880 resultados para phenophase response to climate change
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Climate change as a global problem has moved relatively swiftly into high profile political debates over the last 20 years or so, with a concomitant diffusion from the natural sciences into the social sciences. The study of the human dimensions of climate change has been growing in momentum through research which attempts to describe, evaluate, quantify and model perceptions of climate change, understand more about risk and assess the construction of policy. Cultural geographers’ concerns with the construction of knowledge, the workings of social relations in space and the politics and poetics of place-based identities provide a lens through which personal, collective and institutional responses to climate change can be evaluated using critical and interpretative methodologies. Adopting a cultural geography approach, this paper examines how climate change as a particular environmental discourse is constructed through memory, observation and conversation, as well as materialised in farming practices on the Lizard Peninsula, Cornwall, UK
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In this paper we show how a seemingly unremarkable object – a cattle grid – has come to presence climate change in partial and contingent ways on the Lizard Peninsula, Cornwall, UK. We identify the cattle grid as an ‘anticipatory object’ through which conservation organisations seek to manage the future and adapt to climate change, but which at the same time presences that unthought-of future for others in the landscape. We explore the ways in which the cattle grid acts to presence something that is not only absent – climate change – but has uncertain imminence. We investigate the ways in which the cattle grid make climate relevant as an embodied and experiential process, a physical and intellectual artefact, and the means to imagine climate and the ways it might change. Drawing upon interpretative approaches informed by theorisations of materiality, presence and absence to understand climate change as a social phenomenon, we go beyond a consideration of this ordinary object defined by its function to consider how the object is experienced, the processes and practices through which people relate to it, and the ways in which social meaning accumulates around it. The empirical basis for this argument is provided by in-depth interviews with local representatives of Natural England, residents and farmers.
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This paper presents a global scale assessment of the impact of climate change on water scarcity. Patterns of climate change from 21 Global Climate Models (GCMs) under four SRES scenarios are applied to a global hydrological model to estimate water resources across 1339 watersheds. The Water Crowding Index (WCI) and the Water Stress Index (WSI) are used to calculate exposure to increases and decreases in global water scarcity due to climate change. 1.6 (WCI) and 2.4 (WSI) billion people are estimated to be currently living within watersheds exposed to water scarcity. Using the WCI, by 2050 under the A1B scenario, 0.5 to 3.1 billion people are exposed to an increase in water scarcity due to climate change (range across 21 GCMs). This represents a higher upper-estimate than previous assessments because scenarios are constructed from a wider range of GCMs. A substantial proportion of the uncertainty in the global-scale effect of climate change on water scarcity is due to uncertainty in the estimates for South Asia and East Asia. Sensitivity to the WCI and WSI thresholds that define water scarcity can be comparable to the sensitivity to climate change pattern. More of the world will see an increase in exposure to water scarcity than a decrease due to climate change but this is not consistent across all climate change patterns. Additionally, investigation of the effects of a set of prescribed global mean temperature change scenarios show rapid increases in water scarcity due to climate change across many regions of the globe, up to 2°C, followed by stabilisation to 4°C.
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Climate change could potentially interrupt progress toward a world without hunger. A robust and coherent global pattern is discernible of the impacts of climate change on crop productivity that could have consequences for food availability. The stability of whole food systems may be at risk under climate change because of short-term variability in supply. However, the potential impact is less clear at regional scales, but it is likely that climate variability and change will exacerbate food insecurity in areas currently vulnerable to hunger and undernutrition. Likewise, it can be anticipated that food access and utilization will be affected indirectly via collateral effects on household and individual incomes, and food utilization could be impaired by loss of access to drinking water and damage to health. The evidence supports the need for considerable investment in adaptation and mitigation actions toward a “climate-smart food system” that is more resilient to climate change influences on food security.
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Grassroots innovations emerge as networks generating innovative solutions for climate change adaptation and mitigation. However, it is unclear if grassroots innovations can be successful in responding to climate change. Little evidence exists on replication, international comparisons are rare, and research tends to overlook discontinued responses in favour of successful ones. We take the Transition Movement as a case study of a rapidly spreading transnational grassroots network, and include both active and non-active local transition initiatives. We investigate the replication of grassroots innovations in different contexts with the aim to uncover general patterns of success and failure, and identify questions for future research. An online survey was carried out in 23 countries (N=276). The data analysis entailed testing the effect of internal and contextual factors of success as drawn from the existing literature, and the identification of clusters of transition initiatives with similar internal and contextual factor configurations. Most transition initiatives consider themselves successful. Success is defined along the lines of social connectivity and empowerment, and external environmental impact. We find that less successful transition initiatives might underestimate the importance of contextual factors and material resources in influencing success. We also find that their diffusion is linked to the combination of local-global learning processes, and that there is an incubation period during which a transition initiative is consolidated. Transition initiatives seem capable of generalising organisational principles derived from unique local experiences that seem to be effective in other local contexts. However, the geographical locations matter with regard to where transition initiatives take root and the extent of their success, and ‘place attachment’ may have a role in the diffusion of successful initatives. We suggest that longitudinal comparative studies can advance our understanding in this regard, as well as inform the changing nature of the definition of success at different stages of grassroots innovation development, and the dynamic nature of local and global linkages.
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Purpose The sensitivity of soil organic carbon to global change drivers, according to the depth profile, is receiving increasing attention because of its importance in the global carbon cycle and its potential feedback to climate change. A better knowledge of the vertical distribution of SOC and its controlling factors—the aim of this study—will help scientists predict the consequences of global change. Materials and methods The study area was the Murcia Province (S.E. Spain) under semiarid Mediterranean conditions. The database used consists of 312 soil profiles collected in a systematic grid, each 12 km2 covering a total area of 11,004 km2. Statistical analysis to study the relationships between SOC concentration and control factors in different soil use scenarios was conducted at fixed depths of 0–20, 20–40, 40–60, and 60–100 cm. Results and discussion SOC concentration in the top 40 cm ranged between 6.1 and 31.5 g kg−1, with significant differences according to land use, soil type and lithology, while below this depth, no differences were observed (SOC concentration 2.1–6.8 g kg−1). The ANOVA showed that land use was the most important factor controlling SOC concentration in the 0–40 cm depth. Significant differences were found in the relative importance of environmental and textural factors according to land use and soil depth. In forestland, mean annual precipitation and texture were the main predictors of SOC, while in cropland and shrubland, the main predictors were mean annual temperature and lithology. Total SOC stored in the top 1 m in the region was about 79 Tg with a low mean density of 7.18 kg Cm−3. The vertical distribution of SOC was shallower in forestland and deeper in cropland. A reduction in rainfall would lead to SOC decrease in forestland and shrubland, and an increase of mean annual temperature would adversely affect SOC in croplands and shrubland. With increasing depth, the relative importance of climatic factors decreases and texture becomes more important in controlling SOC in all land uses. Conclusions Due to climate change, impacts will be much greater in surface SOC, the strategies for C sequestration should be focused on subsoil sequestration, which was hindered in forestland due to bedrock limitations to soil depth. In these conditions, sequestration in cropland through appropriate management practices is recommended.
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At present, there is a clarion call for action on climate change across the global health landscape. At the recent WHO-sponsored conference on health and climate (held in Geneva, Switzerland, on Aug 27–29, 2014) and the UN Climate Summit (New York, USA, on Sept 23, 2014), participants were encouraged to act decisively to change the current trajectory of climate disruption. Health inequalities, including those related to infectious diseases, have now been pushed to centre stage. This approach represents a step-change in thinking. But as we are urged toward collective action, is it time to rethink our approach to research, especially in relation to climate change and infectious disease?
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In the face of accelerating climate change and the parlous state of its politics, despair is tempting. This paper analyses two manifestations of despair about climate change related to (1) the inefficacy of personal emissions reductions, and (2) the inability to make a difference to climate change through personal emissions reductions. On the back of an analysis of despair as a loss of hope, the paper argues that the judgements grounding each form of despair are unsound. The paper concludes with consideration of the instrumental value of hope in effective agency to tackle climate change. Overall, the paper’s assessment of personal despair about climate change as philosophically unjustified provides a fresh perspective on aspects of the debate about how to frame climate change in public debate.
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Recent urban air temperature increase is attributable to the climate change and heat island effects due to urbanization. This combined effects of urbanization and global warming can penetrate into the underground and elevate the subsurface temperature. In the present study, over-100 years measurements of subsurface temperature at a remote rural site were analysed, and an increasing rate of 0.17⁰C per decade at soil depth of 30cm due to climate change was identified in the UK, but the subsurface warming in an urban site showed a much higher rate of 0.85⁰C per decade at a 30cm depth and 1.18⁰C per decade at 100cm. The subsurface urban heat island (SUHI) intensity obtained at the paired urban-rural stations in London showed an unique 'U-shape', i.e. lowest in summer and highest during winter. The maximum SUHII is 3.5⁰C at 6:00 AM in December, and the minimum UHII is 0.2⁰C at 18:00PM in July. Finally, the effects of SUHI on the energy efficiency of the horizontal ground source heat pump (GSHP) were determined. Provided the same heat pump used, the installation at an urban site will maintain an overall higher COP compared with that at a rural site in all seasons, but the highest COP improvement can be achieved in winter.
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An improved understanding of present-day climate variability and change relies on high-quality data sets from the past 2 millennia. Global efforts to model regional climate modes are in the process of being validated against, and integrated with, records of past vegetation change. For South America, however, the full potential of vegetation records for evaluating and improving climate models has hitherto not been sufficiently acknowledged due to an absence of information on the spatial and temporal coverage of study sites. This paper therefore serves as a guide to high-quality pollen records that capture environmental variability during the last 2 millennia. We identify 60 vegetation (pollen) records from across South America which satisfy geochronological requirements set out for climate modelling, and we discuss their sensitivity to the spatial signature of climate modes throughout the continent. Diverse patterns of vegetation response to climate change are observed, with more similar patterns of change in the lowlands and varying intensity and direction of responses in the highlands. Pollen records display local-scale responses to climate modes; thus, it is necessary to understand how vegetation–climate interactions might diverge under variable settings. We provide a qualitative translation from pollen metrics to climate variables. Additionally, pollen is an excellent indicator of human impact through time. We discuss evidence for human land use in pollen records and provide an overview considered useful for archaeological hypothesis testing and important in distinguishing natural from anthropogenically driven vegetation change. We stress the need for the palynological community to be more familiar with climate variability patterns to correctly attribute the potential causes of observed vegetation dynamics. This manuscript forms part of the wider LOng-Term multi-proxy climate REconstructions and Dynamics in South America – 2k initiative that provides the ideal framework for the integration of the various palaeoclimatic subdisciplines and palaeo-science, thereby jump-starting and fostering multidisciplinary research into environmental change on centennial and millennial timescales.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Includes bibliography
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Includes bibliography
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The main objective of the present study was to determine the value of impacts due to climate change on the agricultural sector in the Caribbean under the Intergovernmental Panel on Climate Change Special Report on Emissions Scenarios A2 and B2 scenarios. More specifically, the study aimed to evaluate the direction and magnitude of the potential impacts of climate change on aggregate agricultural output and other key agricultural indicators. Further, the study forecast changes in income for agricultural output for key subsectors under the A2 and B2 scenarios, from 2011 to 2050. It analysed the benefits and costs of the key adaptation strategies identified by Caribbean Governments.
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Climate change poses special challenges for Caribbean decision makers related to the uncertainties inherent in future climate projections and the complex linkages between climate change, physical and biological systems, and socioeconomic sectors. At present, however, the Caribbean subregion lacks the adaptive capacity needed to address these challenges. The present report assesses the economic and social impacts of climate change on the coastal and marine sector in the Caribbean until 2050. It aims both to provide Caribbean decision makers with cutting edge information on the vulnerability to climate change of the subregion, and to facilitate the development of adaptation strategies informed by both local experience and expert knowledge.