Climate litigation, science and human rights. Toward an obligation to reduce GHG emissions to the atmosphere?

In international climate change law, there is no customary or treaty norm that expressly establishes an obligation for states to reduce their negative greenhouse gas (GHG) emissions. The 2015 Paris Agreement sets a collective goal of maintaining global GHG emissions below 2° C (trending toward 1.5°) from pre-industrial levels. Yet to achieve this goal, the treaty merely provides procedural and voluntary legal obligations, recalling some general principles of international environmental law (cooperation, common but differentiated responsibilities, sustainable development, precaution, and non-regression). Bindingly, states are only required to prepare, report, and improve steadily their Intended Nationally Determined Contributions (INDCs). The use of scientific evidence and the interpretation of human rights treaties may allow to reach the above target from the duty of states to protect human rights. Indeed, on the one hand, scientific evidence constitutes a parameter for states to assess their national measures aimed at addressing the threat of climate change. On the other hand, the possible inadequacy of such measures may determine a violation of their positive duty to protect human rights and prevent their violations (for instance, the right to life and the right to respect for private and family life). From this perspective, climate litigation stands as a prominent tool to connect the two parameters, one scientific and the other legal, in order to overcome the current gaps in international climate change law and ensure the effectiveness of the Paris Agreement. This interpretation is based on currently climate change litigation developed in the Netherlands, France, and Germany. In those jurisdictions, more ambitious legislative measures have been adopted, bringing INDCs in line with the Paris Agreement goals. The aforementioned interpretation could also become relevant for the first time in Italy, where a climate framework law is missing and INDCs still remain weak (like those in countries such as Egypt, Mexico, Brazil or Ukraine), and before ECHR. In fact, in line with the recalled domestic jurisprudence, the Civil Court of Rome will rule on the case called "Giudizio Universale" and the European Court of Human Rights will have to do the same in the "Duarte" case, being able to consolidate the above interpretation already developed before other national courts. The judgment of the European Court of Human Rights may have a significant legal impact for the legislation of 33 States involved and it can influence the latter courts. In conclusion, this proposal aims to explore the relationship between science, human rights, and climate litigation to argue that international climate change law is bound to remain ineffective unless it is interpreted in line with international human rights law. These three elements may constitute an inseparable trinomial to implicitly derive a duty of states to reduce their GHG emissions in the face of the absence of a new climate agreement. This approach could operate as a limitation to States’ discretion related to GHG emission measures and as an incentive to adopt more ambitious mitigation policies.