Past Climate Variability in South America and Surrounding Regions


Book Description

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.




Quaternary Environmental Change in the Tropics


Book Description

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. 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.




Innovative Approaches Towards Low Carbon Economics


Book Description

Climate change is an inevitable and urgent global challenge with long-term implications for the sustainable development of all countries. To overcome this human crisis, the scientific consensus is driving global action towards low carbon economics. Though this action has to involve all sectors (industries, governments, and citizens) and at all levels (global, national and regional levels), the implementation of climate strategies will predominantly be at the regional level. By establishing an innovative range of model technologies, this book aims to develop systematic quantificational methods, such as uncertain multi-objective programming models and system dynamics models, to provide a new approach to low carbon economics that can serve as a paradigm for general regions. At the same time, it offers decision makers a number of effective strategies for some key issues in regional low carbon development, such as greenhouse gas control, ecological capacity evaluation, regional economic prediction, energy structure optimization, land resource utilization, industrial structure adjustment, low carbon industrial chains, low carbon transportation systems and low carbon tourism. It also provides researchers with a new perspective on how to address social problems using quantitative techniques.




Understanding Earth's Deep Past


Book Description

There is little dispute within the scientific community that humans are changing Earth's climate on a decadal to century time-scale. By the end of this century, without a reduction in emissions, atmospheric CO2 is projected to increase to levels that Earth has not experienced for more than 30 million years. As greenhouse gas emissions propel Earth toward a warmer climate state, an improved understanding of climate dynamics in warm environments is needed to inform public policy decisions. In Understanding Earth's Deep Past, the National Research Council reports that rocks and sediments that are millions of years old hold clues to how the Earth's future climate would respond in an environment with high levels of atmospheric greenhouse gases. Understanding Earth's Deep Past provides an assessment of both the demonstrated and underdeveloped potential of the deep-time geologic record to inform us about the dynamics of the global climate system. The report describes past climate changes, and discusses potential impacts of high levels of atmospheric greenhouse gases on regional climates, water resources, marine and terrestrial ecosystems, and the cycling of life-sustaining elements. While revealing gaps in scientific knowledge of past climate states, the report highlights a range of high priority research issues with potential for major advances in the scientific understanding of climate processes. This proposed integrated, deep-time climate research program would study how climate responded over Earth's different climate states, examine how climate responds to increased atmospheric carbon dioxide and other greenhouse gases, and clarify the processes that lead to anomalously warm polar and tropical regions and the impact on marine and terrestrial life. In addition to outlining a research agenda, Understanding Earth's Deep Past proposes an implementation strategy that will be an invaluable resource to decision-makers in the field, as well as the research community, advocacy organizations, government agencies, and college professors and students.




Use of Proxies in Paleoceanography


Book Description

Paleoceanographic proxies provide infonnation for reconstructions of the past, including climate changes, global and regional oceanography, and the cycles of biochemical components in the ocean. These prox ies are measurable descriptors for desired but unobservable environmental variables such as tempera ture, salinity, primary productivity, nutrient content, or surface-water carbon dioxide concentrations. The proxies are employed in a manner analogous to oceanographic methods. The water masses are first characterized according to their specific physical and chemical properties, and then related to particular assemblages of certain organisms or to particular element or isotope distributions. We have a long-standing series of proven proxies available. Marine microfossil assemblages, for instance, are employed to reconstruct surface-water temperatures. The calcareous shells of planktonic and benthic microorgan isms contain a wealth of paleoceanographic information in their isotopic and elemental compositions. Stable oxygen isotope measurements are used to detennine ice volume, and MglCa ratios are related to water temperatures, to cite a few examples. Organic material may also provide valuable infonnation, e. g. , about past productivity conditions. Studying the stable carbon isotope composition of bulk organic matter or individual marine organic components may provide a measure of past surface-water CO 2 conditions within the bounds of certain assumptions. Within the scope of paleoceanographic investigations, the existing proxies are continuously evolving and improving, while new proxies are being studied and developed. The methodology is improved by analysis of samples from the water column and surface sediments, and through laboratory experiments.




Encyclopedia of Paleoclimatology and Ancient Environments


Book Description

One of Springer’s Major Reference Works, this book gives the reader a truly global perspective. It is the first major reference work in its field. Paleoclimate topics covered in the encyclopedia give the reader the capability to place the observations of recent global warming in the context of longer-term natural climate fluctuations. Significant elements of the encyclopedia include recent developments in paleoclimate modeling, paleo-ocean circulation, as well as the influence of geological processes and biological feedbacks on global climate change. The encyclopedia gives the reader an entry point into the literature on these and many other groundbreaking topics.




Quaternary Coral Reef Systems


Book Description

This book presents both state-of-the art knowledge from Recent coral reefs (1.8 million to a few centuries old) gained since the eighties, and introduces geologists, oceanographers and environmentalists to sedimentological and paleoecological studies of an ecosystem encompassing some of the world's richest biodiversity. Scleractinian reefs first appeared about 300 million years ago. Today coral reef systems provide some of the most sensitive gauges of environmental change, expressing the complex interplay of chemical, physical, geological and biological factors. The topics covered will include the evolutionary history of reef systems and some of the main reef builders since the Cenozoic, the effects of biological and environmental forces on the zonation of reef systems and the distribution of reef organisms and on reef community dynamics through time, changes in the geometry, anatomy and stratigraphy of reef bodies and systems in relation to changes in sea level and tectonics, the distribution patterns of sedimentary (framework or detrital) facies in relation to those of biological communities, the modes and rates of reef accretion (progradation, aggradation versus backstepping; coral growth versus reef growth), the hydrodynamic forces controlling water circulation through reef structures and their relationship to early diagenetic processes, the major diagenetic processes affecting reef bodies through time (replacement and diddolution, dolomitization, phosphatogenesis), and the record of climate change by both individual coral colonies and reef systems over the Quaternary. * state-of-the-art knowledge from Recent corals reefs* introduction to sedimentological and paleoecological studies of an ecosystems encompassing some of the world's richest biodiversity.* authors are internationally regarded authorities on the subject* trustworthy information




The Great Maya Droughts


Book Description

This innovative study argues that the collapse of Classic Maya civilization was driven by catastrophic drought. Between A.D. 800 and 1000, unrelenting drought killed millions of Maya people with famine and thirst and initiated a cascade of internal collapses that destroyed their civilization. Linking global, regional, and local climate change, the author explores how atmospheric processes, volcanism, ocean currents, and other natural forces combined to create the dry climate that pried apart the highly complex civilization in the tropical Maya Lowlands in the ninth and tenth centuries. Drawing on knowledge of other prehistoric and historic droughts, The Great Maya Droughts is a useful study of the relationship of humans to their natural and physical environment. The author tries to understand why the Classic Maya failed to adjust their behavior and culture to the climatic conditions and why civilizations in general sometimes collapse in the face of radical environmental change.