The Specification of Rules of Differentiation in the NDCs to the Paris Agreement

The Paris Agreement has limited problem dissolving power to face the risks of climate change. Compliance with the agreement depends on the specification of legal obligations, in particular of the criteria for differentiation and the distribution of costs for climate protection. The Paris Agreement and its subsequent agreements provide legal terms (equity, fairness, justice), a principle (the principle of common but differentiated responsibilities and respective capabilities, CBDRRC), and rules that seek to operationalize differentiation. However, these criteria remain vague and the Paris Agreement does neither specify qualifying criteria for categories of development nor the weight and relationship of the different criteria to each other. Hence, it remains unclear how the costs for climate protection shall be shared between the Contracting Parties. Consequently, it cannot be said to what extent each single Contracting Party complies with the Paris Agreement. This article seeks to specify the criteria for differentiation based on the nationally determined contributions (NDCs). The NDCs are between law and politics of self-differentiation. They can be subsequent practice in the legal sense and measures to comply with the Paris Agreement, but they also provide room to make transparent where the Contracting Parties do not come to an agreement and want to preserve their sovereign rights. The analysis reveals whether the NDCs have the power to fill vague legal terms, principles, and rules for differentiation of the Paris Agreement with content step-by-step or whether all they can do is making national policies more transparent. As the Contracting Parties to the Paris Agreement could not agree on a common standard structuring commitments and expectations towards other states, a comparison first needs to find the common ground of criteria for differentiation used in the NDCs. Terms, principles, the operationalization of quantifiable parameters, non-quantifiable criteria, and categories, as well as arguments for mutual expectations, need to be analysed. The more of these criteria are used by a representative group of Contracting Parties, the more likely they have the potential to be considered subsequent practice in the legal sense, and the more likely they are to serve as a model for other states and future NDCs. The paper concludes with a proposal for a standard form structuring commitments and expectations of the Contracting Parties towards each other. Based on the criteria found in the comparison between NDCs, the table could be included in subsequent decisions to the Paris Agreement and future NDCs. A common pattern to structure the arguments for differentiation might facilitate the discourse on mutual expectations and an agreement on the relative weight of the criteria for differentiation to each other. It might also be used to analyse progress in the NDCs to come.