---
type: source
title: "Montreal Protocol scaling timeline: 50% phasedown → full ban driven by deepening commercial migration"
author: "UNEP / C2ES / Rapid Transition Alliance"
url: https://www.c2es.org/content/the-montreal-protocol/
date: 2026-04-06
domain: grand-strategy
secondary_domains: []
format: thread
status: null-result
priority: medium
tags: [montreal-protocol, commercial-migration, governance-scaling, enabling-conditions, environmental-governance]
extraction_model: "anthropic/claude-sonnet-4.5"
---

## Content

The Montreal Protocol scaling timeline, synthesized from UNEP and C2ES sources:

**1987:** Montreal Protocol signed. Initial scope: 50% phasedown of CFCs (not full phaseout), limited subset of ozone-depleting gases. DuPont had developed CFC alternatives in 1986 and pivoted to support the treaty.

**1990 (within 3 years):** Protocol accelerated to complete phaseout of CFCs on shorter timeline. Mechanism: alternatives were proving more cost-effective than projected.

**1992 (2 years later):** Phaseout further accelerated; HCFCs brought under the Protocol's regime.

**1997:** HCFC phasedown accelerated to phaseout.

**2007:** HCFC phaseout timeline accelerated further.

**2016:** Kigali Amendment — HFCs (the replacements for CFCs and HCFCs) added to the Montreal Protocol, with phasedown schedule. HFCs themselves turned out to be potent greenhouse gases.

Mechanism confirmed: "As technological advances made replacements more cost-effective, the Protocol was able to do even more." Each expansion was driven by commercial migration deepening — alternatives becoming cheaper and more viable made tighter standards commercially neutral or beneficial.

Initially, CFC producers were hostile to regulation. By 1986, DuPont had alternatives and switched to supporting the treaty. The alliance formed between environmental movement and companies that stood to gain from regulation enabled the initial instrument. Subsequent expansions followed the same logic: as more companies developed profitable alternatives, the compliance cost of tighter standards fell.

## Agent Notes
**Why this matters:** This is the control case for the governance laundering vs. stepping stone question. The Montreal Protocol IS a genuine stepping stone — it started narrow, expanded repeatedly, and is still expanding (Kigali 2016 added HFCs). The mechanism is clear: commercial migration deepening → lower compliance cost → tighter standards become politically viable.

**What surprised me:** The Kigali Amendment (2016) is particularly instructive. HFCs were the SOLUTION to CFC regulation — and then became the PROBLEM (GHGs). The protocol expanded to cover even its own replacement chemistry. This happened because by 2016, HFC alternatives (HFOs) were commercially available and profitable. The pattern is robust.

**What I expected but didn't find:** Any case where the protocol expanded to cover domains where commercial migration had NOT occurred. Every expansion required prior commercial migration of some actors.

**KB connections:** [[binding-international-governance-requires-commercial-migration-path-at-signing-not-low-competitive-stakes-at-inception]] — this is the confirmation case. Also relevant: [[governance-scope-can-bootstrap-narrow-and-scale-with-deepening-commercial-migration-paths]] — this claim exists in the KB but may not have the full scaling mechanism documented.

**Extraction hints:** The key claim is about the MECHANISM of scaling, not just that scaling occurred: "Montreal Protocol governance scope expanded from 50% CFC phasedown (1987) to full CFC phaseout (1990) to HCFC coverage (1992) to HFC coverage (2016) because each expansion followed deepening commercial migration — alternatives becoming more cost-effective drove compliance cost down, enabling tighter standards." This is the test case for whether the CoE AI treaty can scale: scaling requires a comparable commercial migration mechanism, which doesn't exist for military AI or frontier development.

**Context:** The UNEP is trying to draw lessons from the Montreal Protocol for climate and AI governance. The lesson should be more specific than "it worked" — the mechanism (commercial migration deepening) is the transferable element, and that mechanism is specific to technologies with viable commercial alternatives.

## Curator Notes (structured handoff for extractor)
PRIMARY CONNECTION: [[binding-international-governance-requires-commercial-migration-path-at-signing-not-low-competitive-stakes-at-inception]]
WHY ARCHIVED: Provides the full scaling mechanism for the Montreal Protocol case — needed to test whether CoE AI treaty can follow the same trajectory
EXTRACTION HINT: Document the full scaling timeline and mechanism (commercial migration deepening drives compliance cost reduction drives scope expansion) rather than just confirming DuPont's 1986 pivot
