If I fly less will I really help the enviroment?

I just recently took an online "green" test to see how much CO2 I contribute to the atmosphere. Well the results werent that great, I more than double the average American, which is kind of dissapointing becuase I think I try. In any case, my home and car doesnt emit much, and there are things I can do to be better, but what really killed my score is the fact that I seem to be flying way to much. I take 1 overseas trip, and 6-8 domestic flights a year either for business, vacations, or to visit family. It seemed that I was contributing much more CO2 to the enviroment due to the flights. The flights will go on without me, so how would me not flying help the enviroment? Should I seriously reconsider trying not to fly to save the enviroment? Thanks for the input.