3 resultados para imperative
em Publishing Network for Geoscientific
Resumo:
Arctic permafrost may be adversely affected by climate change in a number of ways, so that establishing a world-wide monitoring program seems imperative. This thesis evaluates possibilities for permafrost monitoring at the example of a permafrost site on Svalbard, Norway. An energy balance model for permafrost temperatures is developed that evaluates the different components of the surface energy budget in analogy to climate models. The surface energy budget, consisting of radiation components, sensible and latent heat fluxes as well as the ground heat flux, is measured over the course of one year, which has not been accomplished for arctic land areas so far. A considerable small-scale heterogeneity of the summer surface temperature is observed in long-term measurements with a thermal imaging system, which can be reproduced in the energy balance model. The model can also simulate the impact of different snow depths on the soil temperature, that has been documented in field measurements. Furthermore, time series of terrestrial surface temperature measurements are compared to satellite-borne measurements, for which a significant cold-bias is observed during winter. Finally, different possibilities for a world-wide monitoring scheme are assessed. Energy budget models can incorporate different satellite data sets as training data sets for parameter estimation, so that they may constitute an alternative to purely satellite-based schemes.
Resumo:
Public participation is an integral part of Environmental Impact Assessment (EIA), and as such, has been incorporated into regulatory norms. Assessment of the effectiveness of public participation has remained elusive however. This is partly due to the difficulty in identifying appropriate effectiveness criteria. This research uses Q methodology to discover and analyze stakeholder's social perspectives of the effectiveness of EIAs in the Western Cape, South Africa. It considers two case studies (Main Road and Saldanha Bay EIAs) for contextual participant perspectives of the effectiveness based on their experience. It further considers the more general opinion of provincial consent regulator staff at the Department of Environmental Affairs and the Department of Planning (DEA&DP). Two main themes of investigation are drawn from the South African National Environmental Management Act imperative for effectiveness: firstly, the participation procedure, and secondly, the stakeholder capabilities necessary for effective participation. Four theoretical frameworks drawn from planning, politics and EIA theory are adapted to public participation and used to triangulate the analysis and discussion of the revealed social perspectives. They consider citizen power in deliberation, Habermas' preconditions for the Ideal Speech Situation (ISS), a Foucauldian perspective of knowledge, power and politics, and a Capabilities Approach to public participation effectiveness. The empirical evidence from this research shows that the capacity and contextual constraints faced by participants demand the legislative imperatives for effective participation set out in the NEMA. The implementation of effective public participation has been shown to be a complex, dynamic and sometimes nebulous practice. The functional level of participant understanding of the process was found to be significantly wide-ranging with consequences of unequal and dissatisfied stakeholder engagements. Furthermore, the considerable variance of stakeholder capabilities in the South African social context, resulted in inequalities in deliberation. The social perspectives revealed significant differences in participant experience in terms of citizen power in deliberation. The ISS preconditions are highly contested in both the Saldanha EIA case study and the DEA&DP social perspectives. Only one Main Road EIA case study social perspective considered Foucault's notion of governmentality as a reality in EIA public participation. The freedom of control of ones environment, based on a Capabilities approach, is a highly contested notion. Although agreed with in principle, all of the social perspectives indicate that contextual and capacity realities constrain its realisation. This research has shown that Q method can be applied to EIA public participation in South Africa and, with the appropriate research or monitoring applications it could serve as a useful feedback tool to inform best practice public participation.
Resumo:
In the light of rapidly diminishing sea ice cover in the Arctic during the present atmospheric warming, it is imperative to study the distribution of sea ice in the past in relation to rapid climate change. Here we focus on glacial millennial scale climatic events (Dansgaard/Oeschger events) using the new sea ice proxy IP25 in combination with phytoplankton proxy data and quantification of diatom species in a record from the SE Norwegian Sea. We demonstrate that expansion and retreat of sea ice varied consistently in pace with the rapid climate changes 90 ka to present, and with this present the first IP25 sea ice proxy record resolving the D/O cyclicity going back in time into Marine Isotope Stage 5a. Sea ice retreated abruptly at the start of warm interstadials, but spread rapidly during the cooling phase of the interstadials and became near-perennial and perennial during cold stadials and Heinrich events, respectively. Low salinity surface water and the sea ice edge spread to the Greenland-Scotland Ridge, and during the largest Heinrich events, probably far into the Atlantic Ocean.