On April 13, Working Group III (WGIII) of the Intergovernmental Panel on Climate Change (IPCC) released its report on what can be done to mitigate climate change across sectors. Four years of research and analysis culminated in a week-long meeting in Berlin, during which scientists from developing and industrialized nations discussed mitigation strategies and goals. The 2,000-page report avoids recommending specific policy goals, but instead focuses on providing policy options for different levels of government (nations, regions, cities…) and economic sectors. This publication is the third and final part of the IPCC's fifth assessment report (AR5), an update to the fourth assessment report published in 2007. The Working Group I report found that climate change is unequivocal, and is caused by humans, while the Working Group II report detailed the risks of climate change to society.