More than 150 world leaders are preparing to attend the U.N. Sustainable Development Summit in New York beginning Sept. 25, with the aim of agreeing on a new agenda to tackle global poverty. But a new report warns that African children are being left further and further behind and will make up more than half of the world's poor by 2030. As Henry Ridgwell reports from London, the report authors are critical of both African governments and the international community for failing to adequately tackle the problem.