Determinants of CO2 emissions: empirical evidence from Egypt

Environmental and Ecological Statistics - This paper aims to explore the main determinants of environmental quality in Egypt by utilizing the data covering the years from 1971 to 2014. These...     

Bayesian estimation of European sulphur emissions using monitoring data and an acid deposition model

A statistical method for estimating national emissions of acidifying air pollutants in Europe is presented. The method uses an acid deposition model to match official emissions data from European countries and measured depositions from a monitoring network. An application to 1990 sulphate data demonstrates the method and suggests some tendencies in the reported emissions. The proposed framework may prove useful for verifying national compliance with emissions standards, and the method should be applicable also to other substances than sulphur dioxide. The problem of designing an optimal monitoring network may also be assessed within the proposed statistical framework.     

Methane and carbon dioxide dynamics in wetland mesocosms: effects of hydrology and soils.

Methane and carbon dioxide fluxes in created and restored wetlands, and the influence of hydrology and soils on these fluxes, have not been extensively documented. Minimizing methane fluxes while maximizing productivity is a relevant goal for wetland restoration and creation projects. In this study we used replicated wetland mesocosms to investigate relationships between contrasting hydrologic and soil conditions, and methane and carbon dioxide fluxes in emergent marsh systems. Hydrologic treatments consisted of an intermittent flooding regime vs. continuously inundated conditions, and soil treatments utilized hydric vs. non-hydric soils. Diurnal patterns of methane flux were examined to shed light on the relationship between emergent macrophytes and methane emissions for comparison with vegetation-methane relationships reported from natural wetlands. Microbially available organic carbon content was significantly greater in hydric soils than nonhydric soils, despite similar organic matter contents in the contrasting soil types. Mesocosms with hydric soils exhibited the greatest rates of methane flux regardless of hydrology, but intermittent inundation of hydric soils produced significantly lower methane fluxes than continuous inundatation of hydric soils. Methane fluxes were not affected significantly by hydrologic regime in mesocosms containing non-hydric soils. There were no diurnal differences in methane flux, and carbon dioxide and methane fluxes were not significantly correlated. The highest rates of CO2 uptake occurred in the continuously inundated treatment with non-hydric soils, and there were no significant differences in nighttime respiration rates between the treatments. Implications for hydrologic design of created and restored wetlands are discussed.     

Increased carbon dioxide availability alters phytoplankton stoichiometry and affects carbon cycling and growth of a marine planktonic herbivore

Rising levels of CO₂ in the atmosphere have led to increased CO₂ concentrations in the oceans. This enhanced carbon availability to the marine primary producers has the potential to change their nutrient stoichiometry, and higher carbon-to-nutrient ratios are expected. As a result, the quality of the primary producers as food for herbivores may change. Here, we present experimental work showing the effect of feeding Rhodomonas salina grown under different pCO₂ (200, 400 and 800 μatm) on the copepod Acartia tonsa. The rate of development of copepodites decreased with increasing CO₂ availability to the algae. The surplus carbon in the algae was excreted by the copepods, with younger stages (copepodites) excreting most of their surplus carbon through respiration and adult copepods excreting surplus carbon mostly as DOC. We consider the possible consequences of different excretory pathways for the ecosystem. A continued increase in the CO₂ availability for primary production, together with changes in the nutrient loading of coastal ecosystems, may cause changes in the trophic links between primary producers and herbivores.     

Oxygen and carbon dioxide exchange in the polychaete Nereis virens: influence of ventilation activity and starvation

The influence of ventilation activity and starvation on O₂ uptake and CO₂ production in the polychaete Nereis virens Sars was investigated during September 1986 using worms collected on intertidal flats outside the Nærå Strand estuary, Denmark. The activity level, measured as ventilation rate, , was linearly related to active O₂ uptake, , for worms inhabiting artificial burrows (i.e. tubes) in the laboratory. at 16°C was two and four times the extrapolated standard O₂ uptake ( =0) when was 100 and 500 ml g^-1 h^-1, respectively. The use of tubes had no significant effect on N. viren's temporal ventilation pattern, D_v, compared to natural burrows in sediment. The ventilation rate, , however, was 2 to 3 times higher in tubes than in burrows. Starvation affected both ventilation and gas exchange. increased slightly during the first six days remaining constant thereafter. D_v, on the othe hand, decreased during the first six days followed by a gradual increase to Day 20. The observed decrease in D_v (%) from Day 0 to 1 was attributed to insufficient acclimation of the worms. The time integrated ventilation rate, × D_v, increased gradually throughout the 20 d starvation period. and declined rapidly during the first days of starvation. After 10 d the gas exchange reached steady levels at about 50% of the initial rate. The observed decrease in metabolic rate during starvation was explained by a rapid initial reduction in specific dynamic action (SDA) followed by a gradual exhaustion of readily available metabolic reserves, e.g. glycogen and lipids.     

Economic growth,public welfare and sustainability: an empirical system analysis

SUMMARY

This paper explores the relationships between economic activity and sustainability, growth, and welfare. The issues regarding the nature of the relationships were framed by Ekins in questions which are addressed empirically across countries and the states of the US. The sustainability issue is addressed by comparing nonrenewable energy throughput, a surrogate for impacts, to the renewable energy throughput in the associated ecosystem. The effect of a changing energy intensity, in developing and developed countries, on socioeconomic variables provides clues to social welfare. In developing countries a rising energy throughput (economic growth) and energy intensity is positively related to public welfare while impacts are generally moderate. The reverse appears to be true in developed countries, i.e. as energy throughput and intensity rise in developed countries and the US states, pollution and impacts also rise while socioeconomic variables worsen, so public welfare begins to decline. Economic development appears to pass through three phases which can be characterized by the nature and extent of its energy use. Each phase exhibits characteristic energy, pollution, structural and socioeconomic trends.     

Optimal sequestration of carbon dioxide and phosphorus in soils by gypsum amendment

Gypsum has been applied as a natural fertilizer and soil amendment for centuries in agriculture for providing crop nutrients such as Ca and S, and for improving soil physical properties. Recently, gypsum has been tested for sequestrating CO₂ from the air and for capturing soluble phosphates in the soil, through formation of insoluble calcium phosphates and carbonates. However, the environmental factors controlling these sequestration processes have not been systemically studied. Here, we calculate optimal conditions of sequestration using chemical equilibrium modeling. Our results show that CO₂ carbonation is effective at pH higher than 8.5 at atmospheric concentration. The removal of P is higher than 80 % for pH higher than 6.4, when Ca and P are at stoichiometric ratio. Also, placement of gypsum in subsoil is more effective for CO₂ capture than applying it on soil surface since soil pores often contain higher concentrations of CO₂ due to the soil respiration process. Overall, increases in medium pH, gypsum application rate, or CO₂ partial pressure can increase the effectiveness of the amendment.     

The influence of dissolved oxygen and carbon dioxide on fish schooling behavior

Slow reduction of dissolved oxygen concentrations or slowly increased carbon dioxide (reduced pH) did not cause measurable changes in the density, nearest neighbor orientation, or the swimming speed of experimental schools of the northern anchovy Engraulis mordax, until near-lethal levels were reached. Rapid reductions of oxygen or pH, however, caused significant increases in average swimming velocity. Positive reactions were correlated to rapid reductions of no more than 0.55 mg O₂/l or 0.25 pH units. These responses are related to the hypothesis that metabolic reductions of environmental dissolved oxygen and/or pH may influence the internal structure and behavior of fish schools.     

Revisiting the carbon emissions hypothesis in the developing and developed countries: a new panel cointegration approach

Environmental and Ecological Statistics - Since global warming worsens with economic development and emitted CO2 is one of the main greenhouse gases, it is important to understand...     

Control of hydrogen sulfide emissions using autotrophic denitrification landfill biocovers: engineering applications

Hydrogen sulfide (H₂S) emitted from construction and demolition waste landfills has received increasing attention. Besides its unpleasant odor, longterm exposure to a very low concentration of H₂S can cause a public health issue. In the case of construction and demolition (C&D) waste landfills, where gas collection systems are not normally required, the generated H₂S is typically not controlled and the number of treatment processes to control H₂S emissions in situ is limited. An attractive alternative may be to use chemically or biologically active landfill covers. A few studies using various types of cover materials to attenuate H₂S emissions demonstrated that H₂S emissions can be effectively reduced. In this study, therefore, the costs and benefits of H₂S-control cover systems including compost, soil amended with lime, fine concrete, and autotrophic denitrification were evaluated. Based on a case-study landfill area of 0.04 km², the estimated H₂S emissions of 80900 kg over the 15-year period and costs of active cover system components (ammonium nitrate fertilizer for autotrophic denitrification cover, lime, fine concrete, and compost), ammonium nitrate fertilizer is the most cost effective, followed by hydrated lime, fine concrete, and yard waste compost. Fine concrete and yard waste compost covers are expensive measures to control H₂S emissions because of the large amount of materials needed to create a cover. Controlling H₂S emissions using fine concrete and compost is less expensive at landfills that provide on-site concrete recovery and composting facilities; however, ammonium nitrate fertilizer or hydrated lime would still be more cost effective applications.     

Location of suitable nests by great spotted cuckoos: an empirical and experimental study

Brood parasites depend entirely on their host species to raise their nestlings until independence. Thus, brood-parasite females must discover and select nests that are at a suitable stage for parasitism, and thus, the location of each parasitic egg is crucial in determining the brood-parasite female’s fitness. In relation to host behaviour, one of the main hypotheses proposed to explain how brood-parasite females find and select a suitable nest posits that the most active hosts during nest building should undergo a higher risk of being parasitised (the “host-activity hypothesis”). Here, using the great spotted cuckoo, Clamator glandarius–magpie, Pica pica system, we found that not only cuckoo females parasitise magpie nests regardless of the location and characteristics of nests, but also that the parasite’s observation of host activity near the nest determines a cuckoo female’s decision of laying in a nest. Only one experimental nest (without host activity) was parasitised before the magpie started laying, while 34.14?% of natural active nests were parasitised before the magpie started laying. These observations support the host-activity hypothesis for nest location in great spotted cuckoos.     

A comparison of two cartographic exposure methods using Fucus vesiculosus as an indicator

Morphological variation and vertical distribution of Fucus vesiculosus were quantified at several sites in the Finnish archipelago (Baltic Sea). F. vesiculosus samples were obtained from skerries at geographical distances of 1 km or more (large scale) and at intervals of ca 100 m around a single island (small scale). The results were examined in relation to wave exposure, calculated by Baardseth and effective fetch cartographic methods. Despite the fact that the exposure indices were calculated differently they correlated strongly. Vegetative morphological characteristics of F. vesiculosus illustrate the morphological differences both within and between exposure gradients. The tallest and widest F. vesiculosus plants were found at the sheltered end of the large-scale exposure gradient. Those from equally sheltered sites of the island were smaller in all respects. Thus, the trend from small narrow plants to large wide sheltered plants was expressed differently over the different geographical scales. Consequently localities with similar exposure indices may have morphologically different F. vesiculosus populations. Shores with similar cartographic exposure indices can be different in nature. Underwater topography and shore locations, either close to the mainland or at the outermost sites of the archipelago, affect the exposure. Although a sheltered shore is indicated, the sublittoral zone may be quite exposed to the movements of water. In contrast, in an open shore environment underwater rocks, boulders and shallow water areas can provide sheltered habitats. The depth range of the F. vesiculosus belt exhibited two distinctive patterns. At sheltered sites, around islands in the outermost reaches of the archipelago F. vesiculosus can grow to a maximum depth of 5 m. In exposed habitats the belt becomes narrower, reaching a maximum depth of 3 m. Closer to the mainland F. vesiculosus is found at exposed sites to a maximum depth of 5 m; the depth range at sheltered sites is narrower, only reaching depths of 2 m or less. In conclusion, the changes in plant morphology and in the vertical belt distribution are similar to each other along both gradients at the exposed ends of the wave action spectrum; however, the two gradients diverge at the sheltered ends of the spectrum. Received: 10 August 1998 / Accepted: 11 January 1999     

2003—2010年中国对流层CO2时空分布研究

利用2003年到2010年的美国宇航局(National Aeronautics and Space Administration,NASA)的AIRS(Atmosphere InfraRed Sounder)官方反演的对流层中层(500 hPa)左右一段气柱内的CO2体积混合比产品分析中国地区对流层的CO2体积分数分布时空变化特征。所用数据是对AIRS L3产品2°×2.5°网格数据进行处理分析得到。经过对这8年的观测数据(2003年1月—2010年12月)的数据分析研究发现:中国地区平均CO2的体积分数在空间分布上极不平衡,总体高值集中于北部。CO2对流层中层的高值区集中在35°—45°N,形成东北平原、内蒙古中西部地区、塔克拉玛干沙漠和塔里木盆地4个高值中心,而云南地区和西藏南部上空的CO2值偏低。与中国地区8年平均CO2体积分数变化特征大体一致,每月(8年平均值)分布趋势也呈北部地区和东部地区高而南方体积分数值相对低的特征。CO2月平均体积分数的最高值一般出现在每年的4月或者5月,而每年的最低值则出现在每年的1月。对流层中层CO2体积分数呈现明显季节变化,总体上来说,从2003年到2010年这8年中,平均春、夏两季对流层中CO2含量较高,而秋、冬季CO2低于春夏两季。     

2003—2010年中国对流层CO2时空分布研究

利用2003年到2010年的美国宇航局（National Aeronautics and Space Administration,NASA）的AIRS（Atmosphere InfraRed Sounder）官方反演的对流层中层（500 hPa）左右一段气柱内的CO2体积混合比产品分析中国地区对流层的CO2体积分数分布时空变化特征。所用数据是对AIRS L3产品2°×2.5°网格数据进行处理分析得到。经过对这8年的观测数据（2003年1月—2010年12月）的数据分析研究发现：中国地区平均CO2的体积分数在空间分布上极不平衡,总体高值集中于北部。CO2对流层中层的高值区集中在35°—45°N,形成东北平原、内蒙古中西部地区、塔克拉玛干沙漠和塔里木盆地4个高值中心,而云南地区和西藏南部上空的CO2值偏低。与中国地区8年平均CO2体积分数变化特征大体一致,每月（8年平均值）分布趋势也呈北部地区和东部地区高而南方体积分数值相对低的特征。CO2月平均体积分数的最高值一般出现在每年的4月或者5月,而每年的最低值则出现在每年的1月。对流层中层CO2体积分数呈现明显季节变化,总体上来说,从2003年到2010年这8年中,平均春、夏两季对流层中CO2含量较高,而秋、冬季CO2低于春夏两季。     

Living in a ghetto within a local population: an empirical example of an ideal despotic distribution

Merging patterns and processes about the way individuals should be distributed in a habitat is a key issue in the framework of spatial ecology. Here the despotic distribution of individuals in two distinct and neighboring patches within a local population of a long-lived colonial bird, the Yellow-legged Gull (Larus michahellis), was assessed. There was no density dependence for suitable habitat at the study population, but behavioral data suggested that birds from the good patch precluded birds from the bad patch from breeding in their patch. Younger breeders were almost exclusively found in the bad patch, where individuals were probably attracted by conspecific attraction from the good patch. Most breeding parameters were lower in the bad patch, resulting mainly from a higher vulnerability to environmental perturbations and a higher rate of intraspecific nest predation. Attempts at breeding dispersal between the two patches were only observed from the bad to the good patch. Strikingly, adult survival and large-scale dispersal, two life history parameters that are very conservative in long-lived organisms, were also more affected at the bad patch when catastrophic predation occurred. The study was consistent with an ideal despotic distribution at small spatial scale, and suggests that individual behavior can influence local population dynamics.     

Urban expansion and its contribution to the regional carbon emissions: Using the model based on the population density distribution

The method is used for calculating regional urban area dynamics and the resulting carbon emissions (from the land-conversion) for the period of 1980 till 2050 for the eight world regions. This approach is based on the fact that the spatial distribution of population density is close to the two-parametric Γ-distribution [Kendall, M.G., Stuart, A., 1958. The Advanced Theory of Statistics, vol. 1.2. Academic Press, New York; Vaughn, R., 1987. Urban Spatial Traffic Patterns, Pion, London]. The developed model provides us with the scenario of urbanisation, based on which the regional and world dynamics of carbon emissions and export from cities, and the annual total urban carbon balance are estimated. According to our estimations, world annual emissions of carbon as a result of urbanisation increase up to 1.25 GtC in 2005 and begin to decrease afterwards. If we compare the emission maximum with the annual emission caused by deforestation, 1.36 GtC per year, then we can say that the role of urbanised territories (UT) in the global carbon balance is of a comparable magnitude. Regarding the world annual export of carbon from UT, we observe its monotonous growth by three times, reaching 505 MtC. The latter, is comparable to the amount of carbon transported by rivers into the ocean (196–537 MtC). The current model shows that urbanisation is inhibited in the interval 2020–2030, and by 2050 the growth of urbanised areas would almost stop. Hence, the total balance, being almost constant until 2000, then starts to decrease at an almost constant rate. By the end of the XXI century, the total carbon balance will be equal to zero, with the exchange flows fully balanced, and may even be negative, with the system beginning to take up carbon from the atmosphere, i.e., becomes a “sink”. The regional dynamics is somewhat more complex, i.e., some regions, like China, Asia and Pacific are being active sources of Carbon through the studied period, while others are changing from source to sink or continue to be neutral in respect the GCC.     

Developing an empirical model of phytoplankton primary production: a neural network case study

We describe the development of a neural network model for estimating primary production of phytoplankton. Data from an enriched estuary in the eastern United States, Chesapeake Bay, were used to train, validate and test the model. Two error backpropagation multilayer perceptrons were trained: a simpler one (3-5-1) and a more complex one (12-5-1). Both neural networks outperformed conventional empirical models, even though only the latter, which exploits a larger suite of predictive variables, provided truly accurate outputs. The application of this neural network model is thoroughly discussed and the results of a sensitivity analysis are also presented.     

Decomposition and decoupling analysis of carbon emissions from agricultural economic growth in China's Yangtze River economic belt

Environmental Geochemistry and Health - In this study, carbon emissions from agricultural energy consumption (CEAEC) are fully analyzed using data from the Yangtze River Economic Belt (YEB) between...     

Enhanced adsorption of arsenate on titanium dioxide using Ca and Mg ions

In this study, we report the effects of pH and divalent cations on the adsorption of arsenate (As(V)) by titanium dioxide (TiO₂) nanoparticles. The extent of As(V) adsorption on TiO₂ decreased with increasing pH due to the decrease of positively charged binding sites on the TiO₂ surface. The Langmuir maximum uptake capacity at pH 4 is about three times higher than that at pH 7. Here we show that the relatively low As(V) uptake at circumneutral pH could be substantially enhanced by the addition of common divalent cations such as magnesium and calcium. At a concentration of approximately 7 mM, magnesium and calcium increased the extent of As(V) adsorption from 2.1 to 6.5 and 7.7 mg As(V)/g TiO₂, respectively.     

Estimation of soil carbon saturation and carbon sequestration potential of an agro-ecosystem in China

Soil is believed to be the most important sink for sequestering atmospheric carbon. Hence, estimating soil carbon sequestration potential has been carried out for different regions and agricultural practices. However, soil carbon saturation (SCS), a fundamental concept for estimating soil carbon sequestration potential, has not been estimated for countries or regions. In this study, we estimated SCS of agricultural land for most provinces in China for 1990 by the DNDC model, a carbon and nitrogen biogeochemical cycle model, in order to provide a basis for farmers to select the land use, tillage and fertilization regimes to sequester more carbon. The result showed that SCS was as low as 0.48% in Tianjin and up to 5.14% in Tibet. There was a positive correlation between SCS and the proportion of paddy field in a province. In 1990, cropland soil carbon sequestration potential (SCSP) in China was -0.969 Gt C (-2.706 to 0.767 Gt C). This suggests that agricultural soil will be a carbon source to the atmosphere if agricultural practices are not altered. However, SCSP differed between provinces in China. SCSP was highest in Tibet (7.9 t C ha-1) and lowest in Heilongjiang Province (-60.8 t C ha-1), with a gradual decrease from south to north in China.