By Mini Maurya Rehan, Senior Expert – Climate Policy & Partnerships, Climate Change Hub, WWF-India
The International Court of Justice (ICJ) delivered its Advisory Opinion on climate change on 23 July 2025, setting a landmark in global climate governance. Whilst non-binding, it is an authoritative statement of the law. Arriving just months before UNFCCC COP 30 in Brazil, the Advisory Opinion provides unprecedented legal clarity at a moment that demands decisive global action. COP 30, which begins next week, will be pivotal as the indicators for tracking progress under the UAE Framework for Global Climate Resilience are expected to be finalised.
ICJ backs the Global South’s voice
For decades, developing countries, including India, have urged for clear recognition of Common but Differentiated Responsibilities and Respective Capabilities (CBDR-RC), access to finance, technology transfer and capacity building, and accountability for harm. With the authority of international law, the ICJ has now validated these long-standing demands.
The Opinion has established that developed nations bear the primary responsibility for taking the lead in emission reductions and for supporting climate action of developing countries, declaring these as binding obligations rather than acts of charity. By elevating the principle of CBDR-RC to a “cardinal” norm, the Court has affirmed that obligations must be assessed in light of historical emissions and national capacities. This validates the long-standing position of the Global South, including India, that equity and historical responsibility must remain central pillars of the global climate regime. This strengthens the Global South’s argument that ambitious mitigation from developed countries, coupled with enhanced support for developing ones, is indispensable for keeping the Paris Agreement goal within reach.
Having clarified the legal accountability of countries towards climate damages, the Advisory Opinion extends cumulative emissions as a responsibility for countries to regulate their private actors. States cannot evade their liability by pointing to the diffuse nature of emissions. This opens the door for claims of climate reparations—an outcome that India, alongside other vulnerable nations, can leverage to urge for a more robust Loss and Damage mechanism.
Equally important, the Court underscored that these obligations arise not only from treaty commitments but also from customary international law, thereby binding on all states irrespective of their treaty status. In doing so, the Court made it clear that no country can evade responsibility by withdrawing from, or refusing to join, specific agreements.
COP 30 – India’s moment to lead
The ICJ’s Advisory Opinion does not create new obligations, albeit it clarifies and elevates the existing ones. It arms the Global South with the strongest legal and moral foundation for negotiations at COP 30. The ruling strengthens the case for India to lead at COP 30 and strategically leverage the opinion to urge for:
-Scaled-up climate finance, including full implementation of Article 9.1 of the Paris Agreement (finance to be provided by developed nations to developing nations for mitigation and adaptation). The finance gap arising from COP 29 decision on insufficient New Collective Quantified Goal (NCQG) on climate finance needs to be addressed, with the inclusion of a separate sub-goal on adaptation.
-Enhanced technology transfer and capacity-building support, to enable low-carbon transitions without derailing the developmental priorities of developing countries.
-Recognition of development rights and poverty eradication as legitimate, integral aspects of climate justice.
-UAE Dialogue on implementation of outcomes of first Global Stocktake to lay strong focus on finance and technical support, with explicit reference to Article 9.1 of the Paris Agreement.
-Robust loss and damage (L&D) framework for mobilising scaled-up L&D finance.
The ICJ’s Advisory Opinion has made it unequivocal that climate responsibility is universal, differentiated, and enforceable. It validates India’s long standing principles of equity, CBDR-RC, and the right to development, while sharpening global standards of accountability and human rights, strengthening the legal and moral basis for climate justice.
At COP 30, India has a unique opportunity to shape the global agenda by grounding negotiations in the ICJ Advisory Opinion. By strengthening coalitions across the Global South and beyond, India can push for enhanced means of implementation support while ensuring that climate action aligns with developmental imperatives.
This could be a defining moment for India—and the broader Global South—to lead with a strong voice in advancing climate adaptation and resilience. Building on the momentum set by Pre-COP 30, which underscored the need to strengthen multilateralism and accelerate the implementation of the Paris Agreement with a more people-centred approach, India can steer the global discourse towards a more people-nature-climate centred approach to climate action. Recognising and reinforcing the interdependence between people, nature, and climate will be essential to achieving true resilience and ensuring the well-being of both communities and ecosystems.
The ICJ has provided legal clarity. The task ahead is to convert it into negotiating strength, and in doing so, to reshape the trajectory of climate governance for the decisive decade ahead.