Abstract View
Is Black Carbon the 2nd Largest Contributor to Climate Change?
GEORGIOS A. KELESIDIS, David Neubauer, Liang-Shih Fan, Ulrike Lohmann, Sotiris Pratsinis, ETH Zurich, Switzerland
Abstract Number: 54
Working Group: Aerosols, Clouds and Climate
Abstract
The climate models of the Intergovernmental Panel on Climate Change list CO2, CH4 and black carbon (BC) as the most potent contributors to global warming based on their radiative forcing, RF [1]. Among them, the BC contribution comes with the highest uncertainty. Examining closely these models, it becomes apparent that they might underpredict significantly the direct RF for BC, largely due to their assumed spherical BC morphology [1].
Here, the Rayleigh-Debye-Gans (RDG) theory is interfaced with discrete dipole approximation simulations to estimate the light absorption [2] and scattering [3] of BC accounting for its composition, morphology and coating by weakly or non-absorbing compounds. The RDG-derived mass absorption cross-section of bare and coated BC is coupled with ECHAM-HAM simulations [4] to estimate the regional and global direct RF from BC. Accounting for the fractal-like morphology of BC increases its direct RF, explaining satellite observations of the aerosol absorption optical depth [5] and revealing that BC is the 2nd largest contributor to global warming. So, reducing BC emissions can have an immediate impact on global warming and delay climate effects induced by CO2.
References:
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