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White House Report, “Restoring the Quality of Our Environment,” Report of the Environmental Pollution Panel, President’s Science Advisory Committee, November 1965

RESTORING THE QUALITY OF OUR ENVIRONMENT Report of The Environmental Pollution Panel President's Science Advisory Committee THE WHITE HOUSE NOVEMBER 1965 THE WHITE HOUSE WASHINGTON November 5 1965 Ours is a nation of affluence But the technology that has permitted our affluence spews out vast quantities of wastes and spent products that pollute our air poison our waters and even impair our ability to feed ourselves At the same time we have crowded together into dense metropolitan areas where concentration of wastes intensifies the problem Pollution now is one of the most pervasive problems of our society With our numbers increasing and with our increasing urbanization and industrialization the flow of pollutants to our air soils and waters is increasing This increase is so rapid that our present efforts in managing pollution are barely enough to stay even surely not enough to make the improvements that are needed Looking ahead to the increasing challenges of pollution as our population grows and our lives become more urbanized and industrialized we will need increased basic research in a variety of specific areas including soil pollution and the effects of air pollutants on man We must give highest priority of all to increasing the numbers and quality of the scientists and engineers working on problems related to the control and management of pollution I am asking the appropriate Departments and Agencies to consider the recommendations and report to me on the ways in which we can move to cope with the problems cited in the Report Because of its general interest I am releasing the report for publication For sale by the Superintendent of Documents U S Government Printing Office Washington D C 20402 - Price $1 25 cents ENVIRONMENTAL POLLUTION PANEL PRESIDENT'S SCIENCE ADVISORY COMMITTEE DONALD F HORNIG Chairman Special Assistant to the President for Science and Technology HERBERT F YORK Jr Vice Chairman Professor of Physics University of California San Diego Lewis M Branscomb Chairman Joint Institute for Laboratory Astrophysics Boulder Melvin Calvin Professor of Chemistry University of California Berkeley Richard L Garwin Thomas J Watson Research Center International Business Machines Corporation Yorktown Heights Marvin L Goldberger P ofessor of Physics Princeton University Philip Handler Chairman Department of Biochemistry Duke University Medical Center Franklin A Long Vice President for Research and Advanced Studies Cornell University Ithaca Gordon J F MacDonald Chairman Department of Planetary and Space Physics Institute of Geophysics and Planetary Physics University of California Los Angeles William D McElroy Chairman Department of Biology The Johns Hopkins University George E Pake Provost Washington University St Louis John R Pierce Executive Director Research-Communications Sciences Division Bell Telephone Laboratories Kenneth S Pitzer President Rice University Edward M Purcell Professor of Physics Harvard University Frederick Seitz President National Academy of Sciences IV JOHN W TUKEY Chairman Professor of Mathematics Princeton University and Associate Executive Director Research-Communications Sciences Division Bell Telephone Laboratories Martin Alexander Associate Professor of Soil Science New York State College of Agriculture Cornell University Ithaca H Stanley Bennett Dean Division of Biological Sciences University of Chicago ' Nyle C Brady Director of Office of Science and Education U S Department of Agriculture until August 31 1965 Director of the Cornell University Ex eriment Station Director of Research New York State College of AgrIculture Cornell University Ithaca John C Calhoun Jr Science Advisor to the Secretary of the Interior until February 5 1965 Vice President for Programs Texas A M University System College Station John C Geyer Chairman Department of Sanitary Engineering and Water Resources The Johns Hopkins University Baltimore Aarie J Haagen-Smit Professor of Biochemistry California Institute of Technology Pasadena Norwan Hackerman Vice Chancellor for Academic Affairs University of Texas Austin ' James B Hartgering Director of Research and Education American Hospital Association Chicago David Pimentel Head Dep rtment of Entomology and Limnology New York State College of Agnculture Cornell University Ithaca Rog r Revelle irect r Center for Population Studies Harvard University LO Ul S H RoddIs PreSIdent Pennsylvania Electric Company Johnstown WIlham H Stewart member until June 1965 Office of the Secretary U S Department of Health Education and Welfare Washington James L Whittenberger Professor of Public Health Harvard School of Public Health ' John L Buckley Staff Technical Assistant Office of Science and Technology Washington v Contents Page Acknowledgements Introduction The Effects of Pollution Health Effects Excessive air pollution for short periods Prolonged exposure to ordinary urban air pollution Water-borne pollutants and health Pesticides and human health Effects on Other Living Organisms Why do we care Kinds of effects on organisms other than man Impairment of Water and Soil Resources Excess fertility in waters Soil pollution Polluting Effects of Detergents Deterioration of Materials and Urban Environments Climatic Effects of Pollution IX The Sources of Pollution Municipal and industrial sewage Animal wastes Urban solid wastes Mining wastes Consumer goods wastes Unintentional Releases In Which Directions Should We Go Recommendations A Principles B Actions C Coordination and Systems Studies D Baseline Measurement Programs E Development and Demonstration F Research G Manpower H Incompleteness of Recommendations Appendixes Xl Challenging Tasks for the Men and Women Who Can Improve the Quality of Our Environment X2 Organizational Questions X3 A General Index of Chemical Pollution X4 Standards Development X5 Metropolitan Problems ' X6 Air Problems X7 Water Quality 10 10 10 11 11 11 12 13 16 16 17 23 25 26 29 33 38 VII 1 3 3 3 3 4 4 5 5 5 7 7 7 8 9 9 39 48 57 59 62 66 70 CONTENTS VIII Subpanel Reports Soil Contamination Health Effects of Environmental Pollution Benchmark Surveillance Atmospheric Carbon Dioxide Solid Wastes Y6 Combined Sewers Y7 Effects of Chlorinating Wastes Y8 Agricultural Wastes Y9 Aquatic Blooms Yl0 Effects of Pollutants on Living Organisms Other Than Man Yl1 Improved Pest Control Practices Index Yl Y2 Y3 Y4 Y5 Page 74 91 102 111 134 157 168 170 173 192 227 293 Acknowledgements The study was conducted under the general supervision of Colin M MacLeod Deputy Director Office of Science and Technology The Panel drew on scientists and engineers from within the Federal Government from state governments universities and industry to form subpanels of experts each of which explored a different problem These busy men put in on the average several weeks of their time talking to scientists studying and evaluating information published and unpublished and writing reports The reports are included as the Y Appendixes The members of the subpanels are listed on the following pages SOIL CONTAMINATION H Stanley Bennett Chairman Dean Division of Biological Sciences University of Chicago Martin Alexander Associate Professor of Soil Science New York State College of Agriculture Cornell University Ithaca Sterling B Hendricks Soil and Water Conservation Research Division Agricultural Research Service U S Department of Agriculture Beltsville Maryland H L Lucas Professor and Director of Biomathematics Training Program Institute of Statistics North Carolina State University Raleigh Thomas J Sheets Staff Crops Research Division Agricultural Research Service U S Department of Agriculture Beltsville Maryland Present address Associate Professor of Entomology and Crop Science North Carolina State University Raleigh HEALTH EFFECTS OF ENVIRONMENTAL POLLUTION James L Whittenberger Chairman Professor of Public Health Harvard School of Public Health Aarie J Haagen-Smit Professor of Biochemistry California Institute of Technology Pasadena Lincoln E Moses Executive Head Department of Statistics Stanford University William H Stewart member until June 1965 Office of the Secretary U S Department of Health Education and Welfare Washington IX x RESTORING THE QUALITY OF OUR ENVIRONMENT John R Bagby Jr Staff Communicable Disease Center Public Health Service U S Department of Health Education and Welfare Atlanta Georgia H Bruce Dull Staff Communicable Disease Center Public Health Service U S Department of Health Education and Welfare Atlanta Georgia BENCHMARK SURVEILLANCE Aarie J Haagen-Smit Chairman Professor of Biochemistry California Institute of Technology Pasadena Raymond J Jessen Professor of Business Statistics Graduate School of Business Administration University of California Los Angeles Louis H Roddis Vice Chairman President Pennsylvania Electric Company Johnstown James L Whittenberger Professor of Public Health Harvard School of Public Health Nyle C Brady Director of Science and Education U S Department of Agriculture until August 31 1965 Director of the Cornell University Experiment Station Director of Research New York State College of Agriculture Cornell University Ithaca W J Youden 4821 Upton Street NW Washington John L Buckley Staff Technical Assistant Office of Science and Technology Washington ATMOSPHERIC CARBON DIOXIDE Roger Revelle Chairman Director Center for Population Studies Harvard University Wallace Broecker Professor of Geology Columbia University New York Harmon Craig Professor of Geochemistry Department of Earth Sciences University of California La Jolla Charles D Keeling Scripps Institution of Oceanography La Jolla California J Smagorinsky Weather Bureau Environmental Sciences Services Administration U S Department of Commerce Suitland Maryland SOLID WASTES John C Calhoun Jr Chairman Science Adviser to the Secretary U S Department of the Interior until February 5 1965 Vice President for Programs Texas A M University System College Station Patrick Conley Senior Fellow Mellon Institute Pittsburgh ACKNOWLEDGEMENTS Aarie J Haagen-Smit Professor of Biochemistry California Institute of Technology Pasadena Norman Hackerman Vice Chancellor for Academic Affairs University of Texas Austin Leonhard Katz President Astro Dynamics Inc 2d Avenue Northwest Industrial Park Burlington Massachusetts George J Maslach Dean College of Engineering University of California Berkeley Louis H Roddis President Pennsylvania Electric Company Johnstown James E Hill Staff Bureau of Mines U S Department of the Interior Washington COMBINED SEWERS John C Geyer Chairman Chairman Department of Sanitary Engineering and Water Resources The Johns Hopkins University Baltimore Leonhard Katz President Astro Dynamics Inc 2d Avenue Northwest Industrial Park Burlington Massachusetts EFFECTS OF CHLORINATING WASTES Martin Alexander Chairman Associate Professor of Soil Science New York State College of Agriculture Cornell University Ithaca Deric O'Bryan Staff Geological Survey U S Department of the Interior Washington John C Geyer Chairman Department of Sanitary Engineering and Water Resources The Johns Hopkins University Baltimore AGRICULTURAL WASTES Martin Alexander Chai1'man Associate Professor of Soil Science New York State College of Agriculture Cornell University Ithaca Nyle C Brady Director of Science and Education U S Department of Agriculture until August 31 1965 Director of the Cornell University Experiment Station Director of Research New York State College of Agriculture Cornell University Ithaca Deric O'Bryan Staff Geological Survey U S Department of the Interior Washington XI XII RESTORING THE QUALITY OF OUR ENVIRONMENT AQUATIC BLOOMS Martin Alexander Chairman Associate Professor of Soil Science N ew York State College of Agriculture Cornell University Ithaca John B Moyle Department of Conservation St Paul Minnesota Ruth Patrick Academy of Natural Sciences Philadelphia Pennsylvania Leon Weinberger Division of Water Supply and Pollution Control Public Health Service U S Department of Health Education and Welfare Washington Deric O'Bryan Staff Geological Survey U S Department of the Interior Washington EFFECTS OF POLLUTANTS ON LIVING ORGANISMS OTHER THAN MAN David Pimentel Chairman Head Department of Entomology and Limnology New York State College of Agriculture Cornell University Ithaca Don W Hayne Professor of Experimental Statistics Institute of Statistics North Carolina State University Raleigh Louis A Krumholz Professor of Biology University of Louisville John T Middleton Director Air Pollution Research Center University of California Riverside Lionel A Walford Director Sandy Hook Marine Laboratory Bureau of Sport Fisheries and Wildlife U S Department of the Interior Highlands New Jersey John L Buckley Staff Technical Assistant Office of Science and Technology Washington IMPROVED PEST CONTROL PRACTICES David Pimentel Chairman Head Department of Entomology and Limnology New York State College of Agriculture Cornell University Ithaca Donald A Chant Chairman Department of Biological Control University of California Riverside Arthur Kelman Professor of Plant Pathology and Forestry North Carolina State University Raleigh Present AddressChairman Department of Plant Pathology University of Wisconsin Madison Robert L Metcalf Vice Chancellor University of California Riverside L D Newsom Head Department of Entomology Louisiana State University Baton Rouge Carroll N Smith Staff Entomology Research Division Agricultural Research Service U S Department of Agriculture Gainesville Florida Introduction Environmental pollution is the unfavorable alteration of our surroundings wholly or largely as a by-product of man's actions through direct or indirect effects of changes in energy patterns radiation levels chemical and physical constitution and abundances of organisms These changes may affect man directly or through his supplies of water and of agricultural and other biological products his physical objects or possessions or his opportunities for recreation and appreciation of nature The production of pollutants and an increasing need for pollution management are an inevitable concomitant of a technological society with a high standard of living Pollution problems will increase in importance as our technology and standard of living continue to grow Our ancestors settled in a fair and unspoiled land easily capable of absorbing the wastes of its animal and human populations Nourished by the resources of this continent the human inhabitants have multiplied greatly and have grouped themselves to form gigantic urban concentrations in and around which are vast and productive industrial and agricultural establishments disposed with little regard for state or municipal boundaries Huge quantities of diverse and novel materials are dispersed from city and farm alike into our air into our waters and onto our lands These pollutants are either unwanted by-products of our activities or spent substances which have served intended purposes By remaining in the environment they impair our economy and the quality of our life They can be carried long distances by air or water or on articles of commerce threatening the health longevity livelihood recreation cleanliness and happiness of citizens who have no direct stake in their production but cannot escape their influence Pollutants have altered on a global scale the carbon dioxide content of the air and the lead concentrations in ocean waters and human populations Pollutants have reduced the productivity of some of our finest agricultural soils and have impaired the quality and the safety of crops raised on others Pollutants have produced massive mortalities of fishes in rivers lakes and estuaries and have damaged or destroyed 2 RESTORING THE QUALITY OF OUR ENVIRONMENT commercial shellfish and shrimp fisheries Pollutants have reduced valuable populations of pollinating and predatory insects and have appeared in alarming amounts in migratory birds Pollutants threaten the estuarine breeding grounds of valuable ocean fish even Antarctic penguins and Arctic snowy owls carry pesticides in their bodies The land water air and living things of the United States are a heritage of the whole nation They need to be protected for the benefit of all Americans both now and in the future The continued strength and welfare of our nation depend on the quantity and quality of our resources and on the quality of the environment in which our people live The pervasive nature of pollution its disregard of political boundaries including state lines the national character of the technical economic and political problems involved and the recognized Federal responsibilities for administering vast public lands which can be changed by pollution for carrying out large enterprises which can produce pollutants for preserving and improving the nation's natural resources all make it mandatory that the Federal Government assume leadership and exert its influence in pollution abatement on a national scale We attempt here to describe the problem to distinguish between what is known and what is not and to recommend steps necessary to assure the lessening of pollution already about us and to prevent unacceptable environmental deterioration in the future U di ef III ta fr ep ua de ce fn co at oc ca th fee po to thi the po de be tol Tl cit COl sP kni RESTORING THE QUALITY OF OUR ENVIRONMENT an adequate number to start with They should be selected by use nodern probability methods rhe waters of a single drainage area may vary from small trickles to e lakes In sampling these waters however we can take advantage the way in which the waters flow from smaller streams into larger s and from larger ones into rivers and lakes rhe lands of a drainage area may vary even more widely highly culLted farm lands may grade through rangelands to rocky mountains and erts All are part of the general environment the pollution of all st be considered in the overall result We can take advantage of what know about the likelihood of pollution of different kinds of land in nning the details of the sampling but we must give all lands their ropriate chance to contribute to the final result APPENDIX Y4 Atmospheric Carbon Dioxide ROGER REVELLE WALLACE BROECKER HARMON CRAIG Chairman C J D KEELING SMAGORINSKY Contents Page Section I Carbon Dioxide From Fossil Fuels-The Invisible Pollutant Introduction The Recent Increase in Atmospheric Carbon Dioxide Partition of Carbon Dioxide Among the Atmosphere the Ocean and the Biosphere Probable Future Content of Carbon Dioxide in the Atmosphere Possible Effects of Increased Atmospheric Carbon Dioxide on Climate Other Possible Effects of an Increase in Atmospheric Carbon Dioxide Melting of the Antarctic Ice Cap Rise of Sea Level Warming of Sea Water Increased Acidity of Fresh Waters Increase in Photosynthesis Other Possible Sources of Carbon Dioxide Oceanic Warming Burning of Limestone Decrease in the Carbon Content of Soils Change in the Amount of Organic Matter in the Ocean Changes in the Carbon Dioxide Content of Deep Ocean Water Changes in the Volume of Sea water Carbon Dioxide From Volcanoes Changes Due to Solution and Precipitation of Carbonates Conclusions and Findings Section II Detailed Computations References 111 112 112 114 117 119 121 123 123 123 123 124 124 124 124 125 125 125 125 125 126 126 126 128 131 APPENDIX Y4 Section 1 CARBON DIOXIDE FROM FOSSIL FUELS-THE INVISIBLE POLLUTANT INTRODUCTION Only about one two-thousandth of the atmosphere and one tenthousandth of the ocean are carbon dioxide Yet to living creatures these small fractions are of vital importance Carbon is the basic building block of organic compounds and land plants obtain all of their carbon from atmospheric carbon dioxide Marine plants obtain carbon from the dissolved carbon dioxide in sea water which depends for its concentration on an equilibrium with the carbon dioxide of the atmosphere Marine and terrestrial animals including man procure either directly or indirectly the substance of their bodies and the energy for living from the carbon compounds made by plants All fuels used by man consist of carbon compounds produced by ancient or modern plants' The energy they contain was originally solar energy transmuted through the biochemical process called photosynthesis The carbon in every barrel of oil and every lump of coal as well as in every block of limestone was once present in the atmosphere as carbon dioxide Over the past several billion years very large quantities of carbon dioxide have entered the atmosphere from volcanoes The total amount was at least forty thousand times the quantity of carbon dioxide now present in the air Most of it became combined with calcium or magnesium freed by the weathering of silicate rocks and was precipitated on the sea floor as limestone or dolomite About one-fourth of the total quantity at least ten thousand times the present atmospheric carbon dioxide was reduced by plants to organic carbon compounds and became buried as organic matter in the sediments A small fraction of this organic matter was transformed into the concentrated deposits we call coal petroleum oil shales tar sands or natural gas These are the fossil fuels that power the world-wide industrial civilization of our time Throughout most of the half-million years of man's existence on earth his fuels consisted of wood and other remains of plants which had grown only a few years before they were burned The effect of this burning on the content of atmospheric carbon dioxide was negligible because it only slightly speeded up the natural decay processes that continually recycle carbon from the biosphere to the atmosphere During the last few centuries however man has begun to burn the fossil fuels that were 112 113 locked i the sedimentary rocks over five hundred million years and this combustIOn IS measurably increasing the atmospheric carbon dioxide In the geologic past the quantity of carbon dioxide in the atmosphere was determined by the equilibrium between rates of weathering and photosynthesis and the rate of injection of volcanic carbon dioxide On an earthwide average both weathering and photosynthesis must speed' up when the carbon dioxide content of the air is increased and slow d w w en it is diminished c nsequently over geologic time the carbon dIOXIde ill the aIr must have rIsen when volcanic activity was high and must have gone down when volcanoes were quiescent On a human scale the times involved are very long The known amounts of limestone an o ganic carbon in the sediments indicate that the atmospheric carbo IOXIde has been changed forty thousand times during the past four bIllIOn years consequently the residence time of carbon in the atmosphere relative to sedimentary rocks must be of the order of a hundred thousand years The present rate of production of carbon dioxide from fossil fuel combustion is about a hundred times the average rate of release of calcium an magnesium from the weathering of silicate rocks As long as this rano holds precipitation of metallic carbonates will be unable to maintain an unchanging content of carbon dioxide in the atmosphere Within a few short centuries we are returning to the air a significant part of the carbon that was slowly extracted by plants and buried in the sediments during half a billion years Not all of this added carbon dioxide will remain in the air Part of it will becom diss olved in the ocean and part will be taken up by the bIOsph re chIefly ill trees and other terrestrial plants and in the dead plant ht er alled humus T e part that remains in the atmosphere may haw sIg Ificant e e t on clImate carbon dioxide is nearly transparent to VISIble hght but It IS a strong absorber and back radiator of infrared radiation particularly in the wave lengths from 12 to 18 microns' consequently an increase of atmospheric carbon dioxide could act uch like the glass in a greenhouse to raise the temperature of the lo er air Water vapor also absorbs infrared radiation both in the range of the CO 2 band centered at 15 microns and at wave lengths near 6 3 microns With the average concentration of water vapor in the lower air at mid latitudes the effect of carbon dioxide absorption is reduced to about half that which would exist in an absolutely dry atmosphere Moller 1963 Ozone which is an important constituent of the upper air also absorbs some infrared at wave lengths around 9 6 microns but its princip effect on air temperature is due to its absorption of ultraviolet and VISible sunlight The possibility of climatic change resulting from changes in the quantIty of atmospheric carbon dioxide was proposed independently by the American geologist T C Chamberlain 1899 and the Swedish chemist S Arrhenius 1903 at the beginning of this century Since their time many scientists have dealt with one or another aspect of this question but until very recently there was little quantitative information about what has actually happened Even today we cannot make a useful prediction concerning the magnitude or nature of the possible climatic effects But we are able to say a good deal more than formerly about the change in the quantity of atmospheric carbon dioxide and about the partition of carbon dioxide from fossil fuel combustion among the atmosphere the ocean and the biosphere THE RECENT INCREASE IN ATMOSPHERIC CARBON DIOXIDE During the five years from 1958 through 1962 5 3 x 1016 grams of carbon dioxide were produced by the combustion of coal lignite petroleum and other liquid hydrocarbons and natural gas see Tables 1 and 2 TABLE TABLE Year Year Coal I Lignite 2 0 04 05 05 05 06 06 07 07 08 09 10 10 1950 ' 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 0 37 38 38 38 38 41 44 45 46 48 50 48 50 0 09 09 09 09 09 10 11 13 14 14 14 15 15 0 17 20 21 22 23 25 27 29 29 32 34 36 39 Total 5 61 1 51 3 54 Total As % of Atmospheric CO2 in 1950 11 0 67 72 73 74 76 82 89 94 97 1 03 1 08 1 09 1 15 0 29 31 31 32 32 35 38 40 41 44 46 46 49 93 11 59 4 93 Assumed carbon content coal 75 percent Assumed carbon content lignite 45 percent 3 Assumed carbon content liquid hydrocarbons 86 percent 4 Assumed carbon content natural gas 70 percent Corresponding to a mixture by volume of 80 percent CH4 15 percent C 2H 6 and 5 percent N 2 I 2 Source Computed from Table 2 Coal Lignite Liquid Hydrocarbons I Natural Gas 2 Total 1950 1951 1952 1'953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1 340 1 375 1 375 1 380 1 375 1 500 1 595 1 625 1 665 1 730 1 810 1 760 1 805 530 550 550 555 550 630 665 765 825 845 875 900 905 540 620 655 690 725 790 860 905 930 995 1 075 1 140 1 235 155 180 200 210 220 240 260 285 305 345 375 405 440 2 565 2 725 2 780 2 835 2 870 3 160 3 380 3 580 3 725 3 915 4 135 4 205 4 385 Total 20 335 9 145 11 160 3 620 44 260 1016 grams Natural Gas 4 2 -World Production of Fossil Fuels-1950--62 Millions of Metric Tons I -Carbon Dioxide Produced by Fossil Fuel Combustion 1950-62 Liquid Hydrocarbons 3 115 APPENDIX Y4 RESTORING THE QUALITY OF OUR ENVIRONMENT' 114 I 2 Includes Petroleum and Natural Gasoline Assumed density of 8Xl0- 4 gm cm-3 1000m3 0 8 ton Source 'World Energy Supplies Statistical Papers Series United Nations New York This is 2 25 percent of the 2 35 x 1018 grams of carbon dioxide present in the atmosphere in 1950 assuming an atmospheric carbon dioxide concentration of 300 ppm by volume--445 ppm by weight-and a mass of 5 2 x 1021 grams for the entire atmosphere On the average during 1958-1962 the CO 2 produced each year by fossil fuel combustion was 0 45 percent of the quantity in the atmosphere Beginning in 1958 and extending through 1963 two nearly continuous series of measurements of atmospheric CO 2 content were made One of these series was taken at the U S Weather Bureau station near the top of Mauna Loa Mountain in Hawaii Pales and Keeling 1965 the other at the United States scientific station at the South Pole Brown and Keeling 1965 The measurements were carried out on an infrared gas spectrometer with a relative accuracy for a single measurement of about 0 1 ppm The observing stations are located near the centers of vast atmospheric mixing areas far from uncontrollable sources of contaminants Because of these nearly ideal locations together with the high precision of the instruments and the extreme care with which the samples were taken these measurements make it possible to estimate the secular trend of atmospheric C02 with an accuracy greater by two TABLE orders of magnitude than ever before Some fifteen thousand measurements were carried out during the five-year period The data show clearly and conclusively that from 1958 through 1963 the carbon dioxide content of the atmosphere increased by 1 36 percent The increase from year to year was quite regular close to the average annual value of 0 23 percent By comparing the measured increase with the known quantity of carbon dioxide produced by fossil fuel combustion given in Table 4 we see that almost exactly half of the fossil fuel C02 apparently remained in the atmosphere Tables 3 and 4 show that between 1860 and 1940 the amount of C02 produced by fossil combustion chiefly coal was 7 9 percent and by 1950 10 3 percent of the estimated atmospheric C02 content in 1950 By 1959 the total C02 production was equal to 13 8 percent of the atmospheric C02 Unfortunately the accuracy of measurements of atmospheric C02 before 1958 is too low to allow estimates of the secular variation and it is therefore impossible to compute directly whether the fraction of fossil-fuel C02 remaining in the atmosphere throughout the past hundred years has been constant or slowly or rapidly changing TABLE Decade Decade Lignite 2 Atmospheric CO 2 in 1950 Total 0 46 O 70 1 06 1 49 2 33 3 10 3 26 3 16 3 74 4 11 Total 23 41 0 01 03 0 02 05 0 01 04 08 02 10 15 04 19 21 07 48 31 12 74 35 25 1 14 49 62 2 44 1 07 0 47 73 1 13 1 62 2 6 ' 3 54 4 12 4 37 5 62 8 24 1 13 32 44 2 75 5 15 0 20 31 48 69 1 11 1 53 1 75 1 86 2 39 3 49 1860-69 1870-79 1880-89 1890-99 1900-09 1910-19 1920-29 1930-39 1940-49 1950-59 1 660 2 560 3 850 5 405 8 455 11 240 11 850 11 500 13 570 14 960 85 180 285 495 880 1 270 1 875 2 135 2 995 6 465 5 15 55 140 310 590 1 510 2 335 3 605 7 710 Total 85 050 16 665 16 275 Natural Gas z Total 10 40 80 155 285 485 970 2 400 1 750 2 755 4 200 6 080 9 725 13 255 15 520 16 455 21 140 31 535 4 425 122 415 PARTITION OF CARBON DIOXIDE AMONG THE ATMOSPHERE THE OCEAN AND THE BIOSPHERE Be ause the fossil fuels have been buried for millions of years they contam no Carbon 14 This radioactive isotope is produced in the tmosphere by cosmic ray bombardment of nitrogen and- it has a halflIfe of only about six thousand years Consequently the addition to the mosphere of CO2 from fossil fuel combustion and its subsequent partitIon among the atmosphere the ocean and the biosphere will cause the ratio between radioactive and nonradioactive carbon to decrease This manifests itself as a measurable reduction in the amount of radioative carbon for example in tree rings grown in recent years compared with rings that grew during the 19th Century This reduction due to fossil fuel combustion is called the Suess Effect after Professor Hans Suess who first observed it see Revelle and Suess 1956 13 81 I Assumed carbon content coal 75 percent z Assumed carbon content lignite 45 percent 3 Assumed carbon content liquid hydrocarbons 86 percent 4 Assumed carbon content natural gas 70 percent Corresponding to a mixture by volume of 80 percent CH 4 15 percent C 2H 6 and 5 percent Nz · 1 Source Computed from Table 4 Liquid Hydrocarbons 1 There are measure ents of a somewhat different kind which can give us useful informatlOn however These are determinations of the socalled Suess Effect --1860-69 1870-79 1880-89 1890-99 1900-09 1910-19 1920-29 1930-39 1940-49 1950-59 Lignite Sources From 1860 to 1949 United Nations Department of Economic and Social Affairs World Energy Requirements Proceedings of the International Conference on the Pe ceful Uses of Atomic Energy Vol 1 pp 3-33 1956 For 1950-59 Umted NatlOns World Energy Supplies Statistical papers Series J United Nations New York As % of Coal 1 Coal 1 Includes petroleum and natural gasoline z Assumed density of 8 x 10-4 gm cm-3 1000m 3 0 8 ton 1016 grams Natural Gas 4 4 -World Production of Fossil Fuels 860- 959 Millions of Metric Tons 3 -Carbon Dioxide Produced by Fossil Fuel Combustion 860- 959 Liquid Hydrocarbons 3 117 APPENDIX Y4 RESTORING THE QUALITY OF OUR ENVIRONMENT 116 1 J 17 2-1'2'2 0-65 9 APPENDIX Y4 118 119 RESTORING THE QUALITY OF OUR ENVIRONMENT The measurement of the Suess Effect is beset with many difficulties the chief among them being that the Carbon 14 content of the atmosphere-more precisely the ratio of C 14 to C 12 C 13-varies by 1 or 2 percent from century to century appan ntly depending on the long-te variations in sunspot intensity Tree rmg measurements show that this ratio went up during the 15th and 17th Centuries and down during- he 16th and 18th in each case by about 2 percent Suess 1956 Pnor to the atomic weapons tests of the mid-Fifties the ratio was lower by between 1 and 2 percent than in the middle of the 19th Century This change during the past hundred years was apparently largely due to the Suess Eff ect Taking the Suess Effect as between 1 and 2 percent over the period from 1860 to 1950 during which time the total carbon dioxide produced from fossil fuels was 10% of the atmospheric C02 and assuming that presently occurring changes in the magnitude of the Suess Effect are in the same proportion to C02 from fossil fuel combustion as in the past we can compute both the relative sizes of the oceanic and biosphere reservoirs that are taking up part of the added C02 and the partition of CO 2 between these reservoirs The amount taken up in the biosphere will be different if there are two or more sources of additional carbon dioxide than if fossil fuels are the only source but the amount absorbed by the ocean will not vary Implied in the calculation is the further assumption that any C02 from other sources will have bout th e san e ratio of C 14 to total carbon as the atmosphere Details are gIven m Section II The calculation shows that if the oceanic layer mixing with the atmosphere is several hundred meters thick the amount of exchangable carbon in the biosphere is less than or about equal to that in the atmosphere These are both reasonable values On the other hand if another significant source of C02 is assumed for the last few d cades the amount of C02 added to the biosphere becomes so large that It should have been observed In fact no increase in the biosphere has been noted Perhaps the most striking result is that the ocean takes up a relatively small fraction of the total added C02 probably about 15% In the past the usual scientific belief has been that by far the larger part of any added C02 would be absorbed in the ocean This is undoubtedly true if we consider a sufficiently long time period of the order of thousands or ev n perhaps hundreds of years because the ocean as a whole contams nearly sixty times as much carbon dioxide as the atmosphere Bu over shorter times only the uppermost layers of the oce n take pa 1 e ­ changes with the air Moreover most of the ocea Ic carbon dlOX1 e IS present as carbonate and bicarbonate balanced agamst metallIC catIOns and a markeq increase in oceanic C02 therefore requires an increase in cation concentration which can be brought about only by rock weathering or solution of calcium-rich sediments These are slow processes PROBABLE FUTURE CONTENT OF CARBON DIOXIDE IN THE ATMOSPHERE I 1 We can conclude with fair assurance that at the present time fossil fuels are the only source of CO2 being added to the ocean-atmospherebiosphere system If this held true throughout the last hundred years the quantity of C02 in the air at the beginning of the present decade was about 7 % higher than in the middle of the last century see Table 3 Throughout these hundred years the rate of fossil fuel combustion and thus of C02 production continually increased on the average about 3 2 percent per year The amount produced in 1962 was almost 25 times the annual production in the mid-1860's The rate of increase may be accelerating During the eight years from 1954 to 1962 the average rate of increase was 5 % We can ask several questions about the future C02 content of the atmosphere Two of these questions are 1 What will the total quantity of CO2 injected into the atmosphere but only partly retained there be at different future times 2 What would be the total amount of CO2 injected into the air if all recoverable reserves of fossil fuels were consumed At present rates of expansion in fossil fuel consumption this condition could be approached within the next 150 years The second question is relatively easy to answer provided we consider only the estimated recoverable reserves of fossil fuels The data are shown in Table 5 We may conclude that the total C02 addition from fossil fuel combustion will be a little over 3 times the atmospheric content and that if present partitions between reservoirs are maintained the C02 in the atmosphere could increase by nearly 170 percent The answer to the first question depends upon the rate of increase of fossil fuel combustion Table 6 shows that if this combustion remains constant at the 1959 level the total CO 2 injected into the atmosphere by the year 2000 will be about 28 percent of the atmospheric content in 1950 If the average rate of increase of combustion continues at 3 2 percent per year the quantity injected into the at mosphere b the year 2000 will be about 42 percent if the 5% rate of mcrease dunng the last 8 years persists the quantity injected will be close to 60 percent Assuming further'that the proportion remaining in the atmosphere continues to be half the total quantity injected the increase in amospheric C02 in the year 2000 could be somewhere between 14 percent and 30 percent RESTORING THE QUALITY OF OUR ENVIRONMENT APPENDIX Y4 Based on projected world energy requirements the United Nations Department of Economic and Social Affairs 1956 has estimated an amount of fossil fuel combustion by the year 2000 that with our assumed partitions would give about a 25 percent increase in atmospheric C02 compared to the amount present during the 19th Century For convenience we shall adopt this figure in the following estimate of the effects on atmospheric radiation and temperature POSSIBLE EFFECTS OF INCREASED ATMOSPHERIC CARBON DIOXIDE ON CLIMATE 120 TABLE 5 -Estimated Remaining Recoverable Reserves of Fossil Fuels As % of Atmospheric CO2 in 1950 109 Metric Tons Carbon Dioxide Equivalent 1018 gms Coal and Lignite 1 • • • • • • • • • • Petroleum and Natural Gas Liquids 2 Natural Gas 3 • Tar Sands 2 Oil Shales 2 2 320 212 166 75 198 5 88 67 43 24 63 252 29 18 W27 Total 2 971 7 85 336 1 Assumed to be 20 percent lignite containing 45 percent carbon and 80 percent bituminous coal containing 75 percent carbon 2 Assumed carbon content of petroleum natural gas liquids and hydrocarbons recoverable from tar sands and oil shales 86 percent 3 Assumed composition of natural gas by volume CH4 80 percent C 2H 6 15 percent N2 5 percent Source Computed from data given by M King Hubbert Energy Resources A Report to the Committee on Natural Resources of the National Academy of SciencesNational Research Council NAS Publication lOOO-D 1962 pp 1-141 6 -Estimates of Carbon Dioxide From Fossil Fuel Combustion in Future Decades Assuming Different Rates of Increase of Fuel Use TABLE As percent of Atmospheric CO 2 in 1950 Year Growth rate percent year 1959 1969 1979 1989 1999 2009 o 13 80 17 30 20 79 24 28 27 77 31 26 3 2 13 80 18 00 23 79 31 94 41 96 57 04 5 0 13 80 18 47 26 15 37 90 58 75 93 14 121 One of the most recent discussions of these effects is given by Moller 1963 He considers the radiation balance at the earth's surface with an average initial temperature of 15°C 59°F a relative humidity of 75 percent and 50% cloudiness We may compute from his data that with a 25 percent increase in atmospheric C02 the average temperature near the earth's surface could increase between 0 6°C and 4°C 1 1 OF to 7°F depending on the behavior of the atmospheric water vapor content The small increase would correspond to a constant absolute humidity that is a constant weight of water in the atmosphere The larger increase would correspond to a constant relative humidity that is as the temperature rose the water vapor content would also rise to maintain a constant percentage of the saturation value A doubling of CO2 in the air which would happen if a little more than half the reserves of fossil fuels were consumed would have about three times the effect of a twenty-five percent increase As Moller himself emphasized he was unable to take into account the vertical transfer of latent heat by evaporation at the surface and condensation aloft or of sensible heat by convection and advection For this reason he was unable to consider the interactions between different atmospheric layers in a vertical column In consequence Moller's computations probably over-estimate the effects on atmospheric temperature of a CO 2 increase A more comprehensive model is being developed by the U S Weather Bureau This includes processes of convection and of latent heat transfer through the evaporation and condensation of water vapor Meaningful computations should be possible with this model in the very near future But climatic changes depend on changes in the general circulation in the atmosphere and these will be related to the spatial distribution and time variation of carbon dioxide and water vapor The ratio of CO 2 to water vapor is higher in the polar regions than in low latitudes higher in winter than in summer and much higher in the stratosphere than near the ground For example the volume of carbon dioxide in the atmosphere at high latitudes is about half the volume of water vapor while near the equator it is less than a tenth of the water vapor volume As a result the radiation balance of the earth will be affected differently at different seasons latitudes and heights by changes in the atmospheric C02 content Without a comprehensive model incorporating both the fluid dynamics and the radiation transfer processes of the atmosphere it is not possible to predict how these effects will perturb the general circulation Such a model may be available within the next two years 122 RESTORING THE QUALITY OF OUR ENVIRONMENT APPENDIX Y4 Models of atmospheric thermal equilibrium in which vertical convection is allowed to maintain the observed vertical temperature gradient have recently been constructed by S Manabe of the U S Weather Bureau Manabe and Strickler 1964 Manabe 1965 These show that the effect of infra red absorption from the present atmospheric carbon dioxide at mid latitudes is to maintain a ground temperature about 10°C 18 OF higher than would prevail if no CO 2 were present An increase in the CO2 content without a change in absolute humidity would according to these models produce a somewhat smaller surface temperature rise than that estimated by Moller But a considerable change would occur in the stratosphere where the CO 2 concentration by volume is perhaps 50 times that of water vapor A 25% rise in carbon dioxide would cause stratospheric temperatures to fall by perhaps 2°C 3 6°F at an altitude of 30 kilometers about 100 000 feet and by 4°C PDF at 40 kilometers about 130 000 feet One might suppose that the increase in atmospheric C02 over the past 100 years should have already brought about significant climatic changes and indeed some scientists have suggested this is so The English meteororogist G S Callendar 1938 1940 1949 writing in the late 1930's and the 1940's on the basis of the crude data then available believed that the increase in atmospheric CO 2 from 1850 to 1940 was at least 10% He thought this increase could account quantitatively for the observed warming of northern Europe and northern North America that began in the 1880's From Table 2 and our estimate of the CO2partition between the atmospheric the ocean and the biosphere we see that the actual CO 2 increase in the atmosphere prior to 1940 was only 4% at least from fossil fuel combustion This was probably insufficient to produce the observed temperature changes But it should be noted that up to 2 5% of the atmospheric carbon dioxide after partition with the ocean and the biosphere could also have been added by the oxidation of soil humus in newly cultivated lands As Mitchell 1961 1963 has shown atmospheric warming between 1885 and 1940 was a world-wide phenomenon Area-weighted averages for surface temperature over the entire earth show a rise in mean annual air temperature of about 0 5°C 0 9°F World mean winter temperatures rose by 0 9°C 1 6°F Warming occurred in both hemispheres and at all latitudes but the largest annual rise 0 9°C or 1 6°F was observed between 40° and 70° N latitudes In these latitudes the average winter temperatures rose by 1 6°C 2 8°F The pronounced warming of the surface air did not continue much beyond 1940 Between 1940 and 1960 additional warming occurred in northern Europe and North America but for the world as a whole and also for the northern hemisphere there was a slight lowering of about 0 1 °C 0 2°F in mean annual air temperature Mitchell 1963 Yet dur- ing this period more than 40% of the total CO 2 increase from fossil fuel combustion occurred We must conclude that climatic noise from other processes has at least partially masked any effects on climate due to past increases in atmospheric CO 2content 123 OTHER POSSIBLE EFFECTS OF AN INCREASE IN ATMOSPHERIC CARBON DIOXIDE Melting of the Antarctic ice cap -It has sometimes been suggested that atmospheric warming due to an increase in the CO 2 content of the atmosphere may result in a catastrophically rapid melting of the Antarctic ice cap with an accompanying rise in sea level From our knowledge of events at the end of the Wisconsin period 10 to 11 thousand years ago we know that melting of continental ice caps can occur very rapidly on a geol0 4ic time scale But such melting must occur relatively slowly on a human scale The Antarctic ice cap covers 14 million square kilometers and is about 3 kilometers thick It contains roughly 4 x 1016 tons of ice hence 4 x 1024 gram calories of heat energy would be required to melt it At the present time the poleward heat flow across 70° latitude is 1022 gram calories per year and this heat is being radiated to space over Antarctica without much measurable effect on the ice cap Suppose that the poleward heat flux were increased by 10% through an intensification of the meridional atmospheric circulation and that all of this increase in the flow of energy were utilized to melt the ice Some 4 000 years would be required We can arrive at a smaller melting time by supposing a change in the earth-wide radiation balance part of which would be used to melt the ice A 2% change could occur by the year 2000 when the atmospheric C02 content will have increased perhaps by 250 0 Since the average radiation at the earth's surface is about 2 x 105 gram calories per square centimeter per year a 20 0 change would amount to 2 x 1022 calories per year If half this energy were concentrated in Antarctica and used to melt the ice the process would take 400 years Rise of sea level -The melting of the Antarctic ice cap would raise sea level by 400 feet If 1 000 years were required to melt the ice cap the sea level would rise about 4 feet every 10 years 40 feet per century This is a hundred times greater than present worldwide rates of sea level change Warming of sea water -If the average air temperature rises the temperature of the surface ocean waters in temperate and tropical regions could be expected to rise by an equal amount Water temperatures in the polar regions are roughly stabilized by the melting and freezing of ice An oceanic warming of 1 ° to 2°C about 2°F oc- RESTORING THE QUALITY OF OUR ENVIRONMENT APPENDIX Y4 curred in the North Atlantic from 1880 to 1940 It had a pronounced effect on the distribution of some fisheries notably the cod fishery which has greatly increased around Greenland and other far northern waters during the last few decades The amelioration of oceanic climate also resulted in a marked retreat of sea ice around the edges of the Arctic Ocean Increased acidity of fresh waters -Over the range of concentrations found in most soil and ground waters and in lakes and rivers the hydrogen ion concentration varies nearly linearly with the concentration of free C02 Thus the expected 25 % increase in atmospheric C02 concentration by the end of this century should result in a 25 % increase in the hydrogen ion concentration of natural waters or about a 0 1 drop in pH This will have no significant effect on most plants Increase in photosynthesis -In areas where water and plant nutrients are abundant and where there there is sufficient sunlight carbon dioxide may be the limiting factor in plant growth The expected 25 % increase by the year 2000 should significantly raise the level of photosynthesis in such areas Although very few data ape available it is commonly believed that in regions of high plant productivity on land such as the tropical rain forests phosphates nitrates and other plant nutrients limit production rather than atmospheric C02 This is probably also true of the oceans Biological processes are speeded up by a rise in temperature and in regions where other conditions are favorable higher temperatures due to increased C02 might result in higher plant production After equilibration with the atmosphere the partial pressure in both the air and the uppermost ocean layer would be higher by about 2 5% Burning of limestone -Annual world production of carbon dioxide rom the use of limestone for cement fluxing stone and in other ways IS about 1 % of the total from fossil fuel combustion or 4 x 10-5 of the atmospheric CO 2 content per year Decrease in the carbon content of soils -Since the middle of the Ninetenth Century the world's cultivated farmland has been enlarged by about 50% This is an increase of close to a billion acres or 1 6 million square miles corresponding to 2 7% of the land area of the earth and perhaps to 5 % of forests and grass lands Most soil humus is believed to be concentrated in forests and grassy areas Assume that the total humus is equal to twice the amount of carbon in the atmosphere and that half the carbon in the humus of the newly cultivated lands has been oxidized to carbon dioxide The total injected into the atmosphere from this source becomes less than 5 % of the atmospheric C02 Change in the amount of organic matter in the ocean -About 7% of the marine carbon reservoir consists of organic material Since a 1 % change in the carbon dioxide content of the ocean changes the CO 2 pressure by 12 5% a decrease by 1 % in the marine organic carbon which would increase the total oceanic carbon dioxide by 07 % would raise the carbon dioxide pressure of the ocean and the atmosphere by about 1 % An increase in the temperature of water near the surface during the past one hundred years could have speeded up the rate of oxidation of organic matter relative to its rate of production by photosynthesis Measurements of the content of organic matter in the ocean are neither accurate enough nor sufficiently extended over time to allow a direct estimate of this possibility A change of several percent could have occurred without detection Changes in the carbon dioxide content of deep ocean water -The deep ocean waters contain about 10% more carbon dioxide than they would if they were at equilibrium with the present atmospheric content This is a result of the sinking of dead organic remains from the surface waters and their subsequent oxidation in the depths The combination of biological and gravitational processes can be thought of as a pump that maintains a relatively low carbon dioxide content in the surface waters and in the atmosphere If the pump ceased to act the atmospheric carbon dioxide would eventually be increased five fold Variations in the effectiveness of the pump could have occurred without detection during the past 100 years and could have caused notable changes in the atmospheric carbon dioxide content Changes in the volume of sea water -During the Ice Age the volume of sea water varied by about 5 % Changes of this magnitude would change the carbon dioxide content of the atmosphere by 10 to 15% 124 OTHER POSSIBLE SOURCES OF CARBON DIOXIDE Weare fairly certain that fOssil fuel combustion has been the only source of C02 coming into the atmosphere during the last few years when accurate measurements of atmospheric carbon dioxide content have been available Carbon dioxide may have been produced by other sources during earlier times but it is not now possible to make a quantitative estimate However we can examine the order of magnitude of some of the possible inputs from other sources on the basis of our knowledge of the processes that might be involved Oceanic warming -The average temperature of the ocean cannot have increased by more than 0 15°C during the past century since any greater warming would have caused a larger rise in sea level than the observed value of about 10 centimeters A more probable upper limit is 05°C because most of the sea level rise can be accounted for by glacial melting An average 05°C rise would correspond to 0 5° in the top 400 meters This would cause a nearly 3 % rise in the C02 partial pressure 125 126 RESTORING THE QUALITY OF OUR ENVIRONMENT But during the last several thousand years variations in oceanic volume have been small During the past hundred years world average sea level has varied by less than 10 centimeters This very small volume change would have no appreciable effect on the atmospheric carbon dioxide Carbon dioxide from volcanoes -Over geologic time volcanic gases have been the principal sources of new carbon dioxide injected into the atmosphere On the average the influx of volcanic CO 2 must have balanced the extraction from the atmosphere by rock weathering The present rate of influx of volcanic C02 is close to a hundred fold less than that from fossil fuel combustion No data exist on the worldwide level of volcanic activity over geologic time It is conceivable that the level has fluctuated by two orders of magnitude and that the fluctuations persisted for millenia or even for millions of years Changes due to solution and precipitation of carbonates -Calcium and magnesium carbonate precipitation on the sea floor lower the total CO2 content of ocean water but increase the carbon dioxide pressure and the free C02 content Conversely chemical weathering of limestone and dolomite on land lower the atmospheric C02 and the free C02 content of the sea but increase the total oceanic C02 The rates of these processes are about one order of magnitude lower than the present rate of production of carbon dioxide by fossil fuel combustion We conclude that the only sources of carbon dioxide comparable in magnitude to fossil fuel combustion during the last 100 years could have been a decrease in soil humus due to the increase in the area of cultivated lands a decrease in the content of dissolved organic matter in the ocean or a lowering of the carbon dioxide content of deep ocean waters Marked changes in the oceanic regime would have been necessary for the latter two processes to have significant effects As we have shown none of the three processes are likely to be significant at the present time Nor are any oceanographic data available which suggest that the required changes in the ocean occurred during the last hundred years CONCLUSIONS AND FINDINGS T r0ugh his worldwide industrial civilization Man is unwittingly conductmg a vast geophysical experiment Within a few generations he is burning the fossil fuels that slowly accumulated in the earth over the p st 500 million years The CO 2 produced by this combustion is being mJected mto the atmosphere about half of it remains there The estimated re coverable reserves of fossil fuels are sufficient to produce nearly a 200% mcrease in the carbon dioxide content of the atmosphere By the year 2000 the increase in atmospheric C02 will be close to 25 % This may be sufficient to produce measurable and perhaps marked APPENDIX Y4 127 changes in climate and will almost certainly cause significant changes At present It IS ImpOSSIble to predIct these effects quantitatively but recent advances in mathematical modelling of the atmosphere using large computers may allow useful predictions within the next 2 or 3 years ' Such predictions will need to be checked by careful measurements a series of recise measurements of the CO2 content in the atmosphere should contmue to be made by the U S Weather Bureau and its col laborators at least for the next several decades studies of the oceanic and biological processes by which C02 is removed from and added to the atmosphere should be broadened and intensified temperatures at different heights in the stratosphere should be monitored on a worldwide basis The climatic changes that may be produced by the increased CO 2 content could be deleterious from the point of view of human beings The possibilities of deliberately bringing about countervailing climatic changes therefore need to be thoroughly explored A change in the radiation balance in the opposite direction to that which might result from the increase of atmospheric CO2 could be produced by raising the albedo or reflectivity of the earth Such a change in albedo could be brought about for example by spreading very small reflecting Pfrticles over large oceanic areas The particles should be sufficiently buoyant so that they will remain close to the sea surface and they should have a high reflectivity so that even a partial covering of the surface would be adequate to produce a marked change in the amount of reflected sunlight Rough estimates indicate that enough particles partially to cover a square mile could be produced for perhaps one hundred dollars Thus a 1% change in reflectivity might be brought about for about 500 million dollars a year particularly if the reflecting particles were spread in low latitudes where the incoming radiation is concentrated Considering the extraordinary economic and human importance of climate costs of this magnitude do not seem excessive An early development of the needed technology might have other uses for example in inhibiting the formation of hurricanes in tropical oceanic areas According to Manabe and Strickler 1964 the absorption and reradiation of infrared by high cirrus clouds above five miles tends to heat the atmosphere near the earth's surface Under some circumstances injection of condensation or freezing nuclei will cause cirrus clouds to form at high altitudes This potential method of bringing about climatic changes needs to be investigated as a possible tool for modifying atmospheric circulation in ways which might counteract the effects of increasing atmospheric carbon dioxide n t e temJ erature an other properties of the stratosphere 128 RESTORING THE QUALITY OF OUR ENVIRONMENT Section II DETAILED COMPUTATIONS APPENDIX Y4 Solving for LlB M and LlM we find Calculation of the Relative Sizes of the Ocean and Biosphere Reservoirs and the Probability of Other Sources of Carbon Dioxide at the Present Time A portion of the carbon dioxide coming into the atmosphere will be transferred to the ocean and another part will enter the biosphere We can test the possibility of carbon dioxide sources other than fossil fuel combustion by examining the relative sizes of the required ocean and biosphere reservoirs 1 f-l-C LlM oA -l-C 14 s -LlC 0 C 140 2 • Jll h· B t e reserVOIr system A M 2 a Then at equilibrium 3 Where B A c - We know from measurements of tree rings grown during the middle of the Nineteenth Century compared with those grown during the last few years that for the period 1850-1950 0 02 s During this same period j fractional change of atmospheric CO2 content jA C0 2 produced by fossil fuel combustion bA CO 2 produced by other processes 2 M A Let A CO 2 in atmosphere B equivalent CO 2 in the part of the biosphere that exchanges with the atmosphere AI CO 2 in the oceanic reservoir that exchanges with the atmosphere LlA LlB LlM changes in CO 2 content of these reservoirs 129 0 01 the Suess Effect 0 1 hence j j - s -· 5- -10 The series of atmospheric CO 2 measurements at Mauna Loa and Antarctica from 1958-1963 show that during these years LlA LlB LlM f b A LlA aA LlM oM where a 0 -- owing to the buffer mechanism of 12 5 sea water Bolin and Eriksson 1958 And assuming that CO 2 produced by other processes has approximately the same C14 content as the atmospheric CO2 and knowing that fossil fuel CO 2 contains no C14 A B M i A s Substituting in equations 1 2 and 3 we find for different B values of band A' the values shown III M LlM Table 7 for fl' T and LlB 7· From this table we see that with a Suess Effect of 2 % the most probable value with fossil fuel combustion as the sole source of additional C02 and with effective biosphere sizes of 2 5 to 0 5 times the atmospheric C02 the oceanic reservoir is 2 6% to 6 0% of the volume of the oceans equivalent to a layer of water 100 to 240 meters thick just below the surface The size of the oceanic reservoir varies inversely with the size of the biosphere For a Suess Effect of 1 % probably too low and the same range of biosphere sizes the assumed layer of complete mixing contains 11 % to 14% of the ocean volume and has an effective thickness of 440 to 560 meters 130 TABLE APPENDIX Y4 RESTORING THE QUALITY OF OUR ENVIRONMENT 7 -Possible Sizes of Oceanic and Biosphere Reservoirs and Partition of Added CO 2 Among Reservoirs Cf O 1 b O s 0 2f a 0 5f B M AB A A 7 0 5 1 0 1 5 2 0 2 5 3 5 3 0 2 5 2 0 1 5 0 36 38 40 42 44 AM T o 14 12 10 08 06 AB 13 0 072 038 027 021 018 AM M 0 004 004 004 004 004 b O s O 1j a 0 5f 0 5 1 0 1 5 2 0 2 5 8 5 8 0 7 5 7 0 6 5 16 18 20 22 24 34 32 30 28 26 032 018 013 011 010 004 004 004 004 004 3 5 3 0 2 5 2 0 1 5 86 88 90 14 12 10 08 06 172 088 060 046 038 004 004 004 004 004 b 5f s 0 2f a 0 5f 0 5 1 0 1 5 2 0 2 5 92 94 A layer of water a few hundred meters thick would be acceptable to oceanographers as defining mixing over several decades Hence if the Suess Effect is close to 2% the size of the biosphere reservoir is probably about equal to or less than that of the atmospheric reservoir This coincides with other estimates that the effective size of the biosphere on land including both living organisms and humus ranges from to one times the atmospheric carbon content Possibly the organic content of the oceanic mixing layer should be included in the biosphere reservoir but this is only a few tenths of the atmospheric CO 2 In terms of the amounts of carbon they contain the biosphere reservoir is much smaller than the oceanic reservoir However over short times in the ocean only the relatively small free CO 2 content dissolved and hydrated carbon dioxide needs to be taken into account Most of the oceanic carbon dioxide is present as carbonate and bicarbonate and because of the 'peculiar buffer mechanism of sea water they do not have a very large quantitative effect on the partition between the sea and the air The Table shows if sources other than fossil fuel combustion had contributed much carbon dioxide to the air within the last few decades 131 the biosphere would have increased in size by what is probably an observable amount Such an increase has not been noted We can conclude that at least during the recent past fossil fuel combustion has been the only significant source of C02 added to the ocean-atmospherebiosphere system The available data do not rule out the possibility that in earlier decades carbon dioxide may have come from oxidation of marine or terrestrial humus as well as from fossil fuels but if so more than half of the amount produced was re-absorbed in the biosphere and the ocean REFERENCES Arrhenius Svante 1903 Lehrbuch der kosmischen Physik 2 Leipzig Hirzel Bolin Bert and Eriksson Erik 1958 Changes in the carbon dioxide content of the atmosphere and sea due to fossil fuel combustion Rossby Memorial Volume edited by B Bolin Rockefeller Institute Press New York 1959 pp 130-142 Bolin B and Keeling C D 1963 Large-scale atmospheric mixing as deduced from the seasonal and meridional variations of carbon dioxide Journal of Geophysical Research Vol 68 No 13 pp 3899-3920 Broecker Wallace S 1963 C14 C12 ratios in surface ocean water Nuclear Geophysics Proceedings of conference NAS NRC Publ 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