Cities around the world are exploding in population. They’re also the largest consumers of energy and their thirst is expected to triple in the next 35 years. While some see this as an environmental death sentence, a recent study that examined growing cities, and future energy sources had a pretty optimistic outlook—if cities are planned properly. Researchers spent two years looking at data from 274 cities and found that the highest energy saving potential comes from cities in Asia, Africa, and the Middle East. Cities that are not yet car dependent have the opportunity to build green public transit infrastructure—like bike paths and efficient subways—and could potentially save more than 30 percent of future energy use. Developing cities could leapfrog the west in terms of green energy, like some countries did with mobile phones, skipping the landline networks.