Activists, celebrities and policymakers from around the world show their support for the upcoming United Nations Climate Summit on 23 September in New York in a new video produced by the UN.

“This is the defining issue of our time,” Secretary-General Ban Ki-moon says in the video, while calling on leaders to come with bold announcements to the Summit next week.

Personalities in the video range from actors Antonio Banderas, Li Bing Bing and supermodel Giselle Bündchen, to astronaut Col. Chris Hadfield and renowned chimpanzee expert Jane Goodall.