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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Air pollution: 5 steps to vanquishing an invisible killer

A new report looks at the economics of air pollution. 

110, 150, 520... These chilling statistics are the number of deaths attributable to particulate air pollution for the cities of Southampton, Nottingham and Birmingham in 2010 respectively. Or how about 40,000 - that is the total number of UK deaths per year that are attributable the combined effects of particulate matter (PM2.5) and Nitrogen Oxides (NOx).

This situation sucks, to say the very least. But while there are no dramatic images to stir up action, these deaths are preventable and we know their cause. Road traffic is the worst culprit. Traffic is responsible for 80 per cent of NOx on high pollution roads, with diesel engines contributing the bulk of the problem.

Now a new report by ResPublica has compiled a list of ways that city councils around the UK can help. The report argues that: “The onus is on cities to create plans that can meet the health and economic challenge within a short time-frame, and identify what they need from national government to do so.”

This is a diplomatic way of saying that current government action on the subject does not go far enough – and that cities must help prod them into gear. That includes poking holes in the government’s proposed plans for new “Clean Air Zones”.

Here are just five of the ways the report suggests letting the light in and the pollution out:

1. Clean up the draft Clean Air Zones framework

Last October, the government set out its draft plans for new Clean Air Zones in the UK’s five most polluted cities, Birmingham, Derby, Leeds, Nottingham and Southampton (excluding London - where other plans are afoot). These zones will charge “polluting” vehicles to enter and can be implemented with varying levels of intensity, with three options that include cars and one that does not.

But the report argues that there is still too much potential for polluters to play dirty with the rules. Car-charging zones must be mandatory for all cities that breach the current EU standards, the report argues (not just the suggested five). Otherwise national operators who own fleets of vehicles could simply relocate outdated buses or taxis to places where they don’t have to pay.  

Different vehicles should fall under the same rules, the report added. Otherwise, taking your car rather than the bus could suddenly seem like the cost-saving option.

2. Vouchers to vouch-safe the project’s success

The government is exploring a scrappage scheme for diesel cars, to help get the worst and oldest polluting vehicles off the road. But as the report points out, blanket scrappage could simply put a whole load of new fossil-fuel cars on the road.

Instead, ResPublica suggests using the revenue from the Clean Air Zone charges, plus hiked vehicle registration fees, to create “Pollution Reduction Vouchers”.

Low-income households with older cars, that would be liable to charging, could then use the vouchers to help secure alternative transport, buy a new and compliant car, or retrofit their existing vehicle with new technology.

3. Extend Vehicle Excise Duty

Vehicle Excise Duty is currently only tiered by how much CO2 pollution a car creates for the first year. After that it becomes a flat rate for all cars under £40,000. The report suggests changing this so that the most polluting vehicles for CO2, NOx and PM2.5 continue to pay higher rates throughout their life span.

For ClientEarth CEO James Thornton, changes to vehicle excise duty are key to moving people onto cleaner modes of transport: “We need a network of clean air zones to keep the most polluting diesel vehicles from the most polluted parts of our towns and cities and incentives such as a targeted scrappage scheme and changes to vehicle excise duty to move people onto cleaner modes of transport.”

4. Repurposed car parks

You would think city bosses would want less cars in the centre of town. But while less cars is good news for oxygen-breathers, it is bad news for city budgets reliant on parking charges. But using car parks to tap into new revenue from property development and joint ventures could help cities reverse this thinking.

5. Prioritise public awareness

Charge zones can be understandably unpopular. In 2008, a referendum in Manchester defeated the idea of congestion charging. So a big effort is needed to raise public awareness of the health crisis our roads have caused. Metro mayors should outline pollution plans in their manifestos, the report suggests. And cities can take advantage of their existing assets. For example in London there are plans to use electronics in the Underground to update travellers on the air pollution levels.


Change is already in the air. Southampton has used money from the Local Sustainable Travel Fund to run a successful messaging campaign. And in 2011 Nottingham City Council became the first city to implement a Workplace Parking levy – a scheme which has raised £35.3m to help extend its tram system, upgrade the station and purchase electric buses.

But many more “air necessities” are needed before we can forget about pollution’s worry and its strife.  


India Bourke is an environment writer and editorial assistant at the New Statesman.