This article argues that the UN Framework Convention on Climate Change (UNFCCC)’s conception of common but differentiated responsibilities and respective capabilities (CBDRRC) was never effectively implemented through the Kyoto Protocol. The investments under the Kyoto Protocol’s Clean Development Mechanism suggest that CBDRRC has been used by developed countries to buy a “right to pollute”, i.e., maintaining or even increasing their greenhouse gas emissions, while investing in clean energy in developing nations, thus defeating the essence of CBDRRC as intended under the UNFCCC. Second, it points out that the Paris Agreement reflects a significant shift in the overall concept of CBDRRC, both in terms of its textual understanding as well as its implementation. A qualifier, “in the light of national circumstances”, was added to the principle of CBDRRC in the Paris Agreement, allowing a form of voluntary self-differentiation. This qualifier diluted a top-down, objective analysis of States’ commitments. For several scholars, this shift has meant a softening of the principle, making the “differentiation” more dynamic and flexible. In the authors’ opinion, the qualifier is a fundamental modification of the principle to make it politically more palatable. It completely disregards the notion of historical responsibility for climate change, which was the cornerstone of CBDRRC as conceived under the UNFCCC. Therefore, rather than presenting a more flexible understanding of UNFCCC’s conception of CBDRRC, the Paris Agreement marks a total departure from it. Lacking an explicit redefinition of the principle of CBDRRC, it is misleading to contend that the Paris Agreement is still anchored in it.