Sacramento and San Joaquin Climate Impact Assessment. Sacramento's greenhouse gas reduction target for 2030, surpassing the statewide 2030.The science behind climate change is rooted in the greenhouse effect. The Paris Agreement is a legally binding international treaty on climate change. Possibly additional international GHG emission treaties in the near future. Sacramento is one of the major U.S. cities at greatest risk for catastrophic flooding. Climate change is a global emergency that goes beyond national borders. Look for Country Reports in the Business Source Complete Database. The Protocol also has some major holes of its own.