From The Canberra Times (ACT : 1926 - 1995) Wednesday 5 July 1967
The weather and air pollution
From a Special Correspondent in New York
THERE is evidence to suggest that the Earth's atmosphere may be dirtier than it was a few decades ago, according to a report by two US scientists in Science, the weekly publication of the American Association for the Advancement of Science.
The scientists are Robert A. McCormick and Dr John H. Ludwig of the National Centre for Air Pollution Control, Cincinnati. They note that there has been an increase in carbon dioxide in the atmosphere largely because mankind has burned so much coal and oil in recent decades.
Scientists believe this excess carbon dioxide should make the planet warmer. Nevertheless there has actually been a slight decrease in temperature, first noticed during the 1940s and thought to be continuing today.
Greater effort should be devoted to watching and recording increases in the amount of solid material particles floating in the atmosphere, the scientists suggest.
These particles make the atmosphere more turbid - that is, they reduce its clarity and transparency. This may be a major factor in the world-wide decrease in average air temperature.
They report that experiments done in Washington and Cincinnati show that turbidity can, measurably, reduce the amount of radiation from the sun that reaches the ground.
McCormick and Ludwig suggest that the warming effect of carbon dioxide might be offset by a larger opposite effect produced by loss of clarity in the air.
Dr J. Murray Mitchell the Environmental Science Services Administration in Washington, who has done much research on global temperature trends, says that there seems to have been a drop of a fraction of one degree fahrenheit between the 1940s and 1959.
Since then, throughout virtually all of the United States, and for almost every season, temperatures have averaged at least a degree lower than in earlier decades, the scientist claims.
Comparable studies by a meteorologist in Germany show the same trend and suggest that it may well be world wide.
Dr Mitchell says the reasons for it are hard to determine. Factors that must be considered include possible variation in the heat output of the sun, volcanic eruptions as well as man-made pollution of the atmosphere, and the effects of the interaction between the air and the sea.
In Philadelphia, a pilot programme to study the effect of air pollution on the human body is to be launched by the Philadelphia County Medical Society and the Philadelphia Health Department.
Here is the paper from Science,
Robert A. McCormick, John H. Ludwig (1967), Climate Modification by Atmospheric Aerosols, Science 9 June 1967: Vol. 156 no. 3780 pp. 1358-1359 DOI: 10.1126/science.156.3780.1358
Abstract: Theoretical considerations and empirical evidence indicate that atmospheric turbidity, a function of aerosol loading, is an important factor in the heat balance of the earth-atmosphere system. Turbidity increase over the past few decades may be primarily responsible for the decrease in worldwide air temperatures since the 1940's.
Robert A. McCormick and John H. Ludwig worked at the time at the National Center for Air Pollution Control, Cincinnati which doesn't seem to exist any more or has maybe had a name change. Their work is mentioned by Spencer Weart in his history of climate science: "Discovery of Global Warming."
Robert A. McCormick
I can find almost nothing about Robert A. McCormick despite his seminal paper on air pollution. It is likely that he is Robert Amos McCormick, author of this book: Meteorological Aspects of Air Pollution, Secretariat of the World Meteorological Organization, 1970.
John H. Ludwig
Dr. Ludwig earned his B.S. in civil engineering at the University of California at Berkeley in 1934, an M.S. in civil engineering from CU in 1941, and the M.S. and Sc.D. degrees in industrial health from the Harvard School of Public Health in 1956 and 1958. He graduated first in his class of 166 from the Army Air Corps meteorological school at New York University during World War 11 and served in Greenland. He graduated from the U.S. Army School of Military Government at the University of Virginia in 1945, and he served as a military government officer in Korea.
As assistant commissioner for science and technology of the National Air Pollution Control Administration prior to his retirement in 1972, Dr. Ludwig was the principal scientific and engineering adviser of the program. He is now a member of the Technology Assessment Panel of the U.S. Environmental Protection Agency (EPA) and a valued consultant on air pollution to major international bodies.
He was directly responsible for developing the federal government's primary research facility in the field of air pollution engineering problems into a 230-person staff with a budget of $15 million. At the same time he spearheaded the agency's program of cooperative research and development. Programs jointly sponsored by industry and government were launched with the Manufacturers' Chemists Association and the automobile and petroleum industries.
The numerous technical and advisory committees on which he has served include the Air Pollution Research Advisory Committee of the Coordinating Research Council (of which he held the chairmanship in 1971-72); the World Health Organization Expert Advisory Panel on Air Pollution, the Working Group on Air Pollution of the Economic Commission for Europe (of which he was a member and founding chairman); and the Air Pollution Pilot Project (of which he was director) of the Committee on the Challenges of Modern Society. He is a Diplomate of the American Academy of Environmental Engineers and served as U.S. delegate to the Air Pollution Sector Group of the Organization for Economic Cooperation and Development (OECD). He has been a member or chairman of committees of various professional organizations and joint groups dealing with pollution, weather control, meteorological research, and other subjects.
Source and more details: The University of Colorado
Dr J Murray Mitchell
For more than 35 years, Dr. Mitchell was a senior expert on climate for the National Oceanic and Atmospheric Administration and other Federal agencies.
Long before global climatic trends became big environmental news, he pioneered efforts to understand and alert the nation to the causes of cyclical droughts, periods of heavy rain, long-term changes in temperature and atmosphere and the pressures of human population growth on the climate.
Warnings on the Weather
In the 1960's, before the birth of modern environmentalism, Dr. Mitchell warned that man-made effects on weather and the climate were no longer trivial and should be studied urgently before they grew beyond control.
He studied sunspot cycles, lunar influences, tree rings, volcanic activity and other phenomena for clues to the past and future of the world's climate. In 1976, he termed irresponsible the predictions that the planet faced an impending ice age.
In the mid-70's, when other scientists warned that man's output of heat threatened to melt the polar ice caps and flood coastal regions, he concurred and warned of increasing amounts of carbon dioxide that an industrial world was spewing into the atmosphere.
Dr. Mitchell in recent years cited growing evidence that the world's gradually warming climate - an average of 1 degree over the last century, and 3 to 5 degrees in polar regions -was a result of a greenhouse effect in which the burning of fossil fuels in industrialized nations produces carbon dioxide and other gases that prevent the earth's heat from escaping into space. Such global warming could alter weather patterns and disrupt agriculture.
A Puzzling Arctic Haze
A tall, athletic outdoorsman who enjoyed handball, jogging and hiking, Dr. Mitchell continued to serve as a climatology consultant to the government after he retired as a senior research climatologist for the National Oceanic and Atmospheric Administration in 1986.
John Murray Mitchell Jr. was born in New York City on Sept. 17, 1928, and grew up in Tuxedo Park, N.Y., where he became interested in weather and climate as a teen-ager. He attended the Massachusetts Institute of Technology, earning a bachelor's degree in 1951 and a master's in 1952.
For the next three years, he was a weather officer with the United States Air Force, serving in Alaska, where he observed a puzzling Arctic spring haze that sometimes grew as intense as the smog in Los Angeles. After studying its particles, he postulated that the haze came from industrial Europe and China.
Dr. Mitchell was a research meteorologist with the United States Weather Bureau from 1955 to 1965 and earned a doctorate at Pennsylvania State University in 1960. In 1965, he joined the oceanic and atmospheric administration as a project scientist and became a senior climatologist in 1974, science adviser in 1982 and senior research climatologist in 1983.
He wrote numerous articles for books, encyclopedias, magazines and technical journals, and since 1978 had been executive editor of Weatherwise magazine. He received several awards from the Commerce Department and nongovernmental organizations.
Source and more here at the New York Times: J. Murray Mitchell, Climatologist Who Foresaw Warming Peril, 62 By ROBERT D. McFADDEN Published: October 08, 1990