...in which the author seeks to discredit horses, but is in for a surprise

I started out to try to prove horses will be the end of civilisation, but the figures led me somewhere else. Follow the story:

From this site we learn that no one knows how many horses there are in Australia. It's between 900,000 and 1.8 million. However, I assume this is talking about domestic ones. Another site estimates there are 300,000 feral horses. (It also says there are up to 5 million feral donkeys! Who knew that?) Let's just assume 1.5 million horses combined, to be conservative and get round figures.

How much methane does a horse produce? Easily found (more or less) : 18 kg per year.

So let me get my calculator. That's 27,000,000 kg of methane a year.

But remember, methane is much worse than CO2 for warming. It is 21 times worse in fact.

So this leads us to horses making the equivalent of 27,000 tonnes x 21 = 567,000 tonnes of CO2 each and every year.

According to this site, the average car makes 4 tonnes of CO2 a year. So the horse population is making the equivalent greenhouse gases of 142,000 cars every year.

There are two ways of looking at this. If we had no horses in Australia, we could safely run an extra 142,000 cars on the roads with no net increase in CO2 - equivalent gases. But how many cars are there already in Australia? I am surprised to see it is about 10,000,000!

Hardly seems worth doing away with all those horses after all. Damn!

In fact, if one car makes 4 tonnes of CO2 per year, and a horse makes 18 x 21 = 378 kg of CO2 equivalent per year, then every car owner could run instead 10 horses a year (4,000/378).

For the average family of 4, they could give up the car and have two and bit horses each!

No, horses are our salvation, after all. (At least if you ignore the greenhouse contribution of their decaying excrement and the cost of growing and moving tonnes of feed around the country. Also, at least a car doesn't die from an upset tummy (colic) or get a fright every time it sees an inanimate object it doesn't like the look of. This last point was made by Stephen Fry in an interview on Parkinson, if I recall correctly.)

I still think they are stupid.

VITAL UPDATE (in which the author is vindicated by new information) : No, they are evil after all! Their relatively "green" greenhouse gas bottoms might make you think it is better for the planet to own ten horses instead of one car. But it is all a plan to lure humans to death and injury. Here, from the Australian Medical Journal, no less:

The risk of injury while horse riding has been estimated as between 1 per 320 to 1 per 1000 hours of riding.^4,6 The variation in reported population-based risk of horse-related trauma of between 18.7 injuries per 100 000 to 9.5 injuries per 1000 population per year illustrates the difficulties of accurate data collection and variable inclusion of non-riding injuries.⁷ Interestingly, the overall risk of injury from horse-related activity has been determined to be greater than that of car racing or riding a motorcycle, and the rate of hospitalisation from falls from a horse equivalent to that from playing rugby.

Hehe. I know what horses are thinking. "Get on my back, stupid bipedal feed provider. See how long you last. The earth will be ours! Hahahahahahahaha!"

No, I've upgraded them from "stupid" to "evil".

Nurse?