If that's the metric, sure we have gotten very good at producing more pounds of food per human hour of labor.
Two things worth noting though, pounds of food say little about the nutritional value to consumers. I don't have hood links handy so I won't make any specific claims, just worth considering if weight is the right metric.
As far as human labor hours goes, we've gotten very good at outsourcing those costs. Farm labor hours ignores all the hours put in to their off-farm inputs (machinery, pesticides and fertilizers, seed production, etc). We also leverage an astronomical amount of (mostly) diesel fuel to power all of it. The human labor hours are small, but I've seen estimates of a single barrel of oil being comparable to 25,000 hours of human labor or 12.5 years of full employment. I'd be interested to do the math now, but I expect we have seen a fraction of that 25,000x multiplier materialize in the reduction of farm hours worked over the last century (or back to the industrial revolution).
You really can’t. Human labor is productive, a barrel of oil on its own isn’t going to accomplish crap.
You likely get less useful work out of a gallon of gas in your car than it took to extract, refine, transport, and distribute that gallon of gas. Just as an example gas pumps use electricity that isn’t coming from oil.
Sure, of course there are a lot of losses along the way going from crude in the ground to gas in your car's tank.
This whole thread was about productivity in terms of hours spent by the last person in the chain, the farmer. They can do drastically more today in terms of food production because they can leverage the potential energy in oil to replace human labor, and in that metric all of the externalized costs are ignored.
> because they can leverage the potential energy in oil to replace human labor
Nope, what’s being replaced is animal feed used for animal labor. People didn’t pull a plow by hand and then suddenly swap to tractors.
For thousands of years farmers used sunlight > animal feed > domesticated animals, there’s nothing special about oil here.
Track the in oil energy for a tractor vs the sunlight to grow plants to feed a pair of horses and the tractor is using wildly less energy per year to get vastly more done. You can even make it more obvious by using solar panels in the same fields feeding horses 100 years ago to charge an electric tractor. Oil is cheap, but not necessary there was even wood and coal burning tractors in the early days.
PS: Horses can apparently digest the cellulose in sawdust from several types of trees. It’s unhealthy in large quantities but kind of an interesting fact.
> The human labor hours are small, but I've seen estimates of a single barrel of oil being comparable to 25,000 hours of human labor
That’s just wildly wrong by several orders of magnitude, to the point I question your judgment to even consider it a valid possibility.
Not only would the price be inherently much higher but if everyone including infants working 50 hours per week we’d still would produce less than 1/30th the current world’s output of oil and going back we’ve been extracting oil at industrial scale for over 100 years.
To get even close to those numbers you’d need to assume 100% of human labor going back into prehistory was devoted purely to oil extraction.
What are you claiming is widely wrong exactly? The estimate of comparison between the amount of energy in a barrel of oil and the average amount of energy a human can produce in an hour?
Burning food can produce more useful work in a heat engine than you get from humans doing labor so I’m baffled by what about this comparison seems to make sense to you.
Ignoring that you’re still off by more than an order of magnitude. 100% of the energy content of oil can’t even be turned directly into work without losses. You get about 10% of its nominal energy content as useful work, less if you’re including energy costs of production, refining, and transport.
Even if look at an oil well fire it’s incomplete combustion and not useful work.
You're raising that humans eating food is lossy but then attempt to use the opposite to argue against me when it comes to efficiency in using energy from oil. That's pretty confusing and I'm not sure how it helps, I also am not sure why you are comparing burning food - we eat for much more than just the energy alone and the calorie (a measure of burning food) is a ridiculously stupid metric that assumes we run roughly like a steam engine.
Nope, I’m saying you need to pick a consistent method.
A) If you want move a plow, you can grow some oats/grass/whatever to feed some horses then use those horses, or using the same land for oats/wood/whatever and burn in an early tractor, or use oil. Nobody in 1900 was getting 20 people to pull a plow. All of those methods are turning some amount of chemical energy to produce useful work. As such looking into the chemical energy in food vs oil makes some sense though sunlight vs oil is a better comparison as tractors are burning a far more expensive product not crude oil.
B) Alternatively, you can look at the amount of useful work from a barrel of oil after all losses and compare that to the work done by a horse or person after all losses. But again suddenly oil doesn’t look so hot.
What you tried to do is compare the energy content of oil with some amount of useful work which is a silly comparison.
You were comparing amount of energy between human labor and a barrel of oil? That's such a baffling metric that neither they nor I realized that's what you meant. It's not like you can replace a human with a solar panel, but if you could that would be astoundingly impressive and not diminished toward "horribly unproductive" by the fact that the solar panel is delivering more watts to do the same thing.
The earlier comment or was talking about the massive reduction in the amount of human labor required to cultivate land and the relative productivity of the land.
That comparison comes down to amount of work done. Whether that work is done by a human swinging a scythe or a human driving a diesel powered tractor is irrelevant, the work is measured in joules at the end of the day. We have drastically fewer human hours put into farm labor because we found a massive multiplier effect in fossil fuel energy.
I'm not sure where solar panels came in, but sure they can also be used to store watts and produce joules of work if that's your preferred source of energy.
The confusion lies in why we would measure the efficiency of human labor in joules per unit of work instead of hours of human effort per unit of work.
In particular, if we can make a machine that spends more joules than a human, but reduces the human effort by orders of magnitude, why would that be "horribly unproductive"? Most people would call that amazingly productive. And when they want to broaden the view to consider the inputs too, they're worried about the labor that goes into the inputs, not the joules.
(And if the worry is the limited amount of fossil fuels in particular, we can do the same with renewable energy.)
Joules are just a measure of work, and this all started by an attempt to say how productive we are because we need fewer farmers today. My argument is that we only need fewer farmers because we found a cheap source of energy and have been using that to replace farmers.
When looking at joules its an attempt to compare something like a human cutting a field with a scythe and a tractor cutting it with an implement. The tractor is way more efficient at cutting it when considering only the human hours of labor cutting the field. But of course it is, a single barrel of oil has way more energy potential and even a small tractor will be run with fuel milage tracked by gallons per hour.
Farmers were already using the cheapest source of energy, sunlight. Oil came late to the party here after plant matter and coal because it was slightly more convenient not because it has more energy.
Back in the day, wood powered tractors beat the fuck out of horses, and horses beat the fuck out of human labor because they could digest cellulose. Oil is just very slightly cheaper. Even today people heat their homes with both wood pellets and oil, meanwhile there’s cheaper alternatives.
Two things worth noting though, pounds of food say little about the nutritional value to consumers. I don't have hood links handy so I won't make any specific claims, just worth considering if weight is the right metric.
As far as human labor hours goes, we've gotten very good at outsourcing those costs. Farm labor hours ignores all the hours put in to their off-farm inputs (machinery, pesticides and fertilizers, seed production, etc). We also leverage an astronomical amount of (mostly) diesel fuel to power all of it. The human labor hours are small, but I've seen estimates of a single barrel of oil being comparable to 25,000 hours of human labor or 12.5 years of full employment. I'd be interested to do the math now, but I expect we have seen a fraction of that 25,000x multiplier materialize in the reduction of farm hours worked over the last century (or back to the industrial revolution).