Retired UC Berkeley scientist Harold "Hal" Johnston, whose pioneering research linked nitrous oxides emitted by jet aircraft to destruction of the Earth's protective ozone layer, has died at age 92.
He died peacefully of natural causes at his Kensington home on Oct. 20, according to a news release from the College of Chemistry at UC Berkeley.
He's remembered not only for his discoveries, for which he received the National Medal of Science in 1997, but also for what the College of Chemistry called his "unflappable intellectual honesty" in the face of criticism, especially in the wake of his 1971 paper that drew the world's attention to the possible connection between supersonic aircraft and loss of the ozone.
When the Nobel Prize in Chemistry was awarded to three other scientists for ozone research in 1995, the Royal Swedish Academy of Sciences cited Johnston's work as helping to establish the foundation of our understanding about the threat posed by nitrogen compounds and human activity to the ozone layer, which the Academy called "the Achilles heel of the biosphere."
And when he won the National Medal of Science two years later, a news release from UC Berkeley noted, "His scientific concerns about the effects of man-made chemicals on the ozone layer, heatedly attacked at the time, have been borne out by the subsequent discovery of ozone holes over the Earth's poles."
Here is the College of Chemistry's news release about his death:
Harold "Hal" Johnston, noted atmospheric chemist and winner of National Medal of Science, has died
Harold “Hal” Johnston, professor emeritus of chemistry at UC Berkeley, died on Saturday morning, October 20, 2012. He died peacefully at his home in Kensington, CA, of natural causes. He was 92.
Harold Johnston was born in Woodstock, GA, on October 11, 1920. In 1941 he graduated from Emory University, with an A.B. degree in chemistry and a minor in English literature. He carried out graduate studies at the California Institute of Technology (Caltech) in 1941-42 and 1945-47, and obtained his Ph.D. degree in chemistry with a physics minor in l948.
He was on the faculty of the chemistry departments of both Stanford University (1947-56) and Caltech (1956-57). From 1957–91, he was a professor of chemistry at Berkeley, serving as Dean of the College of Chemistry from 1966–1970. He retired in 1991.
Johnston is most widely recognized for his landmark 1971 paper in Science which showed nitrogen oxides emitted by aircraft in the stratosphere might cause substantial depletion of the Earth’s ozone layer. He was thrust into the public spotlight with the publication of this paper, which was controversial because of its scientific conclusion that human activities could have an environmental impact on a global scale.
Johnston was known for his unflappable intellectual honesty, even in the face of the harsh public criticism that followed this paper. He continued to work toward an honest, unbiased and responsible discussion of the effects of stratospheric aircraft. The extraordinary insights presented in this 1971 paper, as well as Johnston's efforts to communicate the results with the public and policy-makers, led to a transformation in the state of stratospheric science, spurring the initial development of modern programs of stratospheric observation and modeling.
Johnston received numerous prizes for his work in atmospheric chemistry, including the 1997 National Medal of Science. He was elected to the National Academy of Sciences in 1965 and to the American Academy of Arts and Sciences in 1972. Some of his other major awards include the Tyler World Prize for Environmental Achievement (1983), the National Academy of Sciences Award for Chemistry in the Service to Society (1993) and the American Geophysical Union’s Roger Revelle Medal (1998).
Nobel Laureate Dudley Herschbach worked in Johnston’s lab at Stanford and described him as one of his most important influences. Herschbach’s Nobel autobiography states, “My chief mentor at Stanford was Harold Johnston, who imbued me with his passion for chemical kinetics.” Johnston’s pioneering research in atmospheric chemistry and kinetics had a crucial impact on Hershbach, who shared his Nobel Prize with John Polanyi and Berkeley chemist Y.T. Lee.
Berkeley atmospheric chemist Ron Cohen has many fond memories of Johnston. He says, “Hal Johnston taught us all that actions by individuals can have consequences for the atmosphere on a global scale. I'll always remember him telling me of his adventures in science. In one example, he spoke to me about being hired as a consultant by GM to check up on Arie Haagen-Smit's science. Hal reported back to GM that Haagen-Smit was brilliant—and Hal was promptly fired. The story is classic Johnston. He was always in the thick of important stories in atmospheric science, telling the truth as he saw it and letting the chips fall where they may.”
Johnston is survived by his wife of 64 years, Mary Ella Johnston; four children, Shirley Johnston Anderson, Windsor, CA; Linda Banster, Port Republic, VA; David Johnston, Arlington, MA, and Barbara Schubert, Berkeley, CA; six grandchildren and two great-greatchildren; and two living brothers, Richard “Dick” Johnston and William “Bill” Johnston.
There will be no memorial service. Johnston chose to be cremated and wanted his ashes to be taken to the house in which he grew up in Georgia, where his youngest brother still lives.
A transcript of a series of interviews conducted with Johnston in 2005 can be accessed on the Bancroft Library's Regional Oral History Office website.