World Food Programme Fighting Hunger Worldwide

We are at a tipping point in the fight against hunger and malnutrition. The world is becoming a less predictable and more threatening place for the poorest and most vulnerable. As we grow more interconnected, a range of complex risks, including climate change, environmental degradation, population growth, conflict, and food and fuel price volatility, are exacerbating the challenges faced by vulnerable communities. Unless we protect the world's poorest people and empower them to adapt to change and build robust, adaptable and more prosperous livelihoods, we face a future where every shock becomes an opportunity for hunger and poverty to thrive.

The UN says there has been a huge leap in the numbers of Syrian refugees arriving in Jordan, putting a considerable strain on resources. A UN official told the BBC that up to 3,000 were arriving every day and at least 50,000 were waiting to cross. UNHCR says there are now more than 670,000 registered Syrian refugees and people awaiting registration in Jordan, Turkey, Lebanon, Iraq and Egypt.

Editor's note: Three of the United Nations' most senior executives have written a joint opinion piece exclusively for CNN.com. They are Antonio Gutterres, the U.N. High Commissioner for Refugees; Ertharin Cousin, the executive director of the World Food Program; and Anthony Lake, executive director of the U.N. Children's Fund or UNICEF.