David M. Gates, an ecologist who sounded early warnings that fossil fuels, fertilizers and pesticides posed a potentially fatal threat to the global environment, died on March 4 in Ann Arbor, Mich. He was 94.
The cause was heart failure, his daughter Heather Gates said.
Echoing “Silent Spring,” Rachel Carson’s galvanizing 1962 exhortation against pesticides and weedkillers, and presaging the creation of the federal Environmental Protection Agency by President Richard M. Nixon in 1970, Dr. Gates was in the vanguard of scientists who raised the alarm about an ecological crisis that would culminate in global warming from greenhouse gases.
“We will go down in history known as an elegant technological society which underwent biological disintegration for lack of ecological understanding,” he said in 1968.
As he grew more accustomed to playing Cassandra, Dr. Gates grimly predicted a planet “half-starved, depressed billions gasping in air depleted of oxygen and laden with pollutants, thirsting for thickened, blighted water.”
He repeated that dire warning in testimony to congressional committees, in speeches and in publications, and as an adviser to the United States Public Health Service, which helped shaped provisions of the Clean Air Act.
By 1977, he was warning that dependence on coal, oil, gas and other fossil fuels “would mean warmer global climate, raise ocean levels.”
David Murray Gates was born in Manhattan, Kan., on May 27, 1921. He was adopted by Frank C. Gates, a plant ecologist at Kansas State University, and the former Margaret Thompson, a kindergarten teacher.
An Eagle Scout, he graduated from the University of Michigan with a bachelor of science degree in physics in 1942 and earned his master’s and doctorate there, too.
During World War II, working at the University of Michigan and at the Johns Hopkins University Applied Physics Laboratory, he conducted research on a proximity fuse to improve targeting by antiaircraft guns. The fuse was an electronic device designed to detect its target and detonate if it flew within about 75 feet. He later studied radioactivity in the upper atmosphere.
But he also had a passion for botany acquired in boyhood. Merging it with his expertise in physics, he was able to apply a precision to plant ecology that had been lacking in his father’s approach, leading him into a new science, biophysical ecology.
As early as 1959, Dr. Gates propounded the revolutionary theory that a plant would be healthy as long as it maintained an equilibrium between the amount of energy it absorbed and the amount it gave off.
“I elected somewhat arbitrarily to work on plants first,” he recalled, “because they don’t bite and run around.”
In 1965, he left a teaching post at the University of Colorado to become director of the Missouri Botanical Garden, a 70-acre oasis in St. Louis, and a professor at Washington University there. He joined the University of Michigan faculty in 1971 as a professor of botany and director of the biological station. He was named professor emeritus in 1991.
His wife, the former Marian Penley, died in 2006. In addition to his daughter Heather, he is survived by two other daughters, Julie and Marilyn Gates; a son, Murray; and four grandchildren.
Dr. Gates published six books, including the definitive “Biophysical Ecology” in 1980.
He was immortalized several years ago when students on a field trip to Lake of the Clouds in Michigan’s Upper Peninsula discovered a new microscopic blue-green algal diatom species and named it Brachysira gatesii in his honor.