There was something on TV last night (UK, after 11.00pm) that suggested you take your flights as you want, but you get someone else to reduce their carbon emissions as payback. You fly to say... Jamaica, you have to change 30 lightbulbs to energy saving, convert 1 driver to using LPG/unleaded or bicycle and plant a tree.

Nice idea in theory, but how many people would be honest or pushy enough to enforce it?

LTS