With the polar ice caps melting, coral reefs dying, and the planet’s temperature steadily increasing, it’s clear that climate change needs to be addressed—and fast. And while many leaders have been slow to embrace change, young people have been leading the fight for green energy. At a recent climate summit, Greta Thunberg, a teen climate activist from Sweden, accused world leaders of “stealing” children’s futures.

According to CNN, the 15-year-old addressed the U.N. COP24 climate summit on December 15th in Poland, where she had strong words about world leaders’ inaction when it comes to climate change. In her powerful speech, she said the powers that be were “too scared of being unpopular.”

She continued with a call to action and a look toward the future.

Thunberg concluded by saying that “change is coming, whether you like it or not. The real power belongs to the people.” Thunberg’s speech caught the attention of people like director Ava DuVernay and representative-elect Alexandria Ocasio-Cortez, who shared it on their Twitter feeds.

The Guardian reports that during the two weeks of the COP24 summit, leaders agreed on guidelines for implementing the 2015 Paris Climate Accord. Although the talks settled the ways that countries should monitor and report their carbon-cutting efforts, leaders notably didn’t agree on how they would lower emissions. Thunberg’s talk came on the last day of the summit.

The summit wasn’t Thunberg’s first public display of activism. Quartz notes that she’s been spearheading student walkouts every Friday, which she started earlier in 2018. CNN also reports that on December 14th, she called for a global climate strike.

The work Thunberg is doing to stop climate change is inspiring. We just hope those in power finally listen.