The value of technology and of its evolution towards a low carbon economy

This paper assesses the economic value associated with the development of various low-carbon technologies in the context of climate stabilization. We analyze the impact of restrictions on the development of specific mitigation technologies, comparing three integrated assessment models used in the RECIPE comparison exercise. Our results indicate that the diversification of the carbon mitigation portfolio is an important determinant of the feasibility of climate policy. Foregoing specific low carbon technologies raises the cost of achieving the climate policy, though at different rates. CCS and renewables are shown to have the highest value, given their flexibility and wide coverage. The costs associated with technology failure are shown to be related to the role that each technology plays in the stabilization scenario, but also to the expectations about their technological progress. In particular, the costs of restriction of mature technologies can be partly compensated by more innovation and technological advancement.     

Factors Controlling Total Concentration and Aqueous Speciation of Aluminium in an Acidic Headwater Stream of the Bavarian Forest National Park: a Modelling Approach

The purpose of the present paper is to analyse factors controlling total concentration and aqueous speciation of aluminium in the Große Ohe River, using a thermodynamic equilibrium model and a mixing approach. A model compound for humic substances is derived on the basis of the relation between anion deficit and the organic carbon content in the river as well as literature data. An equilibrium speciation model for aluminium is set up, considering this model compound and relevant inorganic solutes. Although the model cannot be verified directly, its results may be viewed as qualitatively correct. Applying the model to measured stream water samples highlights that aqueous speciation of aluminium is mainly controlled by the pH value and discharge and that free aluminium concentrations reach clearly toxic levels during acidic episodes. Comparing measured concentrations of sulfate and H⁺ and calculated concentrations of Al³⁺ with solubility curves of gibbsite like minerals and jurbanite clearly shows that total aluminium concentrations are not controlled by equilibria with these mineral phases alone. The observed relationship can be better explained from a mixture of two distinct waters, representing lowflow and highflow chemistry, and the resulting equilibrium concentrations. This indicates that total aluminium concentration, in particular during high discharge events, is mainly controlled by the mixture of waters with differing chemistry and flowpaths.     

Proton-induced X-ray emission measurements of trace elements in water samples collected from an Indiana coal mining locality

A new method of simultaneous multi-elemental analysis, Proton Induced X-ray Emission (PIXE), was used to detect trace elements in waters associated with a coal strip-mining operation in southern Indiana. Stream, pond, and ground water samples were collected and analyzed monthly from, or near, Sulphur Creek in Sullivan County. The concentrations of 26 major and trace elements were determined in samples from eleven locations: K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Br, Rb, Sr, Mo, Cd, Sn, Sb, I, Ba, Hg, Pb, and U. Elemental concentrations fluctuated considerably throughout the 13-month sampling period and also among sampling sites. Nickel, Zn, As, Cd, Mn, Fe, and Ca were highest in the upstream water which was most acidic (pH = 2.9–4.0) because of old unreclaimed mining operations. The highest values recorded were Ni = 1662 ppb, Zn = 4953 ppb, As = 26 ppb, Cd = 93 ppb, Mn = 5063 ppb, Fe = 63 ppm, and Ca = 325 ppm. The concentrations of these elements decreased downstream as the pH of Sulphur Creek increased which was likely due to the influence of the calcareous glacial till cover in the area and the recent mining activity which disturbed overburden containing a high percentage of calcareous materials. Lead, I, Br, and Ti values were highest (661 ppb, 86 ppb, 70 ppb, and 45 ppb, respectively) in the ground water from the coal seam (pH approximately 7). Other elements which were relatively high in the pH 7 waters closest to the current mining operations (pond, stream, and groundwater) included K (17 ppm), Sr (3408 ppb), Ba (173 ppb), As (14 ppb), Rb (16 ppb), Sn (14 ppb), and Cu (3840 ppb). The highest Cu concentration was recorded at the point where drainage water from the mine entered Sulphur Creek. Gallium, U, Hg, and Mo were found in low (< 13 ppb for Ga and Hg; < 205 ppb for Mo and U) concentrations and only in the ponds within the mine.     

Regional co-development and security:: a comprehensive approach

Concepts of security are no longer limited to the military form, but other potential, economic, ecological, social aspects are becoming included.Emphasis needs to be put on integration of all dimensions of security. Many environmental problems present threats to human health and welfare and hence to the well-being of nations. The environmental issues cannot be ignored in context of any comprehensive security concept, but environmental security should not be treated in isolation.Integration of sustainable development and regional security may address many of the current maritime issues. Such integration may best be handled jointly and at regional levels.With this in mind and the realization that there is now a clear awareness and understanding that issues such as poverty, underdevelopment, population growth, environmental quality and sustainable resource use, are interrelated and interdependent and must be dealt with as such, the paper aims to highlight some aspects of regional security and sustainable development issues with reference to the Mediterranean basin. The aim is to initiate a process to pursue integration of sustainable development and comprehensive regional security with focus on the Mediterranean.The approach is based on the concept of the Common Heritage of Mankind as proposed by Arvid Pardo in 1967. It has 4 dimensions: economic; ethical; environmental; peace and security. In dealing with the proposal of Arvid Pardo the United Nations General Assembly decided to split up the concept: the Conference on the Law of the Sea was to deal with the peaceful uses of oceans and sea-beds; the Conference on Disarmament with the security aspects, then considered as military. UNCED 92 maintained the separation in addressing only environment and development, with management also included. However, peace and security were not included. It is time now to include these elements, and also consider the enforcement issue. The paper aims at illustrating this need through some examples from the Mediterranean basin.     

Water demand for electricity in deep decarbonisation scenarios: a multi-model assessment

This study assesses the effects of deep electricity decarbonisation and shifts in the choice of power plant cooling technologies on global electricity water demand, using a suite of five integrated assessment models. We find that electricity sector decarbonisation results in co-benefits for water resources primarily due to the phase-out of water-intensive coal-based thermoelectric power generation, although these co-benefits vary substantially across decarbonisation scenarios. Wind and solar photovoltaic power represent a win-win option for both climate and water resources, but further expansion of nuclear or fossil- and biomass-fuelled power plants with carbon capture and storage may result in increased pressures on the water environment. Further to these results, the paper provides insights on the most crucial factors of uncertainty with regards to future estimates of water demand. These estimates varied substantially across models in scenarios where the effects of decarbonisation on the electricity mix were less clear-cut. Future thermal and water efficiency improvements of power generation technologies and demand-side energy efficiency improvements were also identified to be important factors of uncertainty. We conclude that in order to ensure positive effects of decarbonisation on water resources, climate policy should be combined with technology-specific energy and/or water policies.     

A heat pulse technique for the determination of small‐scale flow directions and flow velocities in the streambed of sand‐bed streams

The hyporheic zone (HZ) has the capability to eliminate and attenuate nutrients and contaminants in riverine systems. Biogeochemical reactions and the potential elimination of contaminants are strongly controlled by the flow paths and dynamics in the HZ. Nevertheless, an easily applicable method for the field determination of flow patterns in the HZ is still lacking. Therefore, a heat pulse technique, which traces the movement of a short heat pulse in the upper part of the HZ and other sand beds, was developed. Five rods are vertically driven into the sediment of the streambed; one rod with a heater as point source located in about 10‐cm sediment depth and four rods with four temperature sensors in 3 cm distance, arranged concentrically with 7 cm diameter around the heating rod. Subsequently, a heat pulse is applied and the resulting breakthrough curves are indicative of flow velocities and flow directions in the streambed. A rough data analysis procedure is also suggested. In addition, laboratory experiments were performed to test the heat pulse technique. These experiments were validated based on coupled numerical modelling of flow and heat transport. First field tests of the method prove that the method is easily applicable under field conditions. These first field tests showed highly complex flow patterns with flow velocities from 1·8 to 4·9 cm min^?1 and flow directions from parallel to surface flow to opposite to surface flow. This suggests the need for a robust method to quantify hyporheic flow patterns in situ. Copyright © 2011 John Wiley & Sons, Ltd.