The International Regime on Climate Change: On Differentiated Responsibilities and Respective Capabilities

Editor’s Note: It’s EHN’s four-year anniversary this week! Like in previous years, we’ll be celebrating all week long by featuring new and exciting work every day to mark the occasion. Today, we’re bringing you this amazing piece by Lívia Regina Batista, one of our new content editors, on the historical evolution of one of the cornerstone principles in the international climate change regime.

To understand the politics of climate change and international efforts to address the issue, there is a concept of paramount importance: the principle of common but differentiated responsibilities and respective capabilities (CBDRRC). This idea has been central in the global climate discourse since the United Nations Framework Convention on Climate Change (UNFCCC) in 1992.

The interpretation of this principle should be simple and commonsensical, as it builds on quantitative evidence: countries’ past, present and future emissions of greenhouse gases in the atmosphere are different and countries also face different challenges and have different capabilities to deal with climate change.[1]

Therefore, when assessing vulnerable communities, the IPCC talks specifically about small island developing countries, rather than a generic mention of areas located below sea level—which would also include developed countries such as the Netherlands and Belgium. This is because vulnerability to climate change has less to do with geographical location and more with the level of economic developments and socio-political vulnerabilities: the Netherlands will most likely be taken care of, Tuvalu will not.[2] Hence, international cooperation will be critical for vulnerable countries to tackle climate change, without making disadvantaged people worse off. In this sense, the CBDRRC principle is also related to recent discussions on climate justice.

The main idea behind climate justice is that the Global-North should take the lead in combating adverse effects of climate change, bearing the greatest costs, and promoting international cooperation with the Global-South in order to enable them to achieve their own commitments as well. This idea, however, is “[a] major—perhaps the major—source of political contention” in the international climate forum today.[3] An illustration of that is the final text recently adopted at the Conference of the Parties n.º 26 (COP26) in Glasgow, where the preamble merely notes “the importance for some of the concept of ‘climate justice’ when taking action to address climate change.”[4] By implication, for some other countries climate justice is not important.

Indeed, a literature review on the CBDRRC principle shows conflicting interpretations. Throughout the evolution of the contemporary international order, particularly in the text of legally binding documents—including the UNFCCC, the 1997 Kyoto Protocol and now the 2015 Paris Agreement—the meaning given to this principle also changed, emphasizing different elements imbued in it.

The nomenclature of the principle as coined refers to at least three different elements: 
1. The common responsibility to all countries;
2. The differentiated responsibility between countries; and 
3. The different capabilities of countries to mitigate and adapt to climate change harmful effects.

In practice, Global-South countries often focus on the term “responsibilities,” understood as a function of the historical contributions of Global-North countries to greenhouse gases in the atmosphere. On the other hand, Global-North countries generally focus on the term “capabilities,” anticipating the possibility of a rapid evolvement of Global-South countries’ international climate commitments once they further develop and gain more technical and financial capabilities.[5] This understanding shifts the focus from being only on historical responsibilities. 

In her analysis of the relationship between these components in the CBDRRC principle, Lavanya Rajamani focuses on the phrase “common but differentiated.” She argues that using the term “but” implies a differentiation between the justification of the “common responsibility” on the one hand and “differentiated responsibilities” on the other, in the sense that the later “flows from […] causal agencies in creating the problems and the fruits (i.e., “capabilities”) of those actions that causes the problem.”[6] That is, the common responsibility comes from the recognition of climate change as a common concern to humanity—as the climate system is the same for all countries, in a way that any change affects, to a greater or lesser extent, all of us. On the other hand, the differentiated responsibilities imply that countries’ contributions were (and still are) different.

On further analysis, Chandrashekhar Dasgupta argues that including “respective capabilities” as a basis for differentiation only reinforces the historical responsibilities of the Global-North countries. In Rajamani’s words, “the improved capacities are a direct result of industrialization, which, in turn, resulted in an increase in greenhouse gas emissions”—what she calls “historical injustice.”[7] The high per capita emissions of greenhouse gases in developed countries are the cause of climate change—from which “it follows that they have a corresponding obligation to take corrective action.” At the same time, these are also the countries that have the greatest technical and financial capacities to bear the burden, which “further reinforces their obligations regarding corrective action.”[8]

Legally and operationally, however, this has proven to be controversial.

Both the 1992 UNFCCC and the 1997 Kyoto Protocol established a marked differentiation between specific commitments for parties included in Annex I, considered “developed” countries, and general commitments for all parties: a so-called “firewall.”[9] At the time of the ratification of both legally binding documents, countries’ delegations agreed on associating the CBDRRC principle predominantly with a distinction between developed and developing countries—with these groups respectively defined in their annexes, despite the wide variety of national circumstances. In fact, Bodansky et al. have observed that the Kyoto Protocol represented a political commitment between Global-North and Global-South in the negotiations, with the victory of the latter in the operationalization of such differentiation, as they were left out of the quantitative targets.[10] The outcome of the Kyoto Protocol was not enough, however, considering that the largest emitters of greenhouse gases today have not ratified nor were even covered by the commitments, as is the case respectively of the United States of America and China, so that less than 24% of the emissions were considered in the preparation of the document. Thus, this accentuated differentiation proved to be increasingly controversial.[11]

With the note taking of the Copenhagen Agreement in 2009, the CBDRRC principle were explicitly seen as a “political necessity.”[12] However, this accentuated asymmetry between Global-North and Global-South began to erode, since, alongside the quantified commitments assumed by the parties included in Annex I, the non-Annex I parties were invited to submit mitigation goals to be voluntarily implemented at their domestic level. Moreover, if these measures were financed through international cooperation mechanisms, they would have to be submitted to a system of international monitoring within the international regime. From that, “it began to break down the firewall.”[13] In the same sense, the Cancun Agreements signed in 2020, in which countries agreed on simply repeating the main ideas negotiated in Copenhagen. However, there was no indication for these voluntary commitments to later become legally binding.

In the Paris Agreement in 2015, even though the principle of common but differentiated responsibilities and respective capabilities is expressly mentioned, adding “in light of different national circumstances,” all signatory countries have committed to peak their greenhouse gas emissions as quickly as possible and to communicate their Nationally Determined Contributions (NDCs) successively. Nevertheless, it is still expected that Global-North lead this process and assist Global-South meet their own commitments. With this new legal architecture, the Paris Agreement “represents a significant departure from the Kyoto Protocol.” In particular, it “privileges national sovereignty over international prescription,” adopting a new operationalization of the CBDRRC principle: a more nuanced form based on self-differentiation. This means that signatory countries should present their own periodic targets in line with the NDCs. In fact, the Paris Agreement does not define which countries are considered “developing” and which ones are considered “developed,” therefore abandoning the structure of annexes inserted in the UNFCCC. However, “universality of application does not automatically signal uniformity of application”. That is because the operationalization of the CBDRRC principle is still open to different interpretations at the domestic level, as “the expectation would be that parties prepare NDCs that truly reflect their highest possible ambition, within the realm of their possibilities.”[14]

According to Rajamani and Guérin, “it is nevertheless clear that the extent to which many developing countries will meet the mitigation ambition in the Paris Agreement will be linked to the extent of support available.”[15] It is in this sense that, based on the reading of the NDCs presented so far by the signatory countries, it is noteworthy that the Global-South attaches a great importance to financial assistance and the international transfer of climate-related technologies.[16] These mechanisms are mentioned in most of their contributions, as Global South countries indicate different quantitative targets, depending on whether they’d have access to such assistance. However, none of the contributions presented by Global-North countries explains how international cooperation would take place.

The practical outcome of a self-differentiation approach to the CBDRRC principle is a gap between NDCs and the needed reductions in greenhouse gas emissions to achieve the commitment of limiting global warming in 1.5ºC above pre-industrial levels. In this sense, according to IPCC on its special report published in 2018, under emissions in line with the current NDCs, global warming is expected to surpass 1.5ºC above pre-industrial levels, even if these pledges are supplemented with very challenging increases in scale and ambition of mitigation after 2030.[17] The difference in greenhouse gas emissions is 15 to 30 GtCO2 per year in 2030 in scenarios conducive to limiting warming at a maximum of 1.5ºC above pre-industrial levels to 50 to 58 GtCO2 per year in 2030 in the average estimate of unconditional national contributions as currently determined.

This could be an interesting solution for the political unwillingness to agree on each country’s responsibilities, focusing on their sovereignty to define them. However, the way the CBDRRC principle is operationalized since the Paris Agreement does not face such climate (historical) injustice, i.e., it does not address the “historical responsibilities”/”current technical and financial capabilities” dilemma as two sides of the same coin, which ultimately would lead to more commitments to Global-North countries. Neither does it place us on the right track to limit global warming in 1.5ºC above pre-industrial levels, as mentioned above. Therefore, it is crucial to understand how to better operationalize the CBDRRC principle, interpreting it in a way that enhances climate justice, as these ideas should walk along if the goal is to properly address climate change at a global level.


[1] Intergovernmental Panel on Climate Change, “Climate Change 2014: Synthesis Report. Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change” (2014).

[2] Intergovernmental Panel on Climate Change, “Global Warming of 1.5ºC: An IPCC Special Report on the Impacts of Global Warming of 1.5ºC Above Pre-Industrial Levels and Related Global Greenhouse Gas Emission Pathways, in the Context of Strengthening the Global Response to the Threat of Climate Change, Sustainable Development, and Efforts to Eradicate Poverty” (2018), 4.

[3] Maria Ivanova, “Politics, Economics, and Society,” in The Paris Agreement on Climate Change: Analysis and Commentary, ed. Daniel Klein et al. (Oxford University Press, 2017), 21.

[4] Conference of the Parties of the United Nations Framework Convention on Climate Change, Glasgow Climate Pact – available here.

[5] Lavanya Rajamani, “The Reach and Limits of the Principle of Common but Differentiated Responsibilities and Respective Capabilities in the Climate Change Regime,” in Handbook of Climate Change and India: Development, Politics, and Governance,” ed. Navroz K. Dubash (Earthscan, 2012), 120.

[6] Daniel Bodansky, Jutta Brunnée, and Lavanya Rajamani, International Climate Change Law (Oxford University Press, 2017), 127-128.

[7] Rajamani, “The Reach and Limits […],” 121-122.

[8] Chandrashekhar Dasgupta, “Present at the Creation: the Making of the UN Framework Convention on Climate Change,” in Handbook of Climate Change and India: Development, Politics, and Governance,” ed. Navroz K. Dubash (Earthscan, 2012), 89.

[9] Bodansky, Brunnée, and Rajamani, International Climate Change Law, 105; Joanna Depledge, “The Legal and Policy Framework of the United Nations Climate Change Regime,” in The Paris Agreement on Climate Change, 30.

[10] Bodansky, Brunnée, and Rajamani, International Climate Change Law, 106.

[11] See also Simone Schiele’s Evolution of International Environmental Regimes: The Case of Climate Change (Cambridge University Press, 2014), 64-65.

[12] Bodansky, Brunnée, and Rajamani, International Climate Change Law, 111.

[13] Trevor Houser, Copenhagen, The Accord and The Way Forward (Peterson Institute for International Economics, 2010), 13.

[14] Bodansky, Brunnée, and Rajamani, International Climate Change Law, 21, 206, 219. A compilation of the NDCs already submitted can be found here

[15] María Pía Carazo, “Contextual Provisions: Preamble and Article 1,” in The Paris Agreement on Climate Change, 116; Lavanya Rajamani, “Guiding Principles and General Obligations: Article 2.2 and Article 3,” in The Paris Agreement on Climate Change, 134.

[16] Lavanya Rajaman and Emmanuel Guérin, “Central Concepts in the Paris Agreement and How They Evolved,” in The Paris Agreement on Climate Change, 89.

[17] Intergovernmental Panel on Climate Change, “Global Warming of 1.5ºC,” 95.

*Cover image: Tuvalu’s Minister for Justice, Communication & Foreign Affairs Simon Kofe gives a COP26 statement while standing in the ocean in Funafuti, Tuvalu on November 5, 2021. Courtesy Tuvalu’s Ministry of Justice, Communication and Foreign Affairs / Social Media via Reuters.

[*Cover image description: A man dressed in a suit is positioned in front of a small pulpit with two microphones and next to a blackboard. They are in the ocean, covered in water up to his knees. In the background of the picture, there is an island.]

Edited by Anastasia Day and Asmae Ourkiya, reviewed by Emily Webster.

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