Abstract for: Methodological Changes Needed to Meet the World's Grand Challenges
A companion paper to this one identified four "Grand Challenges" for system dynamics. This paper describes the methodological changes seemingly needed to meet those challenges, describing some of the current precedents and rationale for each. The more technical changes are far more explicit model purpose, use of time series, representation of actors' mental models, and working with multiple models. The changes in professional matters are far more soft science expertise, publication in the language of the public and government, incenting synergistic research, and evolving an open-source online curriculum. These changes do not much alter the core of system dynamics but expand the repertoire of expert modeling activities substantially.