Public International Law, which regulates the relations between States, has experienced its greatest expansion and development over the past decades. Some of the issues that came to fall within its purvue question the very continuity of life on the planet. The greatest example of such issues is that of climate change.

The regulation of climate and its evolution, specifically the process of global warming, poses enormous challenges to States, governments, and civil societies: on the one hand, there is certainty about the need for effective regulatory measures; on the other hand, there is scientific uncertainty and the political costs of actions that may slow down economic development.

As a result of this difficult balance, the instruments of International Law only make slow progress in addressing the problem of climate change. This is mainly due to the need to mobilize the will of States to enter into international treaties that impose more invasive measures.

Given this situation, considering the urgency of the issue, the United Nations General Assembly decided, in a resolution voted on in March of this year, to request the International Court of Justice to issue an Advisory Opinion on the obligations of States regarding climate change.

The General Assembly asked the Court to address the following questions:

“a) What are the obligations arising from international law that fall upon States with regard to the protection of the climate system and other components of the environment against anthropogenic emissions of greenhouse gases, for the benefit of present and future generations?

b) What are the legal consequences, in relation to these obligations, for States that have caused significant harm to the climate system and other components of the environment through their actions or omissions, with regard to:

(i) States, including, in particular, small island developing States that, due to their geographical location and level of development, are harmed or particularly affected by the adverse effects of climate change or are particularly vulnerable to these effects;

(ii) Peoples and individuals of present and future generations who are affected by the harmful effects of climate change?”

The Court has set deadlines for States to respond to the questions posed and has allowed the participation of various intergovernmental and non-governmental organizations in the proceedings, which have requested to contribute useful information.

This scenario presents a great challenge to the Court: if it provides a diluted opinion, pointing to only generic obligations, it will show that Law has little to contribute to this vital issue; however, if it is more daring in pointing out more stringent obligations, it runs the risk of seeing States escape compliance with the terms of the Opinion, which, as we know, is not binding like a judgment would be.