Simulating Past and Forecasting Future Climates

1993 ◽  
Vol 20 (4) ◽  
pp. 339-346 ◽  
Author(s):  
Reid A. Bryson
Keyword(s):  
Carbon Dioxide ◽  
Global Climate ◽  
Rapid Change ◽  
Carbon Dioxide Content ◽  
Volcanic Origin ◽  
The North ◽  
The Earth ◽  
History Of ◽  
Climatic History ◽  
Volcanic Aerosols

Climatic change is not a new phenomenon, nor is it random, as most of the variation can be explained in terms of variations in the sunlight reaching the surface of the Earth. The solar energy reaching the surface is modified by the aerosols in the atmosphere, however, and that means primarily aerosols of volcanic origin.The climatic history of the Earth is divided up into episodes with abrupt beginnings and ends. Rapid changes from one climatic state to another are normal. The fluctuations within this century do not appear to be unusual in any respect.To the Author's knowledge there is no evidence that past climatic changes, including those of the last decades, are related to changes in carbon dioxide in the atmosphere—except perhaps for warmer nights in the North American mid-west. It is not possible to simulate past climates using carbon dioxide content as the main variable, but it is possible to do so using calculated solar radiation as modified by volcanic aerosols. This strongly suggests that forecasts of the climatic future based on carbon dioxide increases are suspect.Computerized models of the climate that can simulate decadal and century-long variations of climate as well as variations on the millennium scale, suggest that the climate will not warm dramatically in the next fifty years, but will, rather soon after that, begin a rather rapid change towards the next glacial climate.Changes in our global array of cultures, sufficient to affect the global climate in a way which we perceive as beneficial, probably are not possible within centuries without massive physical conflict. There are both winners and losers when the climate changes in a non-uniform pattern, as it always does. It is a well-known fact that a global change of 0.5°C in mean temperature, such as has happened in recent years, might produce some regions of 10°C change in either direction and some regions with no change at all, and additionally an array of rainfall changes of various magnitudes. Russians would welcome warming of their climate!The problems with attempting to modify the global climate in a particular direction are enormous and would be incredibly costly. This is compounded by our not knowing what the climate would do without intervention. Only one thing is truly clear, and it is that the present knowledge of the climatic effect of changing carbon dioxide content of the atmosphere is totally inadequate as a basis for initiating any global attempt to change the climate.The indicated action would appear to be to engage in some high-quality climatic research based on sound science before taking global risks greater than those that might arise from the putative ‘global warming’.

Effects of Continents and Supercontinents on Climate

2004 ◽  
Author(s):  
John J. W. Rogers ◽  
M. Santosh
Keyword(s):  
Global Climate ◽  
Climatic Conditions ◽  
Polar Regions ◽  
The North ◽  
Rock Types ◽  
Control Climate ◽  
The Earth ◽  
History Of ◽  
Earth’S Climate ◽  
Geologic Record

Continents affect the earth’s climate because they modify global wind patterns, control the paths of ocean currents, and absorb less heat than seawater. Throughout earth history the constant movement of continents and the episodic assembly of supercontinents has influenced both global climate and the climates of individual continents. In this chapter we discuss both present climate and the history of climate as far back in the geologic record as we can draw inferences. We concentrate on longterm changes that are affected by continental movements and omit discussion of processes with periodicities less than about 20,000 years. We refer readers to Clark et al. (1999) and Cronin (1999) if they are interested in such short-term processes as El Nino, periodic variations in solar irradiance, and Heinrich events. The chapter is divided into three sections. The first section describes the processes that control climate on the earth and includes a discussion of possible causes of glaciation that occurred over much of the earth at more than one time in the past. The second section investigates the types of evidence that geologists use to infer past climates. They include specific rock types that can form only under restricted climatic conditions, varieties of individual fossils, diversity of fossil populations, and information that the 18O/16O isotopic system can provide about temperatures of formation of ancient sediments. The third section recounts the history of the earth’s climate and relates changes to the growth and movement of continents. This history takes us from the Archean, when climates are virtually unknown, through various stages in the evolution of organic life, and ultimately to the causes of the present glaciation in both the north and the south polar regions. The earth’s climate is controlled both by processes that would operate even if continents did not exist and also by the positions and topographies of continents. We begin with the general controls, then discuss the specific effects of continents, and close with a brief discussion of processes that cause glaciation. The general climate of the earth is determined by the variation in the amount of sunshine received at different latitudes, by the earth’s rotation, and by the amount of arriving solar energy that is retained in the atmosphere.

Introduction

2004 ◽  
Author(s):  
Robert A. Berner
Keyword(s):  
Climate Change ◽  
Carbon Dioxide ◽  
Carbon Cycle ◽  
Global Climate ◽  
Geological Time ◽  
Short Term ◽  
Quaternary Period ◽  
Geological Time Scale ◽  
The Earth

The cycle of carbon is essential to the maintenance of life, to climate, and to the composition of the atmosphere and oceans. What is normally thought of as the “carbon cycle” is the transfer of carbon between the atmosphere, the oceans, and life. This is not the subject of interest of this book. To understand this apparently confusing statement, it is necessary to separate the carbon cycle into two cycles: the short-term cycle and the long-term cycle. The “carbon cycle,” as most people understand it, is represented in figure 1.1. Carbon dioxide is taken up via photosynthesis by green plants on the continents or phytoplankton in the ocean. On land carbon is transferred to soils by the dropping of leaves, root growth, and respiration, the death of plants, and the development of soil biota. Land herbivores eat the plants, and carnivores eat the herbivores. In the oceans the phytoplankton are eaten by zooplankton that are in turn eaten by larger and larger organisms. The plants, plankton, and animals respire CO2. Upon death the plants and animals are decomposed by microorganisms with the ultimate production of CO2. Carbon dioxide is exchanged between the oceans and atmosphere, and dissolved organic matter is carried in solution by rivers from soils to the sea. This all constitutes the shortterm carbon cycle. The word “short-term” is used because the characteristic times for transferring carbon between reservoirs range from days to tens of thousands of years. Because the earth is more than four billion years old, this is short on a geological time scale. As the short-term cycle proceeds, concentrations of the two principal atmospheric gases, CO2 and CH4, can change as a result of perturbations of the cycle. Because these two are both greenhouse gases—in other words, they adsorb outgoing infrared radiation from the earth surface—changes in their concentrations can involve global warming and cooling over centuries and many millennia. Such changes have accompanied global climate change over the Quaternary period (past 2 million years), although other factors, such as variations in the receipt of solar radiation due to changes in characteristics of the earth’s orbit, have also contributed to climate change.

A late-glacial – Holocene palaeoecological record from Pye Lake on the eastern shore of Nova Scotia, CanadaGeological Survey of Canada Contribution 20080395.

2009 ◽  
Vol 46 (9) ◽  
pp. 637-650 ◽  
Author(s):  
Robert J. Mott ◽  
Ian R. Walker ◽  
Samantha L. Palmer ◽  
Martin Lavoie
Keyword(s):  
Nova Scotia ◽  
Younger Dryas ◽  
Late Glacial ◽  
Forest Composition ◽  
Eastern Shore ◽  
The North ◽  
Tundra Vegetation ◽  
History Of ◽  
Climatic History ◽  
Recent Sediments

Pollen and chironomid analyses and radiocarbon dating at Pye Lake on the eastern shore of Nova Scotia are used to outline the vegetation and climatic history of the area. The coast was deglaciated prior to ∼12 200 14C BP (14 300 cal BP), and herbaceous tundra vegetation invaded the area. Midge-inferred maximum summer surface-water temperatures in the lake ranged between 9 and 11 °C. Subsequent gradual warming to ∼18 °C by 10 800 14C BP (12 725 cal BP) favoured the migration of a variety of herbaceous and shrub taxa into the region. Rapid cooling to ∼10 °C saw vegetation revert to herbaceous tundra communities. This interval, related to the Younger Dryas cold interval of the North Atlantic and Europe, lasted until ∼10 000 14C BP (11 630 cal BP). The climate then warmed again to conditions similar to those that prevailed immediately before onset of Younger Dryas cooling. Further warming saw successive tree species migrate into the area until, by the mid-Holocene, the forests contained most of the taxa prevalent today. Since ∼3500 years ago, cooling of the climate has favoured conifer species over broad-leaved taxa. Agriculture and logging practices in the last 150 years have altered the forest composition, but pollen analysis of the most recent sediments cannot resolve these changes adequately.

scholarly journals Analysis of Long-Term Moon-Based Observation Characteristics for Arctic and Antarctic

2019 ◽  
Vol 11 (23) ◽  
pp. 2805 ◽  
Author(s):  
Yue Sui ◽  
Huadong Guo ◽  
Guang Liu ◽  
Yuanzhen Ren
Keyword(s):  
Global Climate Change ◽  
Large Scale ◽  
Global Climate ◽  
Earth Observation ◽  
Polar Regions ◽  
The Moon ◽  
The North ◽  
The Earth ◽  
The Antarctic

The Antarctic and Arctic have always been critical areas of earth science research and are sensitive to global climate change. Global climate change exhibits diversity characteristics on both temporal and spatial scales. Since the Moon-based earth observation platform could provide large-scale, multi-angle, and long-term measurements complementary to the satellite-based Earth observation data, it is necessary to study the observation characteristics of this new platform. With deepening understanding of Moon-based observations, we have seen its good observation ability in the middle and low latitudes of the Earth’s surface, but for polar regions, we need to further study the observation characteristics of this platform. Based on the above objectives, we used the Moon-based Earth observation geometric model to quantify the geometric relationship between the Sun, Moon, and Earth. Assuming the sensor is at the center of the nearside of the Moon, the coverage characteristics of the earth feature points are counted. The observation intervals, access frequency, and the angle information of each point during 100 years were obtained, and the variation rule was analyzed. The research showed that the lunar platform could carry out ideal observations for the polar regions. For the North and South poles, a continuous observation duration of 14.5 days could be obtained, and as the latitude decreased, the duration time was reduced to less than one day at the latitude of 65° in each hemisphere. The dominant observation time of the North Pole is concentrated from mid-March to mid-September, and for the South Pole, it is the rest of the year, and as the latitude decreases, it extends outward from both sides. The annual coverage time and frequency will change with the relationship between the Moon and the Earth. This study also proves that the Moon-based observation has multi-angle observation advantages for the Arctic and the Antarctic areas, which can help better understand large-scale geoscientific phenomena. The above findings indicate that the Moon-based observation can be applied as a new type of remote sensing technology to the observation field of the Earth’s polar regions.

scholarly journals New Tendencies in Global Climate Change and Their Effects on the Climate of Hungary

Hadmérnök ◽  
2019 ◽  
Vol 14 (1) ◽  
pp. 99-107
Author(s):  
László Földi ◽  
László Halász
Keyword(s):  
Climate Change ◽  
Carbon Dioxide ◽  
Greenhouse Gases ◽  
Climate Models ◽  
Climate Model ◽  
Global Climate ◽  
Regional Climate ◽  
Global Climate Models ◽  
Lower Atmosphere ◽  
The Earth

Defining the term of climate, we investigate the role of natural causes and effects of human activities in climate change. The temperature of the Earth is determined by the balance between the amount of radiation energy received from the Sun and that emitted from the surface of the Earth towards the outer space. Greenhouse gases in the atmosphere, including water vapor, carbon dioxide, methane and nitrous oxides, act to make the surface much warmer, because they absorb and emit heat energy in all directions (including downwards), keeping Earth’s surface and lower atmosphere warm. The primary cause of climate change is the burning of fossil fuels, such as oil and coal, which emits greenhouse gases into the atmosphere – primarily carbon dioxide. We give a review about the activity of the Intergovernmental Panel on Climate Change and the United Nations Climate Change Conferences. Shortly investigate the different global climate models and some regional climate models. Finally discuss the results of regional climate model simulations for the Carpathian Basin.

MEDIEVAL WARM PERIOD OF THE HOLOCENE AND ITS POSSIBLE CAUSES

2020 ◽  
Vol 42 (4) ◽  
pp. 395-405
Author(s):  
Valeriy FEDOROV ◽  
◽  
Pavel GREBENNIKOV ◽  
Keyword(s):  
Heat Transfer ◽  
Global Climate ◽  
Medieval Warm Period ◽  
Warm Period ◽  
Meridional Transport ◽  
The Holocene ◽  
The Earth ◽  
Winter Half ◽  
History Of

A brief overview of reliably established global climate events in the Holocene is provided. On the basis of high-precision astronomical ephemeris with high spatial and temporal resolution, the annual and seasonal insolation of the Earth and hemispheres was calculated for the period 3000 BC-AD 2999. According to the results of calculations, the values of insolation contrast were obtained in a generalized manner (for the regions of the heat source and sink), reflecting the changes in the meridional insolation gradient that controls the meridional heat transfer in the hemispheres. The character of long-term variations of both the annual and seasonal arrival, and the annual and seasonal meridional transport of radiation heat in the hemispheres was obtained. The long-term distribution of insolation characteristics of the Earth and hemispheres (annual and seasonal insolation and insolation contrast in the hemispheres) is analyzed. The synchronicity of the extrema of the irradiation characteristics with the global climatic event in the history of the Earth (the Medieval Warm Period of the Holocene) was revealed. On the basis of the revealed synchronicity, the maximum insolation contrast in the winter half of the year in the Northern Hemisphere (the maximum of meridional heat transfer in the winter half of the year), as well as the maximum of interhemispheric heat transfer may be determined to be the reasons for the Medieval Warm Period.

scholarly journals I.—Notes on the Geological History of the Victoria Falls

1905 ◽  
Vol 2 (12) ◽  
pp. 529-532
Author(s):  
G. W. Lamplugh
Keyword(s):  
Geological History ◽  
Volcanic Origin ◽  
The Earth ◽  
History Of ◽  
Victoria Falls

It is difficult for anyone standing on the brink of the Chasm, after having seen the placid flow of the Zambesi above the Falls, to believe that the fissure into which the river is so suddenly precipitated has been formed gradually by the action of the river itself, and not by some great convulsion during which the very crust of the earth was rent. The narrowness of the abyss, the strange zigzags along which the tumultuous waters rush after their first great plunge, the mystery which has long surrounded the further course of the river after it swings away out of sight among its forbidding precipices, and the knowledge that the rocks across which it plunges are of volcanic origin, are all factors that have aided the illusion. Hence it is not surprising to find that the explanation given by David Livingstone half a century ago, that the majestic Zambesi has here been intercepted by a rent due to some earth movement in the solid rocks, has been adopted without question in all the later descriptions of this wonderful spectacle.

Henry Cavendish (1731–1810): hydrogen, carbon dioxide, water, and weighing the world

2014 ◽  
Vol 307 (1) ◽  
pp. L1-L6 ◽  
Author(s):  
John B. West
Keyword(s):  
Carbon Dioxide ◽  
Respiratory Physiology ◽  
Simple Experiment ◽  
Atmospheric Air ◽  
The Earth ◽  
The World ◽  
History Of ◽  
Air Sample ◽  
Major Figure ◽  
Water Hydrogen

Henry Cavendish (1731–1810) was an outstanding chemist and physicist. Although he was not a major figure in the history of respiratory physiology he made important discoveries concerning hydrogen, carbon dioxide, atmospheric air, and water. Hydrogen had been prepared earlier by Boyle but its properties had not been recognized; Cavendish described these in detail, including the density of the gas. Carbon dioxide had also previously been studied by Black, but Cavendish clarified its properties and measured its density. He was the first person to accurately analyze atmospheric air and reported an oxygen concentration very close to the currently accepted value. When he removed all the oxygen and nitrogen from an air sample, he found that there was a residual portion of about 0.8% that he could not characterize. Later this was shown to be argon. He produced large amounts of water by burning hydrogen in oxygen and recognized that these were its only constituents. Cavendish also worked on electricity and heat. However, his main contribution outside chemistry was an audacious experiment to measure the density of the earth, which he referred to as “weighing the world.” This involved determining the gravitational attraction between lead spheres in a specially constructed building. Although this was a simple experiment in principle, there were numerous complexities that he overcame with meticulous attention to experimental details. His result was very close to the modern accepted value. The Cavendish Experiment, as it is called, assures his place in the history of science.

Introduction

2021 ◽  
pp. 1-5
Author(s):  
Elisabeth Ervin-Blankenheim
Keyword(s):  
Plate Tectonics ◽  
Global Climate ◽  
Life Forms ◽  
Geologic Time ◽  
The Earth ◽  
History Of ◽  
Geologic Record ◽  
Shed Light ◽  
Geologic Processes

Geology offers a unique perspective on the Earth—past, present, and future. It is the language through which the Earth speaks, by means of rocks, geologic processes, the geologic record, and the biography of the Earth. This book explains how geologists arrived at understanding the story of the planet and discusses the three major tenets of geology: geologic time, plate tectonics, and evolution. The development of theories about how the Earth functions is detailed, along with their relevance. Within geology are the keys to understanding the history of the Earth, how that past informs the present, and ways of going forward. The Earth has interacted with life as long as that life has been extant. Life has shaped the Earth and vice versa with times of flowering and the radiation of life forms and other times of extinctions through profound changes in the climate and positions of the continents. These dynamics can shed light on the current changes in and consequences of perturbing the global climate.

scholarly journals XVIII. On the fossil Elk of Ireland

1825 ◽  
Vol 115 ◽  
pp. 429-435
Keyword(s):  
Royal College ◽  
The West ◽  
The North ◽  
Royal Dublin Society ◽  
The Earth ◽  
History Of ◽  
The Subject ◽  
The Mean ◽  
Additional Value ◽  
Mean Time

Notwithstanding the frequent occurrence of the remains of the gigantic elk in Ireland, it is remarkable that precise accounts should not have been kept of all the peculiar cir­cumstances under which they occur entombed in its super­ficial strata. To obtain an opportunity of examining these relations had long been my desire; and as fortunately, dur­ing my avocations last autumn in the north of Ireland, a discovery came to my knowledge that seemed likely to throw light on the subject, I proceeded to its investigation, intending, should the results be found deserving of attention, to place them on record. These results have proved the more interesting, as they apparently lead to the conclusion, that this magnificent animal lived in the countries in which its remains are now found, at a period of time which, in the history of the earth, can be considered only as modern. I had advanced thus far when I became apprized of an analogous discovery made last year in the west of Ireland by the Rev. W . Wray Maunsell, Archdeacon of Limerick; which is not only confirmative of my own experience, but has the additional value of embracing particulars not hitherto noticed by any other observer. Mr. Maunseli's researches, elucidated by the able assistance of Mr. John Hart, Member of the Royal College of Surgeons, have been communicated from time to time to the Royal Dublin Society in the form of letters, and have been entered upon their minutes; and, it is to be hoped, that a distinct publication on the subject may hereafter appear, illustrated by a description of the splendid specimen of the skeleton of the animal now deposited by the liberality of the Reverend Archdeacon in the museum of that Society. In the mean time I propose, after giving a concise account of my own inquiries, to refer briefly to the more prominent points in Mr. Maunseli's discoveries, in as far as they bear immediately on the question of the ancient or modern origin of those remains.

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