Bounding the Role of Black Carbon in Climate was a focused effort to produce an assessment report that summarized the most current knowledge on black carbon (BC) and its role in climate as well as provide a best estimate and uncertainty range for the radiative forcing by BC. The report was published in the Journal of Geophysical Research. This effort resulted from a request for such an assessment by national and international groups trying to formulate policies to mitigate short-term climate warming. It constituted a direct input to the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5), and was structured to accommodate the IPCC framework.