Not sustainable due to the fossil-fuel laden garbage we feed to bovine stock.
Not sustainable because it causes major health issues which stress the healthcare system and limits quality of life - especially the affordable stuff that people tend to think is “normal value”
As I said, all the fossil fuel inputs could be replaced with renewables. In particular: farm machinery can be run on non-fossil energy, nitrogen fertilizer can be made with green hydrogen, and pesticides can be synthesized with feedstocks derived from non-fossil sources like biomass.
The second sentence doesn't make any sense. None of that makes something unsustainable, just regrettable.
It's possible, but we're not doing it because we believe it makes more economic sense to ignore those issues.
When economic sense no longer makes sense sense then we're going to be having issues. And going back to my primary point, everything should really be serving the primary sector, not the other way around really.
The base issue is that fossil fuels are not being charged the cost of their externalities. All the problems stem from this. Do that, and all these subsidiary problems melt away.
Huh? Nitrogen fertilizer is mostly derived from fossil fuels and has been since the 1900s food boom. Aren't phosphates mainly shipped from islands that build up huge stocks of bird poop? The inputs are all fossil fuel intensive.
Nitrogen fertilizer is synthesized from hydrogen and nitrogen. The hydrogen is currently derived from fossil fuels, but there is no requirement that it be so.
Saying "ammonia is produced from fossil fuels, and so must always be" is like saying "cars run on fossil fuels, and so always must". A non sequitur.
Phosphates are derived from large phosphate deposits in various places, such as Florida. Phosphorus will ultimately have to be mined from lower concentration deposits, perhaps ultimately from average crustal rocks, where it appears at about 0.1% concentration. However, build up of mostly insoluble phosphates in soils will I think likely reduce the need for this fertilizer if erosion is kept in check.
This can't be replaced at a volume that can feed the world nor in a way the world can afford. Lots of things can be done in alternative ways if you remove half the requirements (in this case volume and affordability).
It can be replaced at volume that can feed the world. After all, the total energy involved is small compared to what would have to be produced to power the entirety of industrial civilization. Agriculture uses < 2% of total US energy consumption.
Not sustainable because it causes major health issues which stress the healthcare system and limits quality of life - especially the affordable stuff that people tend to think is “normal value”