Stabilizing greenhouse gas concentrations at low levels: an assessment of reduction strategies and costs   总被引：2，自引：8，他引：2  

Detlef P. van Vuuren  Michel G. J. den Elzen  Paul L. Lucas  Bas Eickhout  Bart J. Strengers  Bas van Ruijven  Steven Wonink  Roy van Houdt 《Climatic change》2007,81(2):119-159

On the basis of the IPCC B2, A1b and B1 baseline scenarios, mitigation scenarios were developed that stabilize greenhouse gas concentrations at 650, 550 and 450 and – subject to specific assumptions – 400 ppm CO₂-eq. The analysis takes into account a large number of reduction options, such as reductions of non-CO₂ gases, carbon plantations and measures in the energy system. The study shows stabilization as low as 450 ppm CO₂-eq. to be technically feasible, even given relatively high baseline scenarios. To achieve these lower concentration levels, global emissions need to peak within the first two decades. The net present value of abatement costs for the B2 baseline scenario (a medium scenario) increases from 0.2% of cumulative GDP to 1.1% as the shift is made from 650 to 450 ppm. On the other hand, the probability of meeting a two-degree target increases from 0%–10% to 20%–70%. The mitigation scenarios lead to lower emissions of regional air pollutants but also to increased land use. The uncertainty in the cost estimates is at least in the order of 50%, with the most important uncertainties including land-use emissions, the potential for bio-energy and the contribution of energy efficiency. Furthermore, creating the right socio-economic and political conditions for mitigation is more important than any of the technical constraints.  相似文献   

Tropospheric parameters: combination studies based on homogeneous VLBI and GPS data     

Manuela Krügel  Daniela Thaller  Volker Tesmer  Markus Rothacher  Detlef Angermann  Ralf Schmid 《Journal of Geodesy》2007,81(6-8):515-527

The combination of tropospheric parameters derived from different space-geodetic techniques has not been of large interest in geodesy so far. However, due to the high correlation between station coordinates and tropospheric parameters, the latter should not be neglected in combinations. This paper deals with the comparison and combination of tropospheric parameters derived from global positioning system (GPS) and very long baseline interferometry (VLBI) observations stemming from a 15-day campaign of continuous VLBI observations in 2002 (CONT02). The observation data of both techniques were processed homogeneously to avoid systematic differences between the solutions. We compared the tropospheric estimates of GPS and VLBI at eight co-location sites and found a very good agreement in the temporal behavior of the tropospheric zenith path delays (ZPD), reflected by correlation factors up to 0.98. Following this, a combination of the tropospheric parameters was performed. We demonstrate that the combination of tropospheric parameters leads to a stabilization of combined station networks. This becomes visible in the improvement of the repeatabilities of the station height components. Furthermore, the potential use of independent data from water vapor radiometers (WVRs) to validate space-technique-derived tropospheric parameters was investigated. Correlation coefficients of 0.95 or better were estimated between the tropospheric parameters of WVR and GPS or VLBI. Additionally, the utility of the tropospheric parameters for validation of local tie vectors was investigated. Both tropospheric zenith delays and tropospheric gradients were found to be very suitable to validate the height component and the horizontal components of the local tie, respectively.  相似文献   

Reply to comments by Robert P. Comer     

Detlef Wolf 《Geophysical Journal International》1986,85(2):469-470

  相似文献   

Future aerosol emissions: a multi-model comparison     

Steven J. Smith  Shilpa Rao  Keywan Riahi  Detlef P. van Vuuren  Katherine V. Calvin  Page Kyle 《Climatic change》2016,138(1-2):13-24

  相似文献   

How climate metrics affect global mitigation strategies and costs: a multi-model study     

Mathijs J. H. M. Harmsen  Maarten van den Berg  Volker Krey  Gunnar Luderer  Adriana Marcucci  Jessica Strefler  Detlef P. Van Vuuren 《Climatic change》2016,135(2):203-209

  相似文献   

Granulometric study of the Hanaupah Fan,Death Valley,California     

Hillert Ibbeken  Detlef A. Warnke  Michael Diepenbroek 《地球表面变化过程与地形》1998,23(6):481-492

We applied new granulometric techniques to the various surfaces of the Hanaupah Fan, Death Valley, California, namely the Q1 surface, with an estimated age of 800–490 ka, the younger Q2 (170–105 ka) and Q3 (50–14 ka) surfaces, the <14 ka deposits of the incised channel, and to a (c. 14 ka) Lake Manly shoreline deposit at the northern periphery of the fan. We used these techniques to generate quantitative information on surface clast grain-size distributions, clast sphericity, roundness, and clast orientation to provide a data set that could be used to define fan-segment surfaces, and to help interpret fan genesis. Grain-size analyses were carried out by photo-sieving of 139 surface pictures, by petrographic identification of samples taken in the incised channel, and by identification and measuring of the largest clasts (1452 measurements) on the Q3 surface. The results show that all fan-segment surfaces, regardless of age, have similar size distributions, with a well-defined gravel mode of −2·3 to −3·0 phi, and are poorly to moderately sorted. Samples from the incised channel have distributions that are very similar to each other, regardless of distance from the apex, but display reduced sorting compared to the fan surfaces (which largely lack fines, perhaps from winnowing by secondary overland flow). Only the shoreline deposit is different from the other elements, showing a much narrower, well-defined gravel mode (−3·0 phi), and is moderately well sorted. Sphericity and roundness of clasts on all surfaces show only minor differences, similar to the other sedimentary parameters, indicating a remarkable homogeneity of the surfaces of the sediment body. In addition, measurements of the largest clasts (>100 cm long axis) on the Q3 surface showed no discernible trend either with radial distance or with rock type. These data suggest large depositional episodes that produce extensive sedimentary units without differentiation relative to distance from the source. Of the examined parameters, clast orientation is the best predictor of relative age of fan surfaces. Clast orientation in the main channel is bimodal, i.e. the long axes of clasts are either at right angles or parallel to transport direction. This bimodality disappears with increasing age, and the preferred orientation becomes unimodal (long clast axes normal to transport direction) on the Q1 surface. Although the causes of this change are still in debate, use of this parameter as a relative-age dating tool seems possible. © 1998 John Wiley & Sons, Ltd.  相似文献   

Temporal Gravity Variations near Shrinking Vatnajökull Ice Cap, Iceland     

Wolfgang R. Jacoby  Oliver Hartmann  Herbert Wallner  Peter L. Smilde  Stefan Bürger  Lars E. Sjöberg  Sigurdur Erlingsson  Detlef Wolf  Volker Klemann  Ingo Sasgen 《Pure and Applied Geophysics》2009,166(8-9):1283-1302

Repeated gravity measurements were carried out from 1991 until 1999 at sites SE of Vatnajökull, Iceland, to estimate the mass flow and deformation accompanying the shrinking of the ice cap. Published GPS data show an uplift of about 13 ± 5 mm/a near the ice margin. A gravity decrease of –2 ± 1 μGal/a relative to the Höfn base station, was observed for the same sites. Control measurements at the Höfn station showed a gravity decrease of –2 ± 0.5 µGal/a relative to the station RVIK 5473 at Reykjavík (about 250 km from Höfn). This is compatible, as a Bouguer effect, with a 10 ± 3 mm/a uplift rate of the IGS point at Höfn and an uplift rate of ~20 mm/a near the ice margin. Although the derived gravity change rates at individual sites have large uncertainties, the ensemble of the rates varies systematically and significantly with distance from the ice. The relationship between gravity and elevation changes and the shrinking ice mass is modelled as response to the loading history. The GPS data can be explained by 1-D modelling (i.e., an earth model with a 15-km thick elastic lithosphere and a 7·10¹⁷ Pa·s asthenosphere viscosity), but not the gravity data. Based on 2-D modelling, the gravity data favour a low-viscosity plume in the form of a cylinder of 80 km radius and 10¹⁷ to 10¹⁸ Pa·s viscosity below a 6 km-thick elastic lid, embedded in a layered PREM-type earth, although the elevation data are less well explained by this model. Strain-porosity-hydrology effects are likely to enhance the magnitude of the gravity changes, but need verification by drilling. More accurate data may resolve the discrepancies or suggest improved models.  相似文献   

A revised relaxation-time spectrum for Fennoscandia   总被引：1，自引：0，他引：1  

Karin Wieczerkowski  Jerry X. Mitrovica  & Detlef Wolf 《Geophysical Journal International》1999,139(1):69-86

  相似文献   

The Hanaupah-Fan shoreline deposit at Tule Spring, a gravelly shoreline deposit of Pleisticene Lake Manly, Death Valley, California, USA     

Hillert Ibbeken  Detlef Warnke 《Journal of Paleolimnology》2000,23(4):439-447

The Hanaupah-Fan Shoreline Deposit (HSD) is an as yet undescribed occurrence of shoreline sediments of late Pleistocene Lake Manly in Death Valley, California. It is located in the southern part of Death Valley, at the northeastern periphery of Hanaupah Fan. The HSD is a gently sloping, WSW-ENE elongated ridge, about 600 m long, 165 m wide and 8 m high. Its surface extends from -12 to +28 m in elevation, i.e. it has a vertical range of 40 m. We interpret the deposit as a sediment body that extended from the Hanaupah Fan east into the lake. Rising lake level, and waves approaching both from the north and south eroded fan materials, and produced a sediment body with a complex architecture. Fetch for waves approaching from either direction was about 40 km. The sedimentary inventory consists of cross-stratified gravel beds of various size ranges, dipping towards the north, south, and east, and of horizontal berm gravel beds, and horizontal silt layers. A discordant gravel layer covers the entire surface of the deposit, probably produced by wave action during the last phase of lake regression. This uniform gravel layer forms a surface that is distinctly different from the surrounding fan surfaces. It is relatively fine grained, much better sorted, and densely packed. Rock varnish is very well developed, and imparts a dark color to the surface, which makes it easily recognizable on aerial photographs. No absolute age date is available as yet, but circumstantial evidence places the formation of the deposit at the peak of marine isotope stage 2 (Wisconsinan/Weichsellian glacial maximum)  相似文献   

Cross-Level Inference in Political Science     

Detlef F. Sprinz 《Climatic change》2000,44(3):393-408

Political Science research encounters inferences across levels of analysis; however, they are fraught with challenges. After introducing voting examples of aggregation bias, problems posed by aggregation bias are summarized more generally. Subsequently, the article reviews the major methodological approaches to overcome aggregation bias and to solve the ecological inference (disaggregation) problem. The article highlights the possibility that aggregation bias may lead governments to accept (or reject) international climate agreements when negotiating as blocs of countries as compared to the distribution of the preferences of all countries involved in the negotiations.  相似文献