Climate Mitigation, Adaptation and State Responsibility in International Law: Reflections on the Bonaire Ruling

On 28 January, the District Court of The Hague ruled that the Netherlands had failed to protect the residents of the Dutch Caribbean island of Bonaire from climate-related harm. In a landmark ruling in international environmental law and a key development for climate adaptation, the Netherlands’ obligations were found to have a wide territorial reach with implications for how states must protect vulnerable regions from climate-related harm.

We summarise below the Court’s key observations and reflect on the ruling’s impact on climate litigation.

Background

Bonaire, an island in the Caribbean and special municipality of the Netherlands, enjoys local administrative powers but is governed by the Netherlands.

The island is vulnerable to sea-level rise, extreme heat and other climate-related harms. In 2024, Greenpeace filed a lawsuit which argued that the Netherlands:

• Has failed to take sufficient mitigation and adaptation measures to protect the people of Bonaire from climate-related harms.
• Discriminates against the people of Bonaire by providing less protection than residents in the European Netherlands and by not taking sufficient account of the right of the inhabitants of Bonaire to experience and practise their own distinct culture.
• Breaches human rights obligations under Article 2 (the right to life), Article 8 (the right to private and family life) and Article 14 (the prohibition of discrimination) of the European Convention on Human Rights (“ECHR”).

Greenpeace’s claim went to a full hearing in October 2025.

States’ climate obligations under the European Convention on Human Rights

Member states of the ECHR have positive obligations towards their residents under Article 2 and Article 8 to address the risk caused by climate change.

In weighing up whether the Netherlands had satisfied its obligations, the Court considered two key questions on mitigation and adaptation:

1. Does the Netherlands comply with the equitable contribution it must make under the United Nations Climate Convention, the 2015 Paris Agreement and subsequent COP decisions to limit global warming to less than 1.5 °C, compared to pre-industrial levels, by the end of this century (mitigation)?
2. Has the Netherlands taken sufficient timely and appropriate measures to protect the inhabitants of Bonaire from the effects of climate change (adaptation)?

Mitigation and adaptation measures must be assessed together rather than in isolation. Relying on the European Court of Human Right’s (“ECtHR”) judgment in Verein KlimaSeniorinnen Schweiz and Others v Switzerland (“KlimaSeniorinnen”) (April 2024), the Court held that, within the KlimaSeniorinnen framework, compliance with Articles 2 and 8 ECHR must be determined on the basis of an “overall assessment of all measures taken within a member state”.

The United Nations Climate Convention, the 2015 Paris Agreement and subsequent COP decisions provide the benchmark for assessing whether the Netherlands has satisfied its positive obligations under the ECHR with regard to mitigation and adaptation.  In its analysis, the Court drew on the Advisory Opinions of the International Court of Justice (“ICJ”) (July 2025) and the Inter-American Court of Human Rights (“IACHR”) (June 2025) on climate change. In line with the ICJ’s Opinion, the Court underlined that formal adoption of climate policies is insufficient: those policies must in practice deliver the  outcomes required by the State’s binding climate-related obligations.

A legal framework for mitigation

The Court set out a ‘legal framework for mitigation’ that states should follow in order to comply with these obligations, which builds on the framework established by the ECtHR in KlimaSeniorinnen. States must:

1. adopt general measures specifying a target timeline for achieving carbon neutrality in line with the UN Climate Convention;
2. set out binding, interim greenhouse gas (“GHG”) emissions reduction targets and pathways that are deemed capable, in principle, of meeting the overall national GHG reduction goals;
3. provide evidence showing that the State has duly complied, or is in the process of complying, with the relevant targets;
4. keep those targets updated with due diligence, and based on the best available evidence; and
5. act in good time and in an appropriate and consistent manner when devising and implementing the relevant legislation and measures.

Specifically, in order to meet their obligations under the UN Climate Convention and 2015 Paris Agreement, highly industrialised ‘Annex 1’ countries such as the Netherlands must be climate neutral (‘Net Zero’) by 2050 and achieve a 43% reduction in GHG emissions relative to 2019 levels by 2030.

Furthermore, there are a number of specific administrative, reporting and publication obligations that states must comply with to meet their binding climate obligations. The Netherlands’ obligations to compile both an inventory of GHG emissions and removals by sources and a list of all national and regional programmes and measures to address climate change were deemed particularly relevant.

In assessing mitigation, the Court first considered the Netherlands’ compliance with the GHG reduction targets in the Dutch Climate Act (2019). The Court found that the GHG reduction targets do not meet the UN minimum standards for Annex 1 countries as they are based on a 55% reduction in emissions by 2030 relative to 1990 levels rather than 2019 levels. 

The Court then found that the Netherlands does not meet the requirement of having a binding regulatory framework with interim targets and pathways for GHG emissions for the whole period up to 2050.

Lastly, the Court found that the Netherlands has not quantified its GHG emission allowance as part of the global emission budget that remains to limit global warming to 1.5 °C.

On that basis, the Court ruled that the mitigation measures taken by Netherlands did not comply with its legal obligations in respect of climate change.

Adaptation: a case of unequal treatment

Since 1992, the UN Framework Convention on Climate Change has required member states to draw up, publish and implement national programmes for “measures to facilitate adequate adaptation to climate change”. Member states must account for specific needs and interests of areas that are particularly vulnerable to the adverse effects of climate change (including small island states and territories).

These adaptation obligations were strengthened by the 2015 Paris Agreement. Parties reaffirmed the necessity and urgency of adaptation and committed to transparent reporting on the adaptation measures they have taken and on the results achieved.

Adaptation targets for states were further specified in the 2023 United Arab Emirates Framework for Global Climate Resilience. Member states must draw up and begin implementing national adaptation plans to address climate risk informed by impact and risk assessments. Member states must also establish effective systems for monitoring and evaluating their national adaptation efforts.

In KlimaSeniorinnen, the ECtHR held that states must take adaptation measures aimed at alleviating the most severe or imminent consequences of climate change, taking into account “any relevant particular needs for protection” and “in accordance with the best available evidence”.

The Court in this case ruled that the measures taken by Netherlands did not satisfy the standard required of states. Measures to address climate-related harms were taken “later and less systematically” than the measures taken for the inhabitants of the European Netherlands and did not account for the specific vulnerabilities of Bonaire to climate-related harms. These specific vulnerabilities include that:

• Rising sea levels pose a significant threat to Bonaire. The effects of climate change mean that the island will be partially submerged by 2050.
• Bonaire is vulnerable to hurricanes and extreme weather events.
• Bonaire’s geographical location makes it vulnerable to disruptions in food and energy supplies. It depends on sea and air transport for the supply of food and goods which can be significantly impacted by damage to key infrastructure caused by natural disasters.
• Bonaire suffers from a lack sufficient personnel, resources and specialist knowledge to counter climate-related harms.

The Court ruled that the Netherlands’ failure to take sufficient mitigation and adaptation measures breached the state's legal obligations under Article 8 to protect the right of Bonaire’s inhabitants to life, health, well-being and the enjoyment of their own culture against the negative effects of climate change.

The Court did not find a breach of Article 2. Greenpeace did not persuade the Court that the Netherlands’ failure to fulfil its positive obligations at the collective level could lead to the conclusion that there is an acute threat to the right to life of the inhabitants of Bonaire. The ruling is in line with the high threshold established in KlimaSeniorinnen.

Lastly, the Netherlands was found to have failed to account for Bonaire’s particular vulnerability to climate-related harms resulting in unequal treatment of its people. This is in violation of the prohibition of discrimination under Article 14 of the ECHR and Article 1 of the Twelfth Protocol to the ECHR.

Impact and next steps 

The ruling builds on the precedent set in KlimaSeniorinnen that courts can attribute climate-related harms to a state’s failure to tackle climate change. It will strengthen future claims which seek to hold states legally responsible for insufficient action on climate change which causes harm to individuals.

Greenpeace relied on the Advisory Opinions by the ICJ and the IACHR in arguing that the Netherlands’ adaptation measures were insufficient under international law. Their deployment - by both the claimant and the Court in its ruling – demonstrates the legal weight of these Opinions in domestic courts and how they strengthen the framework for pursing climate accountability claims.

The Court has now ordered the Netherlands to develop a comprehensive climate adaptation plan for Bonaire. The Netherlands also has 18 months to set legally binding interim targets to cut its GHG emissions; failure to do so may pave the way for further claims. The case highlights how states’ legal obligations in respect of climate change extend to all territories under their jurisdiction, with potential consequences for other European countries with overseas territories.