Nobody could have predicted the kids would get this far.

Back in 2015, a group of 21 young Americans decided to sue the US government over climate change. In Juliana v. US, the plaintiffs argue that the government has violated “the youngest generation’s constitutional rights to life, liberty, and property” by adopting policies that promote the use of fossil fuels—despite the knowledge that carbon dioxide emissions are a primary cause of global warming.

That might sound like an extreme claim. But in the years since, the lawsuit has kept succeeding against all odds. The Ninth Circuit Court of Appeals on July 20 denied the Trump administration’s attempt to dismiss the suit (pdf), and the case remains set for trial 0n October 29. ”With the Ninth Circuit again ruling in our favor, we are going strong,” 12-year-old plaintiff Avery M. said in a statement (pdf). “The federal government is trying to block our path but we are persevering. We are optimistic and have the courage to keep standing up for our constitutional rights.”

To the average observer, the case may still seem like a long shot. But the kids are part of a global movement of concerned citizens advancing similar claims. Collectively, the lawsuits are creating new precedents that bolster activism—and may, in the long term, help alter the way governments think about their responsibility to protect citizens against climate change.

The young plaintiffs in Juliana v. US, who are now between 11 and 22 years old, are represented by the legal nonprofit Our Children’s Trust. The organization is involved in similar suits around the country and the globe. In this case, attorneys for the trust argue that a fundamental right to a stable climate that sustains life is implied in the US Constitution.

There’s no explicit mention of climate change in the Constitution, of course, since human-induced global warming wasn’t a concern in the 18th century. But the attorneys argue that, last century, once government officials became aware of the harm their energy policies were causing and persisted in approving measures that endanger the planet, the government ran afoul of the Constitution. The notions of life, liberty, and the pursuit of happiness are meaningless on a planet that can’t sustain life.

The children also claim that, as a result of the government’s past and current policy decisions, their generation has been disproportionately burdened by the environmental impact of climate change. As such, they say they’ve been discriminated against in violation of the Constitution’s Equal Protection Cause.

There’s reason for the plaintiffs to be hopeful about their chances at trial come October. This April, youth in Colombia succeeded in convincing the nation’s high court (pdf, in Spanish) to reverse a February decision denying their climate change lawsuit against the government. The Supreme Court of Justice of Colombia ruled in favor of the youth plaintiffs, who argued that deforestation in the Amazon and increasing temperature threatened their constitutionally-guaranteed rights to a healthy environment, life, health, food and water. Notably, the high court also found that the Colombian Amazon forest has legal personhood and that, as such, the government has a duty to protect the forest.

In Belgium, a climate change case against authorities is expected to proceed to trial this year after three years of procedural disputes. Similarly in India, a hearing is expected soon on the case of a ten-year-old plaintiff, Ridhima Pandey, who last year filed an affidavit with India’s National Green Tribunal arguing that the government has failed to implement its emissions reductions policies and adhere to its environmental laws. In 2016, a seven-year-old Pakistani girl sued the government for its environmental failures, and the case has been allowed to proceed.

Norwegian youth are appealing the Oslo District Court’s January denial (pdf) of their constitutional climate change case to the nation’s highest court. And lawyers in Australia, Canada, and the United Kingdom are working with Our Children’s Trust on filing actions there in the near future.

Although the children involved in the lawsuits may not know one another, they’re involved in a collective international effort. Judges considering the US case have looked at similar cases, like the one in the Netherlands, for guidance. It’s only fitting that the push to hold authorities accountable is a collaborative one, as climate change is an issue that transcends national borders.

In fact, the Dutch government unsuccessfully used that argument to try to disavow responsibility for the effects of its policies. When Dutch citizens sued the government over climate change in 2015, the government argued that the issue of climate change was too big for it to handle alone. But Dutch judges didn’t buy it, ruling in favor of the plaintiffs. The Dutch government was ordered to reduce emissions by 25% within five years. If the US kids keep winning, the American government could face a similar directive.

“Climate change is already destructive,” 13-year-old plaintiff Sahara V. said in a statement after the appeals court decided not to block the US case. “It’s harming me and my family, and will only get worse unless the government starts taking action to stop it rather than cause it.”