Sherwood Rowland: when good science is not enough

If you want to spur action, you need a disaster - as the case of ozone-destroying CFCs shows.

If you want to spur action, you need a disaster - as the case of ozone-destroying CFCs shows.

After his death on Saturday, much will be written about chemist Sherwood Rowland's triumph in getting chlorofluorocarbons (CFCs) and other ozone-destroying chemicals banned. The truth about Rowland's story is a little less inspiring than the legend, however.

Rowland and his colleague Mario Molina published the first paper on the threat to the ozone layer in June 1974. It took thirteen years before the Montreal Protocol, limiting the industrial production of those chemicals, was finally ratified.

Those were extremely painful years for Rowland. His colleagues shunned him for his activism in support of a ban. Almost no university chemistry departments would have him come and speak for nearly a decade -- unthinkable for a chemist of his calibre. Twelve years passed without him being invited to speak to industry groups. James Lovelock, now practically a saint, thought Rowland was going too far: he called for a "bit of British caution" in the face of Rowland and Molina's "missionary" zeal for a ban on CFCs.

If the science establishment doesn't come off too well in that era, Rowland was not without fault either. It may have been in response to pressure from his colleagues, but part of the reason the ban took so long to achieve was that, at a crucial time in the debate, Rowland announced results that cast doubt on the case against CFCs before checking them thoroughly or offering them up for review by others.

In 1976, CFCs' defenders had suggested that the ozone-attacking chemicals might get mopped up by nitrogen in the atmosphere. They would then be rendered safe. Rowland entertained the idea and declared that his estimates of likely ozone depletion by CFCs had been between 20 and 30 percent too pessimistic.

The pronouncement threw the whole issue into confusion at an extremely delicate time. The US National Academy had been about to issue a report into what should be done about CFCs; now they said they needed more time. The Observer declared that the "Aerosol scare 'may be over'". Chaos ensued, and the scientists fell upon each other.

Two months later, Rowland had discovered a mistake in his calculations, but the damage was already done. Because of the confusion, the furore and the persistence of doubts, the National Academy eventually issued its report with significantly weakened conclusions -- so weak in fact, that the following day's New York Times reported the Academy as recommending a curb on aerosols, while the headline of the Washington Post screamed out "Aerosol Ban Opposed by Science Unit".

In the end, it wasn't the carefully-honed arguments of scientists that got CFCs banned. In 1985, scientists announced they had discovered an enormous hole in the ozone layer over the Antarctic. There was a public outcry and the politicians leapt to their feet. The Montreal Protocol was signed two years later. If there's a lesson to be learned from Sherwood Rowland's work, it's that science isn't enough. If you want to spur action, you need a disaster.

In fact, the scientists carried on debating CFCs long after the politicians had moved on. In 1992, five years after Montreal, a group of MIT scientists organised a scientific forum ahead of the environmental summit in Rio de Janeiro. They invited Mario Molina to give a talk. But they scheduled a Brazilian meteorologist to talk first; to Molina's shock, the Brazilian declared to the assembly that the ozone depletion theory was a sham. If there was any depletion, he said, it was due to chlorine from sea spray and volcanoes.

In many ways, the cautious nature of science is its trump card, its ace in the hole. We trust science precisely because it has got things wrong in the past, gives ear to corrective viewpoints and slowly put itself right. But when something is important, we can't wait for all the scientific arguments to be resolved -- because, as the case of Sherwood Rowland shows, that can take longer than any of us can afford.

Michael Brooks's "Free Radicals: the Secret Anarchy of Science" is published by Profile Books (£12.99)

Michael Brooks holds a PhD in quantum physics. He writes a weekly science column for the New Statesman, and his most recent book is At the Edge of Uncertainty: 11 Discoveries Taking Science by Surprise.

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Sadiq Khan gives Jeremy Corbyn's supporters a lesson on power

The London mayor doused the Labour conference with cold electoral truths. 

There was just one message that Sadiq Khan wanted Labour to take from his conference speech: we need to be “in power”. The party’s most senior elected politician hammered this theme as relentlessly as his “son of a bus driver” line. His obsessive emphasis on “power” (used 38 times) showed how far he fears his party is from office and how misguided he believes Jeremy Corbyn’s supporters are.

Khan arrived on stage to a presidential-style video lauding his mayoral victory (a privilege normally reserved for the leader). But rather than delivering a self-congratulatory speech, he doused the conference with cold electoral truths. With the biggest personal mandate of any British politician in history, he was uniquely placed to do so.

“Labour is not in power in the place that we can have the biggest impact on our country: in parliament,” he lamented. It was a stern rebuke to those who regard the street, rather than the ballot box, as the principal vehicle of change.

Corbyn was mentioned just once, as Khan, who endorsed Owen Smith, acknowledged that “the leadership of our party has now been decided” (“I congratulate Jeremy on his clear victory”). But he was a ghostly presence for the rest of the speech, with Khan declaring “Labour out of power will never ever be good enough”. Though Corbyn joined the standing ovation at the end, he sat motionless during several of the applause lines.

If Khan’s “power” message was the stick, his policy programme was the carrot. Only in office, he said, could Labour tackle the housing crisis, air pollution, gender inequality and hate crime. He spoke hopefully of "winning the mayoral elections next year in Liverpool, Manchester and Birmingham", providing further models of campaigning success. 

Khan peroration was his most daring passage: “It’s time to put Labour back in power. It's time for a Labour government. A Labour Prime Minister in Downing Street. A Labour Cabinet. Labour values put into action.” The mayor has already stated that he does not believe Corbyn can fulfil this duty. The question left hanging was whether it would fall to Khan himself to answer the call. If, as he fears, Labour drifts ever further from power, his lustre will only grow.

George Eaton is political editor of the New Statesman.