“Preventing future calamity requires not only agreement but action. Governments and other responsible groups are usually accused of reacting to crises rather than foreseeing and preventing them. We have an opportunity here to show that experts, scientists, lawyers, and governments can foresee potentially catastrophic dangers, and prevent them from happening.” This abstract demonstrates the philosophy, issues and objectives of Multilateral Environmental Agreements (MEAs) adopted since the 1970s. Climate change has been described as “the most challenging environmental issue of our time,” and one cannot help but associate this abstract with the construction of, what is called today, the climate regime. Following the process launched at the Rio Conference, the United Nations Framework Convention on Climate Change (UNFCCC) was adopted in May 1992 and a protocol to the Convention followed in 1997: the Kyoto Protocol. Back in 1992, in “common but differentiated responsibilities” (CBDRs), “common” meant that there is a universal responsibility to act for the benefit of “present and future generations." Thus, common responsibilities embody both the notions of “common concern” and “common heritage of humankind,” two notions “as old as international environmental law itself.” In other words, environmental issues such as climate change have too much of a universal impact for the response to be “solely a matter of domestic jurisdiction.” The CBDR principle is only an expression of differential treatment. Other expressions of differentiation are used in the climate regime and could take precedence in the future. It is parties’ actual obligations that will matter to combat climate change. In order to do so, the climate regime must keep a balance between commitments and assistance. Indeed, although adaptation to climate change and assistance are truly important issues, one has to realize that the fight against climate degradation cannot be fought without commitments from stronger polluters to reduce their emissions. The notion of responsibility is central in CBDR but current contributions to climate change cannot be forgotten. COP22 which will be held in Marrakesh between the 7th and 18th of November 2016, will constitute a new opportunity for developed/developing countries to further debate and enhance the latter principle in the light of the commitments/assistance balance that must be maintained.