They still reckon on another twenty or thirty years' work, as some of the gases that are still in use are the most widely used ones and the ones for which no-one has yet been able to find an adequate substitute. But in the twenty years since the Protocol was first signed, ninety-five percent of the problem has been dealt with, so calmly that no-one really noticed. No wars, no noticeable dragging of feet, not much hiding behind doubts about the science or the mechanism, no noticeable economic or other damage. Business as usual.

The Ozone Protectorate people sound very proud of what they have done, and so they should. So should the governmental leaders from their end. This is what they are for, what they are supposed to do. This is why I pay my taxes.

The Montreal Protocol is a legally-binding treaty signed by almost every country in the world except (as at the end of 2006) Andorra, San Marino, Iraq and East Timor - insignificant tax havens and evil dictatorships for most of the period in question - and the Vatican. Amongst its clauses it:

• outlines a mechamism for addressing the problem
• establishes a group of people to measure and report on the extent of ozone depletion, so we can see if the cure is working
• encapsulates a legally-binding agreement as to how and by when each country should phase out which chemicals,  fully inclusive but flexible enough to allow an extra grace period for certain countries with particular needs
• includes a process  of monitoring to ensure that progress happens according to plan
• creates a central fund, paid for by the rich nations, to compensate those countries for whom phasing out CFCs would bring hardship
• reserves the power to update itself in line with any hypothetical changes in the future about the understanding of ozone depletion

The Montreal Protocol has everything it needs to solve the problem of the ozone layer and -surprise, surprise!- it is doing so. They forecast that the ozone layer will be completely back to normal between 2050 and 2075.

Is it just me, or is this what is wanted for global warming? It's as though the ozone layer was a practice run for the kind of international arrangements we seem to be having difficulty facing now. The differences seem to be ones of scale and compexity. While they aren't trivial, they shouldn't be insoluble. So why is the Montreal Protocol such a success, and the Kyoto Protocol so much less so?

The technologies seem to be coming along. The Stern report justifies the economic sense of action. Is it a matter of political will? If so, bring on some new politicians.