[oddtiger (OP)]

Is the circle of life (more specifically the process by which bacteria breaks down our bodies when we die) still relevant in modern day society or has it essentially been replaced by organic fertilizers(i.e poo)? If it still is relevant (i.e nutrients spread from graveyards to farms somehow) then is there a mathematical upper limit at which point the nutrients gained through the circle of life are not needed for farming? For example if we bury 10 million people this year (random number) vs 11 million, are those extra million people needed to sustain-ably keep using soil for crops?I know it’s a weird question but when you look at farming you start to question if the circle of life has been replaced by science in some way.

Also, there's cremation to consider which according to another forum releases C02 and H20 which is then used by plants eventually(edit), so my question there would be what is lost through cremation of say animals? If I ate an animal vs the plant life that would grow through cremating it would it be the same gain food wise or is common sense right that's it's more efficient and more food for humanity to eat the animal rather than relying on some potentially imperfect process like the emission of H20 and C02?

[alancalverd]

Dead humans don't contribute a lot of nutrient compared with live ones and all the other animals on the  planet. An average corpse consists of about 50 kg water, 20 kg fat and protein (mostly carbon, hydrogen and oxygen) and about 4 kg of useful minerals essential for plant growth.

However, you eat, and thus excrete, around a kilogram of food every day - around 30 tons in a lifetime. Again, most of this is water but feces and urine are representative of the general body composition so sewage treatment plants are used to break down the fats and carbohydrates and capture the minerals as commercial organic fertiliser. "Thamesgro" is one of the major brands in the UK, contributing to the cycle of life along with farmyard slurry (mostly pig and chicken excrement) and field poo from cows and sheep.

Burial in a coffin, or cremation, may be socially tidy but eventually the coffin soup leaks out and the CO2 from the crematorium will get absorbed by plant life somewhere. Woodland burial is far more efficient: you wrap the corpse in rapidly biodegradable materials (the principal purpose of any coffin is to stop dogs and foxes distributing human bones and diseased flesh around the parish) and plant a tree on top of the grave. 100 years later, your descendants can use it to build a house.

Science hasn't replaced the circle of life but civil engineering has enhanced it by ensuring that treated sewage is reasonably free from pathogens, and the Haber-Bosch process for turning atmospheric nitrogen into ammonia-based fertiliser actually accounts for around 30% of your body mass. That is a worrying statistic: when the oil runs out (or the European Union or some other bunch of idiots bans fossil fuels entirely), we will starve.

[evan_au]

Also, there's cremation to consider which according to another forum releases C02 and H20 which is then used by plants that same day

It is true that the water cycle operates fairly quickly, with rain/snow quickly taking water out of the air (in days or weeks), and evaporation putting it back.

However, I understand that the half-life of CO₂ in the atmosphere is around 100 years, ie after 100 years about half of the carbon in your smoke will have been absorbed by plants or algae (and potentially released again when the plant dies and burns or rots).

So I think the "same day" is a bit optimistic.

[oddtiger (OP)]

Edited, thanks.

[oddtiger (OP)]

I’m just a physics student but I tried to compare all the facts for food production vs the circle of life and I’m sure the following interpretation of all the facts is riddled with a fair amount of holes but based on what I’ve been told and my own research I’ve tried to compare the options in optimal conditions, assuming there are no concerns like epidemic for the specific animal and ignoring the disturbing nature of some of these methods just for the sake of logical comparison.

Option a) I or someone eats the animal obtaining some organic molecules/some energy and the organic transfer isn’t perfect but unless there’s some big difference in efficiency (between eating a plant and animal) enough to tilt the scales between the options then I wouldn’t see that as relevant?

Option b) If I could bury it on a farm (theoretically for argument’s sake) it would enrich the soil and contribute to all the natural cycles like the carbon and nitrogen cycle probably but I could instead achieve the same soil enrichment part using fertilizer “mined” from sources like poo or apparently air and water so option a) plus just using fertilizer instead should result in more gain food wise?(i.e 100% for burial vs. 120%  from eating and using air/water/poo for the soil enrichment)

Option b2) I bury it elsewhere and the same waste of soil enrichment is achieved?

Option c) I cremate the already dead animal releasing C02 and H20 which I could theoretically capture using some type of sealed box I guess? And proceed to use that somehow for farming (which may sound messed up but again I’m just considering all the options), but while burning the animal, energy is converted to heat so that would also have to theoretically also be used for farming (which seems legit from one google search =p). So nothing seems to be wasted in an ideal scenario?

Option c2) I cremate it elsewhere and the C02 and H20 is used for various other purposes than farming so I would say this is below 100% transfer?

Option d) Leave the carcass where it fell and eat the flies.-“ dimreepr”

It’s considered the greener option and is probably essentially equivalent to eating the animal.

Option e) ”Composting is the preferred method of carcass disposition in animal agriculture for animals that either die or must be euthanized.   It accelerates the decomposition and provides for soil enrichment. “-“Farming guy” – And according to my research it sounds useful ie for replacing chemical fertilizers.

So my conclusion from the above is that c), a), e) and d) are fair options for agriculture/farming but depending on the region animals could be thought of as a separate area of food production since farming needs are already met, that and the infrastructure needed for option c) make option a) or d) seem like the best option or e) where necessary.

Just from the little research I did it does ring true that nothing is wasted in the sense that nothing is lost but where it goes, comes from and how useful it is can be arguably important if one wants to compare the methods in relation to food production.

“The circle of life is about more than just food.”
Right I realize this but I’m not suggesting upending the circle of life just trying to see what the benefits of each way are in terms of food just because that’s the purpose that I’m interested in, humans will still ultimately end up contributing themselves in one way or another which leads me to maybe a key question, is there a benefit to a human being and an animal dying separately and contributing to the circle of life vs. a human being eating the animal and then eventually dying by themselves?