The case for a consumption-based plastic pollution treaty

WHO WANTS A BALLOON? It doesn’t matter what you produce if no-one is willing to buy it (Photo: İrem Çevik/Pexels — colors adjusted)

The short version

• The plastics treaty talks in Geneva collapsed under the weight of consensus diplomacy.
• The failure may yet prove useful: it exposed the trade-off between ambition and participation.
• The treaty doesn’t need the largest producers to be effective — it needs a critical mass of consumers.
• Once most markets align, global producers will follow.
• The lesson from Montreal and MARPOL: aim for critical mass, not universality.

The fiasco in Geneva drove another nail into the coffin of consensus diplomacy — and it forces progressive governments to rethink how environmental treaties are crafted.

Process adrift

It was never going to be easy, bridging that gap — that fault line haunting the negotiations since the very beginning.

The same divide that split delegates when the mandate was crafted in 2022 still plagues the process today: global rules versus voluntary commitments, top-down against bottom-up.

By the 32nd hour of 14 August, that divide brought the Geneva session to an undignified halt. There was no runway left, and no middle ground to be found.

For civil society, it was the mother of all anticlimaxes. For ministers lured to Geneva by promises of a historic moment, an insult. For Chair Luis Vayas Valdivieso, the final straw. For UNEP, whose behind-the-scenes push for a lowest-denominator text ended in collapse, an embarrassment. And for the spoilers — including the United States — a quiet victory. No one even called for a vote, confirming that the taboo against voting, the illusion of a veto for all, remains perfectly intact.

For the progressive majority, the failure was more complicated. It exposed the oldest truth in multilateralism: the more universal the participation, the lower the ambition. After Geneva, there is no doubt — consensus has killed ambition.

And so the progressives now find themselves in unfamiliar territory. With the dream of consensus shattered, they need a new compass — one that replaces the pursuit of universality with the pursuit of effectiveness, and measures legitimacy by results, not attendance. That means rethinking how this treaty can be designed to have impact over time, exploring concepts like critical mass, tipping points, and incentives for participation and compliance.

In the meantime, the process drifts. The bow may still point toward the horizon, but there is no clear course — at least, not yet.

From ambition to effectiveness

In a recent article, Belgium declared that “a plastics agreement without China is pointless”, because without the largest plastic producers on board “it will never be possible to significantly reduce plastic pollution.”

Implicit in this argument is a recognition of the fact that that the treaty requires a certain number of countries to make an impact, but not necessarily all.

It is a de facto acceptance of the need for a shift in thinking, away from consensus and towards the notion of critical mass. Not just in terms of numbers, but in terms of leverage.

It affirms that in terms of treaty effectiveness, some states are in fact more equal than others. No country is indispensable, but India matters more than Iceland (unless you’re regulating whaling, hot springs or recipes for fermented shark).

And judging by the whispers of frustrated negotiators, Belgium is by no means the only country that sees China as a key player to have on board from the start — a sentiment reinforced by the widespread expectation that the United States will not sign the treaty, and surely never ratify it.

The problem with Belgium’s argument, however, is that it uses production of plastic as principal indicator of relevance and basis for calculating critical mass.

For governments that favour restrictions on production in the treaty — be it of raw materials or final products — that might seem like the reasonable thing to do. If you regulate production, why wouldn’t that be the main metric for assessing issue-specific relevance?

The thing is: it doesn’t matter what you regulate.

What matters is how you enforce it.

The myth of producer power

It has become an article of faith in the plastics negotiations that the world’s largest producers must be part of any meaningful solution. Yet experience tells a different story — one rooted in the basic problem that faces every international treaty: enforcement.

In the absence of a world government to uphold rules and sanction non-compliance, enforcement must be designed into the treaty itself. This can be done through arbitration, peer review, or compliance committees, but it works best when incentives for participation are embedded in the regime so that it becomes self-enforcing.

How is that achieved? By decentralizing enforcement. Each party upholds the rules and, in doing so, creates incentives for others to join. For multilateral treaties addressing collective action problems, leverage lies in shaping markets, not controlling factories. It works best when critical mass is calculated on the basis of consumption rather than production.

The evidence of this can be seen in treaties like the Montreal Protocol and MARPOL, both designed to enter into force only once a decisive share of global consumption was covered — not just an arbitrary number of states. MARPOL required ratification by 15 states representing at least 50 per cent of the world’s merchant fleet tonnage, a practical proxy for market share. The Montreal Protocol used consumption of controlled substances, requiring participation by states accounting for two-thirds of global use before taking effect. Both treaties were calibrated to matter from the outset, recognising that effectiveness precedes universality — and that universality follows through incentives for participation and compliance.

Once that foundation was in place, market forces did the rest. When a regime controls a dominant share of the global market, it doesn’t just create obligations — it sets standards. Producers can either maintain separate production lines for compliant and non-compliant markets, or align with the dominant rules to preserve efficiency. In almost every case, economics decide for them.

This was the quiet genius of both Montreal and MARPOL. By covering much of the world’s consumer base — ozone-depleting substances in one case, design and performance standards for ships in the other — they made compliance cheaper than fragmentation. Instead of coercing participation, they made alignment the path of least resistance.

Over time, this created what political scientists call institutional gravity: the tendency of well-designed regimes to pull others into their orbit. Montreal’s trade restrictions made joining the system the only way to stay in the market; MARPOL’s port-state enforcement did the same for shipping. In both cases, demand-side architecture turned ambition into inevitability — the rules that began with some became the rules that bound all. Eventually, those rules did more than bind; they began to define. What started as compliance became convention — and, eventually, norms, reshaping expectations even beyond the treaty’s reach.

These experiences hold an obvious lesson for the plastics process.

A demand-driven plastics treaty

A consumption-based plastics treaty would begin by redefining what “critical mass” means. Instead of counting producers, it would measure participation by market share.

China produces around 35 percent of the world’s plastics but its share of global consumption is much smaller.

Using plastic waste data as a proxy, China only accounts for about 10% of global consumption. The United States accounts for roughly 16%.

Together, Europe, Latin America and the Caribbean, Africa, and Oceania represent nearly 40% of global plastic consumption — enough to drive market transformation on their own.

Add Canada, Japan, South Korea, and Southeast Asia, and you have more than 50% of global consumption.

Once a treaty covers a controlling share of the world’s consumer markets, harmonized standards become the most efficient way for global producers to operate. The incentives align — fewer product lines, lower transaction costs, predictable regulation.

A consumption-based treaty doesn’t depend on universal participation — it creates it through gravity.

Designing for this logic means embedding it directly in the treaty.

Entry into force should depend on a threshold of states representing a critical share of global consumption, not just an arbitrary number. The same logic should guide amendment procedures: majority decisions coupled with a minimum market share requirement, so the system can be gradually strengthened. And participation should be rewarded — through trade provisions that restrict commerce in regulated products with non-parties, and a financial mechanism that rewards compliant ones.

This is not theory. It’s precisely how the Montreal Protocol and MARPOL became self-reinforcing success stories. Their genius lay in turning economic interdependence into environmental leverage.

We’ll always have Beijing

The road ahead for the plastics treaty is still uncertain.

The most likely next step is the convening, some time in 2026, of another round of talks.

And at that meeting, many governments will be tempted to let themselves slide further down the slippery slope of concessions. They’ve had enough now. They are running out of time and money, and they have to show, to themselves and to the world, that consensus-based multilateralism still works — however imperfectly.

And they can always excuse themselves by pointing fingers at the difficult countries, insist that they tried their best, but that consensus could not be achieved. That an empty shell of a treaty was better than no treaty at all.

They would be lying.

Because the progressives have the chance now to do things differently. To break free from the shackles of consensus and develop a treaty among the progressives. A treaty of the willing.

Leave China be. They will join when the markets tell them so.

It will take courage, and it will take political will. It will require confidence, and diplomatic craft. But it has been done before, and it can be done again.

Will it cost money? Yes. Will it extend the process even further? Surely. Should it still be done? Without a doubt.

Treaties outlive news cycles. There will be annual, perhaps biannual, meetings of parties for decades to come, each costing time and money. This is just the beginning of a very long journey. It is far better to spend two or three more years building something that works than to settle for a hollow framework that can’t evolve.

The world doesn’t need another Paris Agreement or another CBD — grand in vision, thin in enforcement. It needs a new gold standard for MEAs. The ozone layer still protects us today because forty years ago, negotiators understood how to design a regime that maximized impact through market leverage: by anchoring enforcement in consumption, by incentivizing participation and compliance, and by allowing gradual strengthening over time.

That same insight could rescue the plastics treaty from paralysis. Nothing is set in stone; all options remain open. But if negotiators truly want a treaty that changes the world, they must start by changing the way they think about power — from where plastic is made, to where it is bought.