Sixteen-year-old Swedish activist Greta Thunberg spoke at Friday’s climate strike in New York, where an estimated 300,000 people took to the streets. Thunberg inspired the global spread of weekly climate strikes when she started skipping school to protest outside of the Swedish parliament last year. “We will not just stand aside and watch,” Thunberg told a crowd of thousands in her speech at Manhattan’s Battery Park. “We are united behind the science, and we will do everything in our power to stop this crisis from getting worse.”

ALEXANDRIA VILLASEÑOR: It is my honor to introduce Greta Thunberg!

GRETA THUNBERG: Hello, New York City. It is an honor for me to be here with all of you today on this historical day. People are striking today in over 150 countries, on all continents. And when I say all continents, I mean all continents, even Antarctica. Even on Antarctica, people are striking. And we are not in school today. And this time, we are not alone. We have some adults who are not at work today, either.

And why? Because this is an emergency. Our house is on fire. And it’s not just the young people’s house. We all live here. It affects all of us. And we will not just stand aside and watch. We are united behind the science, and we will do everything in our power to stop this crisis from getting worse, even if that means skipping school or work, because this is more important. Why should we study for a future that is being taken away from us, that is being stolen for profit? And some people say we should study to become climate scientists or politicians, so that we can, in the future, solve the climate crisis. But by then, it will be too late. We need to do this now!

This Monday, world leaders are going to be gathered here in New York City for the United Nations Climate Action Summit. The eyes of the world will be on them. They have a chance to prove that they, too, are united behind the science. They have a chance to take leadership to prove they actually hear us. Do you think they hear us?

CLIMATE STRIKERS: No!

GRETA THUNBERG: We will make them hear us.

CLIMATE STRIKERS: Greta! Greta! Greta! Greta! Greta! Greta! Greta! Greta! Greta! Greta! Greta! Greta! Greta!

GRETA THUNBERG: We have not taken to the streets, sacrificing our education, for the adults and politicians to take selfies with us and tell us that they really, really admire what we do. We are doing this to wake the leaders up. We are doing this to get them to act. We deserve a safe future. And we demand a safe future. Is that really too much to ask?

CLIMATE STRIKERS: No!

GRETA THUNBERG: Right now we are the ones who are making a difference. If no one else will take action, then we will. It should not be that way. We should not be the ones who are fighting for the future. And yet, here we are. But we are not just some young people skipping school or some adults who are not going to work. We are a wave of change. Together and united, we are unstoppable. This is what people power looks like. We will rise to the challenge. We will hold those who are the most responsible for this crisis accountable, and we will make the world leaders act. We can, and we will. And if you belong to that small group of people who feel threatened by us, then we have some very bad news for you, because this is only the beginning. Change is coming, whether they like it or not.

AMY GOODMAN: Sixteen-year-old Swedish climate activist Greta Thunberg speaking on Friday at the Global Climate Strike in New York. Today she’s addressing the U.N. Climate Action Summit. Yes, at the United Nations, she’s addressing the U.N. General Assembly.