Advanced global action without finding a smoking gun

chemicial weapons of mass destruction, chemicial weaponsBy Rajendra Shende,

Mandated by the UN, the coalition forces invaded Iraq in 2003 to destroy its “chemicial weapons of mass destruction” without finding a smoking gun. That’s the negative. There’s also been a positive.

Thirty years ago, member-states of the UN reached amazing consensus, without any sign of a smoking gun, and sealed a deal to take daring action. To dramatise the story, 24 countries on that day decided to start destroying what could be called “chemical weapons of mass destruction” that were being emitted, albeit unintentionally, in millions of tonnes annually and getting “stocked” in the sky. Those groups of chemicals were called ozone-depleting substances, mainly chlorofluorocarbons (CFCs), which were predicted to be the cause of the destruction of the Earth’s defence system — the stratospheric ozone layer.

When the final negotiations under the umbrella of the UN Environment Programme ended on September 16, 1987, with a historic agreement called “The Montreal Protocol on Substances that Deplete the Ozone Layer”, there was no smoking gun evidence that CFCs were the cause of the global depletion of the ozone layer. The ozone hole — loss of more than 50 per cent (and even 95 per cent in places) of the ozone — was observed over Antarctica’s stratosphere when the negotiations were taking place, but scientists could not firmly implicate CFCs for it in a conclusive manner. The evidence of the predicted impact on life on Earth was even farther and nowhere visible. The only push came from scientists who theorised the destruction of the ozone layer and the study reports from more than a decade of research after the proposed hypothesis was first made.

Delegates, however, agreed not to give a cynical shrug to the lack of specific attribution and causation. They no longer demanded a smoking gun. They decided to begin action to eliminate production and consumption of CFCs.

The Montreal Protocol proved to be a historic first step. Sealing that one deal began the journey of the most successful multilateral agreement in the annals of not only global environmental accords but for any UN global accord. It gave birth to the concept of the “precautionary principle” which was the seminal theme of the Agenda 21 that the world leaders agreed on five years later, in June 1992, in Rio de Janeiro.

It signalled an approach that necessarily requires action to control inputs of such substances and happenings even before a causal link has been established by absolutely clear scientific evidence.

The story is nothing short of extraordinary. It started with the concurrent publication of two scientific papers in two American universities — one by Richard Stolarsky and Ralph Cicerone of the University of Michigan, and other by Mario Molina and Sherwood Rowland of the University of California-Berkeley. Extraordinary, because a scientific paper is rarely the subject of discussion in the buzzing corridors and glittering halls of the UN.

Second, the papers theorised a postulation, based on the not-so-simple chemistry taking place high up in the sky. Specifically, the papers stated that CFCs being exceptionally stable, once released into the atmosphere, can transgress to the stratosphere 15 km above the Earth. They would then have been decomposed by high-energy solar UV rays and would release chlorine atoms that could eliminate ozone molecules existing in the rarefied concentration of one in a million other molecules.

That would trigger the dangerous loss of ozone in the stratosphere, because each chlorine atom could destroy hundreds and thousands of ozone molecules which form the ozone shield that protects life on the earth. That was a shocking hypothesis, almost like a gunshot fired at close range. UN delegates, used to dealing with conflicts on the ground, could hardly be expected to take note of such a postulation, leave alone take action to eliminate causative reasons.

Subsequent worldwide collaborative scientific study did find the smoking gun within months of the Montreal Protocol’s signing.

Scientists like Susan Solomon of NOAA (now MIT) were able to solve the jigsaw puzzle of chlorine and other species observed over Antarctica by linking them to very low temperature catalytic reactions accelerated by the ice crystals of the polar stratospheric cloud.

The Montreal Protocol has since succeeded in phasing out 98 per cent of the ozone-depleting chemicals, including nearly 100 per cent of CFCs. But more importantly, it phased-in the important precautionary principal lesson in the history books of the UN’s multilateral environmental agreements. Last month’s observations of the ozone layer over Antarctica by NASA records definite slowing of its depletion and better recovery than last year — rare success that exemplifies the positive results of UN efforts and collective global action.

Two years ago, world leaders adopted the Sustainable Development Goals — SDGs — a collective action for a better world by 2030. This agenda carries forward the seminal principle of the precautionary approach.

(Rajendra Shende, an IIT alumnus, is Chairman TERRE Policy Centre and a former UNEP Director. The views expressed are personal. He can be contacted at



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