Climate activist Greta Thunberg called on citizens to “change everything” to avert climate crisis, at the start of a conference in Vienna yesterday organised by former California governor Arnold Schwarzenegger. “We young people are waking up and we promise, we won’t let you get away with it anymore,” 16-year-old Thunberg told delegates. Technological developments in fields such as electric cars and solar energy should not leave people with the impression that they could “solve the crisis without making any efforts”, she said. “Once we realise, we act, we change. Humans are very adaptable,” she added. She was speaking at the Austrian World Summit, an initiative launched by Schwarzenegger, which brings together some 1,200 figures from the worlds of science, politics and business to discuss ways to tackle climate change.