Anthropogenic climate warming is particularly enhanced in the Arctic. The climate forcing agents are CO2, tropospheric ozone, methane, halocarbons and carbonaceous aerosols. A key component is airborne black carbon (BC), which is a highly condensed carbonaceous aerosol released from incomplete combustion of organic matter. Arctic acts as a repository of BC after long-range transport from other emission source areas. Arctic climate is more vulnerable to BC than other regions because of its impact on the albedo of snow, glaciers and sea-ice; accelerating melting and increasing sensitivity to warming. Knowledge about BC sources is a prerequisite for an effective mitigation of the Arctic climate warming but unfortunately the relative contribution of different combustion sources of BC transported to the Arctic is still poorly understood.This project is intended to assist society in targeting efficient mitigation of Arctic climate warming through a reduction of BC emissions. Knowledge about BC sources is a prerequisite for an effective mitigation. In the present research project the sources of Arctic BC will be apportioned with the dual-isotope (13C+14C) approach applied to one key location in western Arctic (Zeppelin mountain, Svalbard) and one in the little studied yet vast Eastern Arctic (Tiksi, Yakutia). Natural abundance radiocarbon analysis allows quantitative apportionment between fossil fuel vs biogenic and biomass combustion sources and stable carbon isotope is informative of the relative importance of wood and grass e.g. crop residues. A reduction in emissions of BC would lead to a slowdown or at least delay in the global warming and in particular a delaying of the rapid melting in the Arctic.