Is flying better than taking a cruise?

I was pondering this because I just used Yahoo's carbon footprint calculator within their green site. They break down your CO2 emissions by home, car and air. Since I don't drive I was basking my ZERO car emissions glory when I read that I will produce 10.9 tons of CO2 in the air this year. Wow! I went back and made up some car numbers for my self, and I was able to produce 13.6 on the road. That made me feel a bit better, but not really.

I have also taken cruise ships before, are they better? How is one to get from the US to Europe or Asia without stinking up the joint aka planet earth. With a bit of searching, I found the following online, From the Guardian UK http://www.guardian.co.uk/travel/2006/dec/20/cruises.green. It quotes lots of sources and it does look like taking an ocean liner to Europe is worse off then taking a long haul jet to England France, Germany or where ever you are going in Europe.