Formation of solid bituminous matter in pegmatites: Constraints from experimentally formed organic matter on microporous silicate minerals

The formation of solid bituminous matter (SBM) on surfaces of microporous silicates was experimentally studied at pressure and temperature conditions typical of late-stage magmatic and hydrothermal processes. Aliquots of microporous silicate minerals (zorite and kuzmenkoite-Mn, Lovozero Alkaline Massif, Kola Peninsula, Russia) were exposed to solid or liquid organic carbon sources (natural brown coal and liquid 1-hexene for synthesis purposes) in a 0.1 M NaCl-solution for 7 days, at constant pressure (50 MPa), and at three individual temperatures (200, 275, and 300 °C). No thermal decomposition of the solid organic sources happened at 200 °C and only a thin film of brown coal derivatives on the silicates’ surfaces and no formation of SBM were observed at 275 °C and 300 °C. But solid bituminous matter on the surfaces of both microporous silicates were detected in experiments with liquid 1-hexene as organic carbon source and at temperatures of 275 °C and 300 °C with a more pronounced formation of SBM at 300 °C compared to 275 °C. The aromatic and aliphatic hydrocarbons, as well as alcoholic compounds of the experimentally produced SBM are similar, if not even partly identical, with natural SBM occurrences of the Khibiny and Lovozero Massifs, Kola Peninsula, Russia, and from the Viitaniemi granitic pegmatite, Finland, as shown by FT-IR and ¹H NMR spectroscopy. This strengthens the hypothesis of formation of natural solid bituminous matter by catalytic reactions between microporous Ti-, Nb- and Zr-silicates and hydrocarbons at postmagmatic hydrothermal conditions.     

中国大陆新生代典型火山区温室气体释放的规模及其成因

火山活动能够将地球深部的碳输送到大气圈,是地质碳排放和深部碳循环的重要形式.火山作用不仅在喷发期能够释放大量温室气体,而且在休眠期也能释放巨量的温室气体.在全球变暖的背景下,定量化地研究火山活动对大气圈温室气体含量增加的贡献具有至关重要的意义.本文利用密闭气室法等该领域国际先进的测试技术,测量并计算了长白山、腾冲、五大连池及青藏高原南部的羊八井等典型火山区的温室气体释放规模.结果显示,我国大陆新生代典型火山区向大气圈输送的温室气体总通量约为8.13×10⁶t·a^-1,接近10⁷t·a^-1级别,相当于全球火山活动导致的温室气体(主要为CO₂)释放总量的6%左右.太平洋构造域火山区的温室气体在释放通量与总量方面均低于特提斯构造域,并且太平洋构造域火山气体的地壳混染程度较低,显示出大洋俯冲带与大陆俯冲带火山区温室气体释放的成因差异.     

Importance of programme design for potential US domestic GHG offset supply and quality

Greenhouse gas (GHG) offsets are a central feature of most regional and national cap-and-trade systems. A greenhouse offset credit represents a tonne of carbon dioxide equivalent (CO₂e) reduced, avoided or sequestered by a project implemented specifically to compensate for emissions occurring elsewhere. Several existing modelling studies estimate the technically and economically achievable supply of GHG offsets from uncapped sources in the US. This analysis is among the few that consider how the design of offset protocols – and the corresponding rules for eligibility, measuring, verifying and awarding offsets – might impact actual offset crediting and the realization of GHG mitigation potential. The presented analysis demonstrates how rules for each of these factors could impact the supply of offset credits, as well as the emissions-reduction benefits of an offset programme. Findings indicate that although lenient offset rules and protocols may bring several times more credits to market than a conservative approach, these gains in offset supply would come at a significant cost to the effectiveness of the cap-and-trade system in achieving its central purpose: reducing overall GHG emissions. In particular, lenient rules and protocols could conceivably lead US emissions to exceed legislative targets by as much as 500 million tonnes CO₂e in 2020.     

Carbon dioxide emissions from Russia's electricity sector: future scenarios

Abstract

This article investigates future greenhouse gas emission scenarios for Russia's electricity sector, a topic of importance since Russia's ratification of the Kyoto Protocol in November 2004. Eleven scenarios are constructed to the year 2020 considering economic and technological details in both the demand and supply sides of the sector. The scenarios are based upon a thorough review of the different factors controlling carbon dioxide emissions, including potential economic growth, changes in energy efficiency and technological development, and that Russia may export large amounts of natural gas to European and Asian markets. The most likely scenario is that Russia will double industrial output over the next 10 years, increase energy efficiency in the demand sector, will remain consistent to the goals of the Energy Strategy 2020 and will implement more efficient technology in the electricity supply sector. Consequently, carbon dioxide emissions will still be 102 million tonnes below 1990 levels in 2010, representing a significant source for emission reduction credits available to be sold on international markets or transferred to the next crediting period.     

Distribution of emissions allowances as an opportunity

Much of the debate on climate policy in the USA focuses on the gain or loss to the macroeconomy of alternative policies to reduce greenhouse gas emissions. However, the economy is made up of multiple individuals, not a single representative agent. This article reports the results of alternative ways of distributing emissions allocations across citizens. Macroeconomic effects interact with the policy for distribution, but the distributional weights are more important for the welfare of individual agents than the economy-wide effects of the emissions reductions. Egalitarian distributions of the emissions allowances have the potential to increase the welfare of most people, even if significant emissions reductions are mandated. Focusing on the distribution of emissions allowances (or the revenues generated from an emissions tax) rather than on aggregate GDP may provide guidance in identifying and implementing politically viable solutions to the climate change mitigation problem.     

IPCC AR6报告解读:强化技术和管理创新的交通运输部门减碳路径北大核心CSCD

IPCC第六次评估报告第三工作组报告交通运输章评估了该行业温室气体的减缓措施和转型路径。1990年以来,全球交通运输部门温室气体排放量一直增长,2019年已经成为全球第四大排放源,仅次于电力、工业以及农业、林业和其他土地利用(AFOLU)部门,其增长速度超过其他最终用途行业。报告强调了交通减排的重要性,主要的减排措施包括三方面:首先是减少需求,其次是对陆路交通部门进行脱碳,再次是对重型的水运和航空运输等进行脱碳。评估的多种燃料和动力技术处于不同的商业化水平,它们未来应用时间节点和规模各有不同。对于陆路交通来说,需要继续推进电气化;对于水运和航空来说需要进一步应用低碳技术,并优化国际管理机制;从中长期来看,所有部门都需要强调运输服务需求管理和运输效率的提升。情景相关的文献评述分析表明,全球温升目标要求全经济部门采取减排措施,特别是交通电气化的减排潜力在很大程度上取决于电力部门的脱碳。如果不采取减缓措施,交通运输部门排放在2050年可能增长65%(相对2010年);如果成功实施减缓战略,该部门的排放量将减少68%,这也与全球1.5℃温升目标要求相一致。关于这些减缓措施的分析和判断,对我国交通运输部门实现碳中和与碳达峰具有重要的参考意义。     

湘南荷花坪锡多金属矿床稀有气体同位素特征及其地质意义

荷花坪锡多金属矿床是南岭中段湘南地区新发现的一个大型矿床,发育有印支期和燕山期2期成岩、成矿作用。文章对不同期矿石中的黄铁矿分别进行了稀有气体同位素研究。测试结果表明,印支期矽卡岩型矿石中的黄铁矿:³He/⁴He=0.15～2.49 Ra,³⁸Ar/³⁶Ar=0.18733～0.18902,⁴⁰Ar/³⁶Ar=310.45～523.98,²⁰Ne/²²Ne=9.727～9.830,²¹Ne/²²Ne=0.0286～0.0310;燕山期蚀变碎裂岩型矿石中的黄铁矿:³He/⁴He=0.15～4.33 Ra,³⁸Ar/³⁶Ar=0.18750～0.18843,⁴⁰Ar/³⁶Ar=331.78～602.62,²⁰Ne/²²Ne=9.736～9.858,²¹Ne/²²Ne=0.0286～0.0305,显示区内两期成矿流体均为大气饱和水、地壳流体和地幔流体的混合流体。印支期矽卡岩型矿石中地幔He所占比例为2.34%～41.40%,平均18.16%;燕山期蚀变碎裂岩型矿石中地幔He所占比例为2.34%～72.12%,平均27.41%,燕山期幔源流体的作用强度略高于印支期。湘南地区印支期基性岩浆活动及荷花坪矿床印支期成矿过程中有幔源物质的参与,二者共同指示南岭地区中生代构造体制的转换或岩石圈伸展减薄可能始于印支主期(244～230 Ma)之后的224 Ma左右,即晚三叠世。     

中国海相油气多期充注与成藏聚集模式研究——以塔里木盆地轮古东地区为例

中国海相盆地经历了早古生代末(加里东期)、晚古生代-早中生代(海西期)和晚新生代(喜山期)三期重大构造变动,深刻影响了海相油气生成、运移与聚集,使得油气分布规律变得非常复杂。中国海相盆地一般发育多套烃源岩,由于它们发育的时代和位置多不相同,生、排烃时间往往不同步,存在多源多期充注的特点。因此,多期油气成藏是海相盆地的一个重要特点。多期成藏是在多期构造运动的影响下,多套烃源层多期成熟排烃的结果。塔里木盆地塔北隆起轮古东地区是一个典型的多期充注型油气藏,目前已确定的主要成藏期包括晚加里东期、晚海西期和晚喜马拉雅期三期。轮古东碳酸盐岩非均质储层形成的缝洞圈闭体系,形成早,后期构造作用使圈闭没有发生大的变化,因此保留了这三期充注的油气;油气地球化学分析资料进一步证实了这三次油气充注成藏过程。通过地质分析,再现了油气充注成藏过程,建立了海相油气多期充注与成藏聚集模式。     

Global warming: a review of this mostly settled issue

Global warming and attendant climate change have been controversial for at least a decade. This is largely because of its societal implications since the science is largely straightforward. With the recent publication of the Fourth Assessment Report of the United Nations’ Intergovernmental Panel on Climate Change (Working Group 1) there has been renewed interest and controversy about how certain the scientific community is of its conclusions: that humans are influencing the climate and that global temperatures will continue to rise rapidly in this century. This review attempts to update what is known and in particular what advances have been made in the past 5 years or so. It does not attempt to be comprehensive. Rather it focuses on the most controversial issues, which are actually few in number. They are:

• Is the surface temperature record accurate or is it biased by heat from cities, etc.?
• Is that record significantly different from past warmings such as the Medieval Warming Period?
• Are human greenhouse gases changing the climate more than the sun?
• Can we model climate and predict its future, or is it just too complex and chaotic?
• Are there any other changes in climate other than warming, and can they be attributed to the warming?

Finally there is a very brief discussion of the societal policy response to the scientific message. Note that much of the introductory material in each section is essentially the same as that which appears in Keller 2003 (hereafter referred to as OR = original review) and its update (Keller 2007). Despite continued uncertainties, the review finds an affirmative answer to these questions. Of particular interest are advances that seem to explain why satellites do not see as much warming as surface instruments, how we are getting a good idea of recent paleo-climates, and why the twentieth century temperature record was so complex. It makes the point that in each area new information could come to light that would change our thinking on the quantitative magnitude and timing of anthropogenic warming, but it is unlikely to alter the basic conclusions.     

Hydropower – A Green Energy? Tropical Reservoirs and Greenhouse Gas Emissions

Reservoirs are man‐made lakes that severely impact on river ecosystems, and in addition, the new lake ecosystem can be damaged by several processes. Thus, the benefits of a reservoir, including energy production and flood control, must be measured against their impact on nature. New investigations point out that shallow and tropical reservoirs have high emission rates of the greenhouse gases CO₂ and CH₄. The methane emissions contribute strongly to climate change because CH₄ has a 25 times higher global warming potential than CO₂. The pathways for its production include ebullition, diffuse emission via the water‐air interface, and degassing in turbines and downstream of the reservoir in the spillway and the initial river stretch. Greenhouse gas emissions are promoted by a eutrophic state of the reservoir, and, with higher trophic levels, anaerobic conditions occur with the emission of CH₄. This means that a qualitative and quantitative jump in greenhouse gas emissions takes place. Available data from Petit Saut, French Guinea, provides a first quantification of these pathways. A simple evaluation of the global warming potential of a reservoir can be undertaken using the energy density, the ratio of the reservoir surface and the hydropower capacity; this parameter is mainly determined by the reservoir's morphometry but not by the hydropower capacity. Energy densities of some reservoirs are given and it is clearly seen that some reservoirs have a global warming potential higher than that of coal use for energy production.