Well, if we'd have gone down that road, plus strong environmental awareness, maybe the Earth wouldn't be warming up so badly right now, and the oceans wouldn't have islands of plastic (= oil) waste. Now, sure, we wouldn't have enjoyed some of the benefits of car technology, but - public transport (esp. trains) makes up for a lot of that. OTOH, public transport pollutes too.
Had we gone down this road, we'd have a thick layer of manure covering everything. Living creatures are a source of CO2 too, and a big one. Look up for a share of greenhouse gases coming form agriculture. Had we used faster horses, that volume of emissions would be effectively doubled or tripled.
>Living creatures are a source of CO2 too, and a big one. Look up for a share of greenhouse gases coming form agriculture.
CO2 emitted by horses comes from the food they eat, which is absorbed from the atmosphere in the first place by the plant when it grows.
And a ton of the greenhouse gases from agriculture come from using oil, a major component of that being from tractors and crop dusters (which wouldn't exist in a horse-only world).
