For Pia Hollenstein, the long-awaited ruling at the European Court of Human Rights for a case brought against the Swiss government by her group, KlimaSeniorinnen, came at an inconvenient time. At 73, the retired nurse and former Parliamentarian from St. Gallen is an avid climber, and on the day of the verdict, she was planning to hike the Grisons Alps. Yet, she knew she couldn’t miss her day in court after a wait that lasted eight long years. “So I flew to Strasbourg,” she tells TIME, “because it was important for all of us to come together to turn whatever happens into something positive.”

The women, who are all over the age of 65, argued that they were especially vulnerable to the health impacts of increasing heat waves due to their age. For the first time, an international court agreed. On April 8, it delivered a landmark verdict in their favor, ruling that Switzerland’s failure to tackle climate change by not reducing its greenhouse gas emissions was clearly violating the rights of the 2,500 members of the group. “The European Court of Human Rights is saying that protecting the climate is protecting human rights,” says Joana Setzer, head of the Grantham Research Institute’s project. “So now, you have to protect people from the threats this will cause to their life and health.”

Although the ruling legally binds the Swiss government to set better climate targets, the state is ultimately responsible for complying. Still, Setzer says the case is especially significant for two reasons: not only is Switzerland now legally obligated to act faster to manage the impact of climate change, but the case has also set a precedent for similar climate lawsuits around the world. “Climate litigation is a transnational issue,” she says. “If the highest human rights court in the E.U. is confirming that this is a human rights issue, then judges will look beyond their jurisdiction to this precedent for climate cases in Australia, Brazil, or Argentina.”

The court’s decision is a multi-generational win as well, one that goes beyond this group of women, says Setzer. “It’s a decision that will apply to and benefit young people all around the world.”

Despite losing the case in several Swiss courts, the KlimaSeniorinnen women kept their hopes alive over the years. “It was quite something to keep the fight going all this time without winning anything,” says Hollenstein, who also sits on the group’s board, “but the most important thing is that we finally got something for human rights.”

As Hollenstein rejoiced over the verdict with other group members in court, Swedish climate activist Greta Thunberg cheered them on from the sidelines. “This is only the beginning of climate litigation,” Thunberg told reporters. “This means that we have to fight even more … because, in a climate emergency, everything is at stake.”

Despite being one of the richest countries in the world, Switzerland has struggled to implement climate policies that sufficiently offset greenhouse gas emissions, especially in meeting targets outlined by ambitious bilateral agreements. For example, as part of its obligations under the 2015 Paris Agreement—which aims to limit global warming by capping global temperature rises to 1.5°C, or 2.7°F, above pre-industrial levels—Switzerland pledged to cut emissions by 50% by 2030 and reach net zero by 2050. But Climate Action Tracker, an independent monitor, has the country’s climate targets and policies “insufficient,” noting that the government will need to substantially improve its climate action by 2030 to meet the agreement’s goals.

The impacts of global warming are increasingly apparent. Last month marked , with scientists warning that climate change could move “into uncharted territory” if temperatures don’t fall by the end of the year, according to a BBC report.

In Europe, one study that in 2022, high temperatures may have been responsible for more than 70,000 excess deaths. Several have why heat has a far greater impact on women’s health, including from the scientific journal Nature, which said it could be partly explained by physiological differences, sociocultural factors, and the fact that women often tend to live longer than men. The KlimaSeniorinnen relied on these findings, along with personal experience, to successfully argue that extreme temperatures were violating their human rights.

Elisabeth Stern remembers Pizol, a mountain in northeastern Switzerland, towering over her backyard when she was a child. “Today, that glacier has disappeared almost completely,” the 76-year-old tells TIME, describing how ice has melted away every summer.

Although Stern joined the KlimaSeniorinnen six years ago, she says the impact of the heat waves on her health really began to intensify in the last two years. “I had a panic attack when I was traveling on public transport and I couldn’t get out because it was so hot,” she says. “It was just an awful experience not knowing what was happening to my body. I could hardly breathe.”

It took nearly 12 hours before Stern’s conditions stabilized and her blood circulation was back to normal again. But even now, whenever temperatures reach above 86°F, she finds herself unable to go outside and do basic functions. “It’s just so unbearably hot that you cannot even sleep in your bed,” she says.

The KlimaSeniorinnen compiled their experiences into the lawsuit against the Swiss government with the backing of Greenpeace, an international non-profit that, nearly a decade ago, the case based on the idea that the climate crisis hurts everyone. In Swiss courts on the regional and national level, however, judges kept throwing it out on procedural grounds.

“From the beginning, we were convinced that Switzerland was violating its obligation to protect these women, but the courts would tell us that it was not in their power to decide this,” says Cordelia Bähr, the lead counsel for the KlimaSeniorinnen.

All domestic legal remedies were exhausted after the Swiss Supreme Court rejected the case. Bähr says the group knew it would have to approach the European Court of Human Rights next. The Swiss government was quick to rebuke the KlimaSeniorinnen’s attempts. “Defining and choosing the measures to be taken is indeed a matter for the government, parliament, and people of Switzerland,” it told the international court.

But in a 250-page-long , the 17-judge judicial bench disagreed with the Swiss government. Not only did it deem that Switzerland’s policies are inadequate and violate the women’s rights to life and rights to health, but it also found that the Swiss Supreme Court’s decision was arbitrary because it rejected the women’s access to court, and that the Swiss authorities had failed to address the complaints and find effective remedies.

One of the most “striking aspects” of the case, says Setzer, was that the judges developed a five-step test designed to assess whether the government’s measures provided adequate protection. “This decision showed that the court very carefully studied the science of the case,” says Setzer. “And it gives very clear, step-by-step instructions of how states should deal with climate litigation.”

Switzerland isn’t the only country that will have to comply with the European court’s instructions. In fact, this ruling will now be legally binding on 46 countries in Europe currently dealing with the rising tide of similar cases in courts.

In Norway, six young climate activists have brought forward a against the Norwegian government to try and prevent the expansion of fossil fuel extraction in the Arctic. In Austria, another plaintiff suffering from a temperature-dependent form of multiple sclerosis has that his condition makes him particularly vulnerable to heat waves. And in the U.K., climate activist group Friends of the Earth, along with two individuals, have brought forward a case against the “inadequate” climate protection policies by the government. The case is scheduled for a hearing.