BBC News
Monday 17 September 2007
There is a popular belief that the ozone layer has been "saved". Not so, says Joe Farman, one of the scientists who discovered the Antarctic ozone "hole" - even as the Montreal Protocol celebrates its 20th birthday, much remains to be done.
It was announced, on 16 September 1987 in Montreal, that a United Nations Environment Programme (Unep) working group had reached an agreement.
Readers of Lewis Carroll may recall the words of an old song that came into Alice's head in Through the Looking Glass: "Tweedledum and Tweedledee agreed - to have a battle".
What was agreed in Montreal 20 years ago? Essentially, governments would be invited to ratify a protocol to control substances that were depleting the ozone layer.
For chlorofluorocarbons (CFCs), a family of chemicals widely used by industry, most notably in aerosols and refrigerators, consumption was to be held at 1986 levels from July 1989, and reduced in steps to 50% of 1986 levels by 1999.
For halons - bromine-containing substances favoured for fire-fighting - consumption would be frozen at 1986 levels in 1992.
Under such measures, the accumulation of chlorine and bromine in the atmosphere would not be stopped, but merely slowed down.
The most important article in the protocol committed member governments to a review every four years. Without this article, the outlook would have been very bleak!
Mapping the Hole
It seemed a very poor return for negotiations that had started in 1977, and was variously termed a success, a compromise, a muddle, and a failure - all with some justification.
Perhaps the working group were overtaken by events; they were trying to complete a protocol which was already too weak given the flood of information which scientists were amassing about the severity of the problem.
The mid-70s saw the publication of several seminal scientific papers identifying the possibility of ozone-destroying chain reactions in the stratosphere.
Ozone depletion in early spring over Antarctica had been reported in the journal Nature in May 1985, much more severe than any prediction, and confirmed by Nasa in October 1985.
In reporting the Nasa results, the Washington Post newspaper gave the world the expressive term "ozone hole".
In 1986, the US National Ozone Expedition (Noze) to McMurdo Station in Antarctica had produced much evidence to support the view that the depletion was driven by chlorine chemistry.
The same year, the giant chemicals company Du Pont, reminded of a promise made in 1975, wrote to its CFC customers in September 1986 declaring that it now accepted the need for some controls.
Against this background, the timing of the announcement of the protocol, and the weakness of the measures, make sense only as a pre-emptive move astutely designed to preserve some credibility for the negotiators, and to give industry time for orderly reorganisation.
World Tour
The protocol was ratified and came into force on 1 January 1989 in line with the timetable.
The review procedure was set in motion at once. By then, a consensus had been reached on the main scientific issues, NGOs had fought vigorous campaigns for public awareness, and industry was responding to the problem much faster than had initially seemed possible.
Various sets of amendments, all named after the cities where they were negotiated - London, Copenhagen, Vienna, and so on - were brought in.
Most notably, in 1999, $232m were committed to fund the complete closure of CFC production in China and India within a decade.
The main concern in all these negotiations was to replace CFCs quickly with new chemicals, hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs) being the options preferred by industry.
Some 75% of global CFC production was in the hands of 13 groups of companies, who were quite content to close down old CFC plant if the protocol would allow reasonable time for the industry to profit from investment in HCFC and HFC production.
The negotiators readily accepted this; these transitional substances were made subject to guidelines rather than controls, and their future was originally left open-ended, as consensus could not be reached on a phase-out date.
In my view this approach was deeply flawed. Technical surveys had already shown that large quantities of CFCs and halons had been released unnecessarily by poor working practices. The quantities of replacements needed were much less than current consumption.
More emphasis should have been placed on prudent long-term goals, with active encouragement of the development of halocarbon-free and energy-efficient technologies, to protect the ozone layer, slow down the forcing of climate change and reduce the cost of technologies such as refrigeration in developing countries.
Easy Cash?
There is still some unfinished business. The amount of halon 1301 (used in large stationary fire protection systems for such things as supercomputers and art collections) in the atmosphere is still rising, and is likely to continue to do so for at least 10 years, despite the fact that production in developed countries ceased in 1994.
There is some production in developing countries, due to cease in 2010; but the main source is now through leaks from existing installations, and during recycling. It is surely time to consider collecting the existing stockpile, and destroying it.
It is also time to reconsider the controls for HCFCs.
Politicians have often stated that the experience gained with the Montreal Protocol would ease the way for slowing down climate change through the Kyoto Protocol.
In fact serious problems are now arising between the Protocols. Under Montreal, developing countries need not control consumption of HCFC22 (used mainly for air-conditioning equipment) until 2016, and may maintain the 2015 consumption level until complete phase-out by 2040.
A by-product of HCFC22 manufacture is HFC23, a greenhouse gas with a global warming potential 11,700 times greater than that of carbon dioxide.
In developing countries, this used to be allowed to escape into the atmosphere. Now, any which is trapped and burnt can be counted as a credit for carbon trading under the Clean Development Mechanism (CDM) of the Kyoto Protocol.
In 2005, the destruction of HFC23 accounted for 64% of the value of all CDM projects, and 51% in 2006. It is reported that an Indian chemicals firm (SRF) has so far sold credits worth $96m in the 2006-7 financial year, its second largest revenue stream.
This example acts as a reminder that international protocols are seen by some as one more set of rules from which to gain advantage.
There is currently much debate on whether carbon trading based so heavily on burning HFC23 constitutes sustainable development.
The moral seems to be there should never be open-ended agreements on future emissions.
Frequent reviews rescued the Montreal Protocol from deficiencies in the original draft, and another comprehensive re-examination is clearly needed.
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