The Meeting of the Parties to the Montreal Protocol (MOP) takes place once a year around November. This is where decisions are normally discussed and approved by the Parties. Parties may decide to hold extraordinary meetings in between regular meetings of the Parties, consistent with the relevant rules of procedure.
The Conference of the Parties to the Vienna Convention (COP) takes place once every three years and it’s where the Parties approve decisions for implementation of the Convention.
The Open-ended Working Group (OEWG) meets once mid-year and deliberates on issues to be further discussed and decisions to be adopted at the MOP/COP at the end of the year. The Open-ended Working group was established pursuant to decision I/5 of the First Meeting of the Parties to review reports of the Assessment Panels and prepare draft proposals for any amendments to the Protocol, among other things. Its mandate was extended pursuant to decision II/5 of the Second meeting of the Parties to consider other issues of relevance to the implementation of the Montreal Protocol.
The Implementation Committee was first established in 1990 along with the Non-compliance procedure for the Montreal Protocol pursuant to Article 8 of the Montreal Protocol, on an interim basis for two years, by decision II/5 of the Second Meeting of the Parties to the Protocol. By decision IV/5 adopted in 1992, the Parties agreed to establish the Implementation Committee on a permanent basis along with the Non-Compliance Procedure under which the Committee operates. The Committee is comprised of 10 parties elected by the meeting of the Parties for two years on the basis of equitable geographical distribution. Outgoing parties may be re-elected for one immediate consecutive term. The Committee elects its own President and Vice-President, each serving for one year at a time. The Vice President also serves as the rapporteur of the Committee.