Speaking via videotaped remarks to a gathering in Hamburg, Germany prior to the G20 Summit, California Gov. Jerry Brown on Thursday announced that his state will host the Climate Action Summit in San Francisco in September 2018. Brown called for global action by citizens to "roll back the forces of carbonization" and address threats related to climate change. The summit, he said, will bring together various subnational government, business, investment and civilian representatives from around the world. Brown's recorded remarks in Europe were introduced by Christiana Figueres, a former United Nations official dealing with the UN framework on climate change.