Scenarios in Global Environmental Assessments: Key characteristics and lessons for future use     

Detlef P. van Vuuren  Marcel T.J. Kok  Bastien Girod  Paul L. Lucas  Bert de Vries 《Global Environmental Change》2012,22(4):884-895

Over the last 10 years a large set of global environmental assessment studies has been published that include scenario projections. Comparison of these studies shows that there is actually a limited set of scenario families that form the basis of many scenarios used in different environmental assessments. Mapping these scenario families allow a simpler comparison across the different assessments. The fact that many assessments can be positioned within these families gives some confidence of their relevance. It is also noticeable that several recent assessments have been focusing on more focussed policy-scenarios as variant to a single baseline. This is partly a response to a different stage in the policy-making process. While there are clear advantages of both categories of scenarios (explorative scenarios and baseline/policy variants), it might be important to test the robustness of scenario outcomes of the policy-scenario approach against the different storyline scenario-families identified in this paper.  相似文献   

The IMO Virtual Meteor Observatory (VMO): Architectural Design     

Detlef Koschny  Jonathan Mc Auliffe  Geert Barentsen 《Earth, Moon, and Planets》2008,102(1-4):247-252

This paper describes the progress on the Virtual Meteor Observatory (VMO), a database which is being developed at ESA/RSSD to store video meteor observations and their derived orbits. The VMO was triggered by a discussion which took place at the first Meteor Orbit Determination (MOD) workshop in Roden, The Netherlands, in September 2006. Representatives of 15 groups working on the determination of meteor orbits and working with the resulting orbits discussed the design and implementation of a database which would combine different meteor orbit datasets. From this the concept of the VMO was born, which will, in the long run, allow accessing meteor observations via the internet. In the beginning, it will focus on meteor orbit data obtained with video systems. This paper presents the architectural design of the database as it has been defined in the meantime.  相似文献   

Toward Improved Estimation of the Dynamic Topography and Ocean Circulation in the High Latitude and Arctic Ocean: The Importance of GOCE     

J. A. Johannessen  R. P. Raj  J. E. Ø. Nilsen  T. Pripp  P. Knudsen  F. Counillon  D. Stammer  L. Bertino  O. B. Andersen  N. Serra  N. Koldunov 《Surveys in Geophysics》2014,35(3):661-679

The Arctic plays a fundamental role in the climate system and shows significant sensitivity to anthropogenic climate forcing and the ongoing climate change. Accelerated changes in the Arctic are already observed, including elevated air and ocean temperatures, declines of the summer sea ice extent and sea ice thickness influencing the albedo and CO₂ exchange, melting of the Greenland Ice Sheet and increased thawing of surrounding permafrost regions. In turn, the hydrological cycle in the high latitude and Arctic is expected to undergo changes although to date it is challenging to accurately quantify this. Moreover, changes in the temperature and salinity of surface waters in the Arctic Ocean and Nordic Seas may also influence the flow of dense water through the Denmark Strait, which are found to be a precursor for changes in the Atlantic meridional overturning circulation with a lead time of around 10 years (Hawkins and Sutton in Geophys Res Lett 35:L11603, 2008). Evidently changes in the Arctic and surrounding seas have far reaching influences on regional and global environment and climate variability, thus emphasizing the need for advanced quantitative understanding of the ocean circulation and transport variability in the high latitude and Arctic Ocean. In this respect, this study combines in situ hydrographical data, surface drifter data and direct current meter measurements, with coupled sea ice–ocean models, radar altimeter data and the latest GOCE-based geoid in order to estimate and assess the quality, usefulness and validity of the new GOCE-derived mean dynamic topography for studies of the ocean circulation and transport estimates in the Nordic Seas and Arctic Ocean.  相似文献   

The feasibility of low CO₂ concentration targets and the role of bio-energy with carbon capture and storage (BECCS)     

Christian Azar  Kristian Lindgren  Michael Obersteiner  Keywan Riahi  Detlef P. van Vuuren  K. Michel G. J. den Elzen  Kenneth M?llersten  Eric D. Larson 《Climatic change》2010,100(1):195-202

The United Nations Framework Convention on Climate Change (UNFCCC 1992) calls for stabilization of atmospheric greenhouse gas (GHG) concentrations at a level that would prevent dangerous anthropogenic interference with the climate system. We use three global energy system models to investigate the technological and economic attainability of meeting CO₂ concentration targets below current levels. Our scenario studies reveal that while energy portfolios from a broad range of energy technologies are needed to attain low concentrations, negative emission technologies—e.g., biomass energy with carbon capture and storage (BECCS)—significantly enhances the possibility to meet low concentration targets (at around 350 ppm CO₂).  相似文献   

Regional abatement action and costs under allocation schemes for emission allowances for achieving low CO<Subscript>2</Subscript>-equivalent concentrations   总被引：1，自引：0，他引：1  

Michel G. J. den Elzen  Paul L. Lucas  Detlef P. van Vuuren 《Climatic change》2008,90(3):243-268

This paper assesses regional abatement action and costs for two scenarios in which atmospheric greenhouse gas concentrations stabilise at 450 and 550 ppm CO₂-equivalent. It evaluates two allocation schemes: Multi-Stage and Contraction & Convergence. It was found that abatement costs as percentages of GDP vary significantly by region, with high costs for the Middle East and the former Soviet Union, medium costs for the OECD regions and low costs or even gains for (other) developing regions. In addition to the abatement costs they incur, fossil-fuel-exporting regions are also likely to be affected by losses of coal and oil exports while the former Soviet Union and South America could experience increased bio-energy exports. Especially in the former Soviet Union and Asia, non-CO₂ abatement options are important in the short term in reducing their emissions. Carbon capture and storage, energy efficiency improvements, bio-energy use and the use of renewables dominate reductions in the long term in all regions. It was found that the regional costs are influenced more by the assumed stabilisation level and baseline scenario than by the allocation regimes explored or the assumptions for different technologies.  相似文献   

Determination of Forty Two Major and Trace Elements in USGS and NIST SRM Glasses by Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry   总被引：39，自引：0，他引：39  

Shan Gao  Xiaomin Liu  Honglin Yuan  Bodo Hattendorf  Detlef Günther  Liang Chen  Shenhong Hu 《Geostandards and Geoanalytical Research》2002,26(2):181-196

Forty two major (Na, Mg, Ti and Mn) and trace elements covering the mass range from Li to U in three USGS basalt glass reference materials BCR‐2G, BHVO‐2G and BIR‐1G were determined using laser ablation‐inductively coupled plasma‐mass spectrometry. Calibration was performed using NIST SRM 610 in conjunction with internal standardisation using Ca. Determinations were also made on NIST SRM 612 and 614 as well as NIST SRM 610 as unknown samples, and included forty five major (Al and Na) and trace elements. Relative standard deviation (RSD) of determinations was below 10% for most elements in all the glasses under investigation. Consistent exceptions were Sn and Sb in BCR‐2G, BHVO‐2G and BIR‐1G. For BCR‐2G, BHVO‐2G and BIR‐1G, clear negative correlations on a logarithmic scale exist between RSD and concentration for elements lower than 1500 μg g^‐1 with logarithmic correlation coefficients between ‐0.75 and ‐0.86. There is also a clear trend of increasing RSD with decreasing concentration from NIST SRM 610 through SRM 612 to SRM 614. These suggest that the difference in the scatter of apparent element concentrations is not due to chemical heterogeneity but reflects analytical uncertainty. It is concluded that all these glasses are, overall, homogeneous on a scale of 60 μm. Our first results on BHVO‐2G and BIR‐1G showed that they generally agreed with BHVO‐2/BHVO‐1 and BIR‐1 within 10% relative. Exceptions were Nb, Ta and Pb in BHVO‐2G, which were 14‐45% lower than reference values for BHVO‐2 and BHVO‐1. Be, Ni, Zn, Y, Zr, Nb, Sn, Sb, Gd, Tb, Er, Pb and U in BIR‐1G were also exceptions. However, of these elements, Be, Nb, Sn, Sb, Gd, Tb, Pb and U gave results that were consistent within an uncertainty of 2s between our data and BIR‐1 reference values. Results on NIST SRM 612 agreed well with published data, except for Mg and Sn. This was also true for elements with m/z 85 (Rb) in the case of NIST SRM 614. The good agreement between measured and reference values for Na and Mg in BCR‐2G, BHVO‐2G and BIR‐1G, and for Al and Na in NIST SRM 610, 612 and 614 up to concentrations of at least several weight percent (which were possible to analyse due to the dynamic range of 10⁸) indicates the suitability of this technique for major, minor and trace element determinations.  相似文献   

Tracing the history of submarine hydrothermal inputs and the significance of hydrothermal hafnium for the seawater budget—a combined Pb-Hf-Nd isotope approach     

Tina van de Flierdt  Martin Frank  James R Hein  Detlef Günther 《Earth and Planetary Science Letters》2004,222(1):259-273

Secular variations in the Pb isotopic composition of a mixed hydrogenous-hydrothermal ferromanganese crust from the Bauer Basin in the eastern Equatorial Pacific provide clear evidence for changes in hydrothermal contributions during the past 7 Myr. The nearby Galapagos Rise spreading center provided a strong hydrothermal flux prior to 6.5 Ma. After 6.5 Ma, the Pb became stepwise more radiogenic and more similar to Equatorial Pacific seawater, reflecting the westward shift of spreading to the presently active East Pacific Rise (EPR). A second, previously unrecognized enhanced hydrothermal period occurred between 4.4 and 2.9 Ma, which reflects either off-axis hydrothermal activity in the Bauer Basin or a late-stage pulse of hydrothermal Pb from the then active, but waning Galapagos Rise spreading center.Hafnium isotope time-series of the same mixed hydrogenous-hydrothermal crust show invariant values over the past 7 Myr. Hafnium isotope ratios, as well as Nd isotope ratios obtained for this crust, are identical to that of hydrogenous Equatorial Pacific deep water crusts and clearly indicate that hydrothermal Hf, similar to Nd, does not travel far from submarine vents. Therefore, we suggest that hydrothermal Hf fluxes do not contribute significantly to the global marine Hf budget.  相似文献   

Azide as a tool to evaluate sediment trap behaviour     

Ulrich Lundgreen  Joanna Waniek  Detlef E. Schulz-Bull  Jan C. Duinker 《Ocean Dynamics》1997,49(1):57-69

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Sea-Surface Temperatures and the History of Monsoon Upwelling in the Northwest Arabian Sea during the Last 500,000 Years     

Kay-Christian Emeis  David M. Anderson  Heidi Doose  Dick Kroon  Detlef Schulz-Bull 《Quaternary Research》1995,43(3)

Arabian Sea sediments record changes in the upwelling system off Arabia, which is driven by the monsoon circulation system over the NW Indian Ocean. In accordance with climate models, and differing from other large upwelling areas of the tropical ocean, a 500,000-yr record of productivity at ODP Site 723 shows consistently stronger upwelling during interglaciations than during glaciations. Sea-surface temperatures (SSTs) reconstructed from the alkenone unsaturation index (U^K′₃₇) are high (up to 27°C) during interglaciations and low (22-24°C) during glaciations, indicating a glacial-interglacial temperature change of >3°C in spite of the dampening effect of enhanced or weakened upwelling. The increased productivity is attributed to stronger monsoon winds during interglacial times relative to glacial times, whereas the difference in SSTs must be unrelated to upwelling and to the summer monsoon intensity. The winter (NE) monsoon was more effective in cooling the Arabian Sea during glaciations then it is now.  相似文献   

Eddy fluxes of CO2, water vapor,and sensible heat over a deciduous forest   总被引：12，自引：0，他引：12  

Shashi B. Verma  Dennis D. Baldocchi  Dean E. Anderson  Detlef R. Matt  Robert J. Clement 《Boundary-Layer Meteorology》1986,36(1-2):71-91

Fluxes of CO₂, latent heat and sensible heat were measured above a fully-leafed deciduous forest in eastern Tennessee with the eddy correlation technique. These are among the first reported observations over such a surface. The influences of solar radiation, vapor pressure deficit and the aerodynamic and canopy resistances on these mass and energy exchanges are examined. Following a concept introduced by McNaughton and Jarvis (1983), examination of our data suggest that the water vapor exchange of a deciduous forest is not as strongly coupled with net radiation as is that of agricultural crops. The degree of decoupling is smaller than in the case of a coniferous forest. This difference may be attributable in part to the greater aerodynamic resistance to water vapor transfer in a deciduous forest. It appears that the concept of decoupling may be extended to the CO₂ exchange of a deciduous forest as well.Published as Paper No. 7832, Journal Series, Nebraska Agricultural Research Division. ATDD Contribution No. 85-17.  相似文献