If, like me, you watched Sir David Attenborough doing his bit for the environment you now probably feel exceptionally guilty. You can somewhat salve your conscience by carbon balancing your life. I just recently invested in energy saving projects to offset the carbon generated by a flight I made and have had trees planted in Devon and Scotland to offset my travel and housing energy use.
http://www.carbonneutral.com/shop/index.asp
I feel very vituous now. Obviously not as good as not making CO2 in the first place but hopefully a step in the right direction.