World military spending has now risen to over $1.2 trillion. This incredible sum represents 2.5 per cent of GDP (global gross domestic product). Even if 1 per cent of it were redirected towards development, the world would be much closer to achieving the Millennium Development Goals.

Every literate woman is a victory over poverty

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

From the Balkans to Africa, from Asia to the Middle East, we have witnessed the weakening or absence of effective governance leading to the ravaging of human rights and the abandonment of longstanding humanitarian principles. We need competent and responsible states to meet the needs of "we the peoples" for whom the UN was created. And the world's peoples will not be fully served unless peace, development and human rights, the three pillars of the UN, are advanced together with equal vigour.

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.

Climate change...is, simply, the greatest collective challenge we face as a human family.