Commentary

Earlier this year, I visited Yale University, in the beautiful Kroon Hall, to discuss the phase down of HFCs, with a broad group of experts and stakeholders. 

These hydrofluorocarbons are used in, among others, refrigeration, air-conditioning, fire extinguishers and building isolation.

HFCs are very potent greenhouse gases. Most have a global warming potential a thousand times higher than that of CO2.

With the 'Kigali Amendment', these gases are regulated and phased down globally under the Montreal Protocol, the treaty that protects the ozon layer.

Many substances successfully regulated by the Montreal Protocol, such as HCFCs and CFCs, not only damage the ozon layer, but also have a devastating climate impact -- with global warming potentials that run in the thousands.

Because the Montreal Protocol has been so successful, it makes her one of the most effective climate treaties to date -- even though her contribution often goes unrecognised.

Some key features of the Montreal Protocol explain part of her success:

1. Each gas is different -- with different uses, different challenges, different solutions. The Montreal Protocol doesn't treat the gases in bulk, but sets out an approach for each specific gas, with tailor made policies that fit the circumstances for that substance.

2. Start and strengthen. First a substance is brought in the regime, with a certain schedule for phase-down. These schedules can be adjusted and accelerated, as experience with implementation grows and alternatives become available.  

3. Decisions by the Meeting of Parties on such adjustments are legally binding on the Parties -- a feature that most treaties lack.

4. There is a fixed approach to differentiated obligations: developed countries start with a phase down of a substance, with developing countries preparing their implementation and following phase down within a decade.

5. An Implementation Committee effectively addresses issues of non-compliance. The focus is on identifying the root cause of compliance problems and on a targeted remedy.

6. The Montreal Protocol has an in-house 'technology and economic assessment panel', the TEAP. This advisory body provides the political decision-making with a solid assessment of the technical and economic possibilities.   

Of course, no treaty is perfect. Lots of work needs to be done, also on the further phase down of HFCs. Still, the track record of the Montreal Protocol on both protection of the ozon layer and on climate speaks for itself.

It's the treaty that delivers. 

After some years of absence, it felt great to be back in the Montreal Protocol community.