then, in 2009, former president lula da silva took a bold step that favored the quilombolas such as sandra and her community. narrator: this meant that the quilombolas were granted legal ownership of these territories. a further symbolic recognition of the contribution of slaves to brazil's history has come from the united nations, which declared an international decade for people of african descent in january 2015. the theme of the decade is "recognition, justice, and development." narrator: professor santos knows that even though slavery has ended, the struggle of the descendants of slaves continues. but sandra is determined and confident that her community will stay. [all singing] narrator: coming up on "21st century," in their own words. [music] [indistinct chatter] narrator: climate change, pollution, and melting glaciers. what can one individual do? filmmaker abbie barnes' story with her own images, in her own words. [music] abbie: my name is abbie, i'm 18 years old, and i live in the southwest of england. i've always had a very deep connection with the natural world around me and ve