I was just looking @ the impact of our upcoming trip to Albuquerque… not only will we save on the cost of the plane tickets, but flying is more than twice as harmful in terms of greenhouse gases.  For two people to fly from Seattle to Albuquerque there is an output of about 2,700 lbs of CO2.  If we only get 30mpg in my Civic, our CO2 output will be about 1,300 lbs.  Given that we got 38mpg on a recent trip to Leavenworth for a friend’s wedding, and 36mpg for another trip to Portland for another wedding, I am expecting over 35mpg average in freeway miles on this 3,600 mile roundtrip to Albuquerque.  I’ve got a new trip computer that calculates the fuel consumption and cost (you tell it how much each fillup costs), so I’ll post full results when we get back, but I fully expect to output less than 1 ton of C02 (less than half a ton for each of us) for this trip.  That should only cost about $10 to offset, so we’re not only reducing our impact, but reducing our costs as well!