AMAP Assessment 2015: Black Carbon and Ozone as Arctic Climate Forcers

This document presents a scientific assessment by the Arctic Monitoring and Assessment Programme of how black carbon and tropospheric ozone, together with co-emitted particulate and gas-phase species, influence Arctic climate. It compiles evidence from monitoring records, field campaigns, and published studies, and applies global and regional chemical transport and climate models to represent emissions, atmospheric transport, seasonal distributions, trends, radiative forcing, and equilibrium temperature response under multiple emission scenarios. The assessment reports substantial methodological uncertainty in measuring black carbon, highlights declining haze-season concentrations at several long-term sites, and estimates that present-day black carbon drives Arctic warming through both atmospheric absorption and deposition on snow and ice. Model experiments indicate aggressive mitigation from 2016 could reduce mid-century Arctic warming by several tenths of a degree, while cloud-related aerosol effects remain highly uncertain.