Actually, you are be sorely wrong. Aviation is ~2% of human CO2 emission, and 12% of transport CO2 emission, versus 74% from roads. Judging from the streets and highways, most of that 74% is coming from household vehicles, and most of the rest is pretty much driven by household consumption.
The numbers seem to be very unreliable, though. Over here (Finland), reputable sources (such as WWF and State Statistics Center) give drastically different numbers for aviation emissions.
A reason could be that in some statistics, only domestic flights are included, and international aviation belongs to no one's statistics.
