Teen climate activist Greta Thunberg had a message for world leaders at the UN climate summit: “You are failing us.”

“We are at the beginning of a mass extinction, and all you can talk about is money and fairy tales of eternal economic growth,” the 16-year-old said with tears in her eyes. “How dare you!”

“If you choose to fail us, we will never forgive you,” Thunberg said to applause.

Listening to the young Swedish climate icon were around 60 leaders, who are expected to make pledges to abandon fossil fuels and slow the rise in global temperatures at the UN event.