Well, the CO2 plan is right out. Sure, you don't dump a load of carbon into the air, but burning ethanol produces aldehydes (quite a lot of them) and breathing aldehydes is like really, tremendously bad for you. Inhaling much less than one part per million of formaldehyde is going to make you want to lie down.
Boru
Boru
‘But it does me no injury for my neighbour to say there are twenty gods or no gods. It neither picks my pocket nor breaks my leg.’ - Thomas Jefferson