babylonbee.com/news/california-to-replace-cars-with-new-greener-horse-drawn-carriages[/QUOTE]
Interestingly, horse transportation ends up emitting about the same amount of CO2 per mile as a car, it's just that the CO2 it emits is part of a carbon cycle whereas petrol is not really, and least not in reasonable timeframes.
... and we tend to feed horses with crop food rather than strictly wild growing grasses. That means farming and that means petrol consumption and clearing of land for crop use.