Climate activist Greta Thunberg should be in school, but instead she's the one schooling the adults.

Today, a group of 16 children from all over the world gathered with the Swedish environmentalist at the United Nations to present an official human rights complaint about the global climate change crisis.

Thunberg gave an impassioned speech about the dangers of inaction, detailing how fossil fuel emissions and large carbon footprints have contributed to the spike in global temperatures, causing glaciers to melt, sea levels to rise, and more frequent natural disasters. If the globe's temperature increases by just 1.5 degrees Celsius, she said, the results would be catastrophic. And, according to Thunberg, cutting emissions in half over the next decade will only decrease by 50% "the risk of setting off irreversible chain reactions beyond human control."

At 16 years old, Thunberg has already made waves in multiple countries with her message of climate change awareness, appearing on the September covers of both British Vogue and Teen Vogue. For two weeks, she sailed on an emissions-free yacht across the Atlantic, from England to New York. Since her arrival in late August, Thunberg has testified on Capitol Hill and led the charge for the global climate strike last week. Millions of people—many of them teens—protested climate change across the globe, with Thunberg documenting some of the most indelible moments on Instagram.

This morning, in front of the United Nations General Assembly for the Climate Summit, Thunberg also took politicians and global leaders to task for leaning on the youth to solve the climate crisis. "This is all wrong. I shouldn’t be standing here. I should be back in school on the other side of the ocean. Yet you all come to me for hope? How dare you! You have stolen my dreams and my childhood with your empty words," Thunberg said. "And yet I’m one of the lucky ones. People are suffering. People are dying. Entire ecosystems are collapsing. We are in the beginning of a mass extinction. And all you can talk about is money and fairytales of eternal economic growth. How dare you!"

"For more than 30 years the science has been crystal clear. How dare you continue to look away, and come here saying that you are doing enough, when the politics and solutions needed are still nowhere in sight," she went on. "You say you 'hear' us and that you understand the urgency. But no matter how sad and angry I am, I don’t want to believe that. Because if you fully understood the situation and still kept on failing to act, then you would be evil. And I refuse to believe that."

Thunberg's speech received support from activists, celebrities, and politicians, such as Beto O'Rourke, Bree Newsome, and more. A gif of Thunberg glaring at Donald Trump as he entered the summit has also positioned itself to become a meme on Twitter.

Thunberg finished her speech with a rousing wake up call. Teens are more than just aware of the mess they have been handed by older generations—they are determined to fix it, even if it is an unfair burden. "You are failing us. But the young people are starting to understand your betrayal," Thunberg declared. "The eyes of all future generations are upon you. And if you choose to fail us I say we will never forgive you. We will not let you get away with this. Right here, right now is where we draw the line. The world is waking up. And change is coming, whether you like it or not."

Related: Jaden Smith Says Al Gore Is His "Mentor" When It Comes to Environmentalism