Which problem is bigger, global warming as caused by CO2 or global dimming caused by air pollutants?

Actually, I have heard some scientists saying that one of the reasons that the climate is not warming as fast as it should is because of the effects of air pollution in Asia which is causing localized cooling in some areas. That is another problem with the man made global warming crowd is that there are way too many variables affecting World wide climate to put all of the blame on man.