Water activists combat climate change and the illegal wetland development flooding towns in Argentina; and citizens in Mexico City use innovative education models and technologies to address the city's water shortage issues.
People who are preserving natural wonders in their home cities are featured. Included: a docent at Mount Vesuvius who has devoted his life to the volcano that destroyed much of the area in previous generations; and a man in Hong Kong who leads neighbors in a fight to preserve a historic forest that has become polluted.
How people are rethinking housing arrangements. Included: three families in Seoul that have joined together to build the home of their dreams; and residents of a housing cooperative in Lyon that share space and the responsibilities.