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Aerosols, the important constituents of our atmosphere, indicate a colloidal system of particulate, gaseous and volatile organic compounds. Aerosols play a significant role in affecting adversely the radiative balance of the Earth as well as the air temperature. Moreover, these not only influence the visibility and overall air quality, but also adversely affect health of living organisms in an ecosystem. In this context, the present attempt at Mohal (1,154 m, 77.12 degrees E, 31.91 degrees N) in the Kullu valley of Himachal Pradesh in the northwestern Himalayan region explains the ever increasing columnar aerosols, their relationship with black carbon (BC) aerosols, impact of local meteorological conditions, long range transport sources and their collective impact on radiative forcing and resultant temperature rise. The aerosol optical depth (AOD) having been under observation for the last half a decade (2006-2010) shows higher values at shorter wavelengths and lower at longer wavelengths. At a representative wavelength of 500 nm, AOD is found to be increasing at the rate of 1.9 % per annum from 2006 to 2010. Overall, AOD values in all the wavelengths (380-1,025 nm) were found between 0.238-0.242, reflecting an increasing trend at the rate of 0.84 % per annum. The monthly mean concentration of BC aerosols is noticed maximum with 6,617 ng m(-3) in January, 2010. The pollution loads in terms of AOD values translate into a temperature rise by similar to 0.54 K day(-1). The local as well as transported aerosols together contribute to the existing aerosols in the present study region. The local sources possibly belong to anthropogenic aerosols including vehicular emissions, biomass burning (like fuel wood for cooking), forest fires, open waste burning, etc. While the transported aerosols most probably include fine mineral dust from the desert regions and the sulphate aerosol from the oceanic regions with the movement of air masses prior to the western disturbances and monsoonal winds in the region.