4,050 research outputs found
Toward a Smart EU Energy Policy: Rationale and 22 Recommendations
We are in desperate need of an EU Energy Policy. The facts are that, yes, there is indeed an EU Energy Policy. It is a policy based on a vision, a vision with three components. The policy is aiming for “markets, competition and efficiency”, it is equally focussing on “a sustainable energy economy”, and thirdly, it wants to “secure the EU’s energy supply”. Three objectives, three separate action lines. Balancing the three objectives in an integrated approach is challenging and difficult. To what extent is the market approach consistent with the other two policy packages? What impact does a climate package with tradable emission rights and non-tradable targets for green energy have on the market designs for gas and electricity? Are the necessary investments in new pipes and wires for securing our energy supplies sufficiently coming under the prevailing regulatory framework? Or, to put it differently; are we smart enough in the way in which we are making implementing steps in order to meet our stated objectives? Our paper ends with a proposed new vision and a set of 22 recommendations to the new European Commission.energy policy; climate change; security of energy supply; EU internal marke
Estimation of the annual organic carbon yield related to carbonated rocks chemical weathering : implications for the global organic carbon cycle understanding.
The aim of this paper is to propose an initial estimation of the annual organic matter yield induced by chemical weathering of carbonates and shales, considering their global surface at outcrop and their organic matter content. The calculation also uses data on river fluxes resulting from carbonate rocks and shales weathering in major world watersheds, published by numerous authors. The results obtained from the studied watersheds have then been extrapolated to a global scale. Despite rather large uncertainty to such an approach, the calculated value of ca. 0.1 Gt implies that the annual organic carbon yield related to carbonates and shales chemical weathering might be a non-negligible component of the global carbon cycle. The individual contributions of different watersheds necessarily depend on the organic matter content of altered rocks. They are also obviously controlled by climatic parameters. The calculated yields do not constitute a direct supply to soils and rivers because of mineralisation when organic carbon is brought in contact with the atmosphere. Even so, the release of fossil organic matter would have implications for the global carbon cycle through the efficiency of the global chemical weathering as a carbon sink. Whatever the chosen hypothesis, the results of this study suggest that the recycled organic yield is a neglected component in the global organic carbon cycle assessment. Because it exists and, in addition, because it might represent a non-negligible carbon pool, fossil organic carbon deserves to be taken into account for a better evaluation of the organic stocks in soils and rivers presently only based on climatic data and current vegetal production
Microbial mat development and dolomite formation under pre-evaporitic conditions during the Atlantic in a temperate area: The Sarliève Lake (French Massif Central)
International audienceThe Sarliève marsh in the Limagne plain, in the heart of the French Massif Central, functioned as an endorheic lake during the Late Glacial and the Early and Middle Holocene. During the Late Boreal and the Atlantic it experienced drastic lowering of the water level as a result of dry and warm climatic episodes. Then, pre-evaporitic conditions triggered the deposition of sediment rich in organic matter (OM) and in carbonates including dolomite. Fifty-one samples from a ca. 1.8 m sediment core section covering the period were analysed using Rock-Eval pyrolysis and gas chromatography-mass spectrometry (GC-MS). Throughout the interval, the OM content remained notable to high [up to 13.35% total organic carbon (TOC)] and of good quality as indicated by low oxygen index (OI) values (<200 mg CO2 g−1 TOC) and high hydrogen index (HI) values (160-660 mg HC g−1) which, as a rule, increased with increasing TOC content. In contrast to the acid fractions, which sometimes contained notable proportions of n-C16 or n-C18 fatty acids (FAs; analysed as the methyl esters, FAMEs), the neutral fractions were almost devoid of low molecular weight compounds. The latter were probably biodegraded during early diagenesis. Conversely, high molecular weight compounds were abundant in both fractions and were dominated by n-alkanols, n-alkanes, steroids and hopanoids in the neutrals and even numbered FAs and hopanoids in the acid fractions. The hopanoids were dominated by regular bishomohopanoids, accompanied by 2-methylated bishomohopanoids, as well as by unidentified bishomohopanoids with methylation in either the D or E ring. These distributions, typical for bacteria, provide support for previous hypotheses on the contribution of microorganisms to the studied record and for providing conditions for the precipitation and growth of dolomite and other pristine carbonate minerals [Bréheret, J.G., Fourmont, A., Macaire, J.J., Négrel, Ph., 2008. Microbially mediated carbonates in the Holocene lacustrine deposits of the Marais de Sarliève (French Massif Central) testify to the evolution of a restricted environment. Sedimentology 55, 557-578]. The preservation of the compounds was probably ensured by persistent reducing conditions during diagenesis, despite variable climatic conditions and related changes in lake level and sedimentation rate. Comparable distributions of hopanoic acids and hopanols, as well as roughly parallel variation with depth in the corresponding components in both fractions, strongly suggest that all the hopanoids derive from the same microbial precursors, slight shifts in the acid/alcohol ratio being governed by limited changes in redox conditions during early diagenesis
A Review of Low Frequency Electromagnetic Wave Phenomena Related to Tropospheric-Ionospheric Coupling Mechanisms
Investigation of coupling mechanisms between the troposphere and the ionosphere requires a multidisciplinary approach involving several branches of atmospheric sciences, from meteorology, atmospheric chemistry, and fulminology to aeronomy, plasma physics, and space weather. In this work, we review low frequency electromagnetic wave propagation in the Earth-ionosphere cavity from a troposphere-ionosphere coupling perspective. We discuss electromagnetic wave generation, propagation, and resonance phenomena, considering atmospheric, ionospheric and magnetospheric sources, from lightning and transient luminous events at low altitude to Alfven waves and particle precipitation related to solar and magnetospheric processes. We review in situ ionospheric processes as well as surface and space weather phenomena that drive troposphere-ionosphere dynamics. Effects of aerosols, water vapor distribution, thermodynamic parameters, and cloud charge separation and electrification processes on atmospheric electricity and electromagnetic waves are reviewed. We also briefly revisit ionospheric irregularities such as spread-F and explosive spread-F, sporadic-E, traveling ionospheric disturbances, Trimpi effect, and hiss and plasma turbulence. Regarding the role of the lower boundary of the cavity, we review transient surface phenomena, including seismic activity, earthquakes, volcanic processes and dust electrification. The role of surface and atmospheric gravity waves in ionospheric dynamics is also briefly addressed. We summarize analytical and numerical tools and techniques to model low frequency electromagnetic wave propagation and solving inverse problems and summarize in a final section a few challenging subjects that are important for a better understanding of tropospheric-ionospheric coupling mechanisms
Toward a Smart EU Energy Policy: Rationale and 22 Recommendation
QM-AI-10-003-EN-C (print)/QM-AI-10-003-EN-N (online)In the spring of 2007, the European Council agreed on a policy vision with three components: the green component (to promote a sustainable energy economy), the market component (to enhance efficiency and competition) and the security of supply component (to secure the EU’s energy supply). With regard to these three components, distinct implementing paths and action lines were developed. The existence of separate implementing paths entails some coordination issues. Coordination is necessary here to guarantee that the three action lines are integrated into a consistent EU Energy Policy. EU Energy policy needs to get smarter and align the incentives deriving from the three components to produce an integrated vision that moves beyond 2020. 22 policy recommendations can then be formulated for the most relevant energy-related issues which the EU is facing nowadays
Flux et crues singulières d'un petit cours d'eau andin ou les effets pervers de l'urbanisation
Sur un petit bassin de haute montagne (4000 m), situé dans les Andes à proximité de La Paz, la canalisation des "rios" en vue de gagner des terrains urbanisables, n'a guère modifié, en termes de bilan annuel, les régimes hydrologiques mais a eu des conséquences inattendues sur leur comportement en crue. Au delà d'un certain débit, bien inférieur au débit maximum décennal, apparaissent des vagues, parfois plus hautes que le canal, qui déferlent à près de 10 m/s, endommageant sur leur passage ponts et parois de l'ouvrage, et provoquant d'importants débordements en zone urbaine. Plus en amont, dans le lit naturel, l'écoulement demeure stable. Plusieurs hypothèses sont avancées pour expliquer ce phénomène. (Résumé d'auteur
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