One thing we think would greatly reduce Co2 pollution is to bring back the horse and buggy in replacement of motorized vehicles.  Motorized vehicles cause pollution to the environment.  These pollutants cause harm to our health.  They have greenhouse gasses that can greatly affect climate change.  The burning of gas and other fuels creates very harmful byproducts.  They also create Co2 which is the most common human cause of greenhouse gasses (Department of Ecology State of Washington).  Horses are selective grazers which causes them to not eat tougher grasses.  This is because they can not digest them (Extension Horse).  Horses are very important to the environment because it increases the plant diversity in an area.  (Lonker, Fenchner, El Wahed).  Horses are one of the biggest contributors to renewable energy and resources.  They produce up to 9.1 tons of manure every year.  This manure can be turned into green energy.  These farms and other energy companies around the farms can use this energy (Middleton Place Equestrian Center).  Lots of horse farmers utilized trough watering for their animals.  This helps the protection of natural water sources.  It also prevents erosion on the edges of the natural water source (Middleton Place Equestrian Center).  Vehicles are America's biggest air pollutant.  They are producing about one - third of all U.S. air pollution (National Geographic).  Highway vehicles release about 1.5 billion tons of greenhouse gasses into the atmosphere every year (U.S. Department of Energy).  As you can see the horse creates a smaller Co2 footprint than motorized vehicles (Extension Horse).

I disagree with your statement because horses create solid waste, which will lead to more machines being build to clean and pick up all of the bowel movements from these horses. Driving a car like a Prius, riding a bike or taking the bus to your location will get you to your desired location but also decrease the carbon being released into the atmosphere.
As well as feeding the horses factory made feed will increase the greenhouse gasses. ultimately everyone switching to riding horses is not an ideal choice to make to reduce Co2 pollution.

Bringing Back horses is a very interesting idea. Yes they don't burn gas to move unlike cars, But if we brought horses back there would be so much extra waste and not to mention methane farts and burps. The methane gas would go into the atmosphere and stay there trapping in heat. Only a small part of their waste could actually be used for green energy, and the rest of it would just stay where it was dropped and would release biogas(methane and carbon dioxide). Also as a person it would be nice to not step on horse poop everywhere I go. To use horses as transportation, that would take lots of energy for them to walk around all day, so they'd need more food and water which would produce more carbon to grow more crops, use more water for them to drink and to grow crops and take more land and resources which the world is running out of. One more reason we got rid of horses and buggys is because this way of transportation is also abusing the animal. Horses weren't made to pull around super heavy cars and be whipped if they need to go faster. Horses and buggys are not the solution to gas cars and just isn't sustainable for the world.