On this International Day for the Abolition of Slavery let us reaffirm the inherent dignity of all men, women and children. And let us redouble our efforts to build societies in which slavery truly is a term for the history books.

The taking of life is too absolute, too irreversible, for one human being to inflict on another, even when backed by legal process. Where the death penalty persists, conditions for those awaiting execution are often horrifying, leading to aggravated suffering.

Saving our planet, lifting people out of poverty, advancing economic growth – these are one and the same fight.

I call for the need of world leaders to address climate change and reduce the increasing risk of disasters- and world leaders must include mayors, townships and community leaders.

Saving our planet requires you to be ambitious in what you aim, and, equally, in how hard you work to reach your goal.

We must follow the wisdom of the Brundtland Report. We must pursue development that meets the needs of the present generation without compromising the ability of future generations to meet their needs.

For my generation, coming of age at the height of the Cold War, fear of nuclear winter seemed the leading existential threat on the horizon. But the danger posed by war to all humanity-and to our planet-is at least matched by climate change.