Other smaller 'warming' factors are increases in tropospheric ozone, soot aerosols from fossil fuel burning, and solar variations. The largest factor decreasing the amount of radiation may be the indirect effect of aerosols, but this is very uncertain. Other smaller factors are stratospheric ozone depletion, and increases in sulfate aerosols and aerosols from biomass burning. In particular because of the large uncertainty in the indirect aerosol effect, we do not have a good sense of the overall change in radiative forcing since pre-industrial times. But the overall picture that scientists have tentatively arrived at is one of climate change that is driven by the warming effect of greenhouse gases, modulated by the other smaller warming or cooling effects.
Climate models can help unravel some of the complexities of atmospheric interactions.
A climate model is a set of equations that simulates the atmosphere, ocean, sea-ice and land surface. In most models each grid square is at least 300 kilometres across, and processes that occur at a scale smaller than the grid may be important. More accurate representation of these 'sub-grid' processes is an ongoing aim of climate model development. The strength of models is that they enable us to integrate our understanding of many complex processes into a whole that is more powerful than the individual parts. They simulate the present climate surprisingly well.