Participatory process models combine the use of technical data with community participation to develop a sustainability plan relevant to each city. In this article, two case study applications in Denver, CO, USA and Broomfield, CO, USA use a participatory process, which combines teams from academia, local governments and community members to create city climate action plans. The participatory process is developed from concepts in community-based participatory research, analytic deliberation, and post-normal science. The refined process model developed in these two case studies goes through seven steps which include creating the deliberative body, co-developing data sets for sustainability analysis, defining sustainability goals, using scenario modeling for potential sustainability actions, prioritizing actions through deliberation, demonstrating consensus or diversity in final action plan, and conducting an outcomes assessment.