This report distills and integrates the findings of the three Working Group contributions to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), providing an integrated view of climate change. It addresses observed changes and their causes; future climate change, risks, and impacts; future pathways for adaptation, mitigation, and sustainable development; and adaptation and mitigation. The report illustrates that many mitigation scenario models cannot reach concentrations of about 450 parts per million (ppm) carbon dioxide equivalent by 2100 in the absence of carbon capture and storage. View report.