The amendments proposed by Mexico and PNG would, while keeping consensus as the initial threshold for decision-making, have the effect of providing an exception to default consensus voting rule for the COP. They would allow COP decisions (with certain exceptions), after all efforts to reach consensus have been exhausted, to be adopted by a three-fourths majority of Parties present and casting an affirmative or negative vote.

The key procedural benefit of the proposed amendments is that they would prevent one Party (or a small group of Parties) from blocking the adoption of a COP decision and could help promote efficiency in the UNFCCC process. In particular, it would allow for mandates or protocols to be adopted even if there is no consensus on the matter.

However, if the proposed amendments do not enter into force for all Parties,2 it will create a system where some Parties will be bound by one set of voting rules (the three-fourths majority rule) while others will be bound by the present rules (the consensus rule). This would create confusion as to which set of rules is to be applied and could undermine the goal of promoting efficiency in the UNFCCC process.