Noble judgement

THE NOBLE for chemistry for the Year 1995 to three atmospher- Scientist on October 11, is a vindication for environmentalists who have Wl6m boarse for decades over phown caused by humanmade LUC WMDcrs of the us $1 million we Dutch scientist Paul k1ft Un Planck Institute for Oft bdamz Germany, Mario Molina of Massachusetis Institute of technology in Cambridge, and F Shrewood of the University of California at Irvine.

By explaining tye chemical mecha- nism the thickness of the ozone layer,the three researchers have contributed to our salvation from a global environmental problem that asepbsc consequences," said the royal Swedish Academy of Sciences in its Nobel citation.

An elated Molina, in a telephonic interview with the Washington Post pointed out that that the award to environmen- tal scientists "shows a certain maturity in field previously considered soft."

Undoubtedly, the Nobel chemistry prize is a befitting tribute to over three decades of painstaking research undertaken by Molina, Rowland and Crutzen. Beginning in the 1970s, the trio, in a series of findings, described the chemical processes by which ozone was formed and destroyed in the atmosphere.The studies showed that human made chemicals like the chlorofluoro- carbons (CFCs) used in aerosols, refrigerants and insulating materials, were breaking down ozone molecules in the upper part of the atmosphere. This ler protects the earth from the harmful effects of the ultraviolet radiation emitted by the sun.

Further alarm was generated as it was scientifically established that unless there was an adequate ozone layer, the sun's ultraviolet rays could trigger off skin cancer and cataracts, and damage natural ecosystems.

The first major step was taken by Crutzen in 1970, when he demonstrated that nitrogen oxides accelerate ozone depletion, identifying for the first time, one of the key processes that determine the natural balance of the ozone layer, He also explained the link between the density of the ozone layer and chemicals released by bacteria in the soil, indicating that the earth operates as a system in which the oceans, air and land are all mutually interfinked.

Criatzen's research was further bolstered by Harold Johnston, a us researcher. Johnston demonstrated the possible threat to the ozone layer by using a planned fleet of supersonic aircraft that could release nitrogen oxides right into the middle of the ozone layer.

The ozone chemistry research then received a big fillip from a seminal paper published by Molina and Rowland in the journal Nature in 1974. The paper focussed on the threat posed to the ozone layer by the proliferation of synthetic CFCs. These chemicals were widely used as propellants in spray cans, as coolants in refrigerators and air conditioners, besides other industrial purposes. Obviously, Molina and Rowland's thesis faced flak from industry which was apprehensive that curbs on CFCs would affect business.

However, dangers of ozone depletion arrested attention in 1985, when the British Antarctic Survey discovered an "ozone hole" over the South Pole, This spurred Crutzen, Molina and Rowland to zero in on the significance of low temperatures for creating icy cloud particles upon which ozone destroying reactions could occur.

The work of Molina, Crutzen and Rowland laid the foundation for the Montreal Protocol, 1987, on phasing out of CFCs. Under the Protocol, the us and 70 other countries agreed on phasing out CFCs by AD 2000.

The fact that ozone depletion was affecting temperate regions, led to the 1992 amendments to the Protocol under which industrialised countries agreed for cFc phase-out by 1995 end. As the Royal Swedish Academy of Sciences pointed out, it was largely because of the three researchers that "it has been possible to make far-reaching decisions on prohibiting the release of gases that destroy ozone."

But there still are sceptics who refuse to accept that CFCs cause ozone depletion. Only this September, there was a hearing in the us on the "myths and realities" ofstratospheric ozone crisis. In recent weeks, us Republicans have even introduced legislation to postpone further action to reduce the marinfac- ture of ozone depleting substances. The recent Nobel chemistry award is certainly a fitting rebuffto the hollerings of the sceptics.