Filmmaker John D. Liu believes we have a solution to climate change, but it's not as simple as reducing carbon dioxide emissions. Liu's film Lessons of the Loess Plateau, recently presented at the Asia Society's headquarters in New York, explores how, with outside investment and local people's commitment and courage, ecosystems destroyed by human habitation and land misuse can be restored. The World Bank's Loess Plateau Watershed Rehabilitation Project, undertaken in...