Vegetation and the Terrestrial Carbon Cycle Modelling the First 400 Million

Total Page:16

File Type:pdf, Size:1020Kb

Vegetation and the Terrestrial Carbon Cycle Modelling the First 400 Million Cambridge University Press 0521801966 - Vegetation and the Terrestrial Carbon Cycle: Modelling the First 400 Million Years D. J. Beerling and F. I. Woodward Frontmatter More information Vegetation and the terrestrial carbon cycle Modelling the first 400 million years Plants have colonised and modified the World’s surface for the last 400 million years. In this book the authors demonstrate that an understanding of the role of vegetation in the terrestrial carbon cycle during this time can be gained by linking the key mechanistic elements of present day vegetation processes to models of the global climate during different geological eras. The resulting simulations of climate and vegetation processes tie in with observable geological data, such as the distributions of coals and evaporites, supporting the validity of the authors’ approach. Simulation of possible conditions in future centuries are also presented, providing valuable predictions of the status of the earth’s vegetation and carbon cycle at a time of global warming. David Beerling is a Royal Society University Research Fellow and Honorary Reader in the Department of Animal and Plant Sciences at the University of Sheffield. He is holder of a 2001 Philip Leverhulme Prize for his work in the earth sciences. Ian Woodward is Professor of Plant Ecology in the Department of Animal and Plant Sciences at the University of Sheffield. He is author of Climate and Plant Distribution (1987) and co-editor of Plant Functional Types (1997). © Cambridge University Press www.cambridge.org Cambridge University Press 0521801966 - Vegetation and the Terrestrial Carbon Cycle: Modelling the First 400 Million Years D. J. Beerling and F. I. Woodward Frontmatter More information Vegetation and the terrestrial carbon cycle: Modelling the first 400 million years D.J. Beerling & F.I. Woodward Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, U.K. © Cambridge University Press www.cambridge.org Cambridge University Press 0521801966 - Vegetation and the Terrestrial Carbon Cycle: Modelling the First 400 Million Years D. J. Beerling and F. I. Woodward Frontmatter More information published by the press syndicate of the university of cambridge The Pitt Building, Trumpington Street, Cambridge, United Kingdom cambridge university press The Edinburgh Building, Cambridge CB2 2RU, UK 40 West 20th Street, New York, ny 10011–4211, USA 10 Stamford Road, Oakleigh, vic 3166, Australia Ruiz de Alarcón 13, 28014 Madrid, Spain Dock House, The Waterfront, Cape Town 8001, South Africa http://www.cambridge.org © D.J. Beerling and F.I. Woodward 2001 This book is in copyright. Subject to statutory exception and to the provisions of relevant collective licensing agreements, no reproduction of any part may take place without the written permission of Cambridge University Press. First published 2001 Printed in the United Kingdom at the University Press, Cambridge Typeface teffLexicon 10/14 pt System QuarkXPress® [se] A catalogue record for this book is available from the British Library Library of Congress Cataloguing in Publication data Beerling, D. J. Vegetation and the terrestrial carbon cycle : modelling the first 400 million years / D.J. Beerling & F.I. Woodward. p. cm. Includes bibliographical references (p. ). `ISBN 0 521 80196 6 1. Carbon cycle (Biogeochemistry)–Mathematical models. 2. Plant ecology–Mathematical models. 3. Paleoclimatology–Mathematical models. I. Woodward, F.I. II. Title. QH344. B43 2001 577Ј.144Ј015118–dc21 ISBN 0 521 80196 6 hardback © Cambridge University Press www.cambridge.org Cambridge University Press 0521801966 - Vegetation and the Terrestrial Carbon Cycle: Modelling the First 400 Million Years D. J. Beerling and F. I. Woodward Frontmatter More information Contents Preface vii Acknowledgements ix 1 Introduction 1 2 Investigating the past from the present 9 3 Climate and terrestrial vegetation 23 4 Climate and terrestrial vegetation of the present 53 5 The late Carboniferous 100 6 The Jurassic 135 7 The Cretaceous 183 8 The Eocene 238 9 The Quaternary 280 10 Climate and terrestrial vegetation in the future 340 11 Endview 353 References 361 Index 395 v © Cambridge University Press www.cambridge.org Cambridge University Press 0521801966 - Vegetation and the Terrestrial Carbon Cycle: Modelling the First 400 Million Years D. J. Beerling and F. I. Woodward Frontmatter More information Preface The study of plant distributions is a continuous feature of ecology. These studies may range from a small area of ground to the whole of the ter- restrial biosphere. The information from such studies underpins our current understanding of the terrestrial biosphere. Unfortunately this information, on its own, is not sufficient to answer large questions, such as what controls the current distribution of plants, or how will the current distribution and behaviour of plants respond to global environmental change? These are important questions and ones which are presented increasingly in order to satisfy human knowledge and decision making. Indeed the question, put to ecologists in the 1980s, of how will terrestrial vegetation respond to global warming could not be answered then and only now, 20 years later, is there some hope that we understand some of the major mechanisms involved and their likely outcomes. There is also no doubt that such questions are good for the development of ecology, in contrast to likely serious consequences for mankind. A feature of long-term studies in ecology is that there is nothing really new, most things have happened before, if only we could have seen them. There is current concern over the rapid increase in atmospheric CO™ concentrations but in geological times the atmospheric CO™ concentrations, and the Earth’s tem- perature have frequently been higher than the present. No doubt plants and vegetation will respond and adapt to future change, however mankind requires a more improbable outcome, that nothing should change, even though atmospheric composition and climate are changing rapidly. An outcome as likely as that expected from the actions of Svein Forkbeard’s son. A more serious question is how much will vegetation change and how much will ecosystem services change, such as water supply, the provision of biomass and the capacity of the biosphere to sequester anthropogenic releases of CO™.These are difficult questions to answer and any approach which makes predictions vii © Cambridge University Press www.cambridge.org Cambridge University Press 0521801966 - Vegetation and the Terrestrial Carbon Cycle: Modelling the First 400 Million Years D. J. Beerling and F. I. Woodward Frontmatter More information viii Preface must have mechanistic underpinning to have any chance of approaching reality. One approach taken in the area of climate change research has been to make predictions back in time, when the environment was different from the present. Predictions can then be made and tested against data collected at the appropriate time. Previous warm periods, such as 6000 years before present, have been a favourite for investigation and have proved useful for testing models developed for the contemporary world. A problem in going further back in time to geological eras is that the information about the climate and the biosphere is much more limited. However the relatively recent application of general circulation models to simulating past climates has provided a useful source of past climatic data. These GCM runs are constrained by proxy estimates of ocean temperatures and are probably reasonable estimates of past climates, although there are limited opportunities for testing their validity. The value of these simulations is that their data can be used to drive vegeta- tion models and the outputs of the vegetation models can be compared with fossil data which have not been used to constrain the GCMs. This approach of looking at past vegetation behaviour, and the carbon cycle in particular, is a new endeavour which implies a number of critical features. In particular it assumes that the contemporary understanding of the carbon cycle applies equally well at any other time. It also assumes that associated processes, for instance the water cycle and vegetation processes, such as succes- sion and responses to climate and atmospheric CO™ have also operated in essentially the same manner as the present. The fact that photosynthesis drives vegetation processes suggests that contemporary understanding will have geological relevance. This book describes approaches to testing quantita- tively how much this relevance amounts to and how we can deal with uncer- tainty in both vegetation and climate models. It is axiomatic that models are wrong, the question is how wrong and how much does this matter. These fea- tures will be tested for a wide range of eras before finally modelling the responses of vegetation to one particular scenario of future climatic change. Not all eras during the life of terrestrial vegetation have been covered, because GCMs are not currently available but those which have been completed have been periods when vegetation has been challenged by a wide variety of unusual conditions. Our final hope is that we can show a range of responses by vegetation and the carbon cycle which stimulate further interest and enquiry, before our predictions of the future become the predictions of the present. D.J. Beerling F.I. Woodward © Cambridge University Press www.cambridge.org Cambridge University Press 0521801966 - Vegetation and the Terrestrial Carbon Cycle: Modelling
Recommended publications
  • Weathering Heights 08 July 2020 James Hansen
    Weathering Heights 08 July 2020 James Hansen In 2007 Bill McKibben asked me whether 450 ppm would be a reasonable target for atmospheric CO2, if we wished to maintain a hospitable climate for future generations. 450 ppm seemed clearly too high, based on several lines of evidence, but especially based on paleoclimate data for climate change. We were just then working on a paper,1 Climate sensitivity, sea level and atmospheric carbon dioxide, 2 that included consideration of CO2 changes over the Cenozoic era, the past 65 million years, since the end of the Cretaceous era. The natural source of atmospheric CO2 is volcanic emissions that occur mainly at continental margins due to plate tectonics (“continental drift”). The natural sink is the weathering process, which ultimately deposits carbon on the ocean floor as limestone. David Beerling, an expert in trace gas biogeochemistry at the University of Sheffield, was an organizer of the meeting at which I presented the above referenced paper. Soon thereafter I enlisted David and other paleoclimate experts to help answer Bill’s question about a safe level of atmospheric CO2, which we concluded was somewhere south of 350 ppm.3 Since then, my group at Climate Science, Awareness and Solutions (CSAS), has continued to cooperate with David’s group at the University of Sheffield. One of the objectives is to investigate the potential for drawdown of atmospheric CO2 by speeding up the weathering process. In the most recent paper, which will be published in Nature tomorrow, David and co-authors report on progress in testing the potential for large-scale CO2 removal via application of rock dust on croplands.
    [Show full text]
  • Robert A. Berner 1935–2015
    Robert A. Berner 1935–2015 A Biographical Memoir by Donald E. Canfield ©2019 National Academy of Sciences. Any opinions expressed in this memoir are those of the author and do not necessarily reflect the views of the National Academy of Sciences. ROBERT ARBUCKLE BERNER November 25, 1935–January 10, 2015 Elected to the NAS, 1987 Bob Berner passed away on January 10, 2015, closing the final chapter of one of the most influential and colorful geochemists of all time. I had the pleasure of working as a Ph.D. student with Bob from 1982 to 1988, a period of particular innovation and transformation in his scientific career. In what follows, I will provide some brief recol- lections of Bob as a person and mentor, while taking full account of his contributions to science. The reader is also directed to Bob’s excellent autobiography (Berner 2013 ). Bob as a Person Bob Berner, walking down the hall, his grey turtle neck half untucked at the back, with a big toothy grin; that’s the way I will remember him. Especially the grin. Bob was, of By Donald E. Canfield course, a scientific legend. We’ll get to that in a moment. But, he was also very much more than that. Bob was fun, and he loved a party. He also loved a good meal and good glass of wine. Bob was a decided Francophile and learned the basics of the French language. He had a favorite Parisian café where he knew the chef personally, and they knew Bob’s favorite meal and wine.
    [Show full text]
  • Target Atmospheric CO2: Where Should Humanity Aim?
    Target Atmospheric CO2: Where Should Humanity Aim? James Hansen,1,2* Makiko Sato,1,2 Pushker Kharecha,1,2 David Beerling,3 Valerie Masson-Delmotte,4 Mark Pagani,5 Maureen Raymo,6 Dana L. Royer,7 James C. Zachos8 Paleoclimate data show that climate sensitivity is ~3°C for doubled CO2, including only fast feedback processes. Equilibrium sensitivity, including slower surface albedo feedbacks, is ~6°C for doubled CO2 for the range of climate states between glacial conditions and ice- free Antarctica. Decreasing CO2 was the main cause of a cooling trend that began 50 million years ago, large scale glaciation occurring when CO2 fell to 425±75 ppm, a level that will be exceeded within decades, barring prompt policy changes. If humanity wishes to preserve a planet similar to that on which civilization developed and to which life on Earth is adapted, paleoclimate evidence and ongoing climate change suggest that CO2 will need to be reduced from its current 385 ppm to at most 350 ppm. The largest uncertainty in the target arises from possible changes of non-CO2 forcings. An initial 350 ppm CO2 target may be achievable by phasing out coal use except where CO2 is captured and adopting agricultural and forestry practices that sequester carbon. If the present overshoot of this target CO2 is not brief, there is a possibility of seeding irreversible catastrophic effects. Human activities are altering Earth’s atmospheric composition. Concern about global warming due to long-lived human-made greenhouse gases (GHGs) led to the United Nations Framework Convention on Climate Change (1) with the objective of stabilizing GHGs in the atmosphere at a level preventing “dangerous anthropogenic interference with the climate system.” The Intergovernmental Panel on Climate Change (IPCC, 2) and others (3) used several “reasons for concern” to estimate that global warming of more than 2-3°C may be dangerous.
    [Show full text]
  • Royal Society: Greenhouse Gas Removal (Report)
    Greenhouse gas removal In 2017 the Royal Society and Royal Academy of Engineering were asked by the UK Government to consider scientific and engineering views on greenhouse gas removal. This report draws on a breadth of expertise including that of the Fellowships of the two academies to identify the range of available greenhouse gas removal methods, the factors that will affect their use and consider how they may be deployed together to meet climate targets, both in the UK and globally. The Royal Society and Royal Academy of Engineering would like to acknowledge the European Academies’ Science Advisory Council report on negative emission technologies (easac.eu/publications/details/easac-net), which provided a valuable contribution to a number of discussions throughout this project. Greenhouse gas removal Issued: September 2018 DES5563_1 ISBN: 978-1-78252-349-9 The text of this work is licensed under the terms of the Creative Commons Attribution License which permits unrestricted use, provided the original author and source are credited. The license is available at: creativecommons.org/licenses/by/4.0 Images are not covered by this license. This report can be viewed online at: royalsociety.org/greenhouse-gas-removal Erratum: The first edition of this report raeng.org.uk/greenhousegasremoval incorrectly listed the area of saltmarsh in the UK as 0.45 Mha, which is instead 0.045 Mha. This error has been corrected in the UK Cover image Visualisation of global atmospheric carbon dioxide scenario on p96 and the corresponding surface concentration by Cameron Beccario, earth.nullschool.net, GGR for habitat restoration adjusted. The using GEOS-5 data provided by the Global Modeling and Assimilation conclusions of this report and the UK net-zero Office (GMAO) at NASA Goddard Space Flight Center.
    [Show full text]
  • Newsletter Number 85
    The Palaeontology Newsletter Contents 85 Editorial 2 Association Business 3 Association Meetings 16 From our correspondents 28,000 leagues across the sea 20 R for palaeontologists: Introduction 28 Future meetings of other bodies 39 Meeting Reports 46 Obituary Richard Aldridge 66 Sylvester-Bradley reports 69 Publicity Officer: Old Fossils, New Media 82 Book Reviews 85 Books available to review 92 Palaeontology vol 57 parts 1 & 2 93–94 Reminder: The deadline for copy for Issue no 86 is 9th June 2014. On the Web: <http://www.palass.org/> ISSN: 0954-9900 Newsletter 85 2 Editorial The role of Newsletter Reporter is becoming part of the portfolio of responsibilities of the PalAss Publicity Officer, which is Liam Herringshaw’s new post on Council. This reflects a broader re-organization of posts on Council that are aimed at enhancing the efforts of the Association. Council now includes the posts of Education Officer and Outreach Officer, who will, along with the Publicity Officer, develop strategies to engage with different target audiences. The Association has done what it can to stay abreast of developments in social media, through the establishment of the Palass Twitter Feed (@ThePalAss), the development of Palaeontology [online] and the work of Palaeocast, which is a project that has received support from the Association. Progressive Palaeontology has more or less migrated to Facebook. Such methods of delivery have overtaken the Newsletter, the News side-boxes on the Pal Ass website and … However, our real asset in the publicity sphere is you, the members. As palaeontologists, we hold the subject-specific knowledge and the links among the different spheres of knowledge in the other sciences that contribute to our understanding of the history of life.
    [Show full text]
  • Women's Climate Action Agenda
    THE Women’s EARTH AND CLIMATE ActION NEtwORK IS PROUD TO PRESENT THE 2014–2015 WOMEN’S CLIMATE ACTION AGENDA WOMEN’S CLIMATE ActION AgENDA WOMEN OF THE WORLD: URGE OUR LEADERS TO HALT GLOBAL CLIMATE CHANGE; DEMAND A JUST AND NECESSARY TRANSITION TO GLOBAL SUSTAINABILITY AND; PRESENT A PLAN FOR OUR COLLEctIVE FUTURE. AUTHORED BY MEMBERS AND ALLIES OF THE Women’s EARTH AND CLIMATE ActION NEtwORK WOMEN ARE LIVING ON THE FRONT LINES OF CLIMATE CHANGE AND ARE READY TO BE ACTIVE PARTNERS IN DEALING WITH CLIMATE CHANGE. IF THE INTERNATIONAL COMMUNITY IS SERIOUS ABOUT ADDRESSING CLIMATE CHANGE, IT MUST RECOGNIZE WOMEN AS A FUNDAMENTAL PART OF THE CLIMATE SOLUTION. PROFESSOR WANGARI MAATHAI NOBEL PEACE PRIZE LAUREATE 1940-2011 P rinted on recycled paper. on recycled rinted WECAN WOMEN’S CLIMATE ACTION AGENDA 2 Women’s Climate Action Agenda The views and statements in the Women’s Climate Action Agenda (WCAA) are those of WECAN’s Core Team, Members, and Allies. The views and state- ments were derived from the collective efforts of participants of the 2013 International Women’s Earth and Climate Summit, held in New York. The WCAA does not necessarily reflect the views of all summit participants. LEAD AUTHORS Osprey Orielle Lake, Claire Greensfelder and Elaine Colligan WECAN Women’s Climate Action Agenda © Women’s Earth and Climate Caucus and eraGlobal Alliance RIGHTS AND PERMISSIONS This publication may be reproduced in whole or in part and in any form for educational or non-profit purposes without special permission from the copyright holder, provided acknowledgment of the source is made.
    [Show full text]
  • Princeton University Press Princeton and Oxford
    PRINCETON UNIVERSITY PRESS PRINCETON AND OXFORD Wagner_ClimateShock_FINAL.indd 3 12/30/14 8:32 AM Copyright © 2015 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 1TW press.princeton.edu All Rights Reserved Library of Congress Cataloging-in-Publication Data Wagner, Gernot, 1980– Climate shock : the economic consequences of a hotter planet / Gernot Wagner and Martin L. Weitzman. pages cm Includes bibliographical references and index. ISBN 978-0-691-15947-8 (hardcover : alk. paper) 1. Climatic changes— Economic aspects. I. Weitzman, Martin L., 1942– II. Title. QC903.W34 2015 363.738’74—dc23 2014028540 British Library Cataloging- in- Publication Data is available This book has been composed in Sabon Next LT Pro, DINPro Printed on acid- free paper. ∞ Printed in the United States of America 1 3 5 7 9 10 8 6 4 2 Wagner_ClimateShock_FINAL.indd 4 12/30/14 8:32 AM Contents Preface: Pop Quiz ix Chapter 1. 911 1 Chapter 2. 411 30 Chapter 3. Fat Tails 48 Chapter 4. Willful Blindness 80 Chapter 5. Bailing Out the Planet 92 Chapter 6. 007 116 Chapter 7. What You Can Do 128 Epilogue: A Different Kind of Optimism 148 Acknowledgments 153 Notes 155 Bibliography 207 Index 243 Wagner_ClimateShock_FINAL.indd 7 12/30/14 8:32 AM Notes PREFACE: POP QUIZ Page ix— Two quick questions: Princeton’s Robert Socolow has started many a presentation with a version of this quiz, asking audiences whether they consider climate change “an urgent matter” and fos- sil fuels “hard to displace.” He groups the resulting views into four broad buckets, reproduced here with permission, and with slight modifications: Is getting the world off fossil fuels difficult? No Yes No A low- carbon world Perhaps most of the unmotivated by general public, and climate parts of the energy Is climate considerations.
    [Show full text]
  • 14.6 Books MH
    Vol 447|14 June 2007 BOOKS & ARTS Dirt cheap soil Precious few societies have taken care of their most fundamental resource. Dirt: The Erosion of Civilizations By David R. Montgomery University of California Press: 2007. 295 pp. $24.95, £15.95 Eric A. Davidson B. FORSTER/GETTY IMAGES B. FORSTER/GETTY If everyday expressions offer clues to what we value, then the common use of ‘dirt-cheap’ to describe anything inexpensive speaks poorly of our appreciation for soil. Like water and air, soil is not efficiently traded and priced in the marketplace, and yet we could not live without it. It doesn’t take a rocket scientist to figure out that food security and human well- being depend on fertile soil. That expression implies admiration for the intelligence of rocket scientists, and similar praise is due to Earth scientist David Montgomery, whose new book insightfully chronicles the rise of agricul- tural technology and the concomitant fall of soil depth just about everywhere in the world, from prehistoric to modern times. The topic could not be more timely, as recent large-scale Dust in the wind: civilizations collapse when their soil runs out. expansion of maize (corn) in the United States and sugar cane in Brazil for biofuel produc- Not all is gloomy. A precious few exam- but Montgomery argues that soil has become tion signals a new era of competition between ples of good soil management are described. a scarce resource. More than a history lesson the energy and food sectors for the globally Montgomery also cites philosophers, agrono- of the legacies of past civilizations, the book finite resource of arable land and the remain- mists, and soil scientists from ancient Greece raises a critical concern for modern times.
    [Show full text]
  • Ecosystem CO2 Starvation and Terrestrial Silicate Weathering: Mechanisms and Global-Scale Quantification During the Late Miocene
    Journal of Ecology 2012, 100, 31–41 doi: 10.1111/j.1365-2745.2011.01905.x CENTENARY SYMPOSIUM SPECIAL FEATURE Ecosystem CO2 starvation and terrestrial silicate weathering: mechanisms and global-scale quantification during the late Miocene David J. Beerling1*, Lyla L. Taylor1, Catherine D. C. Bradshaw2, Daniel J. Lunt2, Paul J. Valdes2, Steven A. Banwart3, Mark Pagani4 and Jonathan R. Leake1 1Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK; 2School of Geographical Sciences, University of Bristol, Bristol BS8 1SS, UK; 3Cell-Mineral Research Centre, Kroto Research Institute, Univer- sity of Sheffield, Sheffield S1 7HQ, UK; and 4Department of Geology and Geophysics, Yale University, New Haven, CT 06520, USA Summary 1. The relative constancy of the lower limit on Earth’s atmospheric CO2 concentration ([CO2]a) during major tectonic episodes over the final 24 million years (Ma) of the Cenozoic is surprising because they are expected to draw-down [CO2]a by enhancing chemical weathering and carbonate deposition on the seafloor. That [CO2]a did not drop to extremely low values suggests the existence of feedback mechanisms that slow silicate weathering as [CO2]a declines. One proposed mechanism is a negative feedback mediated through CO2 starvation of land plants in active orogenic regions compromising the efficiency of the primary carboxylating enzyme in C3 plants (Rubisco) and dimin- ishing productivity and terrestrial weathering. 2. The CO2 starvation hypothesis is developed further by identifying four key related mechanisms:
    [Show full text]
  • Plants As a Force of Nature the Emerald Planet: How Plants Changed Earth's History by David Beerling
    TREE-888; No of Pages 2 ART CLE N PRESS Update Cel I Book Review Plants as a force of nature The Emerald Planet: How Plants Changed Earth's History by David Beerling. Oxford University Press, 2007. $29.95 (307 pages) ISBN 978-0-19-280602-4 William A. DiMichele Department of Paleobiology, Smithsonian Institution National Museum of Natural History, Washington, DC 20560, USA Many of the chapters present syntheses quite different Just how exciting is it to be a scientist? from those we learned in class or commonly encounter in Colleagues and I occasionally talk about text books. Take the origin of leaves (chapter 2). Beerling whether we would recommend this career argues that large, planate leaves could not exist in an to our children in light of the modern atmosphere high in CO2. High levels of this gas suppress pressures on scholarly pursuit and the the abundance of stomata, thus reducing the ability of a evaluation thereof [1] - about the hours planate surface to stay cool by the transpiration of water spent writing and answering emails, vapor to the atmosphere as the leaf is heated by sunlight. applying for grants, serving on commit- Remarkably, the genetic machinery that underlies leaf tees. But, occasionally, we do get that development is almost the same in all vascular plants - feeling of being stars in our own movie. this is true even for lineages that separated in the Early A paleobotanical scene: an SUV sweeps down a steep ramp Devonian, long before planate leaves appeared - implying into an active coal pit. The car does a 180 in a cloud of dust.
    [Show full text]
  • Tipping Points for Abrupt Climate Change the Shadow That Haunts Climate Policy IGSD/INECE∗ Climate Briefing Note: 27 October 2008
    Institute for Governance & Sustainable Development e Montreal Tipping Points for Abrupt Climate Change The Shadow That Haunts Climate Policy IGSD/INECE∗ Climate Briefing Note: 27 October 2008 The paleoclimate records show that past climate changes have included both steady, linear changes as well as abrupt, non-linear changes, where small increases in global warming produced large and irreversible impacts once tipping points were passed. Climate scientists now warn that anthropogenic emissions are pushing the planet’s climate system toward such tipping points sooner than previously expected, and that impacts could be catastrophic. Among potential impacts of passing climate tipping points are the disappearance of Arctic summer sea ice, disintegration of the Greenland Ice Sheet, collapse of the West Antarctic Ice Sheet, shutdown of the Atlantic Thermohaline Circulation, and dieback of Amazonian and boreal forests.1 The catastrophic impacts from these events would include many meters of sea level rise, water shortages, megadroughts, and famine, and could lead to political instability and resource wars.2 Other impacts include release of methane and other global warming gases from permafrost and ocean hydrates, which could set off runaway feedbacks. In a recent study in the Proceedings of the National Academy of Sciences, V. Ramanathan and Y. Feng from Scripps Institution of Oceanography, University of California, San Diego, calculate that greenhouse gas [GHG] emissions as of 2005 have committed the planet to warming of “2.4˚C above the preindustrial surface temperatures,”3 which is within the range of predicted tipping points. See Figure. “Probability distribution for the committed warming by GHG between 1750 and 2005.
    [Show full text]
  • Newsletter 163/2
    THE GEOLOGICAL SOCIETY OF GLASGOW Registered Scottish Charity No. SC007013 President: Dr. Neil Clark www.geologyglasgow.org.uk December 2020 163/2 The discovery of a new fossil bird skull in 2018 dates to the very end of the Cretaceous Period—the final 700 thousand years of the Age of Dinosaurs. It gives us an important glimpse of how birds looked 66.7 million years ago, during the narrow interval of time just before a giant asteroid struck the Earth. Come online on the 10th December to hear Daniel Field’s talk on the ‘Wonderchicken’ In this newsletter: • Lecture details for December, January and Febrary 2021 • AGM Information 1 Lecture Programme 2020-21 (Session 163) This session continues to be different. The Covid-19 pandemic means we have to organise our lectures on-line. We aim to keep to the usual dates of the second Thursdays of each month. The programme is organised for the next few months, but is subject to change. All lectures this session will be held online using Zoom. Invites will be emailed to members a few days prior to the meeting. The lectures will commence at 7.30 pm. Lectures will last about an hour plus there will be time afterwards for questions and a vote of thanks. If you have access to an email address but have not given it to the Society and wish to view these lectures please contact [email protected] The speakers may grant permission for the lecture to be recorded. In these cases it will be posted on Youtube and a link emailed to members.
    [Show full text]