Reservations, and Joining a Treaty in Part
Chapter Seven
Syllabus topic 1, "Environmental Federalism and International Order"
Pages 20 to 22 of 663
In one line
A reservation lets a State join a treaty while refusing one part of it, and environmental treaties differ sharply in whether they allow that.
In exam wording: a reservation, under Article 2, paragraph 1(d), of the Vienna Convention on the Law of Treaties 1969, is a unilateral statement made by a State when signing, ratifying, accepting, approving or acceding to a treaty, whereby it purports to exclude or to modify the legal effect of certain provisions of the treaty in their application to that State.
Why the law has this at all
Because a treaty needs as many parties as it can get, and a State that objects to one article may be willing to accept the other fifty. Before 1951 the rule was that a reservation required the consent of every other party, which meant that one objection kept the reserving State out altogether. The modern rule, drawn from the Court's advisory opinion on reservations to the Genocide Convention and written into the Vienna Convention, trades a little uniformity for a lot of participation.
For an environmental treaty that trade is often exactly the wrong one, and that is why so many of the instruments in this book forbid reservations outright.
The provision itself
Article 19 permits a State to formulate a reservation unless the reservation is prohibited by the treaty, or the treaty provides that only specified reservations may be made and this is not one of them, or, in other cases, the reservation is incompatible with the object and purpose of the treaty.
Article 20 governs acceptance of and objection to reservations. Article 21 states the legal effects: as between the reserving State and a State that accepts the reservation, the provision is modified to the extent of the reservation, for both of them; and where a State objects but does not oppose entry into force, the provision does not apply between the two to that extent.
Article 22 allows withdrawal of a reservation or of an objection at any time. Article 23 requires reservations, acceptances and objections to be in writing and communicated to the parties.
The environmental treaties, and what they say
| Instrument | Reservations |
|---|---|
| Basel Convention 1989 | Article 26 prohibits reservations and exceptions |
| Montreal Protocol 1987 | Article 18 prohibits reservations |
| Vienna Convention on the Ozone Layer 1985 | Article 18 prohibits reservations |
| Framework Convention on Climate Change 1992 | Article 24 prohibits reservations |
| Kyoto Protocol 1997 | Article 26 prohibits reservations |
| Paris Agreement 2015 | Article 27 prohibits reservations |
| Convention on Biological Diversity 1992 | Article 37 prohibits reservations |
| Minamata Convention 2013 | Article 30, paragraph 5, prohibits reservations |
| Stockholm Convention on Persistent Organic Pollutants 2001 | Article 27 prohibits reservations |
| Rotterdam Convention 1998 | Article 27 prohibits reservations |
Reservations, and Joining a Treaty in Part
That is a remarkably consistent pattern, and it is a fact worth carrying into an examination. The modern multilateral environmental agreement is a no-reservations instrument.
Why they do it, and what they use instead
If a treaty forbids reservations, how does it accommodate a State that cannot accept everything? Three devices, and all three are used constantly in Module IV.
- Annexes with different obligations. The Framework Convention on Climate Change lists developed countries in Annex I and puts obligations on them that other Parties do not carry.
- Registered exemptions. The Stockholm Convention on Persistent Organic Pollutants lets a Party register a specific exemption for a listed chemical, for a fixed period, on a public register.
- Grace periods. Article 5 of the Montreal Protocol gives developing country Parties a ten-year delay on the control measures.
Each of these is a reservation in effect, and none is a reservation in law. The difference is that all three are visible, time-limited and negotiated in advance, where a reservation is unilateral and open-ended.
Worked example
A State wants to join the Basel Convention but does not accept the arbitration clause in Article 20 and Annex VI.
- It cannot make a reservation. Article 26, paragraph 1, prohibits reservations and exceptions.
- But Article 20, paragraph 2, makes arbitration optional in the first place: a Party may declare that it recognises arbitration, or the Court, or both, as compulsory. A Party that makes no declaration is simply not subject to compulsory settlement.
- So the State joins without a declaration, and it is in exactly the position it wanted, by a route the Convention itself provides.
That worked example is the pattern of the whole chapter. Modern environmental treaties do not permit reservations because they build the flexibility into the obligations instead.
What it does NOT mean
A declaration is not always a reservation. A State often deposits an "interpretative declaration" saying how it reads a provision. If it does not purport to exclude or modify the legal effect, it is not a reservation, and Article 2(1)(d) is the test. What it is called does not decide.
A prohibited reservation is not simply ignored. The consequence is contested. The better view is that the reserving State's consent to be bound is what must be examined: if the reservation was essential to its consent, it has not validly joined.
Quick revision
- Article 2(1)(d): a unilateral statement excluding or modifying the legal effect of a provision.
- Article 19: permitted unless prohibited by the treaty or incompatible with its object and purpose.
- Articles 20 to 23: acceptance, objection, effects, withdrawal, and the writing requirement.
- Almost every modern multilateral environmental agreement PROHIBITS reservations.
- The flexibility comes instead from annexes, registered exemptions and grace periods.
Reservations, and Joining a Treaty in Part
Test yourself
1. Can a State ratify the Paris Agreement while rejecting the transparency framework? No. Article 27 of the Paris Agreement prohibits reservations. It could set an unambitious contribution, which is a different kind of flexibility, built into the design.
2. What is the test for whether a statement is a reservation? Whether it purports to exclude or modify the legal effect of a provision in its application to that State. The label the State puts on it does not decide.
3. Name the three devices environmental treaties use instead of reservations. Differentiated annexes, registered time-limited exemptions, and grace periods for developing country Parties.
The rest of this subject
These notes are cut from the University's printed syllabus. Open the syllabus itself, or the past papers, for the same subject.