Description

Black carbon is the second largest contributor to global warming after carbon dioxide. When BC is deposited on snow and ice, it darkens an otherwise bright surface. The darker surface may enhance the absorption of solar radiation resulting in an acceleration of snow and ice melting. In addition, BC particles suspended in the atmosphere absorb solar radiation and heat the surrounding air. Atmospheric BC can also alter cloud properties leading to changes in cloud amount and precipitation. Black carbon has multiple sources including domestic combustion for heating and cooking, diesel combustion related to transportation, fossil fuel and biofuel combustion for power generation, agricultural burning, and wildfires. Identification of the sources of black carbon (both the geographical region of the source and the combustion process) is necessary for effectively mitigating its climate impacts. In addition, measurements of black carbon are required to verify whether implemented mitigation strategies that target BC emissions from certain sources are actually leading to reductions in BC concentrations in the Arctic atmosphere. The Arctic Monitoring and Assessment Programme (AMAP) established an expert group that produced a report "The Impact of Black Carbon on the Arctic Climate" in 2011. The report reviewed the current state of science knowledge about BC properties, measurement, modeling, emissions, distributions, trends, and forcing mechanisms. The report concluded with recommendations for improved characterization of Arctic BC, emissions information and model development to address current science and information needs. The AMAP Expert Group is currently working on a report linking radiative forcing by BC in the Arctic to climate responses. The report will be released in 2015.