Constitutionalism and the Climate Crisis: From Recognition to Realisation

Climate change represents one of the most significant global challenges of our time, with far-reaching implications for environmental sustainability, economic development, public health, and social justice. As the impacts of climate change become increasingly evident, legal systems at the national, regional, and international levels are being called upon to develop effective frameworks for mitigation, adaptation, accountability, and resilience. Given the pivotal role that law can play in shaping climate governance, this blog series, edited by Dr Azadeh Chalabi, brings together academics, legal practitioners, and policymakers to contribute blog posts on the theme “Law and the Climate Crisis". Contributions to the series seek to foster critical engagement with the evolving relationship between law and climate change while exploring innovative legal responses to contemporary environmental challenges.

By Dr. Bhavya Singh

Keywords: Environmental constitutionalism; climate justice; climate litigation; constitutional rights; International Court of Justice

Over the past two years, certainly much more has been said about climate change by the international courts, than in the preceding three decades combined. Recently, Switzerland in  Verein KlimaSeniorinnen Schweiz and Others v Switzerland was found to have breached the European Convention of Human Rights by the European Court of Human Rights, and the major reason behind it were their insufficient action against climate change. Then, in a historic ruling, Inter-American Court of Human Rights in its Advisory Opinion OC-32/25 stated very plainly that the Americas face a climate emergency and that there need to be binding legal duties. And, in July 2025 advisory opinion by ICJ confirmed the States’ obligations under the treaty, as well as the customary international law, to prevent the harm that is being caused to the climate system. Moreover, providing license or subsidies in terms of fossil fuels could also amount to the international law violation. Taken together, these opinions have arguably done more to embed environmental and climate rights in the architecture of international law than any prior episode of climate diplomacy.

Domestically, though, the picture looks rather different. As Puentes Riaño notes, amongst the total UN membership, as much as 85%, constituting 164 states, either through their constitutions, legislation or through any of the regional treaties, have now expressly recognised the right to a healthy environment. The Supreme Court of India, for instance, recently held in MK Ranjitsinh v Union of India  that the right to be free from the adverse effects of climate change flows from Articles 14 and 21 of the Constitution, treating it as the natural extension of the right to a clean environment it had already read into the right to life three decades earlier in Virender Gaur v State of Haryana. Section 24 of South Africa's Constitution provides more specificity as it entitles everyone to an environment that does no harm to their health or wellbeing, and obliges the state to protect it by reasonable legislative and other means. France, in 2005, successfully entrenched an Environmental Charter at constitutional rank, and Ecuador’s  2008 Constitution  went furthest of all in granting nature itself justiciable rights.

The difficulty is that recognition of this kind has, in most jurisdictions, produced remarkably little in the way of enforceable outcomes. Constitutional environmental clauses are frequently drafted as directive or aspirational provisions rather than directly enforceable entitlements, leaving courts reluctant to convert them into concrete remedies against government inaction. Even where courts have been willing to act, as the Lahore High Court did in ordering the government to implement its own climate policy framework in Asghar Leghari v Federation of Pakistan, the judgment could specify structures and timelines but could not itself build the institutional capacity needed to deliver them. A constitutional right can be beautifully drafted and still do nothing on its own, it sets no carbon budget, funds no adaptation programme, and cannot force a legislature’s hand.

This is precisely the gap that needs confrontation from the environmental constitutionalism. What the Grand Chamber refused to do in KlimaSeniorinnen tells far more than what it actually decided. The Court  declined to prescribe the measures required for compliance, after having found that Switzerland’s failure, with respect to the adoption of a domestic regulatory framework, a carbon budget, clear emissions targets, violated the private life of the applicant, further leaving it to the Swiss authorities under the Committee of Ministers' supervision. Eighteen months on, the Committee had still not closed its supervision of the case; its most recent  September 2025 review welcomed Switzerland’s revised legislative framework while stopping short of accepting full compliance, and Switzerland was asked to report again in 2026. And therefore, examples like these show that court can tell a government it’s failing. Whether that failure gets fixed is a political question, not a judicial one.

Realising these rights depends on three things recognition alone cannot supply: legislative specificity, of the kind the UK's Climate Change Act 2008 provides by converting policy aspiration into binding carbon budgets monitored by an independent body; institutional infrastructure like the climate councils, ombudspersons, specialised environmental courts which are now emerging across India and Latin America, able to hold government to its own targets between elections; and genuine access to justice, without which even a well-drafted right stays theoretical for those most exposed.

The ICJ's 2025 opinion may sharpen this further. By confirming that failing to regulate private emitters can itself be internationally wrongful, and that states must progressively strengthen their pledges, the Court has handed litigants an external benchmark against which constitutional promises can be measured. Litigants from Vanuatu to the Pacific Islands students behind the case are likely to invoke it domestically, much as Urgenda fed into the Swiss and Indian judgments above.

None of this diminishes constitutional recognition. Naming a right reframes political argument and gives courts, from Strasbourg to New Delhi, a doctrinal hook to build real standards of state conduct. But recognition was never self-executing. What remains is building the scaffolding, budgets, oversight, timelines, remedies, without which environmental constitutionalism st, for those who need it most, a right without a remedy.

Author Bio:

Dr. Bhavya Singh holds a PhD in Law from Jamia Millia Islamia, New Delhi, India. Her research focuses on climate law, environmental governance, environmental constitutionalism and intellectual property, with particular interest in the legal frameworks that support sustainable development and climate justice. She has presented her research at national and international academic conferences and works in interdisciplinary approaches to contemporary environmental challenges.