Omaha chosen to host North American celebration of World Environment Day OMAHA, NE (NET Radio) - Nebraska's largest city has been chosen by the United Nations to host the North American celebration of World Environment Day. Officials with U-N's Environment Program say they chose Omaha because of the city's commitment to environmental and sustainability issues. But an environmental activist based in Omaha says while she's excited about the decision, the city still has some room for sustainability improvement. Clay Masters reports © Copyright 2012, NET Radio