On June 6, 2015, 10,000 lay citizens, representing demographic diversities in 76 countries and 97 locations including 4 in the U.S. (Boston MA, St. Paul MN, Ft. Collins CO, Phoenix AZ), participated in the largest-ever informed single-day public deliberation on climate and energy. 18% of U.S. participants were between ages of 18-24. The model, results and evaluation offer useful insights for supporting decisions about climate change education, engagement and empowerment for young citizens from the Pacific Islands to the American Southwest.