Prof. Nuria Pastor Palomar analyzes in this document the prohibition of reserves that is included in the instruments related to climate change. This conventional technique is not suitable for treaties seeking to protect community interests, with normative obligations and a universal vocation. The formulation by the Parties of other unilateral declarations, at the time of signing or expressing their consent to be bound by the Paris Agreement, refers to some specific aspects of this type of treaty, which have resorted to other flexibility mechanisms, other than those reservations, more suitable for this area.