This is the moral challenge of our generation. Not only are the eyes of the world upon us. More important, succeeding generations depend on us. We cannot rob our children of their future.

The power of the leader is given to him by the people, so he has a duty to engage and listen more attentively and carefully to the aspirations of the people.

Saving our planet, lifting people out of poverty, advancing economic growth... these are one and the same fight. We must connect the dots between climate change, water scarcity, energy shortages, global health, food security and women's empowerment. Solutions to one problem must be solutions for all.

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.

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.

The current model is global suicide. We need a revolution. Revolutionary thinking. Revolutionary action. Natural resources are becoming more and more scarce.

People everywhere look to the United States to use its remarkable power to help lift humanity up and to work for the common good.