Patrick Low, Fellow of Asia Global Institute, compares this latest climate change-related deal to other global pacts aimed at protecting the environment.
Just under two weeks ago, an important new deal was struck under the Montreal Protocol on Substances that Deplete the Ozone layer. This is not as remote or unimportant as it might sound.
It stands as a rare example of how governments can work together on issues that are manageable only with international cooperation.
The Montreal Protocol has been characterised by former UN Secretary General Kofi Annan as "perhaps the most successful international agreement to date."
Among other things, this refers to its singular success in addressing the problem it was set up to fix - a growing hole in the earth's ozone layer over Antarctica, and to a lesser extent the Arctic.
The holes have started to close, although experts reckon it will take more than 30 years to restore the health of the ozone layer to where it was in 1980.
The Montreal Protocol is also the only universal UN Agreement, signed by 196 states and the EU. It has more signatories than any other international agreement or body, including the United Nations itself. The Protocol was negotiated almost 30 years ago, in 1987. It requires its signatories to phase out the use of chlorofluorocarbons, which were the key driver of ozone depletion.
CFCs were widely used in aerosol products, fire-fighting equipment, foams, refrigerators and air conditioning systems until it was understood how harmful they were to the ozone layer, which provides the earth essential protection from the sun.
The new addition to the Montreal Protocol agreed earlier this month has taken on its next big challenge, now that CFCs have virtually disappeared from products. Ninety-eight per cent of all ozone-depleting substances have been phased out.
Chlorine and carbon are both offending substances in chlorofluorocarbons. Chlorine depletes ozone, but given their carbon content, CFCs are also a greenhouse gas. Despite its focus on ozone, therefore, the Protocol clearly has climate change implications.
But precisely because of that focus, The Protocol had the incidental effect of increasing the use of hydrofluorocarbons as substitutes. HFCs have become the fastest growing source of greenhouse gas emissions, increasing at between 10 and 15 per cent annually. CFCs and HFCs are extraordinarily potent greenhouse gases, thousands of times more damaging than carbon dioxide.
So something urgent needed to be done about HFCs, and that is what the Montreal Protocol has just achieved - an agreed phase-out of HFCs starting in 2019. The technology for alternatives to fluorocarbons is available, but substitution will take time, especially in lower-income economies.
In effect, the Montreal Protocol has morphed into a pure climate change agreement, parallel to the new framework agreement on climate change agreed in Paris in December last year.
It was a good decision to keep HFC elimination within the ambit of the Montreal Protocol, with its legally binding reduction obligations.
The Paris Agreement, by contrast, was only made possible by leaving greenhouse gas emissions targets to nationally determined contributions.
Why has the Montreal Protocol been so successful compared to other efforts at international cooperation? The agreement not only binds countries, it contains financial provisions to assist in phase-outs.
Controversially, at least in the early days, the Protocol also contemplates trade sanctions against non-signatories, although the latter were always given incentives to join. With the membership at today's level, the use of such measures is largely moot.
The idea of using trade policy as a punishment mechanism in broader climate change discussions has been highly contentious and vigorously opposed.
Perhaps it was the specificity of its focus made the Montreal Protocol better able to establish strong enforcement provisions as well as strong commitments. There was a readily definable cause and effect relationship. In spite of strenuous opposition from industry in the early days, who challenged the validity of the science, public opinion was supportive of action.
Solutions were also readily available from both technological and commercial perspectives. In all these ways, circumstances were favourably aligned for joint action. What a pity other vital issues in need of cooperation among nations are not so straightforward.
This article first appeared in the South China Morning Post on October 26, 2016 as Why the Montreal Protocol is the most successful climate agreement ever.
The views expressed in the reports featured are the author's own and do not necessarily reflect Asia Global Institute's editorial policy.
Interview I Hong Kong must resurrect itself as the gateway to North Asia for Asean I Heiwai Tang
Interview I Hong Kong's Broken Billionaire Factory Shows City Losing Step I Heiwai Tang
Interview I The Indo-Pacific Economic Framework I Heiwai Tang
Interview I Hong Kong plan to ease COVID restrictions 'comes too late' I Heiwai Tang