As the world population clock ticks past 7 billion, alarm bells are ringing. The gathering force of public protests is the popular expression of an obvious fact: that growing economic uncertainty, market volatility and mounting inequality have reached a point of crisis.

Too many people are living in fear. They are discouraged by uncertainty and angry at their diminished prospects. Around kitchen tables and in public squares, they are asking: who will deliver for my family and my community? In these difficult times, the biggest challenge facing governments is not a deficit of resources; it is a deficit of trust. People are losing faith in leaders and public institutions to do the right thing.

The forthcoming G20 meeting in Cannes takes place against this dramatic backdrop. The leaders of the world's largest economies have a historic opportunity - and a historic responsibility - to reduce the trust deficit. To do so, they must unite. Amid crisis and uncertainty, they must offer clarity of purpose and bold solutions. The time for haggling over incremental steps is long gone. At the 2009 summit in London, G20 leaders showed courage and creativity in stabilizing the global financial system. We need similarly ambitious leadership today.

We all recognize that budgets are stretched thin. For much of the world, fiscal austerity is the new order of the day. Clearly, the immediate priority in Cannes will be to support the decisions taken in Brussels on the crisis within the eurozone. Yet just as clearly, any effective response to these multiple challenges must be global.

More, it must be coupled with an ambitious long-term social agenda. We cannot afford to cut loose those who are most vulnerable - the poor, the planet, women and young people. Those least responsible are paying the highest price. Asking them to wait while other problems are solved is not only counter-productive but also immoral. In Cannes, leaders should agree to a concrete action plan that advances the well-being of all nations and people, not just the wealthiest and most powerful.

For the poor: At last year's G20 summit in Seoul, leaders recognized a fundamental reality - there can be no sustainable growth without development. Emerging economies are the drivers of the future. In Cannes, leaders must show strong support for the pro-poor, pro-growth agenda embodied in the Millennium Development Goals. We know what works; we must continue to invest in policies and programs that yield outsized gains - in women and children's health, food and agriculture and gender equity, to name but a few.

For the planet: Just as there can be no sustainable growth without development, there can be no sustainable development without protecting the planet. Our collective health, wealth and well-being depends on how we husband the earth's "natural capital" - the air, rivers and oceans, soils and forests, its full diversity of flora and fauna.

Next June, 20 years after the original Earth Summit, the United Nations will host a major conference on sustainable development. Rio+20 is an opportunity to define a clear path to a better future - a future of integrated solutions to interrelated problems. That means new initiatives on food and water security. It means advancing on climate change and renewable energy, including innovative means of financing. Above all, it means looking beyond the horizon and thinking strategically about where we must be a decade from now. Three years ago in London, leaders debated how to "stimulate" short-term global growth. In Cannes, we need to focus on boosting smart long-term investment - making the right decisions today to shape the world of tomorrow.

For women and youth: Throughout the world, young people and women have taken to the streets. They are demanding their rights and a greater voice in economic and political life. Together, women and young people make up more than two-thirds of the global population. In every sense, they are the world's next emerging economy. We must listen to them. We must do all we can to meet their needs and create opportunities, from maternal health care to jobs.

Across the broad geography of its membership, the G20 needs to squarely address the crisis of rising inequality. If we fail to do so, the future will come to us with a vengeance. Social alienation and deepening instability will undermine the prospects for peace, security and prosperity for all.

For the leaders in Cannes, this summit is a test. The world is watching. The decisions taken will affect every country and person, directly or indirectly. A failure would be disastrous. With wisdom and foresight, we can use this moment to lay the foundations for a healthy, green and inclusive economic prosperity for everyone. By acting together, now, we can pull back from the brink and make a difference for generations to come. Let us make no mistake: there can be no deferring these hard choices. The clock is ticking.

The author is the secretary-general of the United Nations.

(China Daily 11/03/2011 page9)