ICTP Director K.R. Sreenivasan has published a wide-ranging article on the relationship between physics and sustainable development, focusing specifically on the challenges and opportunities faced by the developing world. The article appears on the eve of the concluding event of the World Year of Physicsâ€”an international conference titled “Physics and Sustainable Development", scheduled to take place in Durban, South Africa, from 31 October to 2 November.