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.

We have seen in the past where leaders have not been open-minded or have not been flexible. That's why the people came out to the streets and shouted and chanted for more reforms and more freedoms.

Between now and 2015, we must make sure that promises made become promises kept. The consequences of doing otherwise are profound: death, illness and despair, needless suffering, lost opportunities for millions upon millions of people.

Sustainable development and climate change are two sides of the same coin

Now, more than ever, we need to connect the dots between climate, poverty, energy, food and water. These issues cannot be addressed in isolation.

You are here to step into the shoes of UN ambassadors - to draft resolutions, to plot strategy, to negotiate with your allies as well as your adversaries. Your goal may be to resolve a conflict, to cope with a natural disaster or to bring nations together on an issue like climate change. You may be playing a role, but you are also preparing for life. You are acting as global citizens.

It is but a short step from hunger to starvation, from disease to death.