850 resultados para Global change and terrestrial ecosystems
Resumo:
Nitrous oxide (N2O) is an important greenhouse gas and ozone-depleting substance that has anthropogenic as well as natural marine and terrestrial sources. The tropospheric N2O concentrations have varied substantially in the past in concert with changing climate on glacial–interglacial and millennial timescales. It is not well understood, however, how N2O emissions from marine and terrestrial sources change in response to varying environmental conditions. The distinct isotopic compositions of marine and terrestrial N2O sources can help disentangle the relative changes in marine and terrestrial N2O emissions during past climate variations. Here we present N2O concentration and isotopic data for the last deglaciation, from 16,000 to 10,000 years before present, retrieved from air bubbles trapped in polar ice at Taylor Glacier, Antarctica. With the help of our data and a box model of the N2O cycle, we find a 30 per cent increase in total N2O emissions from the late glacial to the interglacial, with terrestrial and marine emissions contributing equally to the overall increase and generally evolving in parallel over the last deglaciation, even though there is no a priori connection between the drivers of the two sources. However, we find that terrestrial emissions dominated on centennial timescales, consistent with a state-of-the-art dynamic global vegetation and land surface process model that suggests that during the last deglaciation emission changes were strongly influenced by temperature and precipitation patterns over land surfaces. The results improve our understanding of the drivers of natural N2O emissions and are consistent with the idea that natural N2O emissions will probably increase in response to anthropogenic warming.
Resumo:
While most events related to the International Year of Deserts and Desertification 2006 took mainly a problem-oriented perspective and approach, the Bern Symposium held in May 2006 tried to adopt a more positive attitude by attempting to take stock of experience as well as best and worst practices in the past, both in development practice and in research. Through this deliberate focus on potentials, positive experiences, solutions and pathways, predominant passive and reactive attitudes and hopelessness might be better overcome. The Symposium was organized by CDE, NCCR North-South and Forum SLM.
Resumo:
Climate change, declines in biodiversity, increasing consumption of resources, urbanisation, urban sprawl and demographic change continue to challenge theregions of Europe. In response to these processes of regional and global change, there has been an unmistakeable boom in parks in Europe since the 1990s. Morethan a fifth of the continent is now protected using designations such as regionalnature parks, national parks, UNESCO Biosphere Reserves and World Heritagesites. The responsibilities of these areas are usually diverse and, in addition tonature protection and the conservation of cultural landscapes, increasingly involvethe promotion of sustainable development. In the 22 chapters of this volume, 28 authors from all over Europe analyse and comment on experiences of tackling the challenges of regional and global changein parks. They illustrate discussions with selected case studies and deal with keyissues of current protected area policy: How do parks address the pending challengesand what successes have they had thus far? What pioneering approaches are there in spatial planning and regional development? Which forms of park managementand governance are most promising? This informative and well-illustratedbook also considers which tasks will be assumed by parks in the future and whatroles parks may play in the debate concerning transformations required to promotesustainability in Europe.
Resumo:
Global climate change is becoming an increasing concern among the public health community. Some researchers believe the earth is rapidly undergoing changes in temperature, sea level, population movement, and extreme weather phenomenon. With these geographic, meteorological, and social changes come increased threats to human health. One of these threats is the spread of vector-borne infectious diseases. The changes mentioned above are believed to contribute to increased arthropod survival, transmission, and habitation. These changes, in turn, lead to increased incidence among neighboring human populations. It is also argued that human action may play more of a role than climate change. This systematic review served to determine whether or not climate change poses a significant risk to human exposure and increased incidence of vector-borne disease. ^
Resumo:
Vocational guidance (V.G.) is currently facing both theoretical and methodological reconsiderations. This demands rethinking ethical and scientific assumptions, counselors' role and training. V.G. provides a space to receive information about oneself as well as about labor world and for the elaboration of projects for the future. Many guidance situations in teenagers and young adults are described in this paper, highlighting the main current emergent aspects. There was a remarkable protagonism of those seeking guidance and the reflective frame of the guidance. This frame prepares for the educational stage changes and also for occupational insertion working on aspects that widen autonomous choice and the development of social abilities and attitudes to carry out the vocational project and the development in work. Troubled sociocultural and economic transformations demand an on-going training on the part of counselors. To that end, possible fields of concern and subjects to be worked in said training are suggested.
Resumo:
Vocational guidance (V.G.) is currently facing both theoretical and methodological reconsiderations. This demands rethinking ethical and scientific assumptions, counselors' role and training. V.G. provides a space to receive information about oneself as well as about labor world and for the elaboration of projects for the future. Many guidance situations in teenagers and young adults are described in this paper, highlighting the main current emergent aspects. There was a remarkable protagonism of those seeking guidance and the reflective frame of the guidance. This frame prepares for the educational stage changes and also for occupational insertion working on aspects that widen autonomous choice and the development of social abilities and attitudes to carry out the vocational project and the development in work. Troubled sociocultural and economic transformations demand an on-going training on the part of counselors. To that end, possible fields of concern and subjects to be worked in said training are suggested.
Resumo:
Vocational guidance (V.G.) is currently facing both theoretical and methodological reconsiderations. This demands rethinking ethical and scientific assumptions, counselors' role and training. V.G. provides a space to receive information about oneself as well as about labor world and for the elaboration of projects for the future. Many guidance situations in teenagers and young adults are described in this paper, highlighting the main current emergent aspects. There was a remarkable protagonism of those seeking guidance and the reflective frame of the guidance. This frame prepares for the educational stage changes and also for occupational insertion working on aspects that widen autonomous choice and the development of social abilities and attitudes to carry out the vocational project and the development in work. Troubled sociocultural and economic transformations demand an on-going training on the part of counselors. To that end, possible fields of concern and subjects to be worked in said training are suggested.