Rowland: Friend of the Environment
F. Sherwood Rowland, a native of Delaware, Ohio,
shared the 1995 Nobel Prize in Chemistry for his critical role in discovering
the global environmental threat of a now-banned family of industrial chemicals.
"The three researchers have contributed to our salvation from a global
environmental problem that could have catastrophic consequences," said the Royal
Swedish Academy of Sciences, which awards the chemistry prizes.
They focused public and scientific attention on
the "ozone layer," the Achilles heel of the biosphere, and the depleted
area of that
protective chemical now known as the "ozone hole." In addition, the research
helped to establish atmospheric chemistry as a major field of research, sparking
hundreds of new studies on the thin layer of gases that allows life to exist on
knows that Earth’s atmosphere contains oxygen -- O2
-- a molecule consisting of two atoms of the element bonded together. That’s the
oxygen that people and other animals breathe, and plants release in
photosynthesis. The atmosphere also contains tiny amounts of another gas made
from oxygen. That’s ozone -- O3
-- that has three oxygen atoms. Most of it exists in a layer whose center is
about 12 miles above Earth’s surface. If all the ozone in the atmosphere were
spread over Earth’s surface, the layer would be only 3 mm thick.
Ozone may be distant and rare, but it plays a
key role in allowing life to exist on Earth. Ozone forms a protective shield in
the upper atmosphere that absorbs most of the sun's dangerous ultraviolet (UV)
radiation before it reaches the surface. UV is the reason why too much exposure
to sunlight can cause sunburn. UV radiation has other bad effects on living
things. Without a protective ozone layer in the atmosphere, modern animals and
plants could not exist.
Rowland and atmospheric chemistry pioneers Paul
Crutzen and Mario Molina discovered how ozone forms and decomposes through
chemical processes in the atmosphere. They also showed how sensitive the ozone
layer is to gases that modern society produces as part of important commercial
and industrial processes.
In 1974, Rowland, of the University of
California at Irvine, and Molina published a landmark study in the journal
Nature showing that chlorofluorocarbon (CFC) gases, or "freons" were destroying
the ozone shield. Billions of pounds of CFCs then were used to force the
contents out of aerosol spray bottles; in air conditioners and other cooling
systems; to make plastic foams; and in scores of other applications.
Their conclusion made scientists’ jaws drop in
amazement, and stirred widespread disbelief among people who made CFCs and
products that depended on them. That’s because everyone thought CFCs were
chemically inert, and totally harmless. In addition, CFCs were used in essential
products, and there were no easily available alternatives. Rowland and Molina
showed that the CFCs in a can of hair spray or underarm deodorant could
gradually travel to the ozone layer. Intense ultraviolet light then
broke CFCs apart, leaving chlorine atoms that took part in chemical reactions
In addition to the science, Rowland became a
vocal advocate for a CFC ban. The research led to the Montreal Protocol, a
treaty in which the world’s countries agreed to a phase-out and ban further
uses of CFCs.
Today’s aerosol sprays, air conditioners, and many other products once dependent
on CFCs, use ozone-safe ingredients. Still, the effects of decades of CFC
release linger, with an ozone hole developing over Antarctica every spring.
Large amounts of ozone were destroyed in that big area.
Without this brilliant, brave Ohio chemist and
other pioneering atmospheric scientists, that hole could be allowing intense UV
radiation to pour down on cities elsewhere, increasing the risk of skin cancer
and other health problems.
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