As an anticipated 45,000 people meet in Ecuador for the United Nations’s Habitat III global conference, participating nations release a document urging that cities will be ground zero for mitigation and adaptation to climate change, Henry Gass reports for Christian Science Monitor.

“It’s been a very exciting time for cities in the last 10 years because cities as a source of solutions has been recognized,” said Ani Dasgupta, global director of the World Resources Institute Ross Center for Sustainable Cities, in a conference call with reporters. “There is momentum for the global community to come together and do things, and I think Habitat this time will be different from the past two Habitats.”

More than half of the world’s population lives in cities, and this is expected to grow to encompass two-thirds of the world’s population by 2050, Gass reports. Urban areas are disproportionately responsible for the planet’s emissions — covering only 2% of the Earth’s surface, cities consume 78% of its energy and produce 60% of global emissions.