Greta Thunberg is a Swedish teenager who has been an activist on the issue of climate change. She has been diagnosed with Asperger's and says in the TEDx talk shown below that she only speaks when she thinks it's necessary. "I remember thinking that it was very strange that humans, who are an animal species among others, could be capable of changing the Earth's climate. Because if we were, and if it was really happening, we wouldn't be talking about anything else. ... But no one ever talked about it." For more information about Greta see her Wikipedia article.