Europe suffered an unprecedented heatwave this June, with debilitating effects felt across various walks of life: thousands of deaths, particularly among the elderly, individuals and families suffering in “heat-trap” apartments, hospitals full and caught unprepared, school closures, and productivity losses. Temperatures soared to break records, with June 2026 recorded as the warmest ever June in Western Europe. But this heat wave was not an anomaly, with the World Health Organisation (WHO) describing it as a “dress rehearsal” for future summers, which will be even hotter. That the heatwaves are being caused by climate change is beyond doubt, but in Europe’s case the rate of warming is notable for being over twice the global average, making the effects of the rising temperature particularly challenging.

Adaptation measures are indispensable for coping with these soaring temperatures, which have cost lives and severely affected people’s well-being. According to one estimate, heat-related deaths in the European region in 2023 would have been around 80% higher in the absence of adaptation measures already in place. The EU Strategy on Adaptation to Climate Change, communicated by the European Commission in 2021, recognised the increasing frequency of climate and weather extremes including heatwaves, while also acknowledging that “[c]urrent [adaptation] measures mostly focus on awareness raising, institutional organisation or policy development, but actually rolling out physical solutions, such as creating more green spaces to reduce the impacts of heatwaves or adjusting sewerage systems to better cope with storm overflows, is lagging behind.” An integrated framework for European climate risk and resilience is expected from the European Commission later this year.

The discussion around climate adaptation has entered mainstream political discourse in Europe in the aftermath of the June heatwaves. For example, the lack of an appropriate adaptation plan in France triggered a no-confidence motion against the French government, the European Greens have proposed a heatwave action plan to make Europe “heat-proof” funded by the top five fossil fuel companies, and the candidate from the Social Democratic Party for the forthcoming Berlin senate elections has proposed planting more trees in concrete-heavy parts of Berlin as a reaction to the record temperatures.

What are the implications of this for climate litigation in Europe? Answering this question involves looking at how adaptation has featured in European litigation so far.

Human Rights for Both Mitigation and Adaptation

European courts have shown a proactive disposition in relation to states’ climate change mitigation responsibilities, with pro-climate litigants yielding successful outcomes in cases such as Urgenda, Neubauer, and Verein KlimaSeniorinnen. In these “government framework litigation” cases, courts have found that states’ failure to mitigate greenhouse gas (GHG) emissions in line with the Paris Agreement temperature goals could lead to the violation of rights guaranteed by constitutions and human rights systems.

However, rights-based litigation involving adaptation in Europe has until recently been notable by its absence. Or, rather, it has been present but under the radar in some of the key litigation cases. And the English NAP3 case, which is now being taken to Strasbourg, has seen the climate movement finally grasp the adaptation nettle. This, we argue, is a welcome move. While we understand the reluctance by some to embrace adaptation litigation for strategic reasons – because it diverts attention from mitigation as the primary focus – heatwave-induced suffering leads to a violation of rights such as the right to life, the right to health, and the right to livelihood. Government failure to take adequate climate adaptation measures is therefore something that should be challenged in court.

Adaptation and European Climate Litigation: From Latent to Patent

An examination of the courts’ observations on climate adaptation in mitigation-focussed climate litigation highlights that adaptation measures have only received somewhat latent, cursory mentions. However, some of these observations by the courts provide interesting clues for how they might deal with future adaptation-focused cases.

The 2019 judgment of the Netherlands Supreme Court in Urgenda is a landmark rights-based climate case, which has inspired many others in its wake. The challenge alleged violations of the European Convention on Human Rights (ECHR) due to inadequate Dutch emission-reduction targets for the year 2020, and was therefore clearly a case with a strong mitigation focus. However, climate adaptation measures came up as part of the State’s defence, where it argued that the risks of climate change can be limited through adaptation and mitigation as complementary strategies, and that the petitioner Urgenda failed to “appreciate the adaptation measures that the State has taken or will take”. This argument was rejected by all three Courts. The Hague District Court noted that although adaptation measures could reduce the effects of climate change, they could not eliminate the danger of climate change, adding that “[m]itigation therefore is the only really effective tool.” (para 4.71). The Court of Appeal and the Supreme Court observed that the obligation of the State to reduce CO₂ emissions quicker than it had planned was not diminished by adaptation measures (para. 59 Court of Appeal, para. 7.5.2 Supreme Court). The Supreme Court also clarified that the obligation arising from Articles 2 and 8 of the ECHR to take appropriate measures to counter an imminent threat may encompass both mitigation and adaptation measures (para 5.3.1).

Even though adaptation was not directly at issue in the case, the Urgenda ruling makes it clear that an absence of adaptation measures could also give rise to a claim of the violation of rights guaranteed under the ECHR. This was an important place-marker.

In the 2024 ECHR KlimaSeniorinnen case, where the cause of action involved the violation of the rights of elderly women in the face of increasing and intensifying heatwaves, the litigants’ choice not to focus on adaptation measures was conspicuous. The applicants viewed the potential for adaptation as being “increasingly limited” (para. 335) and chose, therefore, to focus on the state’s responsibility to mitigate climate change. Ultimately, much turned on the applicants’ vulnerability due to their advanced age, particularly in order to decide issues of standing, with both the Swiss Government and the Court bringing into the discussion the distinction between measures required for the applicants and for the public as a whole. The Government argued that the effects of the heatwave suffered by the applicants “had not been sufficiently specific to them”. Consequently, the adaptation to heatwaves required on their part was “a common feature during heatwaves which affected the rest of the population as well” (para. 343). It also argued that Switzerland had already put various effective adaptation measures in place, which had reduced the mortality rates linked to heat (para. 361).

The Court relied on an IPCC Report to conclude that “without effective mitigation (which is at the centre of the applicants’ arguments in the present case…), adaptation measures cannot in themselves suffice to combat climate change” (para. 418). It acknowledged that the effective protection of individuals’ rights from the adverse effects on their life, health, well-being, and quality of life required that mitigation measures should be supplemented by adaptation measures, which should be “put in place and effectively applied in accordance with the best available evidence” (para. 552). However, while making its conclusions on the state’s positive obligations under Article 8, the Court restricted itself to mitigation measures and deemed it unnecessary to examine “whether the ancillary adaptation measures were put in place” (para. 555). It noted further that the applicants were not found to suffer from any critical medical condition “whose possible aggravation linked to heatwaves could not be alleviated by the adaptation measures available in Switzerland or by means of reasonable measures of personal adaptation given the extent of heatwaves affecting that country” (para. 533).

Two elements emerge from this analysis of the ECtHR’s judgment in KlimaSeniorinnen. First, the Court acknowledged that mitigation needed to be supplemented with adaptation to protect the rights guaranteed under the ECHR, but very consciously stopped short of including adaptation measures within the positive obligations of states in respect of climate change (even if the wide margin of appreciation would have equally applied to deciding on specific measures). Second, the Court also cast some of the responsibility for climate change adaptation in the face of heatwaves on individuals.

Adaptation was, in contrast, front and centre in Friends of the Earth and others v Secretary of State for Environment, Food and Rural Affairs (2024) (the “NAP3” case). This was a High Court judicial review brought by Friends of the Earth (FoE) and two individuals – one whose house was at risk from sea-level rise and another, with disabilities, who lived in a care home and was confined to isolation in his air-conditioned room during heatwaves because the sociable common areas were too hot. The claimants were challenging the Government’s most recent “NAP3” national adaptation plan on the basis that it was too vague. On heat, the allegation was that NAP3 lacked long-term planning and funding for the health and social care sectors regarding systematic temperature monitoring and plans to adapt care homes, as well as the absence of appropriate funding for air conditioning. The judge rejected the challenge. Section 58 of the UK Climate Change Act 2008 imposes a duty on the government to set out objectives on adaptation and proposals and policies for meeting them. The claimants argued that these objectives needed to be “in the form of substantive, specific and measurable outcomes” (para. 72), hence their specific care home cooling claim. The judge rejected this, observing that the Act did not prescribe the ambition or specificity of the objectives (paras. 93-6). Nor was he convinced that KlimaSeniorinnen changed this.

While not wanting to dismiss the ECtHR’s remarks on adaptation as obiter (having been made in a mitigation case), he felt the Court would likely grant states a wider margin of appreciation in adaptation cases both in setting relevant objectives and, even more so, in setting out proposals and policies for meeting them (para. 105). In the end, he regarded adaptation as very different to mitigation because while the latter is rooted in an internationally agreed quantitative target of carbon neutrality by 2050, the former has no such equivalent (para. 103). Permission to appeal to the Court of Appeal was denied. Having exhausted their domestic remedies, the claimants took their challenge to the ECtHR in July 2025. We will therefore hear in due course whether the Strasbourg court agrees.

Looking Forwards

There is no doubt that combating the effects of climate change will require a combination of mitigation and adaptation actions by governments. Rights-based climate litigation on both is needed to hold them to account for their choices. The summer 2026 heatwaves have brought home just how much fundamental rights are affected by excessive heat. The forthcoming NAP3 ECtHR ruling could not be timelier, therefore. Both adaptation and heat have featured in climate litigation in the Global South, for example, in the Leghari case in Pakistan which had a strong focus on adaptation, an Indian High Court’s ruling directing the state to implement a “Heat Action Plan”, and most recently, in the Bonaire case where human rights violations were found on account of inadequate measures for both climate mitigation and adaptation. It is now time for adaptation to enter the mainstream in the Global North. For those who remain concerned by that prospect, we offer the following observations. First, there is an argument of consistency: if human rights are the basis for mitigation claims, including victims suffering from heat harms, then it seems odd to say that the law should not be directly addressing those harms via adaptation measures. Second, adaptation cases bring climate harms “home”: these are no longer only happening in distant places or time; they are happening here and now, in Europe. Finally, related to this, cases on adaptation may be more salient to the public because they do not involve abstract (albeit important) discussions on net-zero, percentage reductions, and carbon budgets. People may feel disengaged from that. But, as we have also seen in the aftermath of soaring temperatures this summer, everyone has a view on cooling.