Where does the horse get its carbon? From the grass.
Where does the grass get it's carbon? From the air.
Where does the air get it's carbon? From the horse.
Conversely, where does the SUV get its carbon? From oil that's been sequestered for millions of years and is subsequently being re-introduced into a balanced, cyclical system.
Well now, that's a nice argument you got there. But it's too bad the braindead liberals don't care about logic and facts. They will take away your horse if it suits them too.