赋能、开展绿电绿证交易、做好能耗精细管控和提高全体员工节能意识等措施。这些措施旨在为地面公交企业的绿色低碳转型提供参考,助力实现碳达峰碳中和目标。

绿色金融改革创新减污降碳效应研究

减污降碳是开展绿色金融的重要目标。本文以绿色金融改革创新试验区的设立作为准自然实验,运用双重差分模型分析绿色金融改革创新试验区对二氧化碳、二氧化硫、氮氧化物的减排效果。结果表明,试验区试点政策对二氧化碳、二氧化硫具有显著的减排效果,但对氮氧化物的减排效果不明显。机制分析表明,试验区试点政策未能通过促进技术创新实现二氧化碳、二氧化硫、氮氧化物的减排,但是能通过降低能耗总量与优化用能结构实现二氧化碳、二氧化硫的减排。异质性分析表明,试验区试点政策的减污降碳效果在东部地区、环境治理力度弱的地区、产业结构高级的地区以及金融发展水平高的地区更加明显。本文为如何优化试验区试点政策效果提供了一定的启示。

广西某火电厂建设对区域碳排放影响初析

随着“3060双碳”目标的提出,为研究火电厂建设对区域碳排放的影响,笔者以广西某火电厂为例,根据燃煤发电行业碳排放量核算方法,计算得出该火电厂碳排放总量;分析碳排放对区域降碳的影响,并提出减污降碳措施。结果表明,该火电厂建设会大大增加区域碳排放总量,不利于实现区域降碳目标。所提出的降碳措施可为降低区域碳排放提供依据。

基于低碳需求响应的新型电力系统中源-网-荷-储协调的优化调度

【目的】在我国“双碳”目标的背景下,节能减排已成为当前电力行业的首要战略目标之一。电力系统除了要考虑系统安全可靠性和经济性之外,还需要将“碳减排约束”引入系统各环节中,将呈现全新的低碳运行和管理模式。【方法】针对新型电力系统碳计量与低碳调控运行问题,提出一种基于碳排放流的低碳需求响应调度策略。首先,分析新型电力系统源-网-荷-储各环节的碳排放影响因素,建立基于碳排放流理论精确的碳计量模型。其次,以动态碳排放因子为引导信号建立低碳需求响应机制,进行优化调度。【结果】通过算例验证:基于低碳需求响应的新型电力系统源-网-荷-储协调优化调度方法有效激发激发系统各环节减排潜力,降低碳排放量,提高新能源消纳率。

间作及减量灌溉对农田土壤温室气体排放的互作效应

基于2014年在甘肃省武威市设置的不同灌水水平与种植模式定位试验,设置两种灌水水平,即减量灌水(495 mm, I1)和传统灌水(540 mm, I2);3种种植模式,即玉米‖豌豆(M‖P)、单作豌豆(P)、单作玉米(M),测定土壤呼吸速率和N_(2)O排放速率,并计算农田温室气体排放总量、全球增温潜势(GWP)和温室气体排放强度(GHGI)。2021—2022两年结果表明:(1)I1和M‖P处理均可显著降低土壤呼吸速率、N_(2)O排放速率、CO_(2)排放总量和N_(2)O排放总量(P<0.05),且减量灌水与间作种植模式交互效应显著(P<0.05);与MPI2处理相比,MPI1处理使土壤呼吸速率、N_(2)O排放速率、土壤CO_(2)排放总量和N_(2)O排放总量分别降低8.39%、33.12%、8.75%和32.84%。(2)I2处理土壤温度和土壤含水量显著高于I1处理(P<0.05);不同种植模式下,整个生育期土壤温度整体表现为M> M‖P> P;相关性分析表明,土壤温度和土壤含水量与土壤呼吸速率和N_(2)O排放速率呈显著正相关关系。(3)灌水水平对作物产量无显著影响(P>0.05),种植模式对作物产量影响显著(P<0.01),表现为M‖P处理产量最高;减量灌水与种植模式交互效应对GWP和GHGI影响显著(P<0.05),MPI1处理较MPI2处理的GWP和GHGI分别降低9.45%和10.00%。在绿洲灌区,减量灌水结合玉米‖豌豆种植模式能够有效提高作物产量并减少温室气体排放,可作为河西灌区推广应用的种植模式。

垄作灌溉和减施氮肥对稻田CH_(4)排放、土壤有机酸含量和酶编码基因表达量的影响

【目的】研究不同垄面宽度的垄作灌溉和不同时期减施氮肥对稻田甲烷(CH4)排放、土壤有机酸含量以及CH4形成和转化相关酶编码基因(产CH4古菌中甲基辅酶M还原酶编码基因mcrA和CH4氧化菌中CH4单加氧酶编码基因sMMO)表达量的影响,揭示土壤有机酸以及mcrA和sMMO表达量对稻田CH4通量的影响。【方法】开展3种灌溉模式(淹水灌溉,垄宽分别为80、100 cm的垄作灌溉)和3种施氮处理(常规施氮:135 kg·hm^(−2),其中苗肥47.25 kg·hm^(−2)、分蘖肥54.00 kg·hm^(−2)和穗肥33.75 kg·hm^(−2);返青期减氮:110 kg·hm^(−2),其中苗肥22.25 kg·hm^(−2)、分蘖肥54.00 kg·hm^(−2)和穗肥33.75 kg·hm^(−2);孕穗期减氮:110 kg·hm^(−2),其中苗肥47.25 kg hm^(−2)、分蘖肥54.00 kg hm^(−2)和穗肥8.75 kg hm^(−2))的田间试验,测定生育期内稻田CH4通量、土壤有机酸含量以及mcrA和sMMO表达量,分析稻田CH4通量、土壤有机酸含量以及mcrA和sMMO表达量之间的相互关系。【结果】相同施氮处理下,垄作灌溉稻田CH4排放量较淹水灌溉显著降低,相同灌水模式下,返青期减氮稻田CH4排放量较常规施氮显著降低。垄宽为80 cm的垄作灌溉+常规施氮处理在施肥后10 d土壤总有机酸含量较施肥前高71.7%,淹水灌溉和常规施氮处理高28.8%。返青期减氮下,垄宽为80 cm的垄作灌溉土壤mcrA表达量整体低于淹水灌溉,sMMO表达量除移栽后25 d外均高于淹水灌溉。稻田CH4通量与土壤mcrA表达量和总有机酸含量显著相关(P<0.01),相关系数分别为0.644和−0.348,土壤总有机酸含量与mcrA、sMMO表达量显著相关(P<0.05),相关系数分别为−0.240和0.197。【结论】垄宽80 cm垄作灌溉+返青期减氮处理降低了稻田CH4通量,土壤总有机酸含量和mcrA表达量显著影响稻田CH4通量,sMMO表达量可能间接影响稻田CH4通量。

“光火储”一体化发电系统的季节适应性分析

为探索基于压缩空气储能的“光火储”一体化发电系统的季节适应性,选取一年内4个典型日分别代表春夏秋冬4个季节,研究季节特性对一体化发电系统5种运行模式的影响。结果表明:季节变化时,一体化发电系统性能变化较大,其中模式2、3性能受季节变化影响最大,模式4不受季节影响但性能较差,模式5季节适应性最好。此外,一体化发电系统可依据实际运行条件灵活选择运行模式,避免能源浪费。

排污权与碳排放权交易协同推进机制

随着社会各界对环境的重视程度加强,绿色可持续发展成为了当今时代发展主题之一,排污权交易和碳排放权交易是绿色交易市场建设的重要手段,是健全现代环境治理体系市场化机制的必然要求,是推动建立健全生态产品价值实现机制的关键路径。排污权和碳排放权的交易制度具有管理相似、减排协同、范围交叉等方面的特点,二者的协同,将会极大地提高环境管理效能、降低实施成本、减少污染物排放。总结了碳排放权与排污权交易体系进行的可行性研究现状,并指出了两体系在建设过程中所遇到的问题,提出排污权和碳排放权交易机制协同的路径设计,在此基础上提出完善相关法规体系、推进监测机制协同、提出开展碳排放权交易和排污权交易环境协同效益评估的建议,为全球绿色可持续发展和污染控制提出了一条可行路径。