Anthropogenic and Natural Radiative Forcing: Positive Feedbacks

Direct radiative forcing of anthropogenic organic aerosol

[1] This study simulates the direct radiative forcing of organic aerosol using the GFDL AM2 GCM. The aerosol climatology is provided by the MOZART chemical transport model (CTM). The approach to calculating aerosol optical properties explicitly considers relative humidity–dependent hygroscopic growth by employing a functional group– based thermodynamic model, and makes use of the size distribut...

Enhanced Shortwave Cloud Radiative Forcing Due to Anthropogenic Aerosols

It has been suggested, originally by Twomey (SCEP, 1970), that anthropogenic aerosols in the troposphere can influence the microphysical properties of clouds and in turn their reflectivity (albedo), thereby exerting a radiative influence on climate. This chapter presents the theoretical basis for of this so-called indirect forcing and reviews pertinent observational evidence and climate model c...

Climate response of direct radiative forcing of anthropogenic black carbon

[1] The equilibrium climate effect of direct radiative forcing of anthropogenic black carbon (BC) is examined by 100-year simulations in the Goddard Institute for Space Studies General Circulation Model II-prime coupled to a mixed-layer ocean model. Anthropogenic BC is predicted to raise globally and annually averaged equilibrium surface air temperature by 0.20 K if BC is assumed to be external...

Contributions of natural and anthropogenic radiative forcing to mass loss of Northern Hemisphere mountain glaciers and quantifying their uncertainties

Observational evidence indicates that a number of glaciers have lost mass in the past. Given that glaciers are highly impacted by the surrounding climate, human-influenced global warming may be partly responsible for mass loss. However, previous research studies have been limited to analyzing the past several decades, and it remains unclear whether past glacier mass losses are within the range ...

Relative roles of surface temperature and climate forcing patterns in the inconstancy of radiative feedbacks