As the world’s population looks set to grow to nearly 9 billion by 2040 from 7 billion now, and the number of middle-class consumers increases by 3 billion over the next 20 years, the demand for resources will rise exponentially. Even by 2030, the world will need at least 50 percent more food, 45 percent more energy and 30 percent more water, according to U.N. estimates, at a time when a changing environment is creating new limits to supply. And if the world fails to tackle these problems, it risks condemning up to 3 billion people into poverty.