I don't think you could ever make a sensible comparison. My point was just that the TdF can't be seen as an eco-friendly event in any way at all. It's not like it can offset its emissions against the fact that it promotes active transport, cos it doesn't. It's just a bunch of weird specimens of humanity zooming around impossibly fast, and being extremely entertaining.
If you did want to attempt a comparison ... You'd need to take into account emissions from people driving to the event too, and as F1 has far fewer actual spectators, cos it's in a closed stadium/track thing, TdF would score heavily on that. And all those helicopters (there are loads of them) could probably give an F1 car a run for its money in fuel burning. TBH I know absolutely zip about F1 though. TdF is once a year though, and there are loads of GPs. Maybe include all the GTs - or all top road races ... Gets messy.