Our cities use 75 percent of the energy generated worldwide, making them a major contributor to climate crisis. But stunning ideas can help cities to become more environmentally and worth living. Dedicated people are pushing the local energy transformation in Poland without governmental support, constructing aseimic houses from plastic waste in Indonesia, converting entire housing blocks into energy-saving buildings in Germany, transforming cities into insect paradises, and turning the world's most dangerous city into a safe and green metropolis in Colombia.