North Pacific Environment And Paleoclimate From The Late Pleistocene To Present

The vast area of the North Pacific, spanning ~55˚ longitude, represents a challenge for documenting and understanding the geologic history of ocean, atmosphere, and terrestrial environmental change. Nevertheless, its importance for many issues, including our fundamental understanding of ocean and atmospheric circulation patterns and teleconnections with natural modes of climate variability through time, has led to a steady rise in the numbers of study sites and proxy types. By bringing together a wide range of proxies and timescales that examine the impacts of paleoclimate on ecosystems, water, carbon, and humans, and interactions between marine and terrestrial processes, this Research Topic contributes to an improved understanding of the region’s significance at global, hemispheric, and regional scales.

This study brings together decades of research on the modern natural environment of Washington's Olympic Peninsula, reviews past research on paleoenvironmental change since the Late Pleistocene, and finally presents paleoecological records of changing forest composition and fire over the last 14,000 years. The focus of this study is on the authors’ studies of five pollen records from the Olympic Peninsula. Maps and other data graphics are used extensively. Paleoecology can effectively address some of these challenges we face in understanding the biotic response to climate change and other agents of change in ecosystems. First, species responses to climate change are mediated by changing disturbance regimes. Second, biotic hotspots today suggest a long-term maintenance of diversity in an area, and researchers approach the maintenance of diversity from a wide range and angles (CITE). Mountain regions may maintain biodiversity through significant climate change in ‘refugia’: locations where components of diversity retreat to and expand from during periods of unfavorable climate (Keppel et al., 2012). Paleoecological studies can describe the context for which biodiversity persisted through time climate refugia. Third, the paleoecological approach is especially suited for long-lived organisms. For example, a tree species that may typically reach reproductive sizes only after 50 years and remain fertile for 300 years, will experience only 30 to 200 generations since colonizing a location after Holocene warming about 11,000 years ago. Thus, by summarizing community change through multiple generations and natural disturbance events, paleoecological studies can examine the resilience of ecosystems to disturbances in the past, showing how many ecosystems recover quickly while others may not (Willis et al., 2010).

Earth's climate has undergone dramatic changes over the geologic timescale. At one extreme, Earth has been glaciated from the poles to the equator for periods that may have lasted millions of years. At another, temperatures were once so warm that the Canadian Arctic was heavily forested and large dinosaurs lived on Antarctica. Paleoclimatology is the study of such changes and their causes. Studying Earth's long-term climate history gives scientists vital clues about anthropogenic global warming and how climate is affected by human endeavor. In this book, Michael Bender, an internationally recognized authority on paleoclimate, provides a concise, comprehensive, and sophisticated introduction to the subject. After briefly describing the major periods in Earth history to provide geologic context, he discusses controls on climate and how the record of past climate is determined. The heart of the book then proceeds chronologically, introducing the history of climate changes over millions of years--its patterns and major transitions, and why average global temperature has varied so much. The book ends with a discussion of the Holocene (the past 10,000 years) and by putting manmade climate change in the context of paleoclimate. The most up-to-date overview on the subject, Paleoclimate provides an ideal introduction to undergraduates, nonspecialist scientists, and general readers with a scientific background.

"When combined with computer model simulations, paleoclimatic reconstructions are used to test hypotheses about the causes of climatic change, such as greenhouse gases, solar variability, earth's orbital variations, and hydrological, oceanic, and tectonic processes, This book is a comprehensive, state-of-the art synthesis of paleoclimate research covering all geological timescales, emphasizing topics that shed light on modern trends in the earth's climate." --Book Jacket.

Life on our planet depends upon having a climate that changes within narrow limits – not too hot for the oceans to boil away nor too cold for the planet to freeze over. Over the past billion years Earth’s average temperature has stayed close to 14-15°C, oscillating between warm greenhouse states and cold icehouse states. We live with variation, but a variation with limits. Paleoclimatology is the science of understanding and explaining those variations, those limits, and the forces that control them. Without that understanding we will not be able to foresee future change accurately as our population grows. Our impact on the planet is now equal to a geological force, such that many geologists now see us as living in a new geological era – the Anthropocene. Paleoclimatology describes Earth’s passage through the greenhouse and icehouse worlds of the past 800 million years, including the glaciations of Snowball Earth in a world that was then free of land plants. It describes the operation of the Earth’s thermostat, which keeps the planet fit for life, and its control by interactions between greenhouse gases, land plants, chemical weathering, continental motions, volcanic activity, orbital change and solar variability. It explains how we arrived at our current understanding of the climate system, by reviewing the contributions of scientists since the mid-1700s, showing how their ideas were modified as science progressed. And it includes reflections based on the author’s involvement in palaeoclimatic research. The book will transform debate and set the agenda for the next generation of thought about future climate change. It will be an invaluable course reference for undergraduate and postgraduate students in geology, climatology, oceanography and the history of science. "A real tour-de-force! An outstanding summary not only of the science and what needs to be done, but also the challenges that are a consequence of psychological and cultural baggage that threatens not only the survival of our own species but the many others we are eliminating as well." Peter Barrett Emeritus Professor of Geology, Antarctic Research Centre, Victoria University of Wellington, New Zealand "What a remarkable and wonderful synthesis... it will be a wonderful source of [paleoclimate] information and insights." Christopher R. Scotese Professor, Department of Earth and Planetary Sciences, Northwestern University, Evanston, IL, USA

Late Quaternary Environmental Change addresses the interaction between human agency and other environmental factors in the landscapes, particularly of the temperate zone. Taking an ecological approach, the authors cover the last 20,000 years during which the climate has shifted from arctic severity to the conditions of the present interglacial environment.

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.