In reply to Skol:
> Mmmm. As opposed to what? She would be adding to local economies by purchasing food etc.
Will she be buying locally-sourced food from local independent shops?
> If we are talking about vehicle emitions etc , then I reason that getting her to play for 24 hrs on an Xbox would be more damaging to the environment than me driving her to Scotland and back?
I very much doubt it
> I'm proud of her for wanting to do it!
As you should be. But maybe make US proud by explaining to her why it's not such a great thing.
Look at the Yorkshire Three Peaks, a more acceptable challenge. Or as others have said, get out from under that bridge