DOCSLIB.ORG

Medieval Warm Period in South America

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Medieval Warm Period in South America M EDIEVAL WARM PERIOD IN OUTH MERICA S A SPPI & CO2SCIENCE ORIGINAL PAPER ♦ September 4, 2013 MEDIEVAL WARM PERIOD IN SOUTH AMERICA Citation: Center for the Study of Carbon Dioxide and Global Change. "Medieval Warm Period in South America.” Last modified September 4, 2013. http://www.co2science.org/subject/m/summaries/mwpsoutham.php. Was there a Medieval Warm Period anywhere in addition to the area surrounding the North Atlantic Ocean, where its occurrence is uncontested? This question is of utmost importance to the ongoing global warming debate, since if there was, and if the locations where it occurred were as warm then as they are currently, there is no need to consider the temperature increase of the past century as anything other than the natural progression of the persistent millennial- scale oscillation of climate that regularly brings the earth several-hundred-year periods of modestly higher and lower temperatures that are totally independent of variations in atmospheric CO2 concentration. Hence, this question is here considered as it applies to South America, a region far removed from where the existence of the Medieval Warm Period was first recognized. Cioccale (1999) assembled what was known at the time about the climatic history of the central region of the country over the past 1400 years, highlighting a climatic "improvement" that began some 400 years before the start of the last millennium, which ultimately came to be characterized by "a marked increase of environmental suitability, under a relatively homogeneous climate." And as a result of this climatic amelioration that marked the transition of the region from the Dark Ages Cold Period to the Medieval Warm Period, Cioccale reported that "the population located in the lower valleys ascended to higher areas in the Andes," where they remained until around AD 1320, when the transition to the stressful and extreme climate of the Little Ice Age began. Down at the southern tip of the country in Tierra del Fuego, Mauquoy et al. (2004) inferred similar changes in temperature and/or precipitation from plant macrofossils, pollen, fungal spores, testate amebae and humification associated with peat monoliths collected from the Valle de Andorra. These new chronologies were compared with other chronologies of pertinent data from both the Southern and Northern Hemispheres in an analysis that indicated there was evidence for a period of warming-induced drier conditions from AD 960-1020, which, in their words, "seems to correspond to the Medieval Warm Period (MWP, as derived in the Northern Hemisphere)." They also noted that "this interval compares well to the date range of AD 950-1045 based on Northern Hemisphere extratropical tree-ring data (Esper et al., 2002)," and they thus concluded that this correspondence "shows that the MWP was possibly synchronous in both hemispheres, as suggested by Villalba (1994)." One year later, Haberzettl et al. (2005) worked with five sediment cores extracted from Laguna Potrok Aike (51°58'S, 70°23'W), which is one of the few permanently water-filled lakes in the dry-lands of southern Patagonia, where they analyzed a host of proxy climate indicators, finding that "the sediment record of Laguna Potrok Aike reveals an unprecedented sensitive 2 continuous high resolution lake level, vegetation and climate record for southern Patagonia since AD 400." This history indicates that the climate of the region fluctuated rapidly from the beginning of the record right up to the start of the Medieval Climatic Anomaly (MCA, which was proposed by Stine (1998) to have begun at about AD 870). This earlier interval of time corresponds with the Dark Ages Cold Period of Europe; and it was followed, of course, by the MCA, or what Europeans called the Medieval Warm Period, which was most strongly expressed in the Laguna Potrok Aike data from AD 1240 to 1410, during which period maxima of total inorganic carbon (TIC), total organic carbon (TOC), total nitrogen (TN), carbon/nitrogen ratio (C/N) and δ13Corg indicated, in the Haberzettl et al. stated words of the ten researchers, "low lake levels and warm and dry climate." "there is evidence for lower Thereafter, as the scientists continued, "the lake levels during the MCA MCA ends during the 15th century" and is "followed by the so called 'Little Ice Age'." than today in every proxy." Last of all, "in the course of the 20th century," they report that "Laguna Potrok … This implies that it might Aike reacted like many other Patagonian lakes with a lake level lowering after 1940, have been warmer during AD culminating in 1990, and followed by a subsequent rise and recession." 1240 to 1410 than today. With respect to the question of whether it was warmer during the MCA than during the 20th century," Haberzettl et al. stated "there is evidence for lower lake levels during the MCA than today in every proxy," and that "the existence of lower lake levels in former times was demonstrated by seismic studies which revealed hitherto undated fossil lake level terraces ca. 30 m below the present lake level (Zolitschka et al., 2004)." In addition, they wrote that "TOC and TN as proxies reflecting productivity also show higher values during the MCA than today," even though "present TOC and TN values are elevated due to anthropogenic eutrophication." And so they concluded that "this altogether implies that it might have been warmer during [AD 1240 to 1410] than today." Kellerhals et al. (2010) introduced their study of the climate of the Bolivian Andes by noting that "to place recent global warming into a longer-term perspective and to understand the mechanisms and causes of climate change, proxy-derived temperature estimates are needed for time periods prior to instrumental records and regions outside instrumental coverage." And in this regard they indicated that "for tropical regions and the Southern Hemisphere ... proxy information is very fragmentary." To help fill this data void, the team of six scientists developed what they described as "a reconstruction of tropical South American temperature anomalies over the 3 last ~1600 years ... based on a highly resolved and carefully dated ammonium record from an ice core that was drilled in 1999 on Nevado Illimani [16°37'S, 67°46'W] in the eastern Bolivian Andes," while noting that "studies from other remote ice core sites have found significant + correlations between NH4 concentration and temperature for Siberia and the Indian subcontinent for preindustrial time periods," citing the work of Kang et al. (2002) and Eichler et al. (2009). As for calibrating and validating the NH4+-to-°C transfer function, they said they used "the Amazon Basin subset of the gridded HadCRUT3 temperature data set," which is described by Brohan et al. (2006). With respect to their findings, Kellerhals et al. said that "the most striking features in the reconstruction are [1] the warm temperatures from ~1050 to ~1300 AD [the Medieval Warm Period] compared to the preceding and following centuries, [2] the persistent cooler temperatures from ~1400 to ~1800 AD [the Little Ice Age], and [3] the subsequent rise to warmer temperatures [the Current Warm Period] which eventually seem to exceed, in the last decades of the 20th century, the range of past variation." And in regard to this last observation, the graph of their data suggests that the peak warmth of the Current Warm Period may, in this particular case, actually have been ~0.27°C greater than the peak warmth of the Medieval Warm Period. Reconstructed tropical South American temperature anomalies normalized to the AD 1961-1990 average and smoothed with a 39-year Gaussian filter. Adapted from Kellerhals et al. (2010). Vuille et al. (2012) reviewed the history of the South American summer monsoon (SASM) over the past two millennia, based on information obtained from high-resolution stable isotopes derived from speleothems, ice cores and lake sediments acquired from the monsoon belt of the tropical Andes and Southeast Brazil. This work revealed, as they describe it, "a very coherent behavior over the past two millennia with significant decadal to multi-decadal variability superimposed on large excursions during three key periods: the Medieval Climate Anomaly (MCA), the Little Ice Age (LIA) and the current warm period (CWP)," which they interpreted as "times when 4 the SASM's mean state was significantly weakened (MCA and CWP) and strengthened (LIA), respectively." The nine researchers then hypothesized that "these centennial-scale climate anomalies were at least partially driven by temperature changes in the Northern Hemisphere and in particular over the North Atlantic, leading to a latitudinal displacement of the Intertropical Convergence Zone and a change in monsoon intensity (amount of rainfall upstream over the Amazon Basin)." And with their noting that the intensity of the SASM "today appears on par with conditions during the MCA," it can logically be concluded that the peak temperatures of the MCA and the CWP over the North Atlantic Ocean are likely on a par with each other as well, which suggests that (1) there is nothing unusual, unnatural or unprecedented about today's current level of warmth over the North Atlantic, and that (2) today's level of warmth everywhere need not have been caused by the 40% greater atmospheric CO2 concentration of today. Jenny et al. (2002) studied geochemical, sedimentological and diatom- assemblage data derived from sediment cores extracted from one of the largest natural lakes (Laguna Aculeo) in the central part of the country. From 200 BC, when the record began, until AD 200, conditions there were primarily dry, during the latter stages of the Roman Warm Period. Subsequently, from AD 200-700, with a slight respite in the central hundred years of that period, there was a high frequency of flood events, during the Dark Ages Cold Period.
Load more

Recommended publications
  • Using Patterns of Recurring Climate Cycles to Predict Future Climate Changes D.J
    CHAPTER 21 Using Patterns of Recurring Climate Cycles to Predict Future Climate Changes D.J. Easterbrook Western Washington University, Bellingham, WA, United States OUTLINE 1. Introduction 395 4. Correlation of Temperature Cycles and the Pacific Decadal Oscillation 405 2. The Past is the Key to the Future: Lessons From Past Global Climate Changes 396 5. The Atlantic Multidecadal Oscillation 407 2.1 Past Climate Changes 396 6. Where Is Climate Headed During the Coming 2.2 Magnitude and Rate of Abrupt Climate Changes 396 Century? 407 2.3 Holocene Climate Changes (10,000 Years Ago 6.1 IPCC Predictions 407 to Present) 398 6.2 Predictions Based on Past Cyclic Climate 2.3.1 The Roman Warm Period 398 Patterns 407 2.3.2 Dark Ages Cool Period 398 2.3.3 Medieval Warm Period (900e1300 AD) 400 References 410 2.3.4 The Little Ice Age 401 2.3.5 Climate Changes During the Past Century 403 3. Significance of Past Global Climate Changes 404 1. INTRODUCTION Global warming that occurred from 1978 to about 1998 pushed climate change into the forefront of potential concern. Every day the news media is filled with dire predictions of impending disastersdcatastrophic melting of the Antarctic and Greenland ice sheets, drowning of major cities from sea level rise, drowning of major portions of countries, droughts, severe water shortages, no more snow, more extreme weather events (hurricanes, tor- nadoes), etc. With no unequivocal, cause-and-effect, tangible, physical evidence that increasing CO2 caused this most recent global warming, adherents of this ideology have had to rely on computer models that have proven to be unreliable.
    [Show full text]
  • The Science of Roman History Biology, Climate, and the Future of the Past
    The Science of Roman History Biology, climaTe, and The fuTuRe of The PaST Edited by Walter Scheidel PRinceTon univeRSiTy PReSS PRinceTon & oxfoRd Copyright © 2018 by Princeton University Press Published by Princeton University Press, 41 William Street, Princeton, New Jersey 08540 In the United Kingdom: Princeton University Press, 6 Oxford Street, Woodstock, Oxfordshire OX20 1TR press.princeton.edu All Rights Reserved ISBN 978- 0- 691- 16256- 0 Library of Congress Control Number 2017963022 British Library Cataloging- in- Publication Data is available This book has been composed in Miller Printed on acid- free paper. ∞ Printed in the United States of America 10 9 8 7 6 5 4 3 2 1 conTenTS List of Illustrations and Tables · vii Notes on Contributors · ix Acknowledgments · xiii Maps · xiv Introduction 1 Walter Scheidel chaPTeR 1. Reconstructing the Roman Climate 11 Kyle Harper & Michael McCormick chaPTeR 2. Archaeobotany: The Archaeology of Human- Plant Interactions 53 Marijke van der Veen chaPTeR 3. Zooarchaeology: Reconstructing the Natural and Cultural Worlds from Archaeological Faunal Remains 95 Michael MacKinnon chaPTeR 4. Bones, Teeth, and History 123 Alessandra Sperduti, Luca Bondioli, Oliver E. Craig, Tracy Prowse, & Peter Garnsey chaPTeR 5. Human Growth and Stature 174 Rebecca Gowland & Lauren Walther chaPTeR 6. Ancient DNA 205 Noreen Tuross & Michael G. Campana chaPTeR 7. Modern DNA and the Ancient Mediterranean 224 Roy J. King & Peter A. Underhill Index · 249 [ v ] illuSTRaTionS and TaBleS Maps 1. Western Mediterranean. xiv 2. Eastern Mediterranean. xv 3. Northwestern Europe. xvi Figures 1.1. TSI (Total Solar Irradiance) from 14C. 19 1.2. TSI from 10Be. 19 1.3.
    [Show full text]
  • Oxygen Isotope Evidence for Paleoclimate Change During The
    PALEOCLIMATE RECONSTRUCTION IN NORTHWEST SCOTLAND AND SOUTHWEST FLORIDA DURING THE LATE HOLOCENE Ting Wang A dissertation submitted to the faculty of the University of North Carolina at Chapel Hill in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Geological Sciences. Chapel Hill 2011 Approved by: Dr. Donna M. Surge Dr. Joseph G. Carter Dr. Jose A. Rial Dr. Justin B. Ries Dr. Karen J. Walker © 2011 Ting Wang ALL RIGHTS RESERVED ii ABSTRACT TING WANG: Paleoclimate Reconstruction in Northwest Scotland and Southwest Florida during the Late Holocene (Under the direction of Dr. Donna M. Surge) The study reconstructed seasonal climate change in mid-latitude northwest Scotland during the climate episodes Neoglacial (~3300-2500 BP) and Roman Warm Period (RWP; ~2500-1600 BP) and in subtropical southwest Florida during the latter part of RWP (1-550 AD) based on archaeological shell accumulations in two study areas. In northwest Scotland, seasonal sea surface temperature (SST) during the Neoglacial and RWP was estimated from high-resolution oxygen isotope ratios (δ18O) of radiocarbon-dated limpet (Patella vulgata) shells accumulated in a cave dwelling on the Isle of Mull. The SST results revealed a cooling transition from the Neoglacial to RWP, which is supported by earlier studies of pine pollen in Scotland and European glacial events and also coincident with the abrupt climate deterioration at 2800-2700 BP. The cooling transition might have been driven by decreased solar radiation and weakened North Atlantic Oscillation (NAO) conditions. In southwest Florida, seasonal-scale climate conditions for the latter part of RWP were reconstructed by using high-resolution δ18O of archaeological shells (Mercenaria campechiensis) and otoliths (Ariopsis felis).
    [Show full text]
  • The Influence of Climatic Change on the Late Bronze Age Collapse and the Greek Dark Ages Journal of Archaeological Science
    Journal of Archaeological Science 39 (2012) 1862e1870 Contents lists available at SciVerse ScienceDirect Journal of Archaeological Science journal homepage: http://www.elsevier.com/locate/jas The influence of climatic change on the Late Bronze Age Collapse and the Greek Dark Ages Brandon L. Drake* Department of Anthropology, University of New Mexico, Albuquerque, NM 87131, United States article info abstract Article history: Between the 13th and 11th centuries BCE, most Greek Bronze Age Palatial centers were destroyed and/or Received 28 July 2011 abandoned. The following centuries were typified by low population levels. Data from oxygen-isotope Received in revised form speleothems, stable carbon isotopes, alkenone-derived sea surface temperatures, and changes in 19 January 2012 warm-species dinocysts and formanifera in the Mediterranean indicate that the Early Iron Age was more Accepted 26 January 2012 arid than the preceding Bronze Age. A sharp increase in Northern Hemisphere temperatures preceded the collapse of Palatial centers, a sharp decrease occurred during their abandonment. Mediterranean Sea Keywords: surface temperatures cooled rapidly during the Late Bronze Age, limiting freshwater flux into the Bronze Age Collapse Carbon isotopes atmosphere and thus reducing precipitation over land. These climatic changes could have affected Speleothems Palatial centers that were dependent upon high levels of agricultural productivity. Declines in agricul- SST tural production would have made higher-density populations in Palatial centers unsustainable. The Sea surface temperature ‘Greek Dark Ages’ that followed occurred during prolonged arid conditions that lasted until the Roman Climate change Warm Period. Paleoclimate Ó 2012 Elsevier Ltd. All rights reserved. 1. Introduction suggested that a centuries-long megadrought caused the wide- spread systems collapse of Bronze Age Palatial civilization.
    [Show full text]
  • A Companion to Ancient History Edited by Andrew Erskine © 2009 Blackwell Publishing Ltd
    A COMPANION TO ANCIENT HISTORY A Companion to Ancient History Edited by Andrew Erskine © 2009 Blackwell Publishing Ltd. ISBN: 978-1-405-13150-6 BLACKWELL COMPANIONS TO THE ANCIENT WORLD This series provides sophisticated and authoritative overviews of periods of ancient history, genres of classical literature, and the most important themes in ancient culture. Each volume comprises between twenty-fi ve and forty concise essays written by individual scholars within their area of specialization. The essays are written in a clear, provocative, and lively manner, designed for an international audience of scholars, students, and general readers. ANCIENT HISTORY LITERATURE AND CULTURE A Companion to the Roman Army A Companion to Classical Receptions Edited by Paul Erdkamp Edited by Lorna Hardwick and Christopher Stray A Companion to the Roman Republic Edited by Nathan Rosenstein and Robert A Companion to Greek and Roman Morstein-Marx Historiography Edited by John Marincola A Companion to the Roman Empire Edited by David S. Potter A Companion to Catullus Edited by Marilyn B. Skinner A Companion to the Classical Greek World Edited by Konrad H. Kinzl A Companion to Roman Religion Edited by Jörg Rüpke A Companion to the Ancient Near East Edited by Daniel C. Snell A Companion to Greek Religion Edited by Daniel Ogden A Companion to the Hellenistic World Edited by Andrew Erskine A Companion to the Classical Tradition Edited by Craig W. Kallendorf A Companion to Late Antiquity Edited by Philip Rousseau A Companion to Roman Rhetoric Edited by William Dominik and Jon Hall A Companion to Archaic Greece Edited by Kurt A.
    [Show full text]
  • The Ancient Mediterranean Environment Between Science and History Columbia Studies in the Classical Tradition
    The Ancient Mediterranean Environment between Science and History Columbia Studies in the Classical Tradition Editorial Board William V. Harris (editor) Alan Cameron, Suzanne Said, Kathy H. Eden, Gareth D. Williams, Holger A. Klein VOLUME 39 The titles published in this series are listed at brill.com/csct The Ancient Mediterranean Environment between Science and History Edited by W.V. Harris LEIDEN • BOSTON 2013 Cover illustration: Fresco from the Casa del Bracciale d’Oro, Insula Occidentalis 42, Pompeii. Photograph © Stefano Bolognini. Courtesy of the Soprintendenza Archeologica di Pompei. Library of Congress Cataloging-in-Publication Data The ancient Mediterranean environment between science and history / edited by W.V. Harris. pages cm. – (Columbia studies in the classical tradition, ISSN 0166-1302 ; volume 39) Includes bibliographical references and index. ISBN 978-90-04-25343-8 (hardback : alk. paper) – ISBN 978-90-04-25405-3 (e-book) 1. Human ecology–Mediterranean Region–History. 2. Mediterranean Region–Environmental conditions–History. 3. Nature–Effect of human beings on–Mediterranean Region–History. I. Harris, William V. (William Vernon) author, editor of compilation. GF541.A64 2013 550.937–dc23 2013021551 This publication has been typeset in the multilingual “Brill” typeface. With over 5,100 characters covering Latin, IPA, Greek, and Cyrillic, this typeface is especially suitable for use in the humanities. For more information, please see www.brill.com/brill-typeface. ISSN 0166-1302 ISBN 978-90-04-25343-8 (hardback) ISBN 978-90-04-25405-3 (e-book) Copyright 2013 by The Trustees of Columbia University in the City of New York. Koninklijke Brill NV incorporates the imprints Brill, Global Oriental, Hotei Publishing, IDC Publishers and Martinus Nijhoff Publishers.
    [Show full text]
  • Solar Cycles: Another Prediction
    Solar Cycles another prediction by Miles Mathis March 6, 2020 On February 2, I posted charts of the upcoming Solar Cycles, including in-depth predictions for Cycle 25 and Cycle 26. I showed Cycle 26—which will peak in about 2037—would be similar in strength to Cycle 19, which peaked in 1957 and is the largest on record. That's the good news. The bad news is that the strength of the upcoming Cycles will tend to be fodder for the Global Warming frauds, and I predict they will use the trend to claim victory and continue the scare tactics, using them to sell various treasury dips and new taxes. Because what few have told you is that there is a correlation between global temperatures and longterm Solar Cycles. For instance, the Little Ice Age corresponds to the Maunder Minimum. Mid-20th century warming corresponds to strong Cycles in those decades, and cooling from the late 1950s to the 1990s also follows diminishing Solar Cycles. So a stronger Sun in the upcoming decades will likely lead to a real bump in global temperatures. Remember, the big scare in the 1970s was Global Cooling, when they were sucking from the treasury to respond to that conjob. When that failed to pan out and temperatures flattened, they decided to switch gears and sell the Global Warming scare instead. These people are salesmen and they always have to be selling something. This is not to say we don't have major environmental problems that require immediate action. We do. We have huge problems of pollution and environmental degradation caused by industry, military, government, corporate farming, and general modern lifestyles.
    [Show full text]
  • A Companion to Mediterranean History
    A Companion to Mediterranean History 0002063973.INDD 1 2/18/2014 2:59:17 PM WILEY BLACKWELL COMPANIONS TO HISTORY This series provides sophisticated and authoritative overviews of the scholarship that has shaped our current understanding of the past. Defined by theme, period and/or region, each volume comprises between twenty-five and forty concise essays written by individual scholars within their area of specialization. The aim of each contribution is to synthesize the current state of scholarship from a variety of historical perspectives and to provide a statement on where the field is heading. The essays are written in a clear, provocative, and lively manner, designed for an international audience of scholars, students, and general readers. WILEY BLACKWELL COMPANIONS A Companion to the Medieval World TO BRITISH HISTORY Edited by Carol Lansing and Edward D. English A Companion to Roman Britain A Companion to the French Revolution Edited by Malcolm Todd Edited by Peter McPhee A Companion to Britain in the Later Middle Ages A Companion to Mediterranean History Edited by S. H. Rigby Edited by Peregrine Horden and Sharon Kinoshita A Companion to Tudor Britain WILEY BLACKWELL COMPANIONS Edited by Robert Tittler and Norman Jones TO WORLD HISTORY A Companion to Stuart Britain A Companion to Western Historical Thought Edited by Barry Coward Edited by Lloyd Kramer and Sarah Maza A Companion to Eighteenth-Century Britain A Companion to Gender History Edited by H. T. Dickinson Edited by Teresa A. Meade and Merry E. Wiesner-Hanks A Companion to Nineteenth-Century Britain A Companion to the History of the Middle East Edited by Chris Williams Edited by Youssef M.
    [Show full text]
  • MEDIEVAL WARM PERIOD in OTHER ASIAN COUNTRIES (NOT Including China, Russia Or Japan)
    M EDIEVAL WARM PERIOD IN O THER ASIAN COUNTRIES (NOT Including China, Russia or Japan) SPPI & CO2SCIENCE ORIGINAL PAPER ♦ October 9, 2013 MEDIEVAL WARM PERIOD IN OTHER ASIAN COUNTRIES (NOT Including China, Russia or Japan) Citation: Center for the Study of Carbon Dioxide and Global Change. "Medieval Warm Period in Other Asian Countries.” Last modified October 9, 2013. http://www.co2science.org/subject/a/summaries/asiamwp.php. Climate alarmists have long contended that the Medieval Warm Period (MWP) was not a worldwide phenomenon, primarily because that reality would challenge another of their major claims, i.e., that late 20th-century temperatures were the warmest of the past millennium or more. Thus, it is important to know what has been learned about this subject in different parts of the world; and in this summary attention is focused on Asian countries other than China, Russia and Japan, which are treated individually in other MWP Summaries. In addition to China, Russia and Japan, the MWP has been identified in several other parts of Asia. Schilman et al. (2001)1, for example, analyzed foraminiferal oxygen and carbon isotopes, together with physical and geochemical properties of sediments, contained in two Off the coast of Israel … they cores extracted from the bed of the southeastern Mediterranean Sea off the coast of Israel, where they found evidence for the found evidence for the MWP MWP centered around AD 1200. And in discussing their findings, they make particular mention of the fact that there is an abundance centered around AD 1200. of other well-documented evidence for the existence of the MWP in the Eastern Mediterranean, including, in their words, "high In discussing their findings, they Saharan lake levels (Schoell, 1978; Nicholson, 1980), high Dead Sea levels (Issar et al.
    [Show full text]
  • Medieval Warm Period in Southern Europe
    M EDIEVAL WARM PERIOD IN SOUTHERN EUROPE CO2SCIENCE & SPPI ORIGINAL PAPER ♦ August 20, 2014 MEDIEVAL WARM PERIOD IN SOUTHERN EUROPE Citation: Center for the Study of Carbon Dioxide and Global Change. "Medieval Warm Period in Southern Europe.” Last modified August 20, 2014. http://www.co2science.org/subject/m/summaries/europemwp south.php. Was there really a global Medieval Warm Period? The IPCC used to acknowledge there was; but they have long since changed their view on the subject. Was there really Mounting evidence, however, suggests they were wrong to do so; and in this summary, new and a global Medieval Warm important data from Southern Europe that support their original belief are described and discussed. Period? The IPCC used to Working with a core of 2.5 meters length, which they sampled at intervals of 2 cm in the upper 1 meter and acknowledge there was; but at intervals of 5 cm below that depth, Martinez- Cortizas et al. (1999)1 derived a record of mercury they have long since deposition in the peat bog of Penido Vello in northwest Spain (43°32'N, 7°34'W) that extends to changed their view on the 4000 radiocarbon years before the present, which they analyzed for a number of parameters. This work subject. Mounting evidence, revealed, in their words, "that cold climates promoted an enhanced accumulation and the however, suggests they preservation of mercury with low thermal stability, and warm climates were characterized by a lower were wrong to do so. accumulation and the predominance of mercury with moderate to high thermal stability." And based on these findings and further analyses, they derived a temperature history for the region that they standardized to the mean temperature of the most recent 30 years of their record.
    [Show full text]
  • Global Warming in the Context of 2000 Years of Australian Alpine
    www.nature.com/scientificreports OPEN Global warming in the context of 2000 years of Australian alpine temperature and snow cover Received: 10 November 2017 Hamish McGowan 1, John Nikolaus Callow 2, Joshua Soderholm 1, Gavan McGrath2, Accepted: 28 February 2018 Micheline Campbell 2 & Jian-xin Zhao3 Published: xx xx xxxx Annual resolution reconstructions of alpine temperatures are rare, particularly for the Southern Hemisphere, while no snow cover reconstructions exist. These records are essential to place in context the impact of anthropogenic global warming against historical major natural climate events such as the Roman Warm Period (RWP), Medieval Climate Anomaly (MCA) and Little Ice Age (LIA). Here we show for a marginal alpine region of Australia using a carbon isotope speleothem reconstruction, warming over the past fve decades has experienced equivalent magnitude of temperature change and snow cover decline to the RWP and MCA. The current rate of warming is unmatched for the past 2000 years and seasonal snow cover is at a minimum. On scales of several decades, mean maximum temperatures have undergone considerable change ≈ ± 0.8 °C highlighting local scale susceptibility to rapid temperature change, evidence of which is often masked in regional to hemisphere scale temperature reconstructions. Historical documents, written and oral histories give insight to impacts that shifs in global climate had on empires, economies and the environment over the past two thousand years. Tis includes periods of relative warmth at the height of the Roman Empire known as the Roman Warm Period (RWP)1,2 and the Viking expan- sion during the Medieval Climate Anomaly (MCA), contrasting with social and economic disruption during the cold of the Little Ice Age (LIA)3–5.
    [Show full text]
  • Unfolding the Dynamics Among Climate, Balkan Landscapes, and Humans Over the Past Millennium
    City University of New York (CUNY) CUNY Academic Works All Dissertations, Theses, and Capstone Projects Dissertations, Theses, and Capstone Projects 9-2016 Lessons from the Past: Unfolding the Dynamics among Climate, Balkan Landscapes, and Humans over the Past Millennium Charuta J. Kulkarni The Graduate Center, City University of New York How does access to this work benefit ou?y Let us know! More information about this work at: https://academicworks.cuny.edu/gc_etds/1595 Discover additional works at: https://academicworks.cuny.edu This work is made publicly available by the City University of New York (CUNY). Contact: [email protected] LESSONS FROM THE PAST: UNFOLDING THE DYNAMICS AMONG CLIMATE, BALKAN LANDSCAPES, AND HUMANS OVER THE PAST MILLENNIUM by Charuta Kulkarni A dissertation submitted to the Graduate Faculty in Earth and Environmental Sciences in partial fulfillment of the requirements for the degree of Doctor of Philosophy, The City University of New York 2016 Copyright © 2016 by Charuta Kulkarni All Rights Reserved ii This manuscript has been read and accepted for the Graduate Faculty in Earth and Environmental Sciences in satisfaction of the dissertation proposal requirements for the degree of Doctor of Philosophy. Professor Dr. Rebecca Boger Date: ______________________ ______________________________ Chair of the Examining Committee Professor Dr. Cindi Katz Date: ______________________ ______________________________ Executive Officer Professor Dr. Dorothy Peteet Professor Dr. Arthur Bankoff Professor Dr. Yuri Gorokhovich Professor Dr. Ksenija Borojevic Supervisory Committee THE CITY UNIVERSITY OF NEW YORK iii Abstract Lessons from the Past: Unfolding the Dynamics among Climate, Balkan Landscapes, and Humans over the Past Millennium by Charuta Kulkarni Adviser: Professor Dr.
    [Show full text]