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991.
In recent years, climate policy under the United Nations system has been characterized by bottom-up, national approaches to climate mitigation. This raises concerns about the overall effectiveness of these mitigation policies, for example due to carbon leakage. In response to these concerns, authors have repeatedly suggested that policy makers consider a consumption-based climate policy approach. We analyze the potential merits of a switch to a consumption-based policy approach using the criteria of justice and economic efficiency. We argue that emissions must be understood as being contributed by both, consumers and producers, but that this fact does not by itself settle the question whether consumption or production ought to serve as the climate policy base. Rather, the perspective of justice necessitates an analysis of the distributive consequences of switching from a production- to a consumption-based policy.We find that both (global) cost-effectiveness and justice can be improved if the unilateral climate policies of industrialized countries are based on emissions from consumption. There are preconditions, however, the switch in the policy base must be accompanied by clean technology transfer, and if implemented by border carbon adjustments, import tax revenues need to be channeled to developing and emerging economies. We further show that in such a setting, export rebates are of minor importance for efficiency and justice.  相似文献   
992.
Many developed countries in Annex B of the Kyoto Protocol have been able to report decreasing emissions, and some have officially fulfilled their CO2 reduction commitments. This is in part because current reporting and regulatory regimes allow these countries to displace emissions intensive production offshore. Using a new highly detailed account of emissions embodied in international trade we investigate this phenomenon of emissions leakage. We independently confirm previous findings that adjusting for trade, developed countries emissions have increased, not decreased. We find that the sectors successfully holding or lowering their domestic emissions are often the same as those increasing their imports of embodied CO2. We also find that the fastest growing flow paths of embodied CO2 largely originate outside the Kyoto Annex B signatory nations. Finally, we find that historically the same phenomenon of emissions displacement has already occurred for air pollution, with the result that despite aggressive legislation in major emitters total global air pollution emissions have increased. If regulatory policies do not account for embodied imports, global emissions are likely to rise even if developed countries emitters enforce strong national emissions targets.  相似文献   
993.
The present study focuses on the impact of ocean state (i.e., salinity and temperature) updates on the sea-ice analysis and short-term forecast in an assimilative sea ice–ocean coupled system. A relatively simple sea-ice assimilation scheme was applied to the sea ice–ocean coupled North Atlantic Nucleus for European Modelling of the Ocean (NEMO) system with a focus on the Canadian East Coast. In this assimilation scheme the ocean state was updated directly based on the correlations between the model's sea-ice concentration and the upper ocean salinity and temperature. These correlations were based on a limited time ensemble generated by applying random perturbations to the atmospheric forcing fields. High deviations in the sea-ice conditions were found along the ice edge, implying that the sea-ice edge position is sensitive to small atmospheric forcing variations. Assimilation runs with and without ocean state updates (i.e., sea-ice concentration nudging) were conducted and compared for the winter of 2002. Both continuous and intermittent assimilation schemes were examined. In a continuous sea-ice assimilation experiment, the ocean direct update is unnecessary. When the sea-ice updates are introduced intermittently the ocean state has to be altered to accommodate them, or they will be rapidly diminished by the model's dynamics. The correlations between sea-ice concentration and ocean salinity and temperature based on the first 15 days of January were used for corrections during the entire winter season when, in addition to thermodynamic processes, dynamic processes are responsible for, and even dominate, sea-ice evolution on the Labrador and Newfoundland shelves. This was an adequate choice as was demonstrated by the results of the study which showed that the experiments with ocean state adjustments generated more accurate short-term sea-ice forecasts.  相似文献   
994.
Existing research on people–place dynamics often focuses on either physical environment or social dimensions, but many theoretical models posit that both factors are important. I argue that rural communes provide unique settings to explore both social and environmental aspects of place. Based on qualitative interview data with members of two communes, I address emotional connection to the land, changing social relationships over time, and the interplay of physical and social aspects of place. Results demonstrate how the connections to land and social ties are both prevalent. However, social interaction has decreased while commitment to sharing and protecting the physical environment has endured.  相似文献   
995.
996.
In this study, we developed a prior-knowledge-based spectral mixture analysis (PKSMA) to map impervious surfaces by using endmembers derived separately for high- and low-density urban regions. First, an urban area was categorized into high- and low-density urban areas, using a multi-step classification method. Next, in high-density urban areas that were assumed to have only vegetation and impervious surfaces (ISs), the vegetation–impervious model (V–I) was used in a spectral mixture analysis (SMA) with three endmembers: vegetation, high albedo, and low albedo. In low-density urban areas, the vegetation–impervious–soil model (V–I–S) was used in an SMA analysis with four endmembers: high albedo, low albedo, soil, and vegetation. The fraction of IS with high and low albedo in each pixel was combined to produce the final IS map. The root mean-square error (RMSE) of the IS map produced using PKSMA was about 11.0%, compared to 14.52% only using four-endmember SMA. Particularly in high-density urban areas, PKSMA (RMSE = 6.47%) showed better performance than four-endmember (15.91%). The results indicate that PKSMA can improve IS mapping compared to traditional SMA by using appropriately selected endmembers and is particularly strong in high-density urban areas.  相似文献   
997.
Abstract

Most projects which involve planning of rural areas and towns in developing countries require maps, but many of these countries do not have sufficient large-scale mapping suitable for this purpose, or maps which are up-to-date. With environmental-friendly projects becoming highly desirable, up-to-date and accurate maps are vital. As most large scale mapping projects require technical assistance, this paper discusses aid agreements with donor countries. These opportunities could be of benefit to private entrepreneurs. This paper also examines the project management approach for introducing mapping projects to developing countries. It makes special reference to a large mapping project in Zimbabwe in which the author was personally involved.  相似文献   
998.
In this study, the authors inter-compared the performance of three satellite-rainfall products in representing the diurnal cycle of rain occurrence and rain rate over the Nile basin in eastern Africa. These products are the real time (RT) and post-real-time (PRT) (bias adjusted) versions of Tropical Rainfall Measuring Mission (TRMM) and other sources product known as TRMM-3B42 and the National Oceanographic and Atmospheric Administration Climate Prediction Center (NOAA-CPC) product which is based on the CPC morphing technique (CMORPH). The rainfall diurnal cycles are re-produced using these products with specific focus on assessing effects of geographic location and topographic features. The performance of the satellite products in representing rainfall diurnal cycle shows large variation over the Nile basin. The products overestimate rain occurrence over the lakes, islands, and shores and underestimate occurrence over mountain tops. Overall, CMORPH performs better than TRMM-3B42 RT and TRMM-3B42 PRT in capturing the diurnal cycle of rain rate in Lake Tana basin. However, the difference between the two products is very small for Lake Victoria basin, where both products perform more favorably. Over most of the Nile basin areas, the use of fine versus coarse temporal and spatial resolution of the CMORPH product showed large differences for diurnal cycle of rain occurrence than that of rain rate. Results also show that the bias adjustment of TRMM-3B42 product does not necessarily bring improvements probably since the adjustments are not performed based on local rain gauge data.  相似文献   
999.
Tree rings have been used to reconstruct the occurrence of debris flows and other mass movements. Identification of past activity was typically based on the presence of growth anomalies in trees, with a focus on scars, stem tilting, trunk burial or apex decapitation. Clear guidelines have been missing so far and the dating of events has only rarely been based on thresholds so as to distinguish signal from noise. In a similar way, the spatial distribution of affected trees has not normally been considered in mass movement reconstructions, and was at best used as a subjective exclusion factor. This study therefore aims at improving dating quality of and reducing noise in debris-flow time series. Based on a dataset of 803 increment cores (385 trees) affected by debris flows, we reconstruct event histories using (i) a classical experts' approach, (ii) a weighted index (Wit) of responding trees as well as (iii) Moran's I and Getis–Ord Local Gi indices. We identify similarities and differences in results and then investigate subsets of the tree-ring sample to define ideal sampling positions on debris-flow cones and guidelines for sample depth.  相似文献   
1000.
Recent viewpoints concerning the state of research in transport geography have touched on the issue of insularity and the need to bridge the divide between the largely spatial–analytical or quantitative research in transport geography and the critical or qualitative research prevalent in urban, economic, and most other subfields of human geography. Transport geography has been criticized by some for being a quiet corner of our discipline that has lost its centrality largely because it remains within the analytical framework of the 1960s. This article explores these sentiments by reexamining recent transport-oriented research in highly cited geography journals to assess the degree to which the qualitative–quantitative divide exists within transport geography and between transport and other subfield in human geography, as well as to explore issues of productivity and centrality of transport-oriented research in geography. Results indicate that geographical research involving transport topics is much more prevalent and reflects a wider range of epistemological and methodological approaches than is frequently assumed. Nevertheless, there is still a considerable divide between “mainstream” transport geography and other human geographical research that necessitates much more interaction between transport and other subfields and greater incorporation of alternative research approaches within the mainstream of transport geography. To that end, we propose a preliminary critical transport geography research agenda that is open to a variety of methodological approaches, including quantitative analysis.  相似文献   
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