Past Climate Variability In South America And Surrounding Regions

South America is a unique place where a number of past climate archives are ava- able from tropical to high latitude regions. It thus offers a unique opportunity to explore past climate variability along a latitudinal transect from the Equator to Polar regions and to study climate teleconnections. Most climate records from tropical and subtropical South America for the past 20,000 years have been interpreted as local responses to shift in the mean position and intensity of the InterTropical Conv- gence Zone due to tropical and extratropical forcings or to changes in the South American Summer Monsoon. Further South, the role of the Southern Hemisphere westerly winds on global climate has been highly investigated with both paleodata and coupled climate models. However the regional response over South America during the last 20,000 years is much more variable from place to place than pre- ously thought. The factors that govern the spatial patterns of variability on millennial scale resolution are still to be understood. The question of past natural rates and ranges of climate conditions over South America is therefore of special relevance in this context since today millions of people live under climates where any changes in monsoon rainfall can lead to catastrophic consequences.

Glaciers in the Andes are particularly important natural archives of present and past climatic and environmental changes, in significant part because of the N-S trend of this topographic barrier and its influence on the atmospheric circulation of the southern hemisphere. Strong gradients in the seasonality and amount of precipitation exist between the equator and 30° S. Large differences in amount east and west of the Andean divide also occur, as well as a change from tropical summer precipitation (additionally modified by the seasonal shift of the circulation belts) to winter precipitation in the west wind belt (e. g. , Yuille, 1999; Garraud and Aceituno, 2001). The so-called 'dry axis' lies between the tropical and extra tropical precipitation regimes (Figure 1). The high mountain desert within this axis responds most sensitively to the smallest changes in effective moisture. An important hydro-meteorological feature on a seasonal to inter-annual time-scale is the occurrence of EN SO events, which strongly control the mass balance of glaciers in this area (e. g. , Wagnon et ai. , 2001; Francou et ai. , in press). The precipitation pattern is an important factor for the interpretation of climatic and environmental records extracted from ice cores, because much of this information is related to conditions at the actual time of precipitation, and this is especially so for stable isotope records. Several ice cores have recently been drilled to bedrock in this area. From Huascanin (Thompson et ai. , 1995), Sajama (Thompson et ai.

This book addresses the social implications of climate change and climatic variability on indigenous peoples and communities living in the highlands, lowlands, and coastal areas of Latin America and the Caribbean. Across the region, indigenous people already perceive and experience negative effects of climate change and variability. Many indigenous communities find it difficult to adapt in a culturally sustainable manner. In fact, indigenous peoples often blame themselves for the changes they observe in nature, despite their limited emission of green house gasses. Not only is the viability of their livelihoods threatened, resulting in food insecurity and poor health, but also their cultural integrity is being challenged, eroding the confidence in solutions provided by traditional institutions and authorities. The book is based on field research among indigenous communities in three major eco-geographical regions: the Amazon; the Andes and Sub-Andes; and the Caribbean and Mesoamerica. It finds major inter-regional differences in the impacts observed between areas prone to rapid- and slow-onset natural hazards. In Mesoamerican and the Caribbean, increasingly severe storms and hurricanes damage infrastructure and property, and even cause loss of land, reducing access to livelihood resources. In the Columbian Amazon, changes in precipitation and seasonality have direct immediate effects on livelihoods and health, as crops often fail and the reproduction of fish stock is threatened by changes in the river ebb and flow. In the Andean region, water scarcity for crops and livestock, erosion of ecosystems and changes in biodiversity threatens food security, both within indigenous villages and among populations who depend on indigenous agriculture, causing widespread migration to already crowded urban areas. The study aims to increase understanding on the complexity of how indigenous communities are impacted by climate change and the options for improving their resilience and adaptability to these phenomena. The goal is to improve indigenous peoples rights and opportunities in climate change adaptation, and guide efforts to design effective and sustainable adaptation initiatives.

Climatologists with an eye on the past have any number of sources for their work, from personal diaries to weather station reports. Piecing together the trajectory of a weather event can thus be a painstaking process taking years and involving real detective work. Missing pieces of a climate puzzle can come from very far afield, often in unlikely places. In this book, a series of case studies examine specific regions across North America, using instrumental and documentary data from the 17th to the 19th centuries. Extreme weather events such as the Sitka hurricane of 1880 are recounted in detail, while the chapters also cover more widespread phenomena such as the collapse of the Low Country rice culture. The book also looks at the role of weather station histories in complementing the instrumental record, and sets out the methods that involve early instrumental and documentary climate data. Finally, the book’s focus on North America reflects the fact that the historical climate community there has only grown relatively recently. Up to now, most such studies have focused on Europe and Asia. The four sections begin with regional case studies, and move on to reconstruct extreme events and parameters. This is followed by the role of station history and, lastly, methodologies and other analyses. The editors’ aim has been to produce a volume that would be instrumental in molding the next generation of historical climatologists. They designed this book for use by general researchers as well as in upper-level undergraduate or graduate level courses.

Climate fluctuations can trigger events that lead to mass migration, hunger and famine. Rather than attributing the blame to nature, the contributors look at the underlying causes of social vulnerability, such as the processes and organisation of society in the semi-arid tropics. Past and present susceptibility to destitution, hunger, and famine in the face of climate variability can teach us about the potential future consequences of climate change. By understanding why individuals, households, nations, and regions are vulnerable, and how they have buffered themselves against climatic and environmental fluctuations, present and future vulnerability can be redressed. Through case studies from across the globe, the authors explore past experiences with climate variability, and the likely effects of, and the possible policy responses to, the types of climatic events that global warming might bring.

Cambridge, UK : Cambridge University Press, 1998.

Society today may be more vulnerable to global-scale, long-term, climate change than ever before. Even without any human influence, past records show that climate can be expected to continue to undergo considerable change over decades to centuries. Measures for adaption and mitigation will call for policy decisions based on a sound scientific foundation. Better understanding and prediction of climate variations can be achieved most efficiently through a nationally recognized "dec-cen" science plan. This book articulates the scientific issues that must be addressed to advance us efficiently toward that understanding and outlines the data collection and modeling needed.

Climatologists with an eye on the past have any number of sources for their work, from personal diaries to weather station reports. Piecing together the trajectory of a weather event can thus be a painstaking process taking years and involving real detective work. Missing pieces of a climate puzzle can come from very far afield, often in unlikely places. In this book, a series of case studies examine specific regions across North America, using instrumental and documentary data from the 17th to the 19th centuries. Extreme weather events such as the Sitka hurricane of 1880 are recounted in detail, while the chapters also cover more widespread phenomena such as the collapse of the Low Country rice culture. The book also looks at the role of weather station histories in complementing the instrumental record, and sets out the methods that involve early instrumental and documentary climate data. Finally, the book’s focus on North America reflects the fact that the historical climate community there has only grown relatively recently. Up to now, most such studies have focused on Europe and Asia. The four sections begin with regional case studies, and move on to reconstruct extreme events and parameters. This is followed by the role of station history and, lastly, methodologies and other analyses. The editors’ aim has been to produce a volume that would be instrumental in molding the next generation of historical climatologists. They designed this book for use by general researchers as well as in upper-level undergraduate or graduate level courses.