[kyleperik]

I have seen little consideration made to the carbon cycle which produced this result of methane output in landfills.

It doesn't come from nothing. Methane is a compound generally produced by the breaking down of organic compounds in the absence of oxygen (anaerobic decomposition)

Organic compounds generally gain carbon from the atmosphere. So where is the extra carbon entering the system?

Should the focus not be on disposal methods but on ensuring sustainable regeneration of farmland in this case?

[angusb]

Plastics in landfill also break down to make methane. The carbon source in this case is fossil fuel.

Also, if the food gains the carbon as CO2 but releases it on decomposition as CH4, that’s a big increase in GHG potential, we want to avoid that.

Moreover it shouldn’t matter the original carbon source - if we have the opportunity to capture some methane from concentrated point source like a landfill we should be jumping at it. One of the easiest marginal tons of CO2e saved

[sp332]

https://climate.mit.edu/ask-mit/why-do-we-compare-methane-ca... "Over 20 years, the methane would trap about 80 times as much heat as the CO2. Over 100 years, that original ton of methane would trap about 28 times as much heat as the ton of CO2."

Regularly converting a bunch of atmospheric CO2 to methane is not good.

[Retric]

You are double counting in multiple different ways.

Over 100 years it’s 80x for years 0-19 years and 15x for years 20-99 which averages to 28x by weight. Largely because 1 ton of methane turns into almost 3 tons of CO2.

Except when you start with CO2 at 44.01 g/mol it turns into CH4 at 16.04 g/mol you only get 16.04/44.01 ~= 36.4% as much methane and thus 36.4% of that global warming.

Net result for years 0-19 it’s 29x as bad and years 20-99 it’s 5.5x as bad. And considering the relatively trivial amount of CO2 released as methane vs sequestered in landfills they are a massive reduction in climate change.

[gruez]

>Should the focus not be on disposal methods but on ensuring sustainable regeneration of farmland in this case?

Isn't "sustainable regeneration of farmland" (whatever that means) orthogonal to methane being generated from landfills? After all, food waste in landfills generate the same amount of carbon regardless of how they're farmed. It's not like a rotting tomato that's grown using "sustainable regeneration of farmland" magically emits less methane than one that's grown conventionally.

[Kim_Bruning]

Sometimes I don't know if people are kidding or something.

Obviously things ending up in landfills is not sustainable.

It's rather wiser to use the remains of the tomato to directly or indirectly make fertilizer to fertilize new tomato plants, eg by composting them [1]. Now you've sort of got a cycle going on there, which you could in theory sustain indefinitely. (Hence the word.) Composting has been done since at least roman times.

Properly done, you can reduce methane emissions from composting considerably. (Releasing mostly CO2 back into the air, and the remainder is sufficiently low for 'the environment' to be able to deal with [2])

If you at least believe in the conservation of mass [3], you'll realize that [C released from composting] = [C the Tomato originally captured from the air in photosynthesis].

I'm summarizing entire fields of science, so there's devils in the details here. But closed cycles of chemical reactions where matter cycles endlessly (driven by incoming energy from sunlight, and ultimately emitting waste heat back to space), is a real thing in Biological systems.

[1] https://en.wikipedia.org/wiki/Compost

[2] assuming composting were the only methane source, there'd be more than sufficient methane sinks to handle the flow. Unfortunately, it's not the only methane source. But we still need to deal with the organic waste.

[3] I mean, for one: the total mass of our planet isn't noticeably changing much, that I'm aware of.

(edits for clarity and readability)

[gruez]

> Sometimes I don't know if people are kidding or something. [...]

>It's rather wiser to use the remains of the tomato to directly or indirectly make fertilizer to fertilize new tomato plants [...]

Maybe you should read my comment and the comment I was replying to more carefully. The comment I was replying to says in pretty clear terms that we shouldn't care about "disposal methods"

> Should the focus not be on disposal methods but on ensuring sustainable regeneration of farmland in this case?

Your suggestion of using rotten tomatoes as compost or whatever arguably falls under "disposal methods".

[Kim_Bruning]

I was directly responding to the implicit question about 'sustainable regeneration of farmland', where you added '(whatever that means) '.

I explained one common sustainable regeneration method, and I touch why it meets the required elements of regeneration and sustainability.

You arbitrarily reclassify this as a "disposal method"; without including any counter-reasoning.

You berate me for not reading and not providing an alternative to mere disposal.

As a reminder: "Please respond to the strongest plausible interpretation of what someone says, not a weaker one that's easier to criticize. Assume good faith." --https://news.ycombinator.com/newsguidelines.html

[petre]

> It's rather wiser to use the remains of the tomato to directly or indirectly make fertilizer to fertilize new tomato plants, eg by composting them [1].

Ask any agricultural engineer why that is a bad idea. Tomato pathogens from the old culture end up in your new one. That's one of the ideas behind culture rotation. But one could use that compost for other unrelated cultures like apple trees or grape vine.

[Kim_Bruning]

Huh, here's where my knowledge ends. In theory aerobic composting would run up the temperature of the compost, thus killing most pathogens. In practice clearly not, then.

Is it because composting is not always done perfectly? Or is it because some tomato pathogens intrinsically survive the process due to eg. heat resistance?

[petre]

Dunno, it's just a bad idea. The pathogens can survive in the ground over several seasons, so I'm not surprised if they also survive in the compost. It's not only bacteria and viruses but also fungi. Best practice is to use pathogen free soil and compost, crop rotation. There is even a warning against composting rotten potatoes (related to tomatoes) for avoiding late blight.

https://hgic.clemson.edu/factsheet/tomato-diseases-disorders...

[maxerickson]

There's estimates for how much atmosphere is boiling off and how much stuff is coming in from space.

How noticeable they are will depend on how you've decided to define noticable.

[dscottboggs]

I feel like this indicates that at least moderately-sized composting systems should also have carbon- and methane-capture systems

[lazide]

All I can say is ‘huh?’

Growing plants pulls carbon from the atmosphere.

Rotting puts that carbon back into the atmosphere.

None of that has much to do with sustainable farming, which is about soil fertility, pest control, and micronutrients like fixated nitrogen - and not raw carbon.

Which is why nitrogen fertilizers and pesticides have been so important in producing mass yield improvements in farming.

Are there ways of doing this more naturally, using crop rotating, etc? Yes. In field Composting can help a little too, but has major disease and pest vector issues.

They’re also less efficient when you factor in transportation and land use costs. And they don’t really have any impact on macro level carbon cycle stuff.

I think you’re missing the forest for the trees? Or crossing wires?

[nradov]

A century ago, most food waste was fed to pigs and chickens. Now it rots in landfills.

[conradev]

Isn’t sustainable regeneration of farmland primarily concerned with the… nitrogen cycle?

Carbon is of course a factor in the case of stubble burning, but short of that biomass is being pulled from the atmosphere?

[TaylorAlexander]

Plants get most of their structure by pulling in carbon from the atmosphere and using it to make more plant. Regenerative organic farming generally works to keep that captured carbon in the soil, by using excess plant matter as soil amendment, to put it simply. From what I have seen this has the potential for massive carbon retention over chemical intensive industrial farming which generally does not focus on the use of organic matter as soil amendment.

[sp332]

Good soil has benefits but plants don't get carbon from their roots. They make sugar in the leaves and make that into more complex molecules for growing.

[TaylorAlexander]

The plants get carbon from the atmosphere of course, but retaining organic matter in the soil, which captures that carbon, has other value.

"Soil organic matter significantly improves the soil's capacity to store and supply essential nutrients (such as nitrogen, phosphorus, potassium, calcium and magnesium), and to retain toxic elements. It allows the soil to cope with changes in soil acidity, and helps soil minerals to decompose faster."

https://www.google.com/search?q=benefits+of+soil+organic+mat...

[dscottboggs]

Lol the "nitrogen cycle" is dead at most "modern" farms. They kill all the microbes that perform the nitrogen fixing and then add it back in manually.

[conradev]

Exactly, I thought one of the goals of regenerative agriculture was to reduce or eliminate fertilizer usage to prevent runoff

[IanCal]

Methane has a much greater impact, it's not the mass of carbon we care about it's the frequencies of light that various gasses absorb or let through.