Residents in the Bolivian city of La Paz are facing a mounting crisis. As climate change brings warmer weather, glacial ice in the mountains around La Paz is melting away. But that ice is the city's main source of water and if the trend continues, millions of residents will be without water in just a few years. The mountain region's rich diversity of flora and fauna will also disappear. There have been few efforts to stem the tide until now. The NGO Nature Conservancy is constructing nature reserve areas and working to create a sustainable water management system – all with the help of local indigenous communities, who have lived in harmony with the fragile ecosystem for thousands of years.