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.

The future of any leader or political systems is to be determined by the people of the country.

Millions of people in nearly 80 countries still live in fear of landmines and explosive remnants of war, which take an unacceptable toll on lives and limbs, and people's livelihoods

You are already leaders. Your ideas, your actions and your decisions make a difference. More than any other generation, you have a voice. Social networking is changing how we interact - and it can change our world. You are in touch with peers from around the world. You understand the power of instant communication. I appeal to you to use that power for the common good, the power of communication and the power of networking.

Let us acknowledge and celebrate what youth can do to build a safer, more just world. Let us strengthen our efforts to include young people in policies, programmes and decision-making processes that benefit their futures and ours.

A deal must include an equitable global governance structure. All countries must have a voice in how resources are deployed and managed.

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.