The Most Personal Climate Case in the World

When I called Mex Müllner one afternoon this week, the temperature in his small Austrian village was roughly 91 degrees Fahrenheit. The 43-year-old was indoors, because if he went outside, his muscles would cease effectively communicating with his brain, temporarily paralyzing him. Müllner has multiple sclerosis, and like the majority of MS patients, he experiences Uhthoff’s syndrome, whereby heat exposure makes his neurological symptoms worse. He feels like a remote-controlled car with a defective controller, he told me; the engine and wheels work fine, but because the controller won’t connect, the car won’t move.

“Mex” was once a nickname, but now he uses it as a pseudonym to protect his private life: He is suing the Austrian government for violating his human rights by failing to curb the climate crisis. The case is before the European Court of Human Rights, the decisions of which are binding for implicated countries. People turn to international courts when, like Müllner and his lawyer, they’ve exhausted their options in national courts. The ECHR has indicated that it’s taking Müllner’s case seriously by marking it for priority review, according to Michaela Krömer, Müllner’s lawyer.

The case is part of a raft of recent climate lawsuits testing how the law can be used to press for stronger climate policy. Climate cases globally have more than doubled since 2017; 230 were filed last year alone. But Müllner’s case is unique, and strikingly intimate. If it moves forward, he will be the first individual to get standing in a climate case at the ECHR. All of the lawyers I spoke with for this story think he would probably be the first individual anywhere in the world to have their personal harms from climate change be recognized as a violation of their human rights.

Müllner v. Austria highlights the direct connection between health and climate change. Heat can exacerbate any number of medical conditions, as varied as diabetes and depression, and, for Müllner’s illness, it is the trigger for greater distress. At the same time, Austria has fallen short on its climate commitments: The country recently missed a European Union deadline for submitting a climate plan, and is forecast to miss even the minimum EU emissions-reduction goals, too. Müllner’s lawyer is arguing that, by failing to adequately address greenhouse-gas emissions, Austria has violated Müllner’s rights under the European Convention on Human Rights, which Austria has ratified and which protects “life, freedom, and security” as well as “respect for private and family life.”

The case is similar to many in which children have sued their governments, alleging that inaction on climate is infringing on their right to a livable future. One such case was just successful in South Korea; another, in Germany in 2021, forced the government to pass a more ambitious emissions-reduction target, on the grounds that the prior one unfairly burdened future generations. But for Müllner, the harm is happening now. His disease is robbing him of motor function a little more every year, but heat is why he can’t walk outside on this summer afternoon.

Müllner was diagnosed with MS when he was 23. At first, he could still run and play baseball, in a club he’d started with friends who’d brought back a few bats and mitts from a U.S. vacation. A few years after his diagnosis, he prepared the baseball diamond for winter on a chilly fall day. When he got home, he drew a hot bath to warm up, climbed in, and realized he couldn’t climb out. The controller had disconnected from the car. He had to drain the water and wait for his body to cool before he could leave the tub. Since then, heat has been a prison.

In cool weather, he can walk with the help of crutches. But when the temperature approaches 77 degrees Fahrenheit, he has to use a wheelchair. By that temperature or above, he can’t move at all. In the summer, he spends all daylight hours indoors. But even nighttime sometimes ceases to offer relief. The Austrian national weather service has been reporting greater numbers of summer nights when temperatures didn’t dip below 68 degrees, the threshold at which Müllner says he can start feeling the effects of Uhthoff’s syndrome. Right now, he is waiting for an autumn chill to set in. But in these first days of September, much of the country has been in a heat wave. Austria, like most other places on Earth, is getting hotter, and in fact it’s heating faster than the global average. The annual number of days above 77 degrees have almost doubled in Müllner’s lifetime, according to the complaint. This July was the second-hottest July in the country’s lowlands on record. “The government is sleeping and doing nothing,” Müllner said. He is grateful for the country’s universal health system, which has treated his disease, but doesn’t understand why Austria does not take the right to a livable climate as seriously. Most of the rest of the country appears to agree; the majority of Austrians want the country to do more, according to a 2021 European Investment Bank survey.

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The same court considering Müllner’s case recently heard another, brought by a society of senior women concerned with climate change (and backed by Greenpeace), who sued Switzerland on similar grounds. Older people, and older women especially, are more vulnerable than other groups to extreme heat. The ECHR ruled that the four women who brought the case didn’t have standing as individuals, but that the collective to which they belonged—a society of more than 2,000 KlimaSeniorinnen—did. And Switzerland’s failure to do its share to prevent global warming from exceeding 1.5 degrees Celsius, the goal set by the Paris Agreement, was a human-rights violation, the court said.

But by throwing out the women’s individual cases, the court set the bar very high for determining a true climate victim, Andreas Müller, a professor of human-rights law at the University of Basel, told me. Virtually anyone can claim that their life is degraded by climate change, because, in some way, it probably is; for courts to avoid a flood of cases, they need to set a threshold. Through Müllner, the court “will have to say whether the standard can be met at all,” Müller said. The link between rising temperatures and his disability is so evident that if the court won’t find him as a direct victim of climate change, perhaps no one would qualify. “My hunch is he has a good chance to be accepted.”

Austria has not yet formally responded to the court, but the country will likely argue that it is in compliance with EU targets, several lawyers said. If that argument doesn’t sway the court, and Müllner wins, then Austria might be compelled to strengthen its climate laws, giving future litigants more fuel to claim that EU targets are not sufficient to meet members’ climate obligations. It could have a snowball effect. “The European countries are very nervous about certain cases being lost,” Müller said.

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Nothing about Müllner’s life would change, though: The world has warmed too much for him already. Nor would a win in itself alter the trajectory of climate change: Austria accounts for less than one-quarter of 1 percent of the world’s emissions. Maria Antonia Tigre, the director of global climate-change litigation at Columbia Law School’s Sabin Center, was frank about the use of these cases: “They’re marginal; they’re not going to bring changes of the magnitude we need,” she said. But each is part of a larger strategy to force countries to address climate change more aggressively. More climate litigation could make countries change their laws to avoid further legal conflicts, Tigre said. More high-profile cases may make it harder for countries to produce weak proposals at international climate negotiations. It’s all a pressure campaign, and pressure campaigns can work.

Müllner used to work as an energy consultant, so climate change was on his mind before it was so much in the news. He became involved in climate litigation after seeing a call that Krömer, now his lawyer, posted through the MS Society of Austria. He responded within a day. He sees this case as his civic duty. Everyone is hurt by climate change, to some degree or another, and “if people with disabilities have a problem, you can be quite sure that all the other people will have the same problem some few years later,” he told me. People with disabilities are two to four times more likely to be hurt or die in a climate event, such as a heat wave or flood. But few people have suffered the right mix of specific harms to convince a cautious court. “It’s my lawsuit because I was able to prove my problems with the heat. They are medically proven,” he said. “That’s the reason why I can go to the government and say, ‘Please do something.’” Other people might want to bring cases like this, but they can’t. He can, so he is.