Comparison of marginal abatement cost curves for 2020 and 2030: longer perspectives for effective global GHG emission reductions

This study focuses on analyses of greenhouse gas (GHG) emission reductions, from the perspective of interrelationships among time points and countries, in order to seek effective reductions. We assessed GHG emission reduction potentials and costs in 2020 and 2030 by country and sector, using a GHG emission reduction-assessment model of high resolution regarding region and technology, and of high consistency with intertemporal, interregional, and intersectoral relationships. Global GHG emission reduction potentials relative to baseline emissions in 2020 are 8.4, 14.7, and 18.9 GtCO₂eq. at costs below 20, 50, and 100 $/tCO₂eq., corresponding to +19, −2, and −7 %, respectively, relative to 2005. The emission reduction potential for 2030 is greater than that for 2020, mainly because many energy supply and energy-intensive technologies have long lifetimes and more of the current key facilities will be extant in 2020 than in 2030. The emission reduction potentials in 2030 are 12.6, 22.0, and 26.6 GtCO₂eq. at costs below 20, 50, and 100 $/tCO₂eq., corresponding to +19, −2, and −7 %, respectively, relative to 2005. The emission reduction potential for 2030 is greater than that for 2020, mainly because many energy supply and energy-intensive technologies have long lifetimes and more of the current key facilities will be extant in 2020 than in 2030. The emission reduction potentials in 2030 are 12.6, 22.0, and 26.6 GtCO₂eq. at costs below 20, 50, and 100 /tCO₂eq., corresponding to +33, +8, and −3 %, respectively, relative to 2005. Global emission reduction potentials at a cost below 50 $/tCO₂eq. for nuclear power and carbon capture and storage are 2.3 and 2.2 GtCO₂eq., respectively, relative to baseline emissions in 2030. Longer-term perspectives on GHG emission reductions toward 2030 will yield more cost-effective reduction scenarios for 2020 as well.     

Consistent assessments of pathways toward sustainable development and climate stabilization

Many of the numerous difficult issues facing the world today involve relationships entailing trade‐offs and synergies. This study quantitatively assesses some alternative scenarios using integrated assessment models, and provides several indicators relating to sustainable development and climate change, such as indicators of income (per capita GDP), poverty, water stress, food access, sustainable energy use, energy security, and ocean acidification, with high consistencies among the indicators within a scenario. According to the analyses, economic growth helps improve many of the indicators for sustainable development. On the other hand, climate change will induce some severe impacts such as ocean acidification under a non‐climate intervention scenario (baseline scenario). Deep emission reductions, such as to 2°C above the pre‐industrial level, could cause some sustainable development indicators to worsen. There are complex trade‐offs between climate change mitigation levels and several sustainable development indicators. A delicately balanced approach to economic growth will be necessary for sustainable development and responses to climate change.     

组合人工湿地对城镇污水处理厂尾水中有机物的去除特征研究

采用物理分级和三维荧光光谱法,研究了组合人工湿地对城镇污水处理厂尾水中不同形态有机物的去除特征.结果表明,组合人工湿地对污水处理厂尾水具有较好的深度处理效果,出水水质基本可以达到国家地表水环境质量标准(GB38382-2002)Ⅲ或Ⅳ类水标准.组合人工湿地处理系统对尾水中CODCr和BOD5总体去除率分别达到35.2%和44.3%,对尾水中总有机碳(TOC)、溶解性有机碳(DOC)、颗粒有机碳(POC)的平均去除率分别为46.9%、45.9%、48.3%.组合人工湿地系统不同单元对尾水中有机物的去除贡献率存在差异,其中,潜流湿地单元对尾水中CODCr和BOD5及其不同组分有机碳的去除效率较高.试验期间,由于藻类滋生,表流湿地单元出水中有机物含量波动较大,去除效果明显降低,藻类被打捞后,出水水质明显改善.三维荧光光谱分析结果显示,各个处理单元取样点的水样三维荧光光谱均出现4个明显的荧光峰.人工湿地各单元出水溶解性有机质(DOM)中,类蛋白和类腐殖酸物质含量较高,类富里酸物质含量较低.人工湿地对类蛋白和类腐殖酸物质有较强的去除作用.     

Pelleted organo-mineral fertilisers from composted pig slurry solids, animal wastes and spent mushroom compost for amenity grasslands

In Ireland, conversion of biodegradable farm wastes such as pig manure spent mushroom compost and poultry litter wastes to pelletised fertilisers is a desirable option for farmers. In this paper, results obtained from the composting of pig waste solids (20% w/w) blended with other locally available biodegradable wastes comprising poultry litter (26% w/w), spent mushroom compost (26% w/w), cocoa husks (18% w/w) and moistened shredded paper (10% w/w) are presented. The resulting 6-mo old 'mature' composts had a nutrient content of 2.3% total N, 1.6% P and 3.1% K, too 'low' for direct use as an agricultural fertiliser. Formulations incorporating dried blood or feather meal amendments enriched the organic N-content, reduced the moisture in mature compost mixtures and aided the granulation process. Inclusion of mineral supplements viz., sulphate of ammonia, rock phosphate and sulphate of potash, yielded slow release fertilisers with nutrient N:P:K ratios of 10:3:6 and 3:5:10 that were suited for amenity grasslands such as golf courses for spring or summer application and autumn dressing, respectively. Rigorous microbiological tests carried out throughout the composting, processing and pelletising phases indicated that the formulated organo-mineral fertilisers were free of vegetative bacterial pathogens.     

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD)-induced down-regulation of glucose transporting activities in mouse 3T3-L1 preadipocyte

The possibility that 3T3-L1 preadipocytes, while the level of its glucose uptake activity is relatively low, may offer a useful tool for studying the cause for 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced "lipolytic response" was studied. It was established first, that TCDD causes reduction of glucose uptake, one of the hallmark events of the lipolytic process. Then the function of c-Src was investigated. The antisense c-src oligonucleotide decreased the inhibitory action of TCDD on glucose uptake activity in a sequence specific manner. Since antisense oligonucleotides are known to own their blocking effects to their ability to reduce translation of proteins, Western blotting analysis was performed to verify their effectiveness. As expected, the treatment of pre-adipocytes with antisense c-src oligonucleotide reduced c-Src in a sequence specific manner. The treatment of antisense c-src oligonucleotide alone was sufficient to diminish the inhibitory action of TCDD on glucose uptake activity in 3T3-L1 cells, indicating that c-Src is somehow involved in the action of TCDD. In a similar manner, the contribution of c-Fos was investigated using antisense c-fos oligonucleotide, since c-Fos is known to be one of the most affected proteins by c-Src activation among AP-1 members. The treatment of antisense c-fos oligonucleotide did not block the effect of TCDD on glucose uptake activity in 3T3-L1 cells. Therefore, it is unlikely that c-Fos is very important in the lipolytic signal transduction of TCDD mediated through c-Src. In order to determine the relationship between c-Src and c-Myc in the mitotic signal transduction pathway, the effect of antisense c-myc oligonucleotide was investigated. Basically the same result as antisense c-src oligonucleotide experiment was obtained thereby, suggesting the importance of c-Myc as well as c-Src in the signal transduction of TCDD. To show the effect of antisense c-myc oligonucleotide treatment, the level of c-Myc protein by Western blotting and electrophoretic gel-mobility shift assay was assessed. However, antisense c-myc oligonucleotide treatment increased the activity of c-Myc in a sequence specific manner. This may be the result of cellular compensatory response to the initial suppression of c-Myc by antisense treatment. The observation that antisense c-fos oligonucleotide could not block the effect of TCDD indicates that this preadipocyte model is different from the adipocyte differentiation model.     

Feasible conditions for Japanese woody biomass utilization

Environmental Science and Pollution Research - There is an abundance of woody biomass in Japan. However, its economic feasibility is limited. There have been several discussions on whether...     

Evaluation of waste pyrolysis characteristics in a pressurized fluidized bed reactor

To obtain the distribution of fuel components to gas, tar and char in a pressurized fluidized bed waste pyrolyzer, experiments were conducted with a laboratory scale fluidized bed reactor. Waste samples were fed batchwise from the top of the reactor into the fluidized bed of silica sand and pyrolyzed by nitrogen/nitrogen-O2 gas and the effects of pressure, particle size, heating rate and oxygen addition were investigated. In the case of rubber, the char yield tended to increase a little and the tar yield decrease over the pressure of 304-709 kPa. In comparison with the thermogravimetry data it was clearly demonstrated that the char yield from fluidized bed pyrolysis is much lower. A small amount of oxygen addition decreased both tar and char yields but its further increase did not affect them very much.     

Unusual arsenic speciation in sea anemones

Nine species of sea anemones (Anthopleura asiatica, Actinia equina, Actinodendron arboreum, Phymanthus loligo, Entacmaea actinostoloides, Stichodactyla gigantea, S. haddoni, S. mertensii and Metridium senile) contained arsenic in the range of 1.6-7.0microg As g(-1) (wet mass basis). Irrespective of the species, water-soluble arsenic compounds accounted for more than 80% of the total arsenic. Analysis of water-soluble arsenic compounds by LC/ESI-MS revealed that four arsenicals, arsenobetaine (AB), trimethylarsoniopropionate, arsenocholine (AC) and tetramethylarsonium ion (TEMA), are contained in most species but arsenate, methylarsonic acid, dimethylarsinic acid and trimethylarsine oxide are absent in all species. Interestingly, compositional patterns of the four arsenicals greatly differed from species to species. Only three species (S. gigantea, S. haddoni and M. senile) contained AB at the highest proportions, similar to the majority of marine animals. However, the remaining six species showed unusual compositional patterns of arsenic compounds; AC was most predominant in A. arboreum and P. loligo and TEMA in A. asiatica, A. equina, E. actinostoloides and S. mertensii. On the whole, high proportions (24.6-87.1% of the water-soluble arsenic) of TEMA appear to be a peculiar characteristic of many species of sea anemones. Thus, sea anemones are an important animal group in the arsenic cycling, especially in that they may be donors of TEMA to predators.     

Arsenic contamination in groundwater and its possible sources in Hanam, Vietnam

This study investigated the arsenic (As) level in groundwater, and the characteristics of aquifer sediment as related to the occurrence of As in groundwater in Hanam, Vietnam. The deposition and transport of As-containing substances through rivers were also examined. Arsenic concentrations in 88% of the groundwater samples exceeded the As limit for drinking water based on the WHO standards. The dominating form of arsenic was As(III). The maximum total As content in bore core sediment was found in a peat horizon of the profiles and generally, elevated levels of As were also found in other organic matter-rich horizons. Total As contents of the bore core sediments were significantly correlated with crystalline iron oxide, silt and clay contents, suggesting that As in aquifer sediment was mainly associated with iron (hydr)oxides and clay mineral. In the groundwater, As concentration showed significant correlations with the total concentrations of Fe and HCO (3)(-). Significant correlations between HCl-extractable As and non-crystalline Fe oxide, total C, N, and S were also observed in the profiles. The results support the hypothesis that under favorable reductive conditions established by the degradation of organic matter, the dissolution of iron (hydr)oxides releases adsorbed As into the groundwater. The deposition of As in the sediments from the Red River were significantly higher than that in the Chau Giang River, suggesting that the Red River is the main source of As-containing substances deposited in the study area.