The Arctic Monitoring and Assessment Programme (AMAP), one of the six Working Groups of the Arctic Council, has released its assessment report on black carbon and ozone as Arctic climate forcers, which complements an earlier report on methane as Arctic climate forcer as part of AMAP's assessment on short-lived climate forcers (SLCFs). The report, titled 'AMAP Assessment 2015: Black Carbon and Ozone as Arctic Cimate Forcers,' presents the scientific basis and background data for statements and recommendations made in two related AMAP publications: 'Summary for Policy-makers: Arctic Climate Issues 2015' and 'Climate Issues 2015: Overview Report.' Its conclusions and recommendations focus on scientific issues rather than policy-relevant actions concerned with SLCFs. The first part of the report presents background information on black carbon and tropospheric ozone, including properties and measurement methods and co-emitted species. The subsequent chapters cover: forcing mechanisms for black carbon, ozone and co-emitted species; emissions of black carbon and ozone precursors as a function of the energy sector and geographical region; and transport of black carbon in the Arctic. The analytical part of the report presents: modelling methods used; model-measurement comparisons based on long-term data and recent air-based observations; updated trend analyses for black carbon and tropospheric ozone; and results of radiative forcing and climate-response models.