Today, as many as nine out of ten people breathe polluted air, leading to some 7 million premature deaths each year, of whom 600,000 are children.

Unless we act decisively, this number could double by 2050.

Today, we celebrate International Youth Day, and the power of partnerships across generations.

Today, the world honours a giant of our time; a leader of unparalleled courage and towering achievement; and a man of quiet dignity and deep humanity.

Nelson Mandela was a healer of communities and a mentor to generations.

He remains a moral compass and reference to us all.