Last week the world of science lost one of its giants, and a great friend to NOVA.
Standing 6 feet 5, Dr. F. Sherwood Rowland, of the University of California at Irvine, brought enormous courage to groundbreaking work in chemistry that would ultimately be recognized by the 1995 Nobel Prize.
In 1974, working with his colleague Dr. Mario Molina, Rowland discovered that chlorinated fluorocarbons, or CFCs, used in aerosol sprays and coolants, had the potential to damage the Earth's ozone layer. This thin layer of gas 30,000 feet up in the stratosphere protects life on Earth from the harmful UV radiation that can cause skin cancer.
For years, the team's findings were regarded with skepticism by the scientific community. But Rowland did not shrink from speaking out on the potentially catastrophic consequences of the theory, and he strongly advised politicians and activists to push for a ban on CFCs.
A decade later, British scientists working in Antarctica proved Rowland and Molina right. With a ground-based instrument, they showed that each spring, when the sun emerged following the long polar winter, ozone levels would plunge dangerously low for several months. NASA's satellite measurements revealed the hole to be as tall as Mt. Everest and as wide as the continental United States.
No one knew what the ozone hole portended for the global ozone layer--and CFCs were chemicals that could stay in the atmosphere for 100 years. It turned out that the recurring ozone hole would be an early warning that catalyzed a global environmental treaty.
I first met Rowland in the fall of 1986, while we were producing a NOVA program on the National Ozone Expedition to Antarctica--a scientific team with the urgent mission of solving this complex puzzle of atmospheric chemistry. I remember him saying, "We've got to make hay while the sun shines." He understood that public attention on environmental issues was easily diverted and hard to sustain.
In 1987 NOVA broadcast "The Hole in the Sky," one of the world's first documentaries on ozone depletion and global warming. The program also tracked international progress toward the landmark Montreal Protocol--a global agreement to stop the production of many ozone-depleting chemicals. As Molina would later say, "We started something that was a very important precedent: people can make decisions and solve global problems."
Making complex scientific discoveries is a great contribution. Explaining what they mean to the world's future takes strength and commitment, which Sherwood Rowland had in abundance. Today's discussions of climate change could use more voices like his.