Ratios of stable carbon isotopes in some High Arctic plants and lake sediments

¹³C/¹²C ratios for a number of High Arctic vascular plants (51 determinations), mosses (11), and freshwater algae (11) show considerable variation, particularly among the freshwater algae (range from-6.9 to -36.3). In some cases the stable carbon ratios on modern and fossil materials provide guidance as to whether marine waters formerly occupied a given pond or lake basin. In other cases the ¹³C values for algae collected along the present-day shore of a pond or lake bear no relation to the values obtained on constituents preserved within the bottom sediments, suggesting that major changes have occurred in the last few thousand years.Geological Survey of Canada Contribution No. 17291. Contribution No. 41 from the Cape Herschel Project.     

基于结构分解法的北京能源碳排放增量分析(英文)

确保减碳的首要任务是定量测度化石能源消费碳排放的增量影响因素及其大小。为分析北京市1997-2007年的碳排放增量,本文构建了一个扩展的(调入、进口)竞争型经济—能源—碳排放投入产出模型,从整体特征、不同产业、工业行业3个方面,对1997-2007年北京能源消费的碳排放增量进行了结构分解。分析发现:经济规模增长要素(消费、投资、调出和出口等)是拉动碳排放增长的主导因素,能源强度变动效应却是碳减排的决定性因素;在规模扩张因素中,消费和调出超过投资和出口,是碳排放增长的主要贡献者;2002以来新一轮"高碳"特征的工业化导致CO2排量呈急增之势;产业结构调整、三产比重最大使得服务业成为碳排放增长的最大部门,但工业排放的增长却后来居上;碳增排的重点行业是高能耗业,而碳减排的却是能源工业;两时段各效应在不同产业、不同工业行业的影响方向和大小不一。     

陕西省能源消费结构、产业结构演变对碳排放强度的冲击影响分析

基于陕西省1989-2011年能源消费等统计数据,分析能源消费结构、产业结构的演变特征,建立陕西省能源消费结构-产业结构-碳排放强度系统的VAR模型,对该系统的长期和短期动态关系进行实证分析。结果表明:陕西省的发展模式,是能源消费结构长期以高碳能源为主和产业结构长期以高碳产业为主导。能源消费结构与产业结构的变化对陕西省碳排放强度的减小作用初期微弱;从中长期来,两个结构多元化提高的负效应对碳排放强度的增加有长期持久的抑制作用,且能源消费结构演进对碳排放强度的冲击效果始终大于产业结构变化的冲击效果。优化产业结构和调整能源消费结构尤其是提高低碳产业与低碳能源比重是驱动陕西省碳排放强度下降的有效措施。     

硫化物风化产酸对流域岩石风化和碳循环的影响——以黄河支流三川河流域为例

硫化物风化产酸可加速岩溶作用但抑制大气二氧化碳参与流域碳循环,其复杂的地球化学机制和过程待阐明。本文以黄河二级支流三川河流域为例,通过采集20个三川河及其支流地表水点样和30个柳林泉地下水点样,经实验测试获得了流域比较系统的水化学资料和δ¹³C、δ³⁴ S数据,运用碳、硫同位素分析与水化学平衡计量方法,量化了流域硫化物风化产酸对岩石风化作用的贡献以及对碳循环的影响。计算结果表明：煤系地层硫化物和矿床硫化物的氧化及大气酸沉降所形成的硫酸明显促进了流域碳酸盐岩的溶蚀,对碳酸盐岩溶蚀的贡献约占64.59%;柳林泉水石膏溶解来源的SO₄^2-占69%,河水中石膏溶解来源的SO₄^2-占30%,但这些部分SO₄^2-没有参与溶蚀作用,应当扣除;三川河流域平均岩石风化速率为10.02 mm/ka,其中碳酸盐岩、硅酸盐岩的风化速率分别为9.14 mm/ka和0.88 mm/ka,低于国内外很多流域;由于硫酸抵消了碳酸盐岩石风化作用对大气二氧化碳的吸收,流域岩石风化消耗大气/土壤CO₂通量为116.58 mmol/（km² ·a）,不足珠江流域的1/5,且硅酸盐岩风化的贡献占63.3%。

     

中国不同区域能源消费碳足迹的时空变化(英文)

Study on regional carbon emission is one of the hot topics under the background of global climate change and low-carbon economic development, and also help to establish different low-carbon strategies for different regions. On the basis of energy consumption and land use data of different regions in China from 1999 to 2008, this paper established carbon emission and carbon footprint models based on total energy consumption, and calculated the amount of carbon emissions and carbon footprint in different regions of China from 1999 to 2008. The author also analyzed carbon emission density and per unit area carbon footprint for each region. Finally, advices for decreasing carbon footprint were put forward. The main conclusions are as follows: (1) Carbon emissions from total energy consumption increased 129% from 1999 to 2008 in China, but its spatial distribution pattern among different regions just slightly changed, the sorting of carbon emission amount was: Eastern China > Northern China > Central and Southern China > Southwest China > Northwest China. (2) The sorting of carbon emission density was: Eastern China > Northeast China > Central and Southern China > Northern China > Southwest China > Northwest China from 1999 to 2003, but from 2004 Central and Southern China began to have higher carbon emission density than Northeast China, the order of other regions did not change. (3) Carbon footprint increased significantly since the rapid increasing of carbon emissions and less increasing area of pro-ductive land in different regions of China from 1999 to 2008. Northern China had the largest carbon footprint, and Northwest China, Eastern China, Northern China, Central and Southern China followed in turn, while Southwest China presented the lowest area of carbon footprint and the highest percentage of carbon absorption. (4) Mainly influenced by regional land area, Northern China presented the highest per unit area carbon footprint and followed by Eastern China, and Northeast China; Central and Southern China, and Northwest China had a similar medium per unit area carbon footprint; Southwest China always had the lowest per unit area carbon footprint. (5) China faced great ecological pressure brought by carbon emission. Some measures should be taken both from reducing carbon emission and increasing carbon absorption.     

Spatial variation and driving mechanism of soil organic carbon components in the alluvial/sedimentary zone of the Yellow River

Alluviation and sedimentation of the Yellow River are important factors influencing the surface soil structure and organic carbon content in its lower reaches. Selecting Kaifeng and Zhoukou as typical cases of the Yellow River flooding area, the field survey, soil sample collection, laboratory experiment and Geographic Information System(GIS) spatial analysis methods were applied to study the spatial distribution characteristics and change mechanism of organic carbon components at different soil depths. The results revealed that the soil total organic carbon(TOC), active organic carbon(AOC) and nonactive organic carbon(NOC) contents ranged from 0.05–30.03 g/kg, 0.01–8.86 g/kg and 0.02–23.36 g/kg, respectively. The TOC, AOC and NOC contents in the surface soil layer were obviously higher than those in the lower soil layer, and the sequence of the content and change range within a single layer was TOCNOCAOC. Geostatistical analysis indicated that the TOC, AOC and NOC contents were commonly influenced by structural and random factors, and the influence magnitudes of these two factors were similar. The overall spatial trends of TOC, AOC and NOC remained relatively consistent from the 0–20 cm layer to the 20–100 cm layer, and the transition between high-and low-value areas was obvious, while the spatial variance was high. The AOC and NOC contents and spatial distribution better reflected TOC spatial variation and carbon accumulation areas. The distribution and depth of the sediment, agricultural land-use type, cropping system, fertilization method, tillage process and cultivation history were the main factors impacting the spatial variation in the soil organic carbon(SOC) components. Therefore, increasing the organic matter content, straw return, applying organic manure, adding exogenous particulate matter and conservation tillage are effective measures to improve the soil quality and attain sustainable agricultural development in the alluvial/sedimentary zone of the Yellow River.     

More than Carbon Stocks： A Case Study of Ecosystem-based Benefits of REDD＋ in Indonesia

During the 15th Conference of the Parties(COP 15),Parties agreed that reducing emissions from deforestation and forest degradation and enhancing ’removals of greenhouse gas emission by forests’(REDD+) in developing countries through positive incentives under the United Nations Framework Convention on Climate Change(UNFCCC) was capable of dealing with global emissions.As REDD+ seeks to lower emissions by stopping deforestation and forest degradation with an international payment tier according to baseline scenarios,opportunities for ecosystem benefits such as slowing habitat fragmentation,conservation of forest biodiversity,soil conservation may be also part of this effort.The primary objective of this study is to evaluate ecosystem-based benefits of REDD+,and to identify the relationships with carbon stock changes.To achieve this goal,high resolution satellite images are combined with Normalized Difference Vegetation Index(NDVI) to identify historical deforestation in study area of Central Kalimantan,Indonesia.The carbon emissions for the period of 2000-2005 and 2005-2009 are 2.73 × 10 5 t CO 2 and 1.47 × 10 6 t CO 2 respectively,showing an increasing trend in recent years.Dring 2005-2009,number of patches(NP),patch density(PD),mean shape index distribution(SHAPE_MN) increased 30.8%,30.7% and 7.6%.Meanwhile,largest patch index(LPI),mean area(AREA_MN),area-weighted mean of shape index distribution(SHAPE_AM),neighbor distance(ENN_MN) and interspersion and juxtaposition index(IJI) decreased by 55.3%,29.7%,15.8%,53.4% and 21.5% respectively.The area regarding as positive correlation between carbon emissions and soil erosion was approximately 8.9 × 10 3 ha corresponding to 96.0% of the changing forest.These results support the view that there are strong synergies among carbon loss,forest fragmentation and soil erosion in tropical forests.Such mechanism of REDD+ is likely to present opportunities for multiple benefits that fall outside the scope of carbon stocks.     

南京市土地利用结构碳排放效率增长及其空间相关性

采用南京市11个区2005-2014年的相关数据,首先对不同类型土地的碳排放量进行核算,进一步将其作为非期望产出引入DEA模型并采用Hicks-Moorsteen指数对南京市各区的土地利用结构碳排放效率增长进行估算、比较和分析。研究结果表明：① 碳排放的主要来源是建设用地的间接碳排放,研究期内的土地利用碳排放量呈现出持续增长的发展态势。② 全要素碳排放效率增长及其分解要素均低于传统全要素生产率增长,即不考虑碳排放约束的全要素生产率增长高估了实际的土地利用效率增长水平。全要素碳排放效率增长在研究期内表现出收敛态势和区域之间均衡性的发展特征,源于“低碳和高效”发展理念的深入人心,单位GDP能耗不断降低。③ 南京市各区的技术效率值较低,“技术追赶”效应不明显,开始出现土地利用的规模经济效应,但是范围经济效应不显著。④ 全要素碳排放效率增长在南京市范围内具有空间正相关性,且表现出空间集聚特征。基于此,提出了一些有益的建议。     

A warped m= 2 water maser disc in V778 Cyg?

The silicate carbon star V778 Cyg is a source of 22-GHz water maser emission which was recently resolved by MERLIN. Observations revealed an elongated     -like structure along which the velocities of the maser features show a linear dependence on the impact parameter. This is consistent with a doubly warped   m = 2  disc observed edge-on. Water masers and silicate dust emission (detected by the Infrared Astronomical Satellite and Infrared Space Observatory ) have a common origin in O-rich material and are likely to be co-located in the disc. We propose a detailed self-consistent model of a masing gas–dust disc around a companion to the carbon star in a binary system, which allows us to estimate the companion mass of  1.7 ± 0.1 M_⊙  , the disc radius of  40 ± 3  au and the distance between companions of ∼80 au. Using a dust–gas coupling model for water masing, we calculate the maser power self-consistently, accounting for both the gas and the dust energy balances. Comparing the simulation results with the observational data, we deduce the main physical parameters of the masing disc, such as the gas and dust temperatures and their densities. We also present an analysis of the stability of the disc.