Greta Thunberg: 'It just spiralled out of control' 13 minutes to read By: Leslie Hook Three years after bursting on to the global stage, what's next for the most famous climate activist of her generation? Greta Thunberg turned 18 a few months ago but occasionally she forgets that. "I actually can vote now," she grins. But the words "we children" still sometimes slip into her sentences, out of habit. She is sanguine about the change, but it is a bigger shift than she lets on: that phrase has been a core part of her message. Thunberg became the world's most celebrated climate activist on the back of this idea: that children have to wake the world up to the reality of climate change. She was just 15 when she started the "school strike for climate", for which she skipped classes and sat outside the Swedish parliament — at first alone and later with dozens, then hundreds of others every Friday. As the movement grew, aided by Thunberg's speeches, millions of students joined in. She took a year off school, led protests all over the world and has been nominated for the Nobel Peace Prize three times.