Is Self-Differentiation a Good Way to Reach Equitable Climate Solutions?

By Student Delegate Wenfang Liang

Common but Differentiated Responsibilities and Respective Capacities (CBDRRC) is a general principle under the United Nations Framework Convention on Climate Change (UNFCCC). This principle includes two key concepts—common and differentiated. The “common” is easy to understand: all countries have responsibilities for environmental protection. The “differentiated” is more complex: it involves many issues, such as duty distribution, countries’ development level, and differentiated participation mechanisms.

There is not an operational definition of CBDRRC under the UNFCCC; thus, different countries have different understandings about differentiation. Many countries tend to consider differentiation in a way that maximizes their own interests. For example, developing countries like India and China claim that responsibilities should be differentiated according to historical GHG emission contribution. Developed countries like the U.S and Europe, the largest historical contributors, object strongly to this approach.

The Paris Agreement adopts a self-differentiation approach that allows countries to decide what their capabilities are and what “differentiated” means for them. For example, the U.S. pledges to be net zero by 2050, China by 2060, and India by 2070. These varying contributions underscore the considerable leeway granted under the self-differentiation approach.

Before the 2009 Copenhagen COP15 talks, the interpretation of CBDRRC under the UNFCCC and the Kyoto Protocol was binary. Countries were either Annex I (industrial countries) or non-Annex I countries. Only Annex I countries had quantified emission reduction obligations under the Kyoto Protocol whereas non-Annex I countries could increase carbon emissions for development.

This strict distinction did not reflect the dynamic diversification already underway among developing countries since the 1900s. From 1990 to 2008, Annex I countries’ emissions remained high and non-Annex I countries’ emissions rose by 223%. At the same time, climate change impacts, such as extreme weather, were increasingly obvious and devastating, especially for island countries and coastal areas. The standpoint and capabilities of such countries are more complex than binary. The dichotomous interpretation within the UNFCCC process brought deepening divergences between countries, which resulted in a negotiation collapse in 2009 at Copenhagen.

In the following few years, the debate between the global north and south on how to distribute obligation continued, all while greenhouse gas emissions that are warming the Earth reached record levels.  Subsequent COPs saw developing countries growing more willing to take on some form of climate commitments, although critical questions remained about how to determine specific responsibilities for each country given their vastly different domestic situation.  Strict distinction between developed and developing countries clearly wouldn’t work any longer, and support emerged for an inclusive and open mechanism that moved beyond the Kyoto Protocol’s binary structure.

The Paris Agreement ultimately landed on the self-differentiation approach, which did succeed in attracting broader participation and catalyzing different parties to communicate and work together. 188 Nationally Determined Contributions (NDCs) were provided to the Secretariat in the run-up to or just after COP21, covering far more than the countries that had made commitments under the Kyoto Protocol (38 industrialized countries).

The Paris Agreement requires each Party to prepare, communicate and maintain successive NDCs that it intends to achieve. However, every country has the flexibility to decide on its specific contributions, including any emission reduction target, as well as the balance of mitigation and adaptation measures.  None of these components are strictly mandatory, and true acceptance of the commitments requires a certain amount of faith and trust between parties. And beyond countries’ efforts, outside stakeholders, mostly civil society, will be the judge and jury on whether countries are doing a fair job.

Some think the downside of the Paris Agreement has been its voluntary nature, but we do live in a world with a great resource, development , and political power imbalance. What’s the equitable way to limit temperature rise to no more than 2˚ or 1.5˚? Until the  1990s when emerging economies entered into periods of sustained economic growth, the developed countries of the Global North were both the largest annual polluters and by far the largest contributors to historic emissions. This imbalance resulted in the Kyoto Protocol, a distinctive and binary way to enforce differentiation. However, countries’ interests and pace of growth the past two decades has changed the dynamic significantly. For example, China and India have become two of the world’s largest GHG polluters, and there are large differentiations arising among developing countries with different development speeds.  In addition, the varying pace of development has created a new type of inequality between countries as the negotiations on Paris Agreement issues continue.

Next year will mark the first “Global Stocktake” and the best test to date for the self-differentiation approach of the Paris Agreement. The Stocktake may provide insight into how well the system of NDCs is working, whether effective coordination mechanisms for finance and technology have been established, and whether new challenges including greater inequity between parties are apparent.  The success of self-differentiation, therefore, remains to be seen.


Pieter Pauw et al., Subtle differentiation of countries’ responsibilities under the Paris Agreement (2019),

Nicholas Chan, Climate Contributions and the Paris Agreement: Fairness and Equity in a Bottom-Up Architecture (2016),

Sandrine Maljean-Dubois, The Paris Agreement: A New Step in the Gradual Evolution of Differential Treatment in the Climate Regime? (2016),

Wei Peng et. al, To achieve deep cuts in US emissions, state-driven policy is only slightly more expensive than nationally uniform policy (2021),

Parikh and L. Baruah, Common but differentiated responsibilities among Non-Annex i countries of UNFCCC, 2012.

INDCs as communicated by Parties, INDC,

Comments are closed.