Light-absorbing carbon aerosols (LACs) such as black or brown carbon are important climate warming agents in the earth system. LAC impacts manifest in the Earth’s atmosphere, on land, and in hydrologic systems. For example, either airborne or snow-deposited LAC absorbs solar energy and alters the Earth’s radiative budget. However, the LAC radiative effect in climate models varies by more than a factor of two. Uncertainties arise in large part from the physical and chemical transformations of LAC in the atmosphere during its lifecycle affecting the corresponding treatment in models. Making scientific progress on LAC is critical for winning the battle against the global warming. This session invites submissions on: characterization of LAC emissions, transformations, and sinks; measurements on LAC chemical, microphysical, and optical properties; numerical simulations of LAC and its properties at various scales; assessment of LAC radiative forcing and climate impacts.