Earlier quoted context omitted.
> it takes more energy and more carbon emissions to walk a mile than it takes to drive a vehicle a mile Do you have a source for this? Sounds questionable.
It's false. People will not go into suspend mode when not walking; they still burn calories. A very large person would burn about 130 calories walking a mile. i.e. one large latte. And most people who are this large are not at risk of a caloric deficit by burning an extra 130 calories.
100 miles? That seems very likely. That happens far quicker for the energy leaking heat machine sitting in the seat.
So, while maybe the theme of the statement is correct?