Black Carbons Effects on Climate : Can We Even Say Something about Them?

Sammanfattning: Black carbon affects the atmosphere, clouds, and the albedo of snow. These effects of black carbon are a fact but exactly what they entail is not well known. The atmosphere, the albedo in ice crystals and snow (due to warming of the snows’ surface), clouds’ life time and cloud cover are all influenced because black carbon absorbs radiation, thus altering the radiative forcing (RF).Many models and measurements have been done to evaluate the effects of black carbon but they show very different results. This literature study examines papers and articles to see what and how much we know about black carbon and its climate effects. I conclude that there have been great differences in results that are evident due to the span that black carbon is thought to change the RF in the atmosphere (results ranging from +0.4 to +1.2 Wm-2), and snow (+0.007 to +0.054 Wm-2), as well as the albedo in snow (results ranging from -0.02 to -0.17, only including the results from studies with BC concentration of 1000 ng/g for increased comparability). I as well as many others suggest that models tend to get very different results because they use different starting conditions and equations and because models handle aerosols and clouds in different ways. This is largely because of a lack of information, especially concerning aerosols and clouds.