By Samantha Harvey

By Ilan Kelman

By Ana Kinsella

By Ian Wright

By Hendrikus van Hensbergen

By Scott Rozelle & Natalie Hell

Introduced by Emma Thompson

By Tim Harford

By Gaia Vince

By Heaven Crawley et al.

By Ben Judah

By Malala Yousafzai

By James Cheshire & Oliver Uberti

Edited by Tom Standage

By Hans Rosling

By Dharshini David

By Greta Thunberg