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4 resultados encontrados para: AUTOR: Metcalfe, Sarah
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Perceptions of climate change, the impacts of and responses to climatic variability and extreme weather are explored in three communities in the Yucatan Peninsula, Mexico, in relation to livelihood resilience. These communities provide examples of the most common livelihood strategies across the region: small-scale fisheries (San Felipe) and semi-subsistence small-holder farming (Tzucacab and Calakmul). Although the perception that annual rainfall is reducing is not supported by instrumental records, changes in the timing of vital summer rainfall and an intensification of the mid-summer drought (canicula) are confirmed. The impact of both droughts and hurricanes on livelihoods and crop yields was reported across all communities, although the severity varied. Changes in traditional milpa cultivation were seen to be driven by less reliable rainfall but also by changes in Mexico’s agricultural and wider economic policies. Diversification was a common adaptation response across all communities and respondents, resulting in profound changes in livelihood strategies. Government attempts to reduce vulnerability were foundto lack continuity, be hard to access and too orientated toward commercial scale producers. Population growth, higher temperatures and reduced summer rainfall will increase the pressures on communities reliant on small-scale farming and fishing, and a more nuanced understanding of both impacts and adaptations is required for improved livelihood resilience. Greater recognition of such local-scale adaptation strategies should underpin the developing Mexican National Adaptation Policy and provide a template for approaches internationally as adaptation becomes an increasingly important part of the global strategy to cope with climate change.

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Climate impact on the development of pre-classic maya civilisation
Nooren, Kees ; Hoek, Wim Z. (coaut.) ; Dermody, Brian J. (coaut.) ; Galop, Didier (coaut.) ; Metcalfe, Sarah (coaut.) ; Islebe, Gerald A. (coaut.) ; Middelkoop, Hans (coaut.) ;
Contenido en: Climate of the Past Vol. 14 (August 2018), p. 1253-1273 ISSN: 1814-9324
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Resumen en inglés

The impact of climate change on the development and disintegration of Maya civilisation has long been debated. The lack of agreement among existing palaeoclimatic records from the region has prevented a detailed understanding of regional-scale climatic variability, its climatic forcing mechanisms and its impact on the ancient Maya. We present two new palaeo-precipitation records for the central Maya lowlands, spanning the Pre-Classic period (1800BCE–250CE), a key epoch in the development of Maya civilisation. A beach ridge elevation record from world's largest late Holocene beach ridge plain provides a regional picture, while Lake Tuspan's diatom record is indicative of precipitation changes at a local scale. We identify centennial-scale variability in palaeo-precipitation that significantly correlates with the North Atlantic δ14C atmospheric record, with a comparable periodicity of approximately 500 years, indicating an important role of North Atlantic atmospheric–oceanic forcing on precipitation in the central Maya lowlands. Our results show that the Early Pre-Classic period was characterised by relatively dry conditions, shifting to wetter conditions during the Middle Pre-Classic period, around the well-known 850BCE (2.8ka) event. We propose that this wet period may have been unfavourable for agricultural intensification in the central Maya lowlands, explaining the relatively delayed development of Maya civilisation in this area. A return to relatively drier conditions during the Late Pre-Classic period coincides with rapid agricultural intensification in the region and the establishment of major cities.

Quaternary environmental change in the tropics / Edited by Sarah E. Metcalfe and David J. Nash
Metcalfe, S. E. (ed.) ; Nash, David J. (coed.) ;
Chichester, West Sussex, UK : John Wiley & Sons, Inc. , 2012
Clasificación: 551.60901 / QU3
Bibliotecas: Chetumal
SIBE Chetumal
ECO030008014 (Disponible)
Disponibles para prestamo: 1
Índice | Resumen en: Inglés |
Resumen en inglés

The global climate changes that led to the expansion and contraction of high latitude ice sheets during the Quaternary period were associated with equally dramatic changes in tropical environments. These included shifts in vegetation zones, changes in the hydrology and ecology of lakes and rivers, and fluctuations in the size of mountain glaciers and sandy deserts. Until recently it was thought that such changes were triggered by fluctuations in the distribution of polar ice cover. Now there is increasing recognition that the tropics themselves have acted as drivers of global climate change over a range of timescales, with the oceans playing a key role. The aim of Quaternary Environmental Change in the Tropics is to provide a synthesis of the changes that occurred in tropical terrestrial and marine systems during the Pleistocene and Holocene, complementing data-derived reconstructions with output from state-of-the-art climate models. It is targeted at final-year undergraduate students and research specialists, but will provide an introduction to tropical Quaternary research for a variety of other readers.


Contents in Brief
List of contributors
I Global contexts
1 Introduction
2 Contemporary climate and circulation of the tropics
II Regional environmental change
3 Tropical oceans
4 Africa
5 India, Arabia and adjacent regions
6 China and Southeast Asia
7 Australia and the southwest Pacific
8 Latin America and the Caribbean
III Global syntheses
9 Modelling of tropical environments during the Quaternary
10 Historical environmental change in the tropics
11 Past environmental changes, future environmental challenges

Computerised environmental modelling: a practical introduction using excel / J. Hardisty, D. M. Taylor and S. E. Metcalfe
Hardisty, J. (1955-) ; Taylor, D. M. (coaut.) ; Metcalfe, S. E. (coaut.) ;
Chichester, England : John Wiley and Sons , 1993
Clasificación: 333.7 / H37
Bibliotecas: Chetumal
SIBE Chetumal
ECO030004533 (Disponible) , ECO030001231 (Disponible)
Disponibles para prestamo: 2