Why Climate Change Is An 'All-Encompassing Threat'

Although a candidate just entered the 2020 presidential race with a platform centered on climate change, some experts say Americans aren¿t fully aware of the scope and seriousness of global warming. Among them is David Wallace-Wells, who argues in a new book that the severity of the climate crisis has not yet been acknowledged, let alone addressed. He sits down with William Brangham to discuss.