Sediment records reveal elevated black carbon emissions potentially amplifying Arctic snowmelt

Abstract

Black carbon, an important component of atmospheric aerosols, has an impact on climate change. When deposited on snow and ice, it reduces surface albedo, accelerating melting and amplifying global warming. Here, we analyzed lake sediment records from China and found that existing bottom-up inventories underestimate black carbon emissions prior to the mid-twentieth century. We incorporated a black carbon emission enhancement scheme based on reconstructed historical biomass burning emissions into a numerical climate model to assess this underestimation. The simulations indicated that increased historical emissions enhanced spring and summer radiative effects north of 60°N, leading to regional surface warming and accelerated Arctic snowmelt. Although the response varies with the strength of emission enhancement, the findings suggested that historical BC emission biases could alter the simulated Arctic energy balance and climate evolution. These results highlight the need for improved constraints on historical BC emissions to better assess their climate impacts.