At only 16 years old, Greta Thunberg might seem an unlikely face of climate change activism.

But the Swedish teen’s work inspired last week’s Global Climate Strike, which saw millions of participants worldwide. Addressing the UN on Monday, Thunberg had world leaders’ attention.

When children and teens start speaking up, adults tend to take notice, said Brookline student Kate Avery.

“Adults don't expect youth to have strong opinions on issues, so when they see us becoming activists, it's like a wake-up call,” she said. “A wake-up call is what the world needs.”

Avery, a ninth grader at Brookline High School, was among the crowd of thousands that converged on Boston’s City Hall Plaza Sept. 20. In an interview with the TAB, she shared stories from the climate strike and gave insight into the worldwide movement.

This interview has been edited for length and clarity.

Why did you decide to join the climate strike?

I joined the climate strike because the climate crisis is an important issue to me. I want to have a future where I do more than simply try to survive one natural disaster after another, and to do that we have to act now.

What we are doing today isn't enough. We need more legislation, soon, if we are going to stay within the UN goal of 2 degrees Celsius increase total. To do that, we would have to decrease our carbon emissions by 50 percent in 11 years. Making an effort towards saving my planet and my future is more important to me than a school day.

Do you believe it’s important for other young people to take up the cause? If so, why?

I strongly believe that it is important for young people to take up the cause. We are the ones who will be the most strongly impacted by climate change, but we can't vote and we have very little say in government. We rely on adults to make laws to save the world for us, and to get them to do that, we have to show them that we care.

What was the most memorable part of the strike for you?

There was this one speaker, a Honduran woman, who spoke in Spanish, with a translator, about how climate activists there were persecuted by the government. That was really powerful. Also, the T ride into Boston was really a memorable moment for me. The trains were jam packed — people were wedged together so tightly you almost couldn't move.

Normally it would have been a horrible public transit experience, but there was this feeling of camaraderie because we were all students going to the rally. And everyone was being really nice to complete strangers. At one point a seat opened up, and the people closest to it shouted across the train car to ask if anyone needed the seat. That act of kindness gave me hope that our generation could succeed in creating the future that we want to have.

Do you have any plans for future climate activism?

The next big strike is on Nov. 29, or Black Friday. I am not quite sure whether I will be in Boston that weekend, but my friends and I agreed that whoever is in town will attend. After that, I don't know as of today. We will continue to walk out of school on important dates until more legislation is passed to lower carbon emissions. I also plan to take a journalism class in school next year and use the skills I learn to spread awareness about the issue.

Is there anything else that you would like to add?

The climate crisis is the most important issue that we will see in our lifetimes, and probably in our children's and grandchildren's lifetimes as well (assuming we manage to fix it and they have a planet to live on).

This will not just affect one country or one society, but the future of the entire planet, and the continued existence of all life forms, including humans. It is too big of a problem to ignore. We can't leave it to other people to fix, because we've been doing that for decades, and it isn't working. We are running out of time. That is why we need to put aside other conflicts and work together throughout the world to solve this problem.