From climate change protester Greta Thunberg to Hong Kong democracy activist Joshua Wong, young people have been making headlines this year. And politicians are being forced to pay attention.

So how do young people make themselves heard where adults have failed?

These three teenagers are passionate about issues they see around them. They are learning what it takes to be activists at a youth organisation called The Advocacy Academy in Brixton, London.

Video journalist: Ellen Tsang

Hear more about youth activism on The Real Story from BBC World Service