At the 2014 PEN World Voices Festival, PEN America gathered some of the globe’s most prominent thinkers to speak on a social or political phenomenon of their choosing. Here’s a clip from Noam Chomsky’s oration, in which he addressed the future of humanity and the threats posed by climate change.

You can hear more from today’s most prominent writers and thinkers at the 2018 PEN World Voices Festival this April. Click here to view next month’s schedule and to purchase tickets.