From the Seam to the Stove: greenhouse gas assessment and the coal seam gas industry in Australia

In Australia, Coal Seam Gas (CSG) is a relatively new source of natural gas commonly advocated as a lower greenhouse gas (GHG) emissions alternative to coal. This study investigates how GHG emissions have been, and potentially could be, assessed within the Australian CSG industry. The research involved a document analysis of several Environmental Impact Statements (EISs) and consultant reports prepared as part of the Environmental Impact Assessment (EIA) process for major CSG projects in New South Wales (NSW) and Queensland (Qld). There were found to be inconsistencies in the conduct of greenhouse assessment by the CSG industry, including how complete and transparent assessments were, as well as how effectively they addressed project emission intensity and cumulative impacts. There were also found to be large inconsistencies between assessments carried out for Qld projects and those for NSW projects, likely because of differences in how assessment requirements are applied by planning bodies. This study also highlights how alternative assessment approaches, such as Cumulative Impact Assessment (CIA) and Strategic Environmental Assessment (SEA), have potential to enable a broader and more consistent understanding of emission sources that cross a range of geographical and project boundaries.     

北方地区日光温室气候适宜性区划方法

通过对我国北方地区影响日光温室生产的主要气候因素进行分析,从光、温、风、雪4个方面选取了冬季总辐射、日光温室生产季阴天日数、年极端最低气温、冬季平均气温、生产季月最大风速平均值、年最大积雪深度平均值6个因子作为气候适宜性区划指标,采用加权指数求和的评价方法建立综合气候适宜性区划指标模型,在利用层次分析法对区划指标进行量化分析确定其权重的基础上,借助GIS技术,得到北方地区日光温室发展的气候适宜性区划图。为了细化区划结果,将研究区域气候特征明显不同的典型区域分别进行进一步区划。结果表明:该方法不仅理论性较强,与实际相吻合的区划结果也说明该方法还具有良好的实用性。     

VARIATIONS OF CLOUD FRACTION OVER EAST ASIA UNDER GLOBAL WARMING CONDITIONS IN THE PAST 20 YEARS

Based on the variation of cloud fraction revealed by D2 Cloud Climatic Data of the International Satellite Cloud Climatology Project and trend analysis methods, the trend of different types of cloud fraction over East Asia during 1984-2006 is obtained. The analysis focuses on the relationship between temperature and different cloud fraction under the background of globe warming. The result shows a fluctuating decreasing tendency in the total cloud fraction, high-level cloud and low-level cloud over East Asia with the decrement being 2.24%, 1.65% and 1.68%, respectively, while the mid-level cloud increases by 1.07%. In addition, there are great regional differences in cloud fraction. Temperature and water-vapor content variation caused by the greenhouse effects over East Asia is the primary reason for the variation of cloud fraction. Over the Tibetan Plateau, the Bay of Bengal and the Intertropical Convergence Zone, the temperature is negatively correlated with high-level cloud, but positively correlated with mid- and low-level cloud. However, over the West Pacific and the ocean east and north of Japan, the temperature is negatively correlated with low-level cloud but positively correlated with high-level cloud.     

Poleward expansion of the hadley circulation in CMIP5 simulations

Observational analyses have demonstrated that the Hadley circulation has expanded poleward in recent decades. Important issues are what caused the widening of the Hadley circulation and whether the observed widening is related to anthropogenic forcing. In the present study, we use currently available simulations of the Coupled Model Intercomparison Project Phase-5 (CMIP5) to analyze changes in the width of the Hadley circulation. It is found that CMIP5 historical simulations with greenhouse gas (GHG) forcing generate a total widening of ～0.15o0.06o in latitude (10 yr)-1 for the period 1979--2005, and the widening in CMIP5 historical simulations with all forcings is ～0.17o0.06o per decade. Similar to that in CMIP3, the simulated poleward expansion in CMIP5 is much weaker than the observational reanalyses. In CMIP5 projection simulations for the 21st century, magnitudes of widening of the Hadley circulation increase with radiative forcing. For the extreme projected radiative forcing of RCP8.5, the total annual-mean widening of the Hadley circulation is ～0.27o0.04o(10 yr)-1 in the 21st century. Although CMIP5 underestimates observed poleward expansion of the Hadley circulation, the results of this study suggest that the observed trends in the width of the Hadley circulation are caused by anthropogenic forcing and that increasing GHGs play an important role in the observed poleward expansion of the Hadley circulation, in addition to other forcings emphasized in previous studies.     

中国汽车空调行业HFC-134a需求和排放预测

 近年来HFC-134a作为中国汽车空调行业CFC-12制冷剂最主要的替代品,其消费量增长迅速,是中国消费量最大的HFCs（氢氟烃类物质）。以2005年为基线,通过制冷剂替代、技术进步、熟练操作和政策控制等情景假设,预测了中国汽车空调行业HFC-134a的需求量及排放量。结果表明：到2010和2015年,汽车空调HFC-134a的消费量将分别接近2.0万和3.5万t,排放量将分别接近1.6万和3.0万t,约折合排放21.0 和39.0 Mt CO₂当量。上述排放相对基线情景（即维持当前政策措施和不开展回收活动）,2010年和2015年减排温室气体分别为6.7 和13.0 Mt CO₂当量。     

Coupled Model Simulations of Climate Changes in the 20th Century and Beyond

Several scenario experiments of the IPCC 4th Assessment Report （AR4） are performed by version g1.0 of a Flexible coupled Ocean-Atmosphere-Land System Model （FGOALS） developed at the Institute of Atmospheric Physics, Chinese Academy of Sciences （IAP/CAS）, including the ＂Climate of the 20th century experiment＂, ＂CO2 1% increase per year to doubling experiment＂ and two separate IPCC greenhouse gases emission scenarios AIB and B1 experiments. To distinguish between the different impacts of natural variations and human activities on the climate change, three-member ensemble runs are performed for each scenario experiment. The coupled model simulations show： （1） from 1900 to 2000, the global mean temper- ature increases about 0.5℃ and the major increase occurs during the later half of the 20th century, which is in consistent with the observations that highlights the coupled model＇s ability to reproduce the climate changes since the industrial revolution; （2） the global mean surface air temperature increases about 1.6℃ in the CO2 doubling experiment and 1.5℃ and 2.4℃ in the A1B and B1 scenarios, respectively. The global warming is indicated by not only the changes of the surface temperature and precipitation but also the temperature increase in the deep ocean. The thermal expansion of the sea water would induce the rise of the global mean sea level. Both the control run and the 20th century climate change run are carried out again with version g1.1 of FGOALS, in which the cold biases in the high latitudes were removed. They are then compared with those from version g1.0 of FGOALS in order to distinguish the effect of the model biases on the simulation of global warming.     

日光温室的纹理特征分层提取

针对高分辨率影像上日光温室的信息提取问题,该文提出了利用支持向量机、最近邻算法结合纹理特征在不同层上分别提取连片日光温室和独栋日光温室的方法。实验表明:纹理特征能提高分类精度,在大尺度的层上,分类精度提升幅度较大,但在小尺度的层上,分类精度提升幅度会比较小;并不是参与运算特征数越多,分类精度越高,多数情况下光谱+纹理组合的分类精度最高;提取连片日光温室的最优方案是支持向量机和光谱+形状+纹理(7像素×7像素),总精度为92.86%,Kappa系数为0.90,而提取独栋日光温室最优方案为SVM和光谱+纹理(11像素×11像素),总精度为88.39%,Kappa系数为0.86。     

Emission of methane and nitrous oxides from agricultural soils and related global warming potentials of Murshidabad District,West Bengal

Agricultural activities emit substantial amounts of methane (CH4) and nitrous oxides (N2O), the two important greenhouse gases (GHG) with high global warming potentials (GWP). So far, many studies have already been carried out at national and state level, but lack micro‐level (district or block‐level) inventory in India. The present study sheds light on the flux of CH4 and N2O (from all possible sources) from agricultural soil of various blocks in the Murshidabad district, based on the inventory prepared, using the IPCC methodology, with adjusted emission factors and coefficients appropriate for the local level. The economy of the Murshidabad district almost completely rests on agriculture as more than 80 per cent of the population is directly or indirectly dependent on it for their livelihood. Paddy is the dominating crop, cultivated on more than 60 per cent of the gross cropped area. The present work is based on the review of various literature and reports collected from respective state government offices and websites. Results show that CH4 and N2O emission from the agricultural fields are 126.405 Gg and 0.652 Gg respectively for the year 2011?12 with a large scale spatial variation (block‐level) within the district.     

温室气体强迫与东亚亚热带季风演变耦合效应及动力机制研究

基于主要温室气体（CO₂、CH₄和N₂O）强迫因子和石笋δ¹⁸О观测资料（1~2002 年）,分别利用关联性耦合模型和非线性统计-动力学方法,分析温室气体强迫与东亚亚热带季风演变耦合度的时序规律和定量反演模拟温室气体强迫对近2 000 a东亚亚热带季风演变影响的非线性趋势和相对贡献。研究发现：① 温室气体与季风演变耦合度的高低对应季风的强弱变化,即两者耦合作用越强,东亚亚热带季风越强;反之,两者耦合强度越小,东亚亚热带季风越弱;耦合度峰谷值对应季风极强降水和极端干旱时段。② 时序演变规律为：N₂O和CO₂相互作用与季风演变间耦合效应最强,成为东亚亚热带季风演变的主要驱动力。其次,N₂O一次项和CO₂非线性项对季风演变起主要的负反馈调节机制。③ 时序演变阶段上有所不同：1~180年,CH₄因子对季风演变主要起负反馈调节机制;180~1760年和1760~2002年,对季风演变起主要的驱动和调节机制分别为CO₂因子和N₂O因子;但1900年后N₂O和CO₂相互作用与季风演变的耦合驱动效应近百年来明显增强,耦合度在中等-较强（或极强）之间来回波动转换,耦合作用明显增强,在耦合度由较强（或极强）转弱至中等时,东亚亚热带季风也随之减弱。     

The impact of shale gas on the costs of climate policy

The use of shale gas is commonly considered as a low-cost option for meeting ambitious climate policy targets. This article explores global and country-specific effects of increasing global shale gas exploitation on the energy markets, on greenhouse gas emissions, and on mitigation costs. The global techno-economic partial equilibrium model POLES (Prospective Outlook on Long-term Energy Systems) is employed to compare policies which limit global warming to 2°C and baseline scenarios when the availability of shale gas is either high or low. According to the simulation results, a high availability of shale gas has rather small effects on the costs of meeting climate targets in the medium and long term. In the long term, a higher availability of shale gas increases baseline emissions of greenhouse gases for most countries and for the world, and leads to higher compliance costs for most, but not all, countries. Allowing for global trading of emission certificates does not alter these general results. In sum, these findings cast doubt on shale gas’s potential as a low-cost option for meeting ambitious global climate targets.

POLICY RELEVANCE

Many countries with a large shale gas resource base consider the expansion of local shale gas extraction as an option to reduce their GHG emissions. The findings in this article imply that a higher availability of shale gas in these countries might actually increase emissions and mitigation costs for these countries and also for the world. An increase in shale gas extraction may spur a switch from coal to gas electricity generation, thus lowering emissions. At the global level and for many countries, though, this effect is more than offset by a crowding out of renewable and nuclear energy carriers, and by lower energy prices, leading to higher emissions and higher mitigation costs in turn. These findings would warrant a re-evaluation of the climate strategy in most countries relying on the exploitation of shale gas to meet their climate targets.