Comment by time_to_smile | Hacker News Reader

Comment by time_to_smile | Hacker News Reader

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> the enormous increase in agricultural output in the US has been sustained without any significant increase in these two inputs. Land use has stayed roughly flat, while labor has fallen dramatically. That suggests it’s technology that instead accounts for the big upswing in production.

It's mind blowing to me that I could find no reference to the Haber process[0] in the article at all.

The missing input here is fossil fuels.

Certainly mechanical automation has played a factor, but the number 1 contributor to increased crop yields worldwide is the use of nitrogen based fertilizer. We have completely disrupted the natural nitrogen cycle and are completely dependent on nitrogen fixation for modern day agriculture. The Haber process is an essential part of nitrogen fixation and is also completely dependent on natural gas as a feedstock for the process.

We have had amazing growth in agricultural output in the last century not because of our inventive minds but because of our ready access to hydrocarbons.

In a world increasingly at risk because of this dependence on hydrocarbons it's borderline irresponsible to use agricultural production as a proxy for "technology" and not even mention the relationship to fossil fuels.

[0].https://en.wikipedia.org/wiki/Haber_process

I was reading the 3rd edition of Limits to Growth (2003) and was very interested to see this article and its take on corn yields as one of their collapse scenarios relied on arithmetic growth in ag yield versus exponential increase in requirements. They did note in the book that some organic farming techniques were able to increase yield substantially without need for as much fertilizer, which itself masks soil salinization. A closer reading of their charts seemed to indicate that there is enough land and yield available for the 21st century so long as the land is not destroyed by pollutants or climatic events.

They didn't go into depth about these topics and I don't know much about farming. Do you think there are non-fertilizer based techniques that would be sufficiently beneficial?

The current system (as noted above) is dependent upon fossil fuel inputs, and it may be a driver of a future decline as you note. Unfortunately we've boxed ourselves in -- we don't have the industrial capacity / biology for something as basic as cover cropping to meet estimated demand should everyone want/need to be sustainable/regenerative:

https://www.nature.com/articles/s42003-020-1022-1?proof=t

Thank you for that info. I didn't know what a cover crop even was.

For anyone else that doesn't know this video helped me: https://www.youtube.com/watch?v=-XTeKmccl7w

EDIT: ...and so did scrolling down below the abstract in the linked article. ^_^;

I feel like this is a little disingenuous.

It is currently most economical to source the hydrogen for the Haber process from natural gas, but there are many alternative ways to produce hydrogen. I wouldn't call that true "dependence".

"most economical" is not just some minor feature. If you were to switch to another means of producing hydrogen the price of the process would rise dramatically. The only non-fossil fuel hydrogen generation process is water electrolysis (well and biomass, but guess what's involved in efficiently producing large quantities of biomass).

If you currently eliminated fossil fuels from the process the price required to maintain our current food levels would escalate dramatically. In practice this would mean likely that both food production will drop and food prices would rise.

I don't think it's disingenuous. Maybe I should add "affordable" as a prefix to nitrogen fixation, but "less economic" fertilizer means "less economic" food which is a fairly big problem.

According to the IEA (International Energy Agency) [1] the current (well, as of 2018) production cost of hydrogen using methane as a feedstock is $ 0.9-3.2 /kg, while using renewables is 3.0-7.5 USD/kg. However, as the cost of renewables goes down, there will be plenty of places in the world where the cost of producing H2 (including transportation to the place of use) will be below $2/kg, so quite competitive with methane (not to mention that the price of methane is about twice now what it was in 2018).

[1]https://www.iea.org/data-and-statistics/charts/hydrogen-prod...

[2] https://www.iea.org/reports/the-future-of-hydrogen

Given the rapid drop in green hydrogen costs, this argument is itself becoming outdated. We will just switch green sources of ammonia and there will be minimal if not nonexistent increases in cost.

From the other reply's (very green optimistic) source [0]:

> While less than 0.1% of global dedicated hydrogen production today comes from water electrolysis, with declining costs for renewable electricity, in particular from solar PV and wind, there is growing interest in electrolytic hydrogen.

When do you think we'll see >50% of hydrogen produced with green energy via electrolysis?

I'm betting: "not within our lifetime", but enjoy taking long views on these things and being wrong. Just curious when you think that's realistically feasible, and when we'll reach 10% (again, I'll still vote "not within our lifetime")?

I'd be delighted to be wrong on this, but still haven't convinced myself. I would be genuinely interested to see your targets on this and then we can interpolate and come up with some milestone we can agree will be seen in our lifetime if you're correct.

0. https://www.iea.org/reports/the-future-of-hydrogen

It will happen by around 2030. It might reach 100% shortly afterwards. Also, hydrogen production should increase by well over an order of magnitude in 25-30 years.

We've banned this account for using HN to post only about one thing and ignoring our request to stop. Sorry, but you can't do that here.

https://news.ycombinator.com/item?id=29301556

A lot of the progress is due to fossil fuels/fertilizer to be sure, but given unlimited access to fossil fuels in 1900, a single person would still do a tiny fraction of the work a modern farmer can do thanks to modern equipment. I think it is a massive understatement to say that the output of the last century isn't due to inventive minds, ignoring the fact that the Haber process was invented itself.

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