The DDPP issued a report on the first phase of its work, preliminary findings on technically feasible pathways, at the UN Climate Summit in September 2014, at the invitation of Secretary General Ban Ki-moon. This report summarized each country team’s initial research. In the fall of 2015, all 16 teams published stand-alone reports describing in greater detail their research into national DDPs. This 2015 Synthesis Report provides a cross-cutting analysis of the aggregate results, complementing the executive summary published in September 2015.