'We are doing this to get world leaders to wake up'

This weekend Greta Thunberg spoke at the UN youth climate summit.

It's a big meeting in New York where world leaders are meeting to talk about climate change and what they can do about it.

Greta told crowds that she and they would "do everything in our power to stop this crisis."

Read more about climate change here, find out more about the more about the summit and check out these seven young climate activists from around the world.

Watch more: Climate and the environment