Electricity isn’t an energy source; it has to be generated, using some other energy source to do so.
Hydro, nuclear fission.
The electricity that powers the European and Japanese rail systems is mostly generated by plants that burn coal, with significant help from nuclear reactors and a rather smaller assist from hydroelectric plants.
That's a gross distortion.
IEA electricity stats for Europe 2008.
The releavant numbers are these:
coal: 934062 GWh.
nuclear: 921778 GWh.
gas: 868798 GWh.
hydro: 541784 GWh.
wind: 120067 GWh
oil: 103812 GWh.
Nuclear is not a "significant help", it is as big as coal. You could try and argue that you can't use the average grid mix; the countries that have the most electrified rail are also the ones who burn the most coal, but I find that rather unlikely(given France's interest in electrified rail it may be the reverse).
Hydro is not a "small assist", it's almost 60% the size of coal.
Of these, only the hydroelectric plants are a renewable energy source[...]
There's no such thing as renewables. The sun uses up 600 million tonnes of hydrogen every second; so called renewable energies merely mooch an infinitesimal amount of this power.
[...]the others are poised just as firmly on the downslope of depletion as the diesel oil that runs American locomotives.
Nuclear fission is sustainable on geological time scales.
Average crust(not ore, any random junk rock) contains ~3 ppm U, ~10 ppm Th. A tonne of average crust contains ~1.0 TJ of usable energy; equivalent to 28 tonnes of anthracite coal.
Coal is turning out to be much less abundant than the cozy estimates of a few decades ago made it sound[...]
Would that it were true, but it's not.
Fissionable uranium is well down its own depletion curve
We're finding high grade uranium(<$130/kg) much faster than we're using it up, with a miniscule amount of exploratory effort. There's no particular significance to the $130/kg number; in a conventional LWR that uses ~0.5% of the usable energy $130/kg yellowcake corresponds to ~$3 per barrel of oil equivalent. Uranium is log-normal distributed; go to an ore grade one tenth as rich and you find ~30 times more uranium.
Uranium depletion is silly doomer porn.
Yes it is.
Replacing tractors with horses would be a good move since horse manure is a perfect fertilizer for agricultural soil.
Replacing tractors with horses would be a bad move, since they'll be getting most of their energy from grains and alphalpha, perfectly good human food; they'll be needing food, basic care, and housing all year round and you'll need a lot more horses than than the tractors you replace.
Herbicide resistance GMO crops don't need tilling; it does not suffer the soil carbon loss which the manure is intended to remedy.
Since tractors don’t produce excrements, fertilizers have to come from somewhere else.
The fuel needed to operate agricultural implements can be made from pyrolysis and syngasification of agricultural waste, while sequestering carbon in the form of char and recycling P and K.
If you think that's too technically difficult, you can use a gasifier, fueled by some mixture of wood, briquetted wood waste or agricultural waste; it's really not very picky and it's very low tech.
Manure does not magick fixed nitrogen, potassium or phosphorus into existance; it just recycles them. As such you either use the artificial NPK or you suffer pre-green revolution yields.
Horses are no substitute for pesticides. You will be using pesticides at least occassionally or risking catastrophic crop failures.
Horses have more advantages over tractors. They reproduce themselves, while tractors don’t.
And that's an advantage? Horses carry with them an energy wasting reproductive machinery; the tractor leaves that machinery at the factory, where it can be put to good use.
Horses cost a lot of energy to manufacture; before they are usable they require years of investment in the form of food energy, one of the most expensive forms of energy and significant amounts of time and effort.
That means more oil saved
What oil?
[...]and other resources like water and metals, because if you switch to horses you don’t have to manufacture tractors.
Iron is not exactly scarce and it's recyclable with fairly low tech equipment. It takes a lot more water to make and sustain a horse than it take to make a tractor; it's not even in the same league. It takes ~10 000 gallons of water to grow a single bushel of wheat and it takes ~40 000 gallons of water to make a modern 4-seat car. A horse will eat 2-3 tonnes of food per year, of that about 1 tonne of which will be grains(~35 bushels), and you'll need many horses to replace just one tractor.
And while tractors need fossil fuels to operate, horses don’t.
They need fuel, but they don't need fossil fuels. Liquid fuels are best, but wood gas generators are doable. It's been used for this purpose as early as world war II.
Large tractors have engines of up to 500 horsepower, which makes them consume up to twice as much fuel as a large SUV.
When you turn off the ignition, the fuel consumption stops. Horses don't have any ignition to turn off, they just go into an idle mode where they burn slightly less fuel.
