There is a funny little website for those with too much time on their hands (and me), called Flight Diary. It keeps a list of all flights one has done and offers statistics like total flight distance and emissions. link
Over the course of the last two years I have
– boarded 18 flights (4 domestic, 14 international)
– flown 77,789 km
– spent 106 hours (more than four days) on board an airplane
– polluted the atmosphere with 9.5t of CO2
Guess I have to buy that patch of rainforest one day, only way to eradicate that carbon footprint.