The Paris Effect

The judgment of the European Court of Human Rights (ECtHR) in the case Verein KlimaSeniorinnen v. Switzerland is a striking example of the Paris effect: The influence of the non-binding collective goals of the Paris Agreement (PA) on the interpretation of domestic constitutional law or international human rights law in climate litigation. In its ground-breaking and bold ruling, the ECtHR established positive obligations for Switzerland to take steps to protect against the adverse effects of climate change on the enjoyment of the right to private and family life enshrined in Art. 8 European Convention on Human Rights (ECHR). For this finding, the Court interpreted ECHR rights dynamically in line with international climate goals and commitments, relying on the scientific and political consensus about climate change and its negative impacts. By basing the human rights risk assessment on this consensus, the Court took a logical step from a human rights perspective. Moreover, it did not fall into the trap of pitting democracy against human rights and demonstrated that human rights protection is a key element of democratic governance. Contrary to what Judge Eicke maintained in his partial dissent, the majority did not compromise the concept of “effective political democracy” or, as argued by some scholars, turn the PA consensus upside down, establishing obligations of result and a regional judicial supervisory mechanism. Instead, the Court’s decision proves to be an essential element in triggering the necessary democratic debates on which the PA relies “from the bottom up”. Reinforcing the procedural limb of Art. 8 ECHR will be an essential step towards further strengthening democratic decision-making in the societal transition to climate neutrality.

The Paris Effect on Climate Litigation

The PA operationalizes the United Nations Framework Convention on Climate Change (UNFCCC). The agreement has been interpreted as leaving it largely to the Contracting states to decide on their level of climate ambition (see here). Binding commitments undertaken under the PA are limited to those of conduct. The PA goals – to keep global warming to well below 2°C compared with pre-industrial levels and to pursue efforts to limit temperature increase to 1.5°C (Art. 2 (1) (a) PA) – as well as the pathway to meet these goals – achieving climate neutrality by the second half of the century and reaching global peaking of greenhouse gas (GHG) emissions as soon as possible (Art. 4 (1) PA updated in COP 26, Glasgow Climate Pact) – are not binding among parties. According to Art. 4 (2) PA, each party has the legal obligation to prepare, communicate and update nationally determined contributions (NDCs) and to pursue measures that aim for meeting these NDCs. Pursuant to Art. 4 (3) PA, Contracting states’ successive NDCs will represent a progression beyond the previous NDC, i.e. an increased level of climate ambition, and reflect the state party’s highest possible ambition, i.e. its best efforts in light of individual responsibilities and capabilities. Overall, parties to the PA are not subject to a duty of result to submit NDCs that are consistent with the climate goals or to actually achieve their NDCs.

Despite its goals being non-binding, and yet perhaps precisely because of its “bottom-up” nature, the PA has triggered climate litigation at international level and domestically in several countries. This is happening in an environment where public debates focus on the failure of states to adequately reduce greenhouse gas emissions to meet the PA temperature goals (cf. UNEP Emissions Gap Report).

Several highest courts have ordered governments to adopt substantive and procedural measures for effective climate action that align with the goals of the PA (I call this the Paris Effect). For example, in September 2018, the Dutch Supreme Court in Urgenda v. the Netherlands drew on the temperature goal expressed in the PA as a basis for establishing a duty of care for the Dutch state as regards CO₂ reduction efforts (para. 50). In Germany, the Federal Constitutional Court (FCC) held in its first climate ruling in May 2021 that the statutory provisions of the Climate Act were insufficient to meet the PA temperature goal that the Act had incorporated into domestic law. The French Conseil d’État took a similar decision in July 2021 regarding the claim by Carême acting in his capacity as mayor of the municipality of Grande-Synthe (see also Carême v. France, paras. 35-36).

The Paris Effect on the Dynamic Interpretation of the ECHR

The KlimaSeniorinnen case brought a novel set of facts and new legal questions before the Court. For the first time, the ECtHR was called to decide on matters of climate change and it was unclear if the Convention’s rights could be applied to this existential, yet diffuse, environmental threat. The Court found a violation of Art. 8 ECHR. For this finding, it did not rely on the right to a healthy environment, as endorsed by the UN General Assembly. Instead, it based its ruling on the already existing harmful impacts and the risk of potentially irreversible and serious adverse effects on the enjoyment of Art. 8 ECHR caused by climate change (paras. 519, 545). In defining the positive obligations flowing from Art. 8 ECHR, the Court interpreted the Convention in line with the international commitments undertaken by the states, most notably under the UNFCCC and the PA.

To this end, the Court applied the standards of dynamic and evolutive interpretation as developed in its case law, interpreting the Convention – as a so-called living instrument – within its factual and legal context, which includes other rules of international law (cf. Art. 31 (3) c) Vienna Convention), at least if all Convention states are subject to them (paras. 434, 455-456). To justify the dynamic interpretation of Art. 8 ECHR, the Court explicitly relied on the scientific and political consensus among Convention states about the critical effects of climate change on the enjoyment of human rights, as reflected in the UNFCCC and the PA (paras. 455-456). A failure to maintain a dynamic interpretative approach would hinder human rights from accommodating social change (para. 456). Emphasizing that it interpreted the Convention and did not add a – consciously rejected – judicial enforcement mechanism to the PA (para. 454), the Court did not further engage with the PA’s “bottom-up” nature or the concept of self-differentiation, as pointed out by the Swiss and intervening governments (paras. 352, 366).

Contrary to what has been argued, the Court did not simply incorporate the PA commitments into Art. 8 ECHR (para. 454), nor did it invert PA obligations of conduct into human rights obligations of result. Instead, it developed a human rights-based duty of appropriate and consistent conduct. Accordingly, it required Switzerland to establish a regulatory framework and an administrative process that would protect citizens from the adverse impacts of climate change on their life, health, well-being and quality of life (paras. 544-550). Additionally, it held that “[e]ffective respect for the rights protected by Art. 8 ECHR requires that each Contracting State undertake measures for the substantial and progressive reduction of their respective GHG emission levels, with a view to reaching net neutrality within, in principle, the next three decades” (§ 548). To this end, Convention states would have to act “in good time, in an appropriate and consistent manner” (para. 548) which would require Convention states to establish a residual CO₂ budget or make their CO₂ reduction targets otherwise quantifiable, as NDCs alone would not suffice (paras. 571-572).

It follows that the Court will, from now on, thoroughly review the appropriate level of ambition – “the State’s commitment to the necessity of combating climate change and its adverse effects, and the setting of the requisite aims and objectives” (§ 543) – and the internal consistency of a state’s climate action, including compliance. The requisite level is determined on the basis of equity and the respective capabilities of a state, and quantifiable by means of the residual CO₂ budget (para. 571, with reference to the principle of CBDR-RC). This seems to suggest that the Court developed a state duty to exercise due diligence geared towards the PA goals, which, thereby, gain indirect legal force. This arguably goes beyond what the majority of states understands as a duty of conduct under the PA, but ties in with how scholars have derived duties of “appropriate” conduct, i.e., due diligence, from the PA (see here and here).

Logical step from a human rights perspective

From a human rights perspective, the Court arguably took a logical step. This is because human rights obligations are inherently different from inter-state obligations. Even if neither the PA goals nor the requirement to align NDCs with these goals are binding among PA parties, this does not mean that a Convention state is not accountable to those under its jurisdiction for protecting against foreseeable, potentially irreversible, and serious adverse effects of climate change on the enjoyment of human rights. If there is a political consensus that such effects will inevitably occur once the temperature goals are exceeded, requiring effective CO₂ reduction programs as part of the state’s positive obligations to its citizens seems logical. Conversely, it would be flawed not to bring human rights to bear on a challenge that jeopardizes a state’s ability to keep its human rights promises in the future. Otherwise, the longstanding interpretative guideline that human rights shall be interpreted to be “practical and effective, not theoretical and illusory” (paras. 545-548) would appear hollow.

In support of its provision of judicial review, the Court invoked its complementary function to the democratic process of Convention states which are not purely majority-bound but democracies based on the rule of law (para. 412). It added that the inherent characteristics of democratic governance undermine effective responses to climate change because the democratic process is focused on short-term gains and leaves young and future generations un(der)represented (para. 420). One could further adduce that the ECtHR further strengthens democratic governance through its judgment by triggering political debate, establishing the positive obligation to increase climate action, yet leaving the manner of implementation (i.e. the means and methods) to the Convention states’ margin of appreciation (see paras. 440, 543, 572). “Effective political democracy” is thereby rather reinforced than compromised (but see Judge Eicke, para. 20).

Reinforcing democracy through the procedural limb of Art. 8 ECHR

However, it should be noted that climate change differs from other human rights constellations. It is not the individual who opposes a repressive state, nor is it the individual who demands protection from the state against certain third parties or unforeseeable natural disasters, but it is the individual who demands that the state commit the whole of society to avoid future harm to themselves and everyone else over the next 30 years and beyond. Creating space for political debate is thus a crucial step in this process. The majority of the Court was therefore right to strengthen the procedural part of Art. 8 ECHR by requiring access to information to enable people to participate in designing and implementing climate change policies and regulations, in addition to ensuring responsive governance (§ 554). In this case, the ECtHR could also have examined in more detail whether there was a violation of these procedural elements of Art. 8 ECHR (cf. Judge Eicke, § 68). The Aarhus Convention, even if originally designed for linear, local environmental issues (§ 501), is an existing instrument whose potential could be further exploited in this respect. The more people who are constructively involved in thinking about how to achieve the necessary CO₂ transition, the smaller the risk that climate action can successfully be purported to come at the expense of democratic governance.